Search

In the search for new ways to bring attention to the conservation of neglected species, marketing is increasingly recognised as offering new insights. Brand creation frameworks provide guidelines to create names or symbols for products that will differentiate them from the competition. In this paper, we examine if species common names that follow these guidelines can improve their fundraising potential. Using a novel choice experiment format that employs a budget allocation task, we evaluate if species common names influence donor preferences, where participants were given real money to donate to the species of their choosing. We model the data collected, which is fractional response data, using a Hierarchical Bayesian Dirichlet regression. Our results indicate that while all attributes are positively related to making a donation, Appeal and Familiarity coefficients are statistically significant but Name is not. There were also no statistically significant interactions between Name and any of the socio‐economic variables. Our results on the importance of Appeal and Familiarity follow past research but contradict past research on the importance of common names, although the latter looked at common names in isolation. This suggests that species traits should not be tested in isolation when trying to understand the drivers of donations to wildlife conservation, as some traits that may appear important when tested separately become comparatively irrelevant when placed in a more realistic context where respondents have to consider multiple species traits. Future research into the influence of common names should investigate the possible impact of name sentiment as well as whether names with geographic references increase support from donors from those areas. [ABSTRACT FROM AUTHOR]

Read the Feature Paper: Mapping the potential extinction debt of butterflies in a modern city: implications for conservation priorities in urban landscapes Commentaries on this Feature Paper: Extinction debt at different spatial scales; Setting conservation priorities when what you see is not what you get [ABSTRACT FROM AUTHOR]

Given the problem of hybridization with domestic cats, there is a growing need to identify populations of the European wildcat Felis silvestris silvestris in order to protect the genetic integrity of this subspecies. In this paper, we use known locations of observations of wildcats or recovered carcasses to reassess the distribution of the wildcat in France and, in cases where carcasses were collected, we use both phenotypic and molecular genetic analyses to distinguish wildcats from hybrids with domestic cats. Spatially explicit multivariate analysis of wildcat' genotypes was then performed to define genetic units. Our study confirms the presence of wildcats in a large area of c. 155 000 km2, suggestive of a range of expansion, and divided into two clearly distinct and unconnected areas - the Pyrenees and the north-eastern part of France. However, European wildcat populations may be decreasing in the French Pyrenees, whereas the north-eastern part represents the main area (MA) of wildcat presence. This extension does not appear to be primarily due to hybrids, as both wildcats and hybrids were located throughout the MA. In addition, we found that genetic diversity of wildcats in the MA is remarkably high, suggesting that French populations are not threatened by a lack of genetic diversity. Furthermore, wildcats of the MA are structured into two genetically distinct populations that are contiguous and probably extend into Germany to form the largest area of wildcat presence in Europe and an area of major interest for their conservation. Our study calls for localized examination of the feasibility and usefulness of wildlife corridors to enhance connectivity between the different populations, thereby allowing sufficient levels of immigration and gene flow within the regional meta-population to ensure the long-term viability of these populations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In recent years, population viability analysis has become a popular tool to assess the relative risk of extinction among populations. Viability estimates for spatially structured populations require movement data that are often unavailable. In this paper, a diffusion approximation model was used to explore the effects of different spatial scenarios resulting from assumptions about movement rates. Census data for 13 breeding islands occupied by California sea lions Zalophus californianus californianus in the Gulf of California were used to explore three potential scenarios: unlimited movement between sites (panmictic population), limited movement (several clusters of populations) and no movement between islands (isolated islands). Predicted viability estimates were different for each scenario, but contrary to expectations, the mean extinction risk estimates were generally lowest when movement was unlimited (panmictic scenario). However, despite an extensive dataset, the confidence of the viability predictions for each scenario was low. In some cases, uncertainty in predictions within a scenario was greater than differences between scenarios. Therefore, it is recommended that in situations where movement rates and spatial structure are unknown, extinction risk estimates should reflect both the confidence intervals for each risk estimate and the uncertainty resulting from different spatial scenarios. This study also provides the first estimate of population viability (considering spatial structure) for California sea lions in the Gulf of California and an evaluation of population status based on the IUCN criteria for species listing. [ABSTRACT FROM AUTHOR]

