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Numerous recent papers have demonstrated a central role for genetic factors in the extinction process or have documented the importance of gene flow in reversing population declines. This prompted one recent publication to declare that a revolution in conservation genetics has occurred. Contemporaneously with this revolution are a series of papers demonstrating long-term population persistence for several species despite having little or no detectable genetic variation. In a couple of notable cases, populations have been shown to have survived for centuries at small population size and with depleted levels of genetic variation. These contradictory results demand an explanation. In this review, I will show that these results do not necessarily fly in the face of theory as sometimes stated. The reconciliation of these two sets of observations relies on the incorporation of two major concepts. (1) Genetic factors do not act in a vacuum and it is their interaction with the environment, the strength and type of selection imposed, and the life history of the organism that determine the relative importance of genetic factors to extinction risk. (2) The relationship between molecular estimates of genetic variation and evolutionary potential, the relevance of genetic bottlenecks to adaptive genetic variation, and the nature of the stochastic process of extinction must be better integrated into expectations of population viability. Reports of populations persisting for hundreds of generations with very little detectable genetic variation provide us not only with valuable information but also with hope. However, recent studies suggest that we should not be sanguine about the importance of genetic diversity in the conservation of biodiversity.

Rabbits are considered by biologists to be among the worst invasive species. Their impact on invaded ecosystems, epitomized in Australia and on islands worldwide (e.g. North, Bullock & Dulloo, 1994; Williams et al., 1995; Burbidge & Moris, 2001; Garzon-Machado et al., 2010), has earned them a well-deserved place in the infamous Invasive Species Specialist Group’s ‘100 of the Worst Invasive Alien Species’ list. Rabbits are capable of profoundly altering communities, ecosystems and landscapes by sapping biodiversity and biomass from the basic trophic levels of often fragile ecosystems. However, they also have more complex, and hitherto seldom documented effects on higher trophic levels (Zedler & Black, 1992; Priddel, Carlile & Wheeler, 2000; Oliver, LuqueLarena & Lambin, 2009; Denyer, Hartley & John, 2010). In the context of a few, but loud voices attempting to question the importance of alien invasive species (but see Lambertini et al., 2011; Lockwood, Hoopes & Marchetti, 2011), the paper by Brodier et al. (2011) is well timed. It reminds us that restoration ecology and the fight against biodiversity loss are possible, in particular on islands, as they generally have many endemic and threatened species. This paper also highlights two very important, yet previously overlooked points. The first is the importance of longterm follow-up after restoration programmes. The second is the need to consider the indirect (and consequently often hidden) effects that alien invasive species can have on seemingly unconnected species. By monitoring the populations, several petrel species and their avian predator (the brown skua, Catharacta skua) following the removal of rabbits, Brodier et al. (2011) show that rabbits compete for space with blue petrels, Halobaena caerulea. Following rabbit eradication, the competition for burrows was removed and the blue petrel population increased up to eightfold in a few generations. Brown skua also increased their survivorship in response to the increase in its main prey, the blue petrel. Interestingly, the population of another petrel, the Antarctic prion, Pachyptila desolata, was also impacted by the rabbits. Following the eradication, the Antarctic prion population declined fourfold (to exclusion) in areas of deep soil and remained stable where the soil was too shallow for blue petrel (and rabbits). The resulting system, illustrated in Fig. 1, shows that one unexpected, and up to now unreported, effect of rabbits was to erode the niche partitioning of nesting seabirds on the island. Removing the rabbits led to both a competitor release (of the blue petrel, freed from the competition with rabbits) and to an apparent competitor release (of the shared predator, the brown skua, boosted by increased blue petrel availability). The combination of direct and indirect interactions restricted Antarctic prions to shallow soil areas, less favoured by the blue petrel. This neat system shows how alien invasive species can have effects beyond the trophic level constituting their resources. The contrast between the spectacular recovery of the blue petrel, the increased survival but stable number of skua breeding pairs and the decrease of the Antarctic prion also illustrates well the difficulties to forecast outcomes that conservation program may face even in relatively simple trophic webs. This is especially so in the current context of global climate change, which already affects subantarctic islands (Chapuis, Frenot & Lebouvier, 2004; Dowding et al., 2009), and which could have played a role in the system, for example, in the delayed recovery of the skua. Monitoring population densities, survival and predator diet, every year, on this remote, far reaching island, for long after the rabbit eradication might have been seen as a risky bet. As it turned out, the bet paid off, in the best currency ever: knowledge and understanding. Deciphering the indirect effects a terrestrial herbivore can have on a community of seabirds with which they have few interactions if any, is crucial in our battle against alien invasive species (Bergstrom et al., 2009; Genovesi, 2011). It demonstrates very well that if we were to ‘judge alien species only on their effects’, we would miss all but the tip of the iceberg and would allow important but unapparent, indirect effects of alien invasive species on native ecosystems. One regret from this study is that the monitoring effort conducted after rabbit eradication was not also implemented Animal Conservation. Print ISSN 1367-9430

Global biodiversity is increasingly under threat and species loss has prompted the argument that our natural world is experiencing a sixth major extinction event (PimmB Woodroffe, 2000; Treves & Karanth, 2003; Whitman et al., 2004). Parasites are increasingly linked to population impacts in wild felid and canid species (Pedersen et al., 2007). Many predator species exist in small and fragmented populations, vulnerable to stochastic events and other ongoing sources of population loss, which can drive them locally, if not globally, extinct. The Iberian lynx is a key example of an imperiled predator and is currently the most endangered felid in the world (Nowell & Jackson, 1996; Baillie, Hilton-Taylor & Stuart, 2004). This species may lose the survival battle without intense and continued conservation intervention. In their paper, Lopez et al. (2009) provide an excellent example of endangered species management, which demonstrates the importance of long-term population monitoring programs and the effectiveness of careful intervention design. Through their monitoring program, the authors identify the emergence of feline leukemia virus (FeLV) in the core population of Iberian lynx on the Iberian Peninsula. This pathogen is commonly found in domestic cats, which are considered the primary host (Arjona et al., 2007). While previous low-level FeLV exposure had been identified in the Iberian lynx population before the 2007 outbreak (Luaces et al., 2008; Meli et al., 2009), no associated mortality or other impacts had been identified. Then, inexplicably, FeLV emergence in 2007 causes an outbreak with mortality levels that threaten the survival of the species. Viral sequence from the 2007 outbreak is distinct from previous infections in the population but consistent with transmission from locally infected cats (Meli et al., 2009). In response to the outbreak, a FeLV control program is undertaken by the authors and other partners, which utilizes a test, removal and vaccination approach in Iberian lynx coupled with reduction of the sympatric feral cat population. It is successful and FeLVassociated mortality in the Iberian lynx ceases. What can we learn from the approach taken by Lopez and colleagues? Firstly, intervention for the Iberian lynx disease outbreak is designed and implemented through a partnership approach between many national stakeholders, project participants and experts. Often in wildlife management crises, consultation and inclusiveness of stakeholders is avoided in order to streamline processes and expedite action. But this can backfire when partner agencies and stakeholders are required in downstream management activities. This paper serves as a reminder that wildlife management is better implemented inclusively rather than exclusively. Secondly, this study demonstrates the dynamic and unpredictable nature of pathogen invasion outcomes in a population. In this case, FeLV invasion in the population was not identified as an important problem but this changed dramatically in the 2007 outbreak. This highlights the danger of defining the threat level of a pathogen for a species. It is becoming clearer that pathogen behavior can vary widely between species, and within and between populations over space and time. A number of factors influence pathogen invasion outcomes as they operate and interact at the level of the host, pathogen and/or the environment, which can influence host susceptibility and/or pathogen virulence and change the nature of an outbreak in a susceptible host population (Hudson et al., 2002). Thus, as in forensic sciences, we are reminded to be cautious with ‘pathogen profiling’ or reliance on expected behavior of a pathogen, as seen here in the divergent nature of FeLV invasion in Iberian lynx or for example, distemper outbreaks in African wild dogs in Botswana (Alexander et al., 1996; Alexander et al., 2008)

Anthropogenic activities are one of the main threats to species living in human‐dominated landscapes and can promote behavioral changes in birds. This paper presents a novel approach to test how a migratory species responds to habitat alterations occurring in nesting territories during winter, when the species is absent. From 2000 to 2016, we collated territory and nest monitoring data for the endangered Egyptian vulture Neophron percnopterus in the north of Spain, to test the effects of overwinter habitat alterations (OHA) around breeding territories on the species reproductive output. We monitored 70 different nest sites and observed OHA around the nesting area in 39 cases. Probability of switching to another nesting site almost tripled after OHA. Pairs that switched experienced substantially decreased breeding success and avoided reusing the nest for 4.8 ± 4.64 years. The presence of determinate landscape elements that provide screening, such as forest patches, increased nest reoccupancy probability after OHA by more than 0.3, to 0. 55 (compared to 0.24 when no screening was present). We also found that the distance and the situation of the OHA were critical factors explaining reproduction probabilities at nest sites. Our results demonstrate how OHA can strongly impact the breeding behavior of long‐lived species. This highlights the need to examine the long‐term impact of OHA rather than focusing only on disturbances during sensitive periods, as is often the case with habitual mitigation measures.

Global trait-based analyses can shed light on the factors predisposing species to high extinction risk, and can help bridge knowledge gaps in speciose and poorly known taxa. In this paper, I conduct the first global comparative study of crayfish extinction risk. I collated data on intrinsic (biology and ecology) and extrinsic (environment and threats) factors for 450 crayfish species assessed on the IUCN Red List. Phylogenetic multiple regression models were used to identify correlates of risk in all species; in centres of diversity (American cambarids and Australian parastacids); and among threat types (agriculture, water management, pollution). I assessed the relative ability of threat maps quantifying specific threats (e.g. river fragmentation, mercury deposition) or a generic threat (human population density) to predict crayfish extinction risk. I also quantified the effects of range size on extinction risk with variation partitioning and multiplicative bivariate regressions. Crayfish with small range size, small body size, habitat dependency on caves, and with ranges in areas of low precipitation, high altitude and high human population density were at higher risk of extinction. Correlates of risk varied between American cambarids and Australian parastacids, suggesting that centres of diversity shape patterns of extinction risk in crayfish. The explanatory power of models ranged between 31 and 65%, with low explanatory power for models based on threat types. Few specific threat measures were significantly related to extinction risk, suggesting that large-scale threat mapping may not be informative for freshwater invertebrates. In the absence of population data for most freshwater invertebrates, trait-based models are powerful and cost-effective tools for understanding and mitigating drivers of extinction risk.

Wildlife managers consider animal translocation a means of increasing the viability of a local population. However, augmentation may disrupt existing resident disease dynamics and initiate an outbreak that would effectively offset any advantages the translocation may have achieved. This paper examines fundamental concepts of disease ecology and identifies the conditions that will increase the likelihood of a disease outbreak following translocation. We highlight the importance of susceptibility to infection, population size and population connectivity ‐ a characteristic likely affected by translocation but not often considered in risk assessments ‐ in estimating outbreak risk due to translocation. We then explore these features in a species of conservation concern often translocated in the presence of infectious disease, the Mojave Desert tortoise, and use data from experimental tortoise translocations to detect changes in population connectivity that may influence pathogen transmission. Preliminary analyses comparing contact networks inferred from spatial data at control and translocation plots and infection simulation results through these networks suggest increased outbreak risk following translocation due to dispersal-driven changes in contact frequency and network structure. We outline future research goals to test these concepts and aid managers in designing effective risk assessment and intervention strategies that will improve translocation success.

Although it is today accepted that population viability analyses are needed at a meta-population level for most species, usually only single populations are monitored in the context of management and conservation programmes. This paper outlines a fairly general and easy-to-implement approach based on counts and capture–recapture data that allow the dynamics of single populations to be assessed even when they are highly connected to other populations. This approach was motivated by a study of the French population of the slender-billed gull Larus genei, which experienced a sharp population increase in the 1980s and 1990s, suggesting that the species was not at risk of extinction. However, several recently raised concerns indicate that the observed population increase is unlikely to have been achieved uniquely by an intrinsic growth rate. We estimated local adult survival probability at 0.81 (0.79–0.83), which is considerably lower than that of other gull species of comparable size. Moreover, local fecundity observed in slender-billed gulls [0.66 (0.47–0.85)] is lower than that observed in similar species. Massive reproduction failures and the low demographic parameters observed could be caused by chick exposure to aerial and terrestrial predation, leading to permanent emigration. Unrealistically high demographic parameter values would be needed to generate the observed local population increase. The results of our study indicate that connections with other neighbouring populations are responsible for the local population dynamics, and that about 10% of the individuals may be immigrants into this local population annually. However, our results suggest that the population of the slender-billed gull may be stable at the west Mediterranean scale. The high annual fluctuations of population size observed at a larger scale also highlight the necessity for coordinated international action to protect a maximum of potential breeding sites in order to protect the species.

A model of the metapopulation structure of narwhals Monodon monoceros in Baffin Bay, Hudson Bay and adjacent waters is proposed based on satellite telemetry data collected over two decades from six coastal aggregations of narwhals in the eastern Canadian high Arctic, Hudson Bay and West Greenland. In addition, data on seasonal catches of narwhals in 11 Inuit communities are used to provide information on the occurrence of narwhals. The tracking data suggest that disjunct summer aggregations of narwhals are, to some extent, demographically independent subpopulations, with minimal or no exchange with other summering aggregations. We propose that these should be considered separate stocks for management purposes. Year-round satellite tracking of individuals demonstrates that whales return to the same summering areas the following year, suggesting inter-annual site fidelity. We propose that the narwhals in Canada constitute five separate stocks, with limited exchange between three of the stocks. Coastal summer aggregations in Greenland constitute two stocks in addition to two fall and winter aggregations supplied by narwhals from several summering areas. Several narwhal stocks mix on the wintering areas in Baffin Bay, but the metapopulation structure is likely maintained through a combination of lifehistory traits and migratory routes, as mating most likely occurs after the initiation of the return migration toward summering areas. The metapopulation structure in Baffin Bay narwhals will be impacted differentially by Inuit subsistence hunting, depending on the migratory schedule of narwhals and dates at which whales occur in different seasonal hunting areas. It is therefore important to identify which narwhal stocks contribute to which subsistence hunts in order to assess the sustainability of those hunts. This paper proposes a preliminary stock model for this purpose.

The lack of information on the protection status of birds in the winter period is a serious concern, as the survival of many populations depends on this period. Here, we consider the seasonal changes in distribution patterns of bird species in central Spain to assess the value of protected areas (PA) for simultaneously conserving breeding and wintering avifauna. We used a stepwise algorithm of complementarity to select the minimum set of Universal Transverse Mercator 10 × 10-km squares containing all species at each period and then contrasted selected areas in order to test the degree to which breeding and wintering birds overlap. Using Gap analysis, we identified areas that are still unprotected. Our results show both a weak correlation and a scant overlap between areas that are important for bird conservation during breeding and wintering periods. Thus, we conclude that valuable areas for bird diversity differ between seasons, implying that breeding hot spots are not good surrogates for overwintering hot spots. This paper addresses the need of identifying not only important areas for breeding birds, but also wintering birds, revealing potential gaps in current PA networks. Future conservation policies should take these results into account in order to optimize bird conservation, especially considering that the appropriate protection of the bird species overwintering in Spain will, overall, benefit European breeding populations.