The Ethiopian wolf (Canis simensis) is a very rare, endangered, endemic species surviving in isolated mountain pockets in the Ethiopian highlands, with nearly 50% of the global population living outside protected areas. In this paper we compare the ecology and behaviour of an Ethiopian wolf population living in Guassa, a communally managed area in the Central Highlands, with that of the Bale Mountains National Park in the Southern Highlands. Ethiopian wolves live at lower density in Guassa (0.2±0.05/km²) than in the Bale Mountains, but giant molerats (Tachyoryctes macrocephalus), the main prey for Ethiopian wolves in Bale Mountains, do not occur in the Central Highlands. Faecal analysis identified nine prey categories across wet and dry seasons common to both populations. In total, rodents accounted for 88% of prey volume in wolf diets. Home-range size was positively related to pack size (r² = 0.85) and there was no difference in mean home-range sizes in both areas. In Guassa, however, wolves spent less time in the presence than in the absence of humans, but wolves spent similar amounts of time in the presence and absence of cattle. These findings suggest wolves can cope with, or adapt to, the presence of livestock and people in communally managed areas. [ABSTRACT FROM AUTHOR]

Climate warming is driving species to shift their geographical distribution poleward to track suitable climatic conditions. Two strategies have been suggested to help species respond to climate warming: facilitating distribution change or improving persistence. We questioned whether habitat management in favour of duck hunting activities interacted with duck responses to climate warming. We studied nonbreeding waterbird community changes (110 species) over 28 years at 851 sites in South-West Europe, where habitat management is a common practice to attract and hunt ducks. We hypothesized that duck species targeted by habitat management do not need to track temperature changes as much as non-hunted species, because of the availability of suitable habitats provided by hunting land managers. We used the community temperature index (CTI) to assess the temporal responses of communities and species to climate warming. We compared the effect of hunting status with other functional traits on species responses, controlling for phylogenetic relatedness. The CTI trend has increased over the study period, indicating a community adjustment to climate warming. However, hunted ducks contributed to almost 40% of the negative contributions to this community adjustment, suggesting that hunted ducks do not shift their distribution as much as the other waterbirds do. Winter fidelity associated with the provision of attractive feeding grounds might explain why ducks did not seem to shift their distribution in response to climate warming. This study suggests the broad impact of human activities on wildlife, including on large-scale distribution processes, and questions the long-term consequences on duck populations. [ABSTRACT FROM AUTHOR]

In this article, the author comments on a paper about the use of assignment tests in quantifying the degree of connectivity between demes that comprise a metapopulation. The paper demonstrated the accuracy of assignment tests in providing parameterization of migration rates in population viability analysis (PVA) models. It also showed how genetic data can be used to measure individual abundances in each dataset. The author commends the paper for bridging the gap between deoxyribonucleic acid (DNA) fingerprint and PVA models.

Human activities are affecting habitats and wildlife populations worldwide. Tropical forests are one of the most affected environments, mainly due to deforestation and poaching. Since high levels of anthropogenic pressure on forest ecosystems, including illegal logging and hunting, occur in southwest Myanmar (Rakhine State), we analyzed the effects of human disturbance on medium to large mammals in this region. We used camera‐trapping data collected over three consecutive years to investigate occurrence probabilities of 10 species: five common species exploited for bushmeat consumption, and five threatened species targeted by the illegal wildlife trade. We used a hierarchical single‐species multi‐season occupancy model implemented in a Bayesian framework to evaluate the effects of human disturbances and persistent habitat characteristics, such as the proportion of remaining pristine evergreen forest and the elevation, on occurrence probabilities. We found that occupancy probabilities of three out of five target species for the illegal wildlife trade were positively linked to forest habitats, whereas among common species hunted for bushmeat consumption the Northern red muntjak and the Malayan porcupine were negatively affected by human presence. The effects of human and habitat covariates were varied for other species of both groups. We confirmed results from previous studies that human disturbance is a driver of occurrence probabilities for some species in tropical areas. Our findings suggest that as protection of rainforest habitat is fundamental to the conservation of tropical ecosystems, law enforcement, patrolling, and local engagement activities are also recommended to mitigate forest and species exploitation. Finally, camera trapping could be a first step to identify areas where human presence affects species occupancy and help local authorities to develop more fine‐tuned conservation plans. [ABSTRACT FROM AUTHOR]