The conservation of endangered affiliate species, which are critically dependent on the presence of another species, is often hindered by a poor understanding of the relationships between the interacting partners. The parasitic stage of endangered unionid bivalves constitutes a tight host–affiliate linkage between the mussels and their host fishes. However, the threats resulting from potential shortages of the host species are rarely sufficiently quantified and incorporated into conservation strategies. In this paper, we integrated both host quality and availability analyses to assess the potential threats to the endangered thick-shelled river mussel Unio crassus that result from the impairment of its host resources in Central Europe. The experimental determination of the compatibility of U. crassus parasitic larvae (glochidia) with its potential host fishes revealed an intermediate level of host specificity. At least, some glochidia successfully developed on 14 of the 27 potential hosts that were evaluated. Nevertheless, only three fish species (Scardinius erythrophthalmus, Phoxinus phoxinus and Cottus gobio) enabled the majority of the attached glochidia to transform successfully. Subsequently, our analysis of host availability at sites inhabited by living or extirpated populations of U. crassus showed that the local extirpations of U. crassus are likely associated with an impaired status of the fish assemblage and with the absence of the primary host fishes. These results indicate that the availability of host fish resources may have played at least an additive role in the present pan-European decline of U. crassus and that the evaluation of host limitation without precise data on the host compatibility or host abundance may be ineffective for identifying the threats to particular species. It demonstrates a strong need for more thorough incorporation of host limitation issues into conservation strategies for U. crassus and probably also for other species of freshwater mussels that were previously considered safe from host limitation.

California sea lions Zalophus californianus occupy 26 islands in the Gulf of California (GoC), Mexico. Although human presence is prohibited on these islands without a government permit, the law is not enforced and tourism to the islands is increasing. Tourists, along with local fishermen, often come ashore to get close to the animals, which may disrupt behaviors critical for reproduction. In this paper, we report the results of an experimental study on the behavioral effects of human disturbance on California sea lions in the GoC. To document effects, we recorded sea lion behavior immediately before and in 10-min intervals for up to an hour after experimental human disturbance. Our results showed few behavioral responses of sea lions to human disturbance. Adult females and juveniles demonstrated immediate responses, but these were not consistent between years, apparent an hour after disturbance, or evident across other age and sex classes. These results suggest that California sea lions may be resilient to human disturbance and a possible flagship species for ecotourism, but further studies of the physiological and population-level effects of human disturbance are needed.

Chytridiomycosis is an emerging disease of amphibians with global impact (Skerratt et al., 2007). Innate immune defenses may contribute to the ability of some species to coexist with endemic Batrachochytrium dendrobatidis (Bd) (Retallick, McCallum & Speare, 2004; Woodhams et al., 2007b). We appreciate the thoughtful commentaries by Fisher (2007), Garner (2007) and Kurtz & Scharsack (2007) to the paper ‘Resistance to chytridiomycosis varies among amphibian species and is correlated with skin peptide defenses’ (Woodhams et al., 2007a). The commentators endorsed the ecological immunology approach of the work and its utility for informing conservation. They included excellent suggestions for future studies including the following: (1) Examining population, family and individual level variation in amphibian immune defenses. (2) Testing for mucosal antibodies, immune memory and induction of innate defenses in addition to constitutive innate defenses. (3) Determining how behavioral differences among species affect the rate of encountering the pathogen and response to encounter. (4) Understanding how environmental conditions affect innate immunity. The commentators pointed out that immunity can vary among lineages of frogs (Pearman & Garner, 2005) and stickleback fish (Rauch, Kalbe & Reusch, 2006), suggesting that some of the among-species differences we detected might be due to differences among lineages within species. This is true, however, as the work cited by the commentators illustrates, fully exploring variation in disease susceptibility within even a single species requires very large, complex experiments. For our initial exploration of variation among species, we chose to use single sibships to minimize withinspecies variation, maximizing the power of our comparisons among species. This also minimized the probability of chance differences in peptide expression between infected and control frogs. This was advantageous because we could collect peptides only from uninfected control frogs, because depletion caused by norepinephrine induction could have affected the survival of infected frogs. We agree that much remains to be investigated in terms of variation in innate immunity among sibships and populations; however, it seems likely that variation of skin peptide defenses among species is greater than within-species variation. For example, Apponyi et al. (2004) found substantial variation on a large geographic scale in the composition of skin peptides profiled within two species of Australian treefrogs, and also showed that most species produced profiles containing distinctive families of peptides, and that on smaller geographical scales profiles did not differ among individuals within species. Our own studies of peptide variation among individuals of two populations of Rana muscosa in the Sierra Nevada Mountains of California suggest very limited variation in skin peptides (Woodhams et al., 2007b). This suggests that sibship-level differences in skin peptide defenses are not likely to have affected the results of this study in which four species from the same region were compared. Some antimicrobial peptides are constitutive and others may be induced in response to infection (Boman, Nilsonn & Rasmuson, 1972; Zasloff, 2002; Cunliffe & Mahida, 2004; Izadpanah & Gallo, 2005). Here, peptide induction has two meanings: transcription and storage in glands or secretion from glands onto the skin. We did not test for induction of skin peptides in response to Bd exposure in this study. However, the constitutive peptide defenses may be a good measure of immune condition before Bd exposure. Any induction of new skin peptides that may occur in response to Bd infection may not be effective because chytridiomycosis leads to mortality of susceptible species between 18 and 48 days post-infection (Berger et al., 2004; Woodhams et al., 2007a), and production of peptides in granular glands after discharge can take as long as 6 to 421 days (Flucher et al., 1986; Giovannini et al., 1987; Rollins-Smith & Conlon, 2005). Of course the quantity of peptides released from the granular glands after administration of norepinephrine is

To understand the distribution and relative abundance of cave-dwelling bats and to identify those sites that would be important for conservation of bat species, 25 underground sites that had not been previously surveyed were investigated in this 3-year study (from December 2003 to April 2006) in Funiu Mountain of Henan province, China. Approximately 80 000 bats were recorded, representing 12 species. The most abundant species were Rhinolophus affinis, Miniopterus schreibersi and Hipposideros pratti. The roosts were evaluated for their conservation importance. The most important sites in the area are Yunhua and Nanzhao caves, which serve as hibernaculums and nursery roosts to c. 13 740 and 11 803 bats, respectively, representing seven species. By means of cluster and correspondence analysis, the distribution of bat species was different between the two sides of the mountain and was highly dependent on the size of the cave. The underground sites in the south region hosted c. 80% of the total bats, representing 11 species. The sites in the north region hosted 20% of the total bats, representing seven species. Presently, none of the caves in the region has adequate protection and some bat populations are under serious threat. Many large caves that contained large bat populations and several species of concern had been developed as tourist sites, and so some advice on protecting the most important local habitats was sought based on the assessment of the conservation status of underground sites. This paper presents basic data concerning the distribution of cave-dwelling bats and the patterns of cave use on Funiu Mountain. The data will help local governments and policy-makers develop suitable strategies to promote local tourisms while protecting important habitats of animal species.

Neutral genetic markers, such as mitochondrial DNA (mtDNA) sequences, are commonly used to discover independently evolving groups of populations in nature. These groups are often considered to be units of conservation because they preserve distinct organismal histories. However, because of the time lag between the isolation of populations and the evolution of diagnostic neutral markers, adaptive traits could be unrepresented by units defined by neutral markers. The concept of ecological exchangeability potentially provides a way to preserve populations possessing local adaptations that lack diagnostic neutral markers. Populations are surveyed for differences in fitness traits, either directly, or by examining morphological or genetic traits that could indirectly serve as proxies for them. The purpose of this paper is to compare the nature of units of conservation defined by neutral gene surveys and ecological exchangeability, using data recently available for the great tit Parus major, a wide-ranging Palearctic species. mtDNA surveys reveal a lack of differentiation across thousands of kilometer. In contrast, studies of body size and clutch size show locally adapted differences between populations separated by a few kilometer, meaning that these populations could be classified as ecologically in exchangeable. These two types of markers have dramatically different consequences for the geographic and evolutionary scale of conservation units. The concept of ecological exchangeability might be an inappropriate way to diagnose units of conservation in birds owing to the time required to document local adaptations and their potential ubiquity. Neutral genetic markers continue to provide a theoretically sound way of identifying units of conservation, and these units ought to be integrated into conservation plans without delay.