Maintaining animal populations in captivity can be a useful way to conserve species, especially those that are extinct in the wild or endangered in their native habitats. These animals could be reintroduced into the wild from captivity if conditions improve. However, captive populations of endangered species are often established with few wild‐caught individuals and are maintained in novel habitats, conditions which may make these populations prone to morphological divergence. Changes in cranial morphology, in particular, may limit reintroduction success because these morphological changes may alter cranial functionality related to capturing and consuming prey. To assess whether unintentional morphological changes occur in captivity, we examined the crania and mandibles of 275 specimens of wild, captive and reintroduced Mexican wolves Canis lupus baileyi. We detected significant differences in skull size and shape among these populations. Captive specimens displayed the greatest overall shape variation and were significantly differentiated from the wild population in regions of the skull that are essential to cranial functionality. The reintroduced population displayed the narrowest trait distribution, with cranial morphology that grouped consistently with the captive morphotype. The small number of individuals of the founding population along with the increased variation in cranial morphology among captive Mexican wolves suggests that morphological changes in captivity may be related to genetic changes such as genetic drift or relaxed selection. This study helps to define the changes that may occur in captivity, the potential mechanisms behind these shifts, and the ways in which morphological variation in captive populations may impact conservation initiatives. [ABSTRACT FROM AUTHOR]

The age at which individuals reproduce for the first time is a key demographic factor impacting population dynamics and is subject to substantial variation across animal populations. There is also widespread empirical evidence that age of first reproduction responds to changes in population density over time, especially for long‐lived birds and mammals. The density dependence in age of first reproduction has profound impacts on the size of the non‐breeding ('floater') part of the population. A better understanding of floater dynamics in raptor populations is urgently needed for comprehensive assessments of conservation status and management. We use the European near‐endemic red kite Milvus milvus, a long‐lived raptor of conservation concern, as an example to investigate total population dynamics with an age‐structured demographic model. Using published estimates of survival and reproduction, we model the red kite population in Germany over four decades, considering also density dependence in the age of first reproduction in different model scenarios. Based on the literature and the results of our simulations, we show that age of first reproduction for the red kite most likely responds non‐linearly to density and that this general feedback mechanism should regularly be considered in demographic simulations. Our model results have far‐reaching implications for the conservation status of the red kite, as they highlight a drastic decrease of juvenile and non‐breeding individuals in the population over time – driven both by declining vital rates and a density‐dependent shift towards a younger age of first breeding. This process is not visible when judged only by the size of the breeding population, which our model estimates to be of similar size today as in the 1980s. The total red kite population reconstructed for Germany, however, seems diminished to nearly 50% of its former size. [ABSTRACT FROM AUTHOR]

Abstract: Measuring population changes and trends is essential to identify threatened species, and is requested by several environmental regulations (e.g. European Habitat Directive). However, obtaining this information for small and cryptic animals is challenging, and requires complex, broad‐scale monitoring schemes. How should we allocate the limited resources available for monitoring, to maximize the probability of detecting declines? The analysis of simulated data can help to identify the performance of monitoring scenarios across species with different features. We simulated data of populations with a wide range of abundance, detection probability and rate of decline, and tested under which circumstances open‐population N‐mixture models can successfully detect the decline of populations. We tested multiple monitoring strategies, to identify the ones having the highest probability of detecting declines. If 30 sites are surveyed, strong declines (≥30%) can be successfully spotted for nearly all the simulated species, except the species with lowest abundance and detection probability. Weaker declines are successfully identified only in species that are easy to detect and have high abundance. Increasing the number of sites quickly increases model power, but hundreds of sites would require monitoring to measure trends of the least detectable species. For most of species, performance of monitoring was improved by: surveying many sites with a few replicates per site; surveying many small sites instead of a few large sites; combining data from sites monitored for multiple species. Our findings show that one single monitoring approach cannot be appropriate for all the species, and that surveying efforts should be modulated across them, according to their detection probabilities and abundances. We provide quantitative values on how the number of surveys and the number of sites to be surveyed can be assigned to different species, and emphasize the need of planning to maximize the performance of monitoring. [ABSTRACT FROM AUTHOR]