The relative importance of genetic factors in increasing the risk of extinction has been hotly debated in the past and has tended to be downplayed by ecologists researching the correlates of extinction of island endemics. More recently, Frankham has argued that there is now sufficient evidence to regard the past controversies over the contribution of genetic factors to extinction risk as mostly resolved. For example, evidence indicates that the majority of threatened species including island endemics have a lower genetic diversity than taxonomically related nonthreatened species, implying that genetic factors such as inbreeding can increase the probability of extinction before extinction events occur. Yet, recent ecological research on the correlates of extinction for over 220 species of island birds found compelling evidence that exotic mammalian predators were the sole drivers of extinctions, and neglected to even mention any role of genetic factors. This paper discusses how two research groups working towards identifying and understanding the correlates of extinction for island endemics can reach such distinct conclusions. Part of the reason for the different perspectives is that ecological research has tended to focus on the correlates of historical extinctions of island endemics while conservation geneticists have concentrated on genetic correlates of currently threatened extant species. Identifying whether the population growth rate is positive or negative is crucial to this debate because even the geneticists agree that inbreeding will have little time to impact populations that are declining rapidly due to high predation rates. Inbreeding depression is likely to have a greater impact on extinction probability in species suffering from gradual habitat loss and range contraction, which typify the deterministic causes of population decline in continental species, rather than the intense predation pressure commonly associated with declines and extinctions of oceanic island endemics.

Wild parrots represent one of the greatest commercial interests in the legal trade in wild birds. Although it is difficult to quantify, there is a considerable illegal trade in wild parrots. Thirty-six per cent of the world's parrot species are listed by the International Union for the Conservation of Nature as threatened or near threatened, and 55% of these are threatened to some degree by trade. In this paper, we investigate the impact of protection on the number of nests that failed because of nestlings being taken by humans (hereafter nest take) and on nesting success in parrots. We collate data on parrot nest take from published and unpublished studies from Africa, Asia and Australasia, including countries and sites with and without national and local parrot protection measures in place. Nest take was insignificant in Australia, where all studies were from areas with both local and national protection. For less developed countries, levels of nest take were variable between studies, spanning the whole range from 0 to 100%. Protection significantly reduced nest take and correspondingly increased nesting success. Our results corroborate those for the Neotropics; thus, the advantages of protection appear to be independent of geographical location or political and economic conditions. We analysed data on legal trade in wild-caught parrots before and after implementation of the 1992 Wild Bird Conservation Act (which practically eliminated import of parrots to the USA) and found that there was no apparent shift in parrot imports to other global regions from the Neotropics. We suggest that conservation of parrots globally would benefit from similar legislation introduced in other regions, such as the EU (15), which is responsible for more than 60% of global imports of wild parrots.

Since the early 1990s, large and rapid population declines of three species of vulture (Gyps spp.) endemic to south Asia have occurred on the Indian subcontinent and have led to these species being listed by IUCN as critically endangered. Evidence of rates of population decline, cause of death and toxicity is consistent with these declines being caused by poisoning of vultures through the ingestion of tissues from livestock treated with the anti-inflammatory drug diclofenac. In this paper, analysis of repeated surveys in and near protected areas widely spread across India shows that populations of two other vulture species, Egyptian vulture Neophron percnopterus and red-headed vulture Sarcogyps calvus, have also declined markedly and rapidly, but probably with a later onset than Gyps vultures in the same region. The declines continued at least up to 2003. It is recommended that these two species are considered for inclusion in the IUCN Red List and for urgent remedial conservation measures. Research is needed to determine whether or not the principal cause of these declines is diclofenac poisoning and to establish population trends in other scavenging birds in the Indian subcontinent.

Many taxa, including amphibians, have been shown to have a taxonomically non-random distribution of threatened species. There are three possible non-exclusive reasons for this selectivity: non-random knowledge of species conservation status, clades endemic to different regions experiencing different intensities of threatening process and the effects of clade-specific biological attributes on the susceptibility of species to these processes. This paper tests the sufficiency of the first two explanations using extinction risk evaluations from the 2004 Global Amphibian Assessment. Our results indicate that they cannot alone account for the degree of non-randomness in extinction risk among amphibian families. The overall distribution of threatened amphibians remained taxonomically non-random when species of unknown conservation status were omitted, and significant selectivity was detected not only at a global geographic scale but also in country- and site-specific data sets. Furthermore, the same families tend to be over- or underthreatened within different countries. Together, these results suggest that biological differences among amphibian families play an important role in determining species' susceptibility to anthropogenic threatening processes.

Although hyperdiverse groups like terrestrial arthropods are almost certainly severely impacted by habitat fragmentation and destruction, few studies have formally documented such effects. In this paper, we summarize the results of a multifaceted research approach to assess the magnitude and importance of anthropogenic population extinction on the narrowly endemic trapdoor spider genus Apomastus. We used geographical information systems modeling to reconstruct the likely historical distribution of Apomastus, and used molecular phylogeographic data to discern population genetic structure and detect genetic signatures of population extinction. In combination, these complementary lines of inference support direct observations of population extinction, and lead us to conclude that population extinction via urbanization has played an important role in defining the modern-day distribution of Apomastus species. This population loss implies coincident loss of genetic and adaptive diversity within this genus, and more generally, suggests a loss of ground-dwelling arthropod population diversity throughout the Los Angeles Basin. Strategies for minimizing this loss are proposed.

The endemic pink pigeon has recovered from less than 20 birds in the mid-1970s to 355 free-living individuals in 2003. A major concern for the species' recovery has been the potential genetic problem of inbreeding. Captive pink pigeons bred for reintroduction were managed to maximise founder representation and minimise inbreeding. In this paper, we quantify the effect of inbreeding on survival and reproductive parameters in captive and wild populations and quantify DNA sequence variation in the mitochondrial d-loop region for pink pigeon founders. Inbreeding affected egg fertility, squab, juvenile and adult survival, but effects were strongest in highly inbred birds (F greater than or equal to 0.25). Inbreeding depression was more apparent in free-living birds where even moderate levels of inbreeding affected survival, although highly inbred birds were equally compromised in both captive and wild populations. Mitochondrial DNA haplotypic diversity in pink pigeon founders is low, suggesting that background inbreeding is contributing to low fertility and depressed productivity in this species, as well as comparable survival of some groups of non-inbred and nominally inbred birds. Management of wild populations has boosted population growth and may be required long-term to offset the negative effects of inbreeding depression and enhance the species' survival.

Predicting the threat of extinction aids efficient distribution of conservation resources. This paper utilises a comparative macroecological approach to investigate the threat of extinction in Neotropical birds. Data on ecological variables for 1708 species are analysed using stepwise regression to produce minimum adequate models, first using raw species values and then using independent contrasts (to control for phylogenetic effects). The models differ, suggesting phylogeny has significant effects. The raw species analysis reveals that number of zoogeographical regions occupied, elevational range and utilisation of specialised microhabitats were negatively associated with threat, while minimum elevation and body mass were positively associated, whereas the independent contrasts analysis only identifies zoogeographical regions as important. Confining the analysis to the 582 species restricted to a single zoogeographical region reveals elevational range and number of habitats occupied to be negatively correlated with threat whether the analysis is based on the raw data or on independent contrasts. Analysis of four contrasting zoogeographical regions highlights regional variation in the models. In two Andean regions the threat of extinction declines as the elevation range across which the species occurs increases. In the presence of substantial human populations on high Andean plateaus, a species with a greater elevational range may be more likely to persist at some (relatively) unsettled altitudes. In Central South America, the strongest predictor of threat is minimum elevation of occurrence: species with a lower minimum are less threatened. The minimum elevation result suggests that lowland species experiencing an ecological limit to their minimum elevation (min. elevation >0 m) may be more at risk than those not experiencing such a limit (min. elevation = 0 m). Finally, in southern Amazonia, where there is little altitudinal variation, the only weak predictors of threat are body size, larger species being more threatened, and number of habitats, species occupying more habitats being less threatened. These contrasting results emphasise the importance of undertaking extinction risk analyses at an appropriate geographical scale. Since the models explained only a low percentage of total variance in the data, the effects of human-mediated habitat disturbance across a wide range of habitats may be important.

Many species have strong habitat preferences that directly influence population viability. For successful reintroduction of threatened populations that rely on habitat structures, the correct placement of artificial structures is also important to population persistence. In this paper, we present a hierarchical approach to the problem of translocating animals that rely on permanent habitat structures, in which we first use population dynamics data to identify areas of suitable habitat, and then identify optimal configuration for habitat structures. We use data collected from a non-endangered, conspecific population of the endangered riparian woodrat (Neotoma fuscipes riparia) to examine the degree to which the distribution of dens in translocation sites might influence the likelihood that animals persist in their new environment. We characterize the habitats in which dens occur, analyze their spatial clustering, and compare them to temporal changes in population status for sex and age classes. We compare the potential efficacy of translocation efforts using spatial analysis versus solely habitat-based approaches and identify the optimal spatial configuration of dens that should be considered in this translocation effort. We found that patterns of habitat use were positively correlated with overstorey cover, and animal weight was positively correlated with understorey cover. Woodrats appear to select den locations on the basis of understorey cover, but also benefit from dense overstorey cover and distance to nearest tree. Our results suggest that in translocation efforts, artificial dens should be placed in clusters within a radius of 15 m, as values above and below this value showed negative correlations with body mass. Translocations should occur after reproductive events, which occur in April and August for woodrats in southern California. Our analyses provide practical guidelines in determining appropriate timing and spacing for translocation events in the context of animal condition, minimizing disease transmission, and reproduction.

Studies on the effects of nonindigenous invasive species and habitat fragmentation on native ecosystems have become priorities for conservation biologists. This is relevant particularly for islands with high degrees of endemism. In the present paper the role of fragmentation and possible effects of introduced Rattus rattus on endemic rodents (Macrotarsomys bastardi and Eliurus spp.) and the gray mouse lemur (Microcebus murinus) were assessed for dry deciduous forests in Madagascar. Capture rates of endemic rodents declined significantly with declining fragment size. Macrotarsomys bastardi was never caught in primary forest fragments < 600 ha or outside the primary forest but captures of M. bastardi were correlated to changes in vegetation structure associated with fragmentation rather than to fragment size per se. Eliurus spp. were also found in small primary-forest fragments and in secondary forests close to primary forests, suggesting that secondary forests can serve as buffer zones or corridors for this species. The lemur M. murinus was caught in all types of primary and secondary forest. This species did not seem to respond to fragmentation of primary forests. Even though it was found in most secondary-forests, capture rates declined as these secondary forest formations increased in size. This indicates that secondary forests are suboptimal habitats for M. murinus. Rattus rattus were caught in all vegetation formations except for the open savanna. Their capture rates increased as forest fragments became smaller, indicating that mosaics of different habitat types are beneficial for introduced rats. There was no significant relation between capture rates of R. rattus and the endemic species. In conclusion, these results suggest that (1) native Malagasy rodents of the dry deciduous forest are more sensitive towards forest disturbance than M. murinus; (2) there is no indication for negative interactions between introduced rats and the native small-mammal fauna.

A companion paper in this issue describes the mapping of Cape Sable seaside sparrow (Ammodramus maritimus mirabilis) habitat using satellite imagery. In general, those maps are correct. However, testing against an independent survey of the sparrow population does identify errors. Those errors fall into two categories, model errors and bird errors. The model errors result from genuine problems with the model. More interesting for conservation are the bird errors, which are more numerous. They are of two types. (1) Commission errors: some suitable habitat does not contain birds. These are areas where prior events have depleted sparrow numbers, but because the sparrows do not disperse long distances, they cannot occupy it quickly. (2) Omission errors: some birds remain in unsuitable habitat that was formerly suitable. This results from the sparrow's very high site fidelity. Often, they will not leave an area even when it is no longer suitable. The consequences of these bird errors are that some habitat and some birds are not contributing to the species' survival. Thus, an estimate of only the amount of habitat or only the sparrow population may present an overly optimistic view of the sparrow's plight.

Estimating the risk of extinction or decline requires estimates of the variability in vital rates, such as survival and fecundity. This paper describes a method for estimating variance of survivals and fecundities from census data. The method involves calculating an estimate of the variance in survival and fecundity due to demographic stochasticity and subtracting this estimate from an estimate of total variance. The method is demonstrated by applying it to the data set on acorn woodpeckers by Stacey & Taper (1992), and tested in a series of simulations. The results show that the method can estimate the environmental variance with no bias. The main advantages of this method are its simplicity, its independence of the underlying distribution, and its applicability to estimating the variance of fecundity as well as of survival.

The decline of amphibian populations worldwide is a recognized phenomenon. A variety of important causes have been linked to the declines but perhaps the most renowned cause, in terms of popular press exposure, funding dispersal and papers published, is disease. In particular, chytridiomycosis, a disease caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), is a lethal emerging infectious disease that has had profound effects in some amphibian species, but occurs without catastrophic effects in others (Fisher, Garner & Walker, 2009b). Bd affects species differentially. In many cases it is the major threat to animals already stressed by other critical challenges, such as habitat destruction, pollution, invasive species and climate change. In addition to its impact on amphibian populations, the spread and presence of Bd is likely to impact human activities via effects on the pet, bait and food trade (Schloegel et al., 2009, 2010).

In their recent paper, Sato H Gharrett et al., 1999; McGinnity et al., 2003; Tallmon et al., 2004), but claimed the close geographical proximity, similar habitat and small genetic differences among remnant populations might considerably reduce this risk. In a recent review, Edmands (2007) stated that concerns over outbreeding should be taken seriously, as the effects of outbreeding can be, in some cases, as damaging as severe inbreeding. Here, we raise concerns about mixing of populations as a strategy to increase genetic variation, and we bring evidence of likely outbreeding depression observed in the rehabilitation project of the endangered freshwater salmonid marble trout Salmo marmoratus, started in Slovenia in 1993 (Crivelli et al., 2000). Since the beginning of the rehabilitation project, four marble trout populations went extinct due to landlsides (Predelica) and severe flood events (Gorska, Sventarska and Zakojska). The seven remnant populations of marble trout living in Slovenian streams are genetically distant (FST=0.66, Fumagalli et al., 2002), present a very low effective population size (for the Huda Grapa population a total population size ranging from 29 to 60 individuals was estimated between 2000 and 2007) and very low genetic variability estimated at 14 microsatellite loci (for Huda Grapa Ho=0.046, Fumagalli et al., 2002). In order to expand the genetic variability of marble trout living in the watershed, a new population (Gatsnik) was created in 1998 in a previously fishless stream by mixing the progeny of marble trout from two remnant populations from isolated streams with similar habitat (Trebuscica and Lipovesck). After two generations, the population of Gatsnik presented the typical features associated with maladaptation and outbreeding depression, that is lower annual survival rate (0.39 0.02 for trout born in the stream, higher than 0.55 for other marble trout populations living in the study area, Vincenzi et al., 2008), reproductive underperformance at the F2 generation and unusual morphological abnormalities (Fig. 1). Moreover, preliminary results from a egg-to-fry experiment performed in the fish farm for the F1 generation of Gatsnik showed 80.4% of mortality from fertilization to hatching (35.6 29.2% for the remnant populations) (D. Jesensek, pers. comm.). The translocation experiment in Gatsnik is still ongoing and may provide unequivocal evidence of outbreeding effects in 3–4 years. Nevertheless, despite the striking contrast of salmonid species in lifehistory traits may hinder generalizations, what we observed in the marble trout population of Gatsnik urges now further considerations on the opportunity of mixing populations of salmonids to increase their genetic variability. As recently reviewed by Willi et al. (2006), small populations are predicted to have low potential to adapt to environmental changes, as genetic variation and potential response to selection should be positively related to population size. Moreover, individuals in small populations may have lower fitness and be inbred, which may decrease an adaptive response to unpredictable environmental changes. Apart from the obvious cases of overexploitation, pollution and human-induced fragmentation, the small population size and low heterozygosity frequently observed in endemic