Preserving large carnivores that perceive humans as prey brings conservation values into direct conflict with human security. Informing when and where humans and large carnivores occupy the same space may reduce attack frequency and promote coexistence. Here, we demonstrate a methodology to better understand the spatiotemporal relationship between a population of large carnivores and humans. The carnivore of study was the estuarine crocodile C rocodylus porosus, a large semi-aquatic predator responsible for 705 recorded human attacks over the last 20 years. Crocodiles were captured every August over 3 years and individuals greater than 2.5 m in length were implanted with an acoustic transmitter ( n = 84). The transmitter emitted a coded pulse detected when in proximity to underwater hydrophones deployed throughout the river. The telemetry data informed which previously captured crocodiles were present during subsequent trapping episodes and adult population size was estimated using a closed-population model. Over 3 years, 24 of the tagged crocodiles were detected 269 times moving through a shallow-water area where humans frequently entered the water. The tagged crocodile presence was extrapolated to the population level to provide a probability of adult crocodile presence across a range of temporal scales. The results showed that between September and December, the probability of crocodile presence within the human entry zone was 0.97 ± 0.01 during darkness but decreased to 0.07 ± 0.01 during daylight, except around periods of high tide when it increased to 0.71 ± 0.02. Human visitors confined their activity to shallow water during daylight hours, but no consideration was given to the significant rise in crocodile presence with season and tide. The observed patterns in crocodile and human behaviour, around this shallow-water river crossing, exhibited parallels with historical incidences of crocodile attack. [ABSTRACT FROM AUTHOR]

Population monitoring must robustly detect trends over time in a cost-effective manner. However, several underlying ecological changes driving population trends may interact differently with observation uncertainty to produce abundance trends that are more or less detectable for a given budget and over a given time period. Errors in detecting these trends include failing to detect declines when they exist (type II), detecting them when they do not exist (type I), detecting trends in one direction when they are actually in another direction (type III) and incorrectly estimating the shape of the trend. Robust monitoring should be able to avoid each of these error types. Using monitoring of two contrasting ungulate species and multiple scenarios of population change (poaching, climate change and road development) in the Serengeti ecosystem as a case study, we used a 'virtual ecologist' approach to investigate monitoring effectiveness under uncertainty. We explored how the prevalence of different types of error varies depending on budgetary, observational and environmental conditions. Higher observation error and conducting surveys less frequently increased the likelihood of not detecting trends and misclassifying the shape of the trend. As monitoring period and frequency increased, observation uncertainty was more important in explaining effectiveness. Types I and III errors had low prevalence for both ungulate species. Greater investment in monitoring considerably decreased the likelihood of failing to detect significant trends (type II errors). Our results suggest that it is important to understand the effects of monitoring conditions on perceived trends before making inferences about underlying processes. The impacts of specific threats on population abundance and structure feed through into monitoring effectiveness; hence, monitoring programmes must be designed with the underlying processes to be detected in mind. Here we provide an integrated modelling framework that can produce advice on robust monitoring strategies under uncertainty. [ABSTRACT FROM AUTHOR]

Extreme natural events such as cold waves, droughts, floods or hurricanes can drastically impact wildlife populations and are expected to become more frequent and more intense in the coming decades. When populations experience abnormally high declines within a short time interval due to such phenomena, the losses can be referred to as natural population die-offs ( NPDOs). Although such events have been observed and population declines have been recorded, there is currently little known about which species might be most affected. Using a database of 72 NPDOs from 31 terrestrial herbivorous mammals, we modelled the effects of four biological traits (adult body mass, foraging strategy, home-range area and territoriality) on the degree of population loss (severity) caused by extreme natural events. We found that the susceptibility to large NPDOs decreases with increased home-range size for a given body mass. Foraging strategy was also found to be significantly associated with NPDO severity, with grazers and mixed feeders experiencing larger declines than browsers. Our analyses moreover suggested that wide-ranging browsers might be less susceptible to large NPDOs than browsers with small home ranges. Identifying the traits shaping high biological sensitivity and/or limited adaptive capacity to extreme natural events can help us to identify those populations most likely to become increasingly vulnerable to NPDOs, allowing tailored interventions to be implemented to avoid local extinctions. This will be of the utmost importance for those populations already experiencing high levels of anthropogenic impact and distributed in regions where exposure to extreme natural events is expected to increase in the coming decades. [ABSTRACT FROM AUTHOR]