Sequences from complete mitochondrial cytochrome b genes of 34 tigers support the hypothesis that Sumatran tigers are diagnostically distinct from mainland populations. None of the latter, including Bengals, Siberians, or Indochinese tigers, were found to have fixed diagnostic characters. Phylogenetic analysis of these sequences confirms these results. Within the framework of a phylogenetic species concept, current evidence thus supports the recognition of two distinct taxa, and within the context of this definition they could be ranked at the species level. This paper also documents a previously unrecognized nuclear insert of mitochondrial DNA that includes, minimally, mitochondrial homologues of a control region that lacks the feline mitochondrial repeat sequences, a complete cytochrome b gene, and complete tRNAThr and tRNAsurPro genes. In a phylogenetic analysis of the nuclear cytochrome b-like sequences and various feline mitochondrial sequences, the nuclear insert clusters with lion mitochondrial cytochrome b sequences, which suggests the insert is at least as old as the split between lions and tigers. The results of this study emphasize the importance of doing more to conserve Sumatran tigers. Because they are underrepresented in zoos relative to Bengals and Siberians, an effort should be made to increase captive breeding stocks of Sumatrans. That Sumatrans are a distinct taxonomic entity relative to mainland populations can be used in educational programs to increase conservation efforts within Indonesia.

Human anxiety about predators is deeply embedded in our evolutionary history and psychology. Sharks, as archetype predators, attract a disproportionate amount of fear because of our poor ability to assess the real threat associated with ‘fearsome’ risks such as shark bites (Sunstein & Zeckhauser, 2011). This disconnection between reality and human imagination is illustrated by the extreme media attention that surrounds incidents of shark bite (Muter et al., 2012) and the actual numbers of attacks that occur. Fatalities from shark bites remain much lower than in other recreational activities. For instance, in Western Australia, annual fatality rates from shark bite, at their highest, were 1.3 year−1 (2008–2013; Australian Shark Attack File, 2013; http://taronga.org.au/animalsconservation/conservation-science/australian-shark-attackfile/annual-australian-shark-attack-report-summary-2013), compared with cycling [average of 5 year−1 (2009– 2013); www.bitre.gov.au/statistics/safety/fatal_road_crash _database.aspx] and ocean swimming [average of 12.5 year−1 (2008–2013); http://surflifesavingwa.com.au/documents/ coastal-safety-web.pdf]. Analysis also suggests per capita incidents are declining in some locations such that any absolute increase in numbers of fatalities simply reflects growing human populations using coastal environments (Wetherbee, Lowe & Crow, 1994; West, 2011). Despite the relatively low risk of fatalities, governments have invested significant economic and human resources in mitigating risk associated with shark bites. Historically, such strategies have largely relied on catch-and-kill programs with the goal of driving localized depletions of animals that are considered a threat to humans. Currently, lethal programs, largely based on nets, which started in the 1930s (New South Wales, Australia) and 1960s (Queensland, Australia and KwaZulu-Natal, South Africa), each catch between 600 and 1500 sharks annually. While the frequency of shark bite incidents has also declined over this period, due either to the nets themselves or broader issues relating to general declines in shark populations or environmental change, there is growing recognition of the high ecological costs of lethal programs, particularly in terms of bycatch of other harmless sharks and nontarget species including cetaceans, turtles and rays. Irrespective of destructive bycatch, some of the most compelling reasons for moving beyond catch-and-kill programs for shark mitigation lie in our understanding of sharks themselves, their place in marine environments, their increasing economic value as a tourism resource and the fact that, as Hazin & Afonso (2014) show here, alternatives are now available. Sharks are highly susceptible to overexploitation with 15% of the world’s species threatened (Dulvy et al., 2014). Species targeted by lethal shark hazard mitigation programs are among some of the most vulnerable. We also know the oceans need sharks: as apex predators, they play critical roles in maintaining ecosystem structure and promoting resilience (Ferretti et al., 2010). Healthy shark populations increasingly generate significant tourism dollars and associated economic benefits for local communities, including species usually considered ‘dangerous’ (Gallagher & Hammerschlag, 2012). Finally, improvements in our understanding of shark biology derived from, for instance, telemetry and neuroscience can underpin nonlethal mitigation strategies such as warning systems predicated on movements and deterrents (Hammerschlag, Gallagher & Lazarre, 2011; Huveneers et al., 2013). Hazin & Afonso (2014) demonstrate the practical value of nonlethal strategies as an alternative to the traditional policy of catch and kill. Following an upsurge in incidents with sharks and bathers in north-eastern Brazil, the Metropolitan Region of Recife deployed longlines and drumlines to capture and relocate sharks thought to be a threat. This and a companion paper (Hazin et al., 2013) show that over a 4-year period, once potentially dangerous sharks had been captured and relocated, they tended to move away from protected beaches when released. Furthermore, mortality rates of bycatch not considered to be a threat to humans were generally much lower than in nets, as indeed was also the case for the target species. Importantly, when the program was in place, human interactions with sharks were very low, and increased at times when the program was suspended. Overall, bs_bs_banner

Pizzatto & Shine (2012) noted the serious impacts that the introduced cane toad Rhinella marina has caused to its predators in Australia. The toad’s range is expanding at an increasing rate and additional negative consequences are predicted. Control measures have been ineffective or in some cases have not been tried. Female toads have a very high fecundity, and the species has a high potential growth rate. High removal rates of the toad population are needed to eliminate the species, suggesting that physical removal is not practical (Shine & Doody, 2010). One approach to controlling the toad species is biological control, which has been effective in some cases in Australia and elsewhere (Saunders et al., 2010). Biological control usually involves introduction of a species that in its native range controls the population of the pest species. However, introducing an exotic species as a biocontrol agent can have negative effects on nontarget species and potentially on ecosystem function (Simberloff & Stiling, 1996). Use of a native species as a biological control agent eases these concerns, but may involve a protocol to increase the abundance and distribution of a native control agent. In the case of the cane toad, one goal of biocontrol can be slowing the rate of expansion. Individuals at the leading edge of expansion have greater locomotor endurance, and the authors suggest that this may be due to escape from a lungworm parasite that infects toads behind the leading edge. Therefore, the authors test aspects of a general hypothesis that posits that lungworm parasites can be used as a biocontrol agent to slow the toads’ advance. This may not be an entirely satisfactory solution, but slowing the toads’ advance might buy time to develop other ways to control the species’ numbers. As the lungworm is already present in the toads and likely was present in the toads when they were introduced to Australia in 1935, it is not considered an exotic species. The authors suggest that one way to increase the prevalence of lungworm infection is to infect a native tree frog species, Litoria caerulea, which does not seem to be negatively affected by the parasite. They also propose three primary assumptions necessary for biocontrol to work in this case: the parasite does not harm the tree frogs, the tree frogs can maintain an infection over the long term, and infective larvae of the parasite can be transmitted to cane toads and reduce viability of the toads. They test aspects of these assumptions in their paper. Pizzatto and Shine showed that the tree frogs were infected at a 50% rate at the end of the experiment, and this was after placing the lungworm in the mouths of the frogs. All parasite-exposed frogs survived, and their growth rate was not different from that of uninfected controls. It would be important to compare the growth of infected frogs and uninfected frogs as the ‘parasite-exposed’ treatment apparently contained frogs that were not infected or had cleared the infection. Of those frogs that were infected, they had on average a low intensity (1.67 parasites per frog). It is unclear that this intensity would have the desired effect of transmission of larvae to toads. To test for transmission to the toads, lungworm larvae were put in boxes housing five toads. About half of the toads were infected under these laboratory conditions. In terms of fitness effects on the toads, there was no survival difference between infected and uninfected, no difference in body mass and no difference in sprint speeds. The authors did find that toads exposed to lungworms had lower stamina than did controls. Laboratory conditions are likely to maximize transmission of parasites as toads were under high density conditions, and their movements were constrained. However, under these conditions, parasite prevalence in frogs and toads averaged 50%. Importantly, only minor fitness effects were seen in the toads. Based on these results, it seems doubtful that control would be effective in nature. There are other reasons to be skeptical that biocontrol would be effective in this case. Is the lungworm a factor in population control in other parts of the toads’ range where prevalence is high? If not, why would it be expected to work bs_bs_banner

Cane toads, Bufo marinus, are among the iconic poster children of invasive species, in part thanks to Mark Lewis’s 1988 Australian documentary, ‘Cane Toads: An Unnatural History’, and subsequent follow-up, ‘Cane Toads: The Conquest’. Unfortunately, the conquest in his latest video refers to what the cane toads have achieved, not the Australians’ efforts to control them, despite the impressive research program of Rick Shine and his colleagues at the University of Sidney, among others. In this issue’s featured paper, Pizzatto & Shine (2012) show that a lungworm parasite of the invasive cane toad, apparently brought to Australia along with the toad, can infect native green tree frogs, Litoria caerulea, with no evident detrimental effect on the frogs. These frogs can maintain the infection for up to 120 days postexposure, and infective lungworm larvae in the native frogs’ feces can then infect cane toads, substantially reducing their stamina. This leads to the intriguing suggestion that biological control of the cane toad could be undertaken by deliberately infecting these native frogs, which could then disseminate the lungworm to the cane toads, as a sort of ‘Typhoid Mary’ – an asymptomatic carrier of the pathogen that, while remaining healthy, spreads disease to others. The authors are not ready to advocate this approach in this system, ‘except in areas of high conservation value where toads are likely to have major impacts’, primarily on the grounds of possible undetected effects on green tree frog viability and secondarily on animal welfare grounds – although if, in fact, the parasite has no effect on green tree frogs, it is not clear how infecting them is imposing suffering. A more important reason to avoid the ‘Typhoid Mary’ approach in this case would seem to be because a close relative of the green tree frog, the splendid tree frog (Litoria splendida), has been found to be very sensitive to this lungworm parasite, at least in laboratory trials (Pizzatto & Shine, 2011a). I wonder if the likelihood of spread to L. splendida by deliberately infected L. caerulea would actually be greater than spread to cane toads, considering the two native frogs are congeners. The concept is certainly novel, and we need novel ways to control invasive pests. However, this approach, while using a native species to spread the parasite, ultimately depends on the use of an exotic organism. Although it is true that many parasites and parasitoid insects are quite host specific, unfortunately, this is not always the case. A parasitoid fly introduced as a biological control agent for gypsy moth and other pest Lepidoptera was subsequently found to impact populations of several native giant silk moth species in North America (Boettner, Elkinton & Boettner, 2000). Other examples of negative effects of biological control agents are cited by Howarth (1991), Simberloff & Stiling (1996) and Barratt et al. (2010). Current regulations emphasize the need for host specificity of any introduction, and concern for non-target impacts is more and more a concern in the regulatory environment (Hajek, McManus & Junior, 2007; Barratt et al., 2010). The cane toad is also an iconic poster child for biological control gone wrong, and in our efforts to control it, we must ensure that things are not made worse – if that is possible. Typhoid Mary unknowingly spread the bacteria that cause typhoid fever to other members of her own species, as a rather unsanitary cook to a whole series of human families. A possible approach in the cane toad system might be to take heavily infected cane toads and release them at the invasion front (where the lungworm is often absent), or otherwise enhance the level of lungworm parasites, if this can be done in a way that would not significantly increase the toad population – perhaps by releasing small infected metamorphs that would likely be cannibalized by larger cane toads (Pizzatto & Shine, 2011b). So far, efforts to identify a truly cane toad-specific pathogen for use as a biological control agent have been unsuccessful, as have been efforts to induce autoimmunity and disrupt metamorphosis (Pallister et al., 2011). Alarm pheromones and translocation of parasitic lungworms to the invasion front may provide new tools in the management of this damaging pest species (Saunders et al., 2010). Unfortunately, at present, a truly effective and safe ‘integrated toad management’ program still seems elusive.

Statistical models that include random effects are becoming more common in population ecology all the time. Random effects are two or more effects of some grouping factor that belong together, in the sense that we can imagine they were generated by a common stochastic process. Thus, they are similar, but not identical, and therefore assumed to be exchangeable. Models with random effects contain as a description of this common stochastic process so-called prior distributions, with estimable hyperparameters, for instance the mean and the variance for normally distributed random effects. Models with random effects have intrinsically more than one level; therefore, they are often called hierarchical models (Royle & Dorazio, 2008) or multilevel models (Gelman & Hill, 2007). Interest in hierarchical models often focuses on the hyperparameters, but the realizations from the process described by the prior distributions, that is, the random effects, can also be estimated. The main difference to treating a set of effects as fixed is that in a random effects model, the parameters of a grouping factor are no longer estimated independently. Rather, the assumption that they come from a common prior distribution induces a dependence, which means that the estimate of each is somewhat influenced by the estimate of all other effects comprising that factor. This is often called borrowing strength from the ensemble. One consequence of treating a factor as random is that its effect estimates are pulled in towards the overall mean, which is called shrinkage in the literature. If the assumption of a common stochastic process is reasonable, borrowing strength and shrinkage typically leads to better estimates compared with their fixed effects counterparts (Gelman, 2005; chapter 4 in Kery & Schaub, 2012). Hierarchical models are not at all intrinsically Bayesian; rather, they can be analysed using likelihood or Bayesian methods (Royle & Dorazio, 2008), though Bayesian analysis is often easier, especially for ecologists using MCMC engines like WinBUGS (Lunn et al., 2000) or JAGS (Plummer, 2003). One particularly interesting use of hierarchical model is as a formal way of combining information, for instance, coming from different studies. A good example is the feature paper by Halstead et al. (2012), where estimates of survival probabilities of a snake species from radio-tracking data at multiple study sites in the same region are combined in a hierarchical model that is fitted using the WinBUGS software. Sample size at each site was fairly low. Hence, Halstead and colleagues treated each study site as a replicate and estimated the hyperparameters of the distribution that collects together the sitespecific parameters, which were treated as random effects. Hierarchical modelling thus provides a formal way of combining this information, where study sites with more information (e.g. more snakes or with more precise estimates) get more weight in contributing to the estimates of the overall mean and the among-site variability (the mean and the variance hyperparameters). Site-specific estimates are shrunken towards the mean, where the degree of shrinkage depends on the precision of the site-specific estimates. This is a desirable property, as it avoids possible overinterpretation of patterns that may be due to some idiosyncrasy of a small sample. Borrowing strength typically also helps against boundary estimates that are frequent in survival analysis with small sample size. Thus, not only were Halstead and colleagues able to obtain a formal estimate of the regional mean of the interesting parameters, but arguably they also obtained better site-specific estimates owing to the sharing of information among all sites. In a sense, what they did is a meta-analysis. A further advantage of combining data from several studies is increased precision of the site-specific estimates, because they borrow strength from the entire dataset. Increased precision means to have more power to detect an effect, which is especially advantageous when dealing with rare species, where sample size is typically small to very small. A similar approach was chosen by Papadatou et al. (2012) who estimated survival probabilities of several bat species (i.e. where species was bs_bs_banner