After a steady decline in the early 20th century, several terrestrial carnivore species have recently recovered in Western Europe, either through reintroductions or natural recolonization. Because of the large space requirements of these species and potential conflicts with human activities, ensuring their recovery requires the implementation of conservation and management measures that address the environmental, landscape and social dimensions of the problem. Few examples exist of such integrated management. Taking the case of the otter ( Lutra lutra) in Switzerland, we propose a multi-step approach that allows to (1) identify areas with potentially suitable habitat, (2) evaluate their connectivity, (3) verify the potentiality of the species recolonization from populations in neighbouring countries. We showed that even though suitable habitat is available for the species and the level of structural connectivity within Switzerland is satisfactory, the level of connectivity with neighbouring populations is crucial to prioritize strategies that favour the species recovery in the field. This research is the first example integrating habitat suitability and connectivity assessment at different scales with other factors in a multi-step assessment for species recovery. [ABSTRACT FROM AUTHOR]

Rapidly increasing elephant populations are raising concerns, especially within enclosed conservation areas in southern Africa. Elephant immunocontraception is an effective management tool, enabling conservation managers to control elephant population growth rates, but the behavioural consequences of this intervention needs to be studied more intensively and over longer periods of time. This is especially important as the potential risk of disturbance, and the ethical concerns over the welfare of wildlife, can compromise the success of management interventions. We determined the influence of immunocontraception application on behaviour of family groups. The disruption effect of immunocontraception darting on the family groups within the population was minimal, with no significant changes found in the mobility of family groups. Analysis of family group fission and fusion indicated that family groups spent more time alone during the second year of contraception application; this could be a consequence of maturation of the relatively young population. There was no significant relationship between bulls' association with family groups and the number of oestrous females present in the group. With negligible short-term effects on the behaviour of family groups, immunocontraception may be an effective, flexible management tool. Furthermore, this study showed that monitoring and assessment of behavioural assays during active adaptive management is important to determine conservation outcomes and to ensure future management success. [ABSTRACT FROM AUTHOR]

The future of wild tigers is dire, and the Global Tiger Initiative's ( GTI) goal of doubling tiger population size by the next year of the tiger in 2022 will be challenging. The GTI has identified 20 tiger conservation landscapes ( TCL) within which recovery actions will be needed to achieve these goals. The Amur tiger conservation landscape offers the best hope for tiger recovery in China where all other subspecies have most likely become extirpated. To prioritize recovery planning within this TCL, we used tiger occurrence data from adjacent areas of the Russian Far East to develop two empirical models of potential habitat that were then averaged with an expert-based habitat suitability model to identify potential tiger habitat in the Changbaishan ecosystem in Northeast China. We assessed the connectivity of tiger habitat patches using least-cost path analysis calibrated against known tiger movements in the Russian Far East to identify priority tiger conservation areas ( TCAs). Using a habitat-based population estimation approach, we predicted that a potential of 98 (83-112) adult tigers could occupy all TCAs in the Changbaishan ecosystem. By combining information about habitat quality, connectivity and potential population size, we identified the three best TCAs totaling over 25 000 km2 of potential habitat that could hold 79 (63-82) adult tigers. Strong recovery actions are needed to restore potential tiger habitat to promote recovery of Amur tigers in China, including restoring ungulate populations, increasing tiger survival through improved anti-poaching activities, land-use planning that reduces human access and agricultural lands in and adjacent to key TCAs, and maintaining connectivity both within and across international boundaries. Our approach will be useful in other TCLs to prioritize recovery actions to restore worldwide tiger populations. [ABSTRACT FROM AUTHOR]

Sampling animal populations with camera traps has become increasingly popular over the past two decades, particularly for species that are cryptic, elusive, exist at low densities or range over large areas. The results have been widely used to estimate population size and density. We analyzed data from 13 camera trap surveys conducted at five sites across the Kaa- Iya landscape, Bolivian Chaco, for jaguar, puma, ocelot and lowland tapir. We compared two spatially explicit capture-recapture ( SCR) software packages: secr, a likelihood-based approach, and SPACECAP, a Bayesian approach, both of which are implemented within the R environment and can be used to estimate animal density from photographic records of individual animals that simultaneously employ spatial information about the capture location relative to the sample location. As a non-spatial analysis, we used the program CAPTURE 2 to estimate abundance from the capture-recapture records of individuals identified through camera trap photos combined with an ad hoc estimation of the effective survey area to estimate density. SCR methods estimated jaguar population densities from 0.31 to 1.82 individuals per 100 km2 across the Kaa- Iya sites; puma from 0.36 to 7.99; ocelot from 1.67 to 51.7; and tapir from 7.38 to 42.9. Density estimates using either secr or SPACECAP were generally lower than the estimates generated using the non-spatial method for all surveys and species; and density estimates using SPACECAP were generally lower than that using secr. We recommend using either secr or SPACECAP because the spatially explicit methods are not biased by an informal estimation of an effective survey area. Although SPACECAP and secr are less sensitive than non-spatial methods to the size of the grid used for sampling, we recommend grid sizes several times larger than the average home range (known or estimated) of the target species. [ABSTRACT FROM AUTHOR]

The delimitation of the spatial equivalent of isolated populations or interacting sets of local populations is crucial for conservation management. In Amphibia, spatial organization in metapopulations requires knowledge on the individual variation of annual migratory capacity within local populations to delimit core habitats around the breeding site and to estimate the connectivity among neighbouring populations. The migratory behaviour of 143 adult Bufo calamita was monitored using radio-telemetry at eight localities covering a latitudinal range from 41° to 54° N. Aims of the study were to assess the geographic variation of migratory distance moved by males and females and to model their capacity for dispersal assuming exclusively unidirectional movements. Migratory range was not sex-biased, but was three times lower in population inhabiting sandy areas than in those on clay soils, probably because of the scarcity of moist shelters causing more frequent and more distant movements. For conservation management of local natterjack populations, we propose to use the migratory capacity of the 50% most sedentary individuals to delimit the core area around a given breeding site. To estimate the potential genetic connectivity between neighbouring local population, we propose to use the minimum migratory capacity of the 5% of individuals that moved most. Estimates obtained for populations in central Europe and the UK indicate a core area of 600 m around the breeding site and a maximum distance of 2250 m between the breeding ponds to maintain connectivity. Thus, the principal conservation problem in the UK is that most populations are isolated by distance and prone to local extinction. In contrast, core areas of populations in Spain extend to distances of about 5 km and connectivity is maintained up to a distance 12 km between neighbouring breeding ponds. [ABSTRACT FROM AUTHOR]

The author comments on several studies that used random effects models as means of borrowing strength in survival studies of wild invertebrates. He notes the challenge in the estimation of survival in wild vertebrate populations. He cites that a Bayesian approach was used in the studies by B. J. Halstead et al and D. W. Hosmer et al to estimate a mixed version of their models. He also suggests the reasons for using random effects models in demographic studies of wild vertebrates.

Divergent habitat utilization and niche partitioning can cause high degrees of ecological specialization even in generalist species. For example, sex-specific specialization results in differential habitat use, which, if neglected in monitoring studies, can lead to biased estimates of population sizes. However, many widely used methods of population monitoring such as bioacoustical surveys of echolocating bats cannot take such demographic differences into account, due to methodological limitations. Here, we use ecological niche factor analysis (ENFA) to derive habitat suitability maps (HSMs) of male and female parti-coloured bat Vespertilio murinus using previously published radio-tracking data. The ENFA revealed that males and females were highly specialized and ecologically segregated. Accordingly, we found that significantly more high-quality habitats were available for males than for females, with no spatial overlap between sexes. The HSMs allowed us to estimate the skew in the distribution of the sexes in space. Our approach provides a way to estimate intra-species spatial segregation and consequently generate a more accurate prediction of effective population size and niche requirements of vulnerable species. This study also highlights the importance of making geographic and environmental data, as well as animal occurrence and movement data publicly available for the benefit of conservation efforts. [ABSTRACT FROM AUTHOR]