As tropical logging increases in scope, understanding the capacity of tropical secondary forests for sustaining oldgrowth (OG) forest biodiversity has become a critical question in tropical conservation. There is growing realization that tropical conservation cannot be limited to pristine habitats in protected areas (Sekercioglu et al., 2007; Chazdon et al., 2009). To better integrate secondary forests into conservation schemes, it is essential to understand the proportion of native forest biodiversity that can persist in secondary forests (Chazdon et al., 2009). This is particularly urgent in light of the growing significance of the UNReducing Emissions from Deforestation and Forest Degradation in Developing Countries program (Grainger et al., 2009). For preserving tropical biodiversity, the ideal way to sequester carbon is to preserve OG forests. However, the magnitude of the climate change problem means that preserving OG is not enough. Secondary forests can also sequester large amounts of carbon, even 100 years after the start of regrowth (Silver, Ostertag & Lugo, 2000). The Biological Dynamics of Forest Fragments Project (BDFFP) has pioneered the experimental approach in tropical forest fragmentation studies, by taking advantage of forestclearing operations near Manaus, Brazil (Laurance et al., 2002). BDFFP worked with landowners to make sure that they left forest patches in squares of 1, 10 and 100ha to be compared with extensive OG, resulting in an excellent experimental setup. Now, hundreds of papers later and entering its fourth decade, BDFFP scientists are again skillfully taking advantage of circumstances beyond their control (Sberze, Cohn-Haft & Ferraz, 2010). It has proven logistically challenging to keep cleared much of the land that was initially deforested. Even though this has reduced the isolation of the original forest fragments, it has also led to many new and interesting questions about the biodiversity value of the different types of secondary growth (Antongiovanni & Metzger, 2005; Barlow et al., 2007; Laurance et al., 2007). A large part of the tropical conservation literature focuses on diurnal birds, as they are relatively easy to sample. However, sampling nocturnal species can be challenging (Borges, Henriques & Carvalhaes, 2004; Bhattacharjee, 2008) and these birds have received little attention in tropical conservation studies. Sberze et al. (2010) rectify this by combining state-of-the-art modeling with intensive fieldwork. The densities of nocturnal birds can be notoriously difficult to estimate (Borges et al., 2004), especially considering the problems with estimating distance based on vocalizations (Alldredge, Simons & Pollock, 2007). Therefore, Sberze et al. (2010) used occupancy modeling (MacKenzie, 2006) based on detection data to estimate the likelihood that a site is occupied by a species. Extensive field sampling covered all months of the year and the authors accounted for spatial autocorrelation by quantifying it in their models. Vocalization playback of focal species further increased the chances of their detection. The findings are encouraging, although not surprising for those who have field experience with tropical night birds. OG and 30-year-old secondary forest (SF) did not differ in species richness. Each habitat was estimated to host 10–12 nocturnal bird species. Only one species, the potooNyctibius leucopterus, clearly avoided second growth. However, Nyctibius griseus and the nightjarsCaprimulgus griseus andCaprimulgus nigrescens preferred it, defying the authors’ predictions for C. nigrescens. Neither of the focal owl species differed significantly in its preference for OG versus secondary forest, which was also unexpected for Lophostrix cristata. Of the six other nocturnal species detected, two potoo species did not have enough detections for parameter estimation, but three owl species showed higher point estimates of occupancy for SF than for OG. The preference for SF and embedded forest fragments is likely due to the higher abundances of small mammals, on which many owls feed, and better foraging habitat for nightjars that usually prefer to feed in open areas (del Hoyo, Elliott & Sargatal, 1999). Nevertheless, the location of this study presents an unusual best-case scenario for forest birds, as the SF survey points are within 0–2km of extensive primary forest. Birds of prey can cover large areas while foraging and even non-predatory resident tropical songbirds are capable of covering 6km in 2h (Sekercioglu et al., 2007). As the authors themselves are first to point out, some of the seemingly SF-preferring species may have source populations in OG. The possibility of nocturnal birds nesting inOG and ‘commuting’ to SF, analogous to some tropical bats (Evelyn & Stiles, 2003), also remains to be

The subsidization of predators occurs when humans directly or indirectly alter resource availability in such a way as to increase the density of a predator population above levels that would occur without the additional resources. Subsidized predators can drastically impact prey populations because subsidies insulate the predator populations from the effects of declines in prey populations (Sinclair et al., 1998). Such scenarios become problematic for conservation practitioners when the enhanced predator population influences species of conservation concern. Examples of this are widespread: subsidized ravens influence tortoise ecology (Boarman, 2003); subsidized predatory beetles influence insect herbivore populations (Rand & Louda, 2006); subsidized mountain lions influence bighorn sheep demographics (Rominger et al., 2004); and in the example presented by Shapira, Sultan & Shanas (2008), subsidized red foxes Vulpes vulpes influence gerbil ecology. Shapira et al.’s fox-gerbil example is particularly interesting because the influence of foxes is best seen not in altered densities of gerbils per se, but in the behavior of these taxa. In areas near farms, the availability of crops and favorable habitat apparently subsidize foxes. As a result, in areas where foxes are putatively more abundant, gerbils are not only less abundant but are also less active, and show decreased foraging efficiency. This suggests that foxes in this agricultural region have altered gerbil biology not by direct predation alone, but also by creating a landscape of fear (Brown, Laundre & Gurung, 1999; Laundre, Hernandez & Altendorf, 2001), from which the gerbils have somehow rendered a microhabitat-level map of the perceived risk of predation. It is harder, however, to address the effect of actual predation on gerbils as Shapira et al. do not present information on the diet of foxes. Indeed, the differential activity rates and behaviors of gerbils at sites near and far from foxes are potentially confounded by several concerns. Foxes are not uniformly distributed but are found near farms. While this is, of course, a primary point of Shapira et al.’s paper, it nonetheless means that many of the factors making the farmed areas so different from the more natural surrounding areas are also presumably correlated with fox distributions and may also influence gerbil biology. In addition, which of the two gerbil species, or the ratio of the two species, that is being examined at each study site is not clear. This is important, because if the two gerbil species differ in their foraging and behavior, then observed differences in gerbil ecology and behavior that are attributed to foxes may in fact be a function of which gerbil species is visiting the seed tray. Finally, the foraging behavior of the predator itself may differ across study sites. Shapira et al. did not study the ecology of the foxes, but we know that predator behavior is not static. Just as prey alter their behavior to address perceived risks of predation, predator behavior also changes as a function of prey density and behavior (Lima, 2002; Quinn & Cresswell, 2004). Nonetheless, differential intensity of fox use of the landscape does appear to be the most parsimonious explanation for the observed patterns of gerbil ecology, as these patterns match our understanding of how subsidized predators and their prey should interact. In a world in which anthropogenic landscape change is a seemingly ubiquitous concern for conservationists, can we predict a prioriwhere and which predators are likely to become problematic in such situations, and can we make recommendations as we attempt to identify solutions? Although a full examination of these two questions is beyond the scope of this commentary, we know enough about the ecology of predators, of prey and of their intraand interguild interactions to make some generalizations that may carry predictive power and applied relevance. For instance, we know that larger carnivores may suppress populations of other guild members in the same way in which predators influence prey: through predation and by creating landscapes of fear (Linnell & Strand, 2000; Creel, Spong & Creel, 2001). At the Israeli–Jordanian study sites, the generalist and mid-sized red fox apparently outcompetes