Estimating population size is central to species-oriented conservation and management. However, in spite of recent development in monitoring protocols, there are gaps in our ability to accurately and quickly estimate numbers of individuals present, especially for the cryptic and often non-breeding components of structured vertebrate populations. Yet knowing the size and growth trajectory of all stage classes of a population is critical for species conservation. Here we use data from 2 years of non-invasive genetic sample collection from the cryptic, non-breeding component of an endangered bird of prey population to evaluate the impact of variability in population estimates on demographic models that underpin conservation efforts. A single non-invasive sample collection in 2003 conclusively identified 47 individual non-breeding imperial eagles, 2.8 times more than were visually counted. In 2004, our comprehensive genetic and observational analyses determined that 414 imperial eagles ( n=308 non-breeders+68 territory holders+38 chicks) were present. This estimate was 326% larger than the 127 birds visually observed ( n=21 non-breeders+68 territory holders+38 chicks) and 265% larger than the population size predicted by demographic models with the same number of breeders ( n=156±7.2;± se). Our study builds on a body of work that demonstrates that conventional visual estimation of cryptic components of structured populations may not always be effective. Furthermore, we show that reliance on those estimates can result in inaccuracies in the demographic models that are often the foundation for subsequent conservation action. [ABSTRACT FROM AUTHOR]

Although tropical forest vertebrate populations are often heavily impacted by both habitat loss and subsistence hunting, in many human-dominated landscapes their fate depends on the wider habitat matrix outside protected areas. This study used line-transect surveys to examine patterns of vertebrate species richness and encounter rates (ER) throughout Mexico's Yucatan Peninsula across a broad spectrum of anthropogenic forest disturbances. Censuses were carried out at eight forest sites, including two localities within the Sian Ka'an Biosphere Reserve, a communally managed protected area, a private forest reserve and three communal-tenure landholding units. Species richness increased with increasing forest cover in the surrounding landscape, but was not affected by the degree of hunting pressure. Responses to different forms of disturbance varied markedly across species and functional groups. Aggregate ER of old-growth specialists were positively correlated with forest cover, but unrelated to hunting pressure. Hunting pressure was strongly related to aggregate ER of game species, particularly of preferred prey, and a meta-analysis of species-specific correlations showed a significant effect of hunting pressure on the ER across individual game species. Sampling within old-growth forest of Sian Ka'an yielded relatively high ER for almost all species. In comparison, low ER were obtained for several species at Sian Ka'an sites consisting of a higher proportion of open habitat. Landholding units showed low relative abundances, but species ER varied depending on disturbance type. The communally managed reserve exhibited high ER for both game and non-game species. Synthesis of these results with comparable data from 19 additional Mesoamerican sites shows that species-specific ER found across the Yucatan Peninsula are within the ranges observed elsewhere, with a consistent pattern of lower abundances in hunted sites. It is critical that private, communal and public-sector reserves are integrated into a coordinated management approach across the wider landscape in this biodiversity hotspot and throughout the Mesoamerican Biological Corridor. [ABSTRACT FROM AUTHOR]

In parts of the Indo-Pacific, large-scale exploitation of the green turtle Chelonia mydas continues to pose a serious threat to the persistence of this species; yet very few studies have assessed the pattern and extent of the impact of such harvests. We used demographic and genetic data in an age-based model to investigate the viability of an exploited green turtle stock from Aru, south-east Indonesia. We found that populations are decreasing under current exploitation pressures. The effects of increasingly severe exploitation activities at foraging and nesting habitat varied depending on the migratory patterns of the stock. Our model predicted a rapid decline of the Aru stock in Indonesia under local exploitation pressure and a shift in the genetic composition of the stock. We used the model to investigate the influence of different types of conservation actions on the persistence of the Aru stock. The results show that local management actions such as nest protection and reducing harvests of adult nesting and foraging turtles can have considerable conservation outcomes and result in the long-term persistence of genetically distinct management units. [ABSTRACT FROM AUTHOR]

Fisheries are considered a major driver of population declines for many marine vertebrate species, and yet for some, data on the levels of direct catch are lacking, often due to the logistical challenges in assessing artisanal fisheries in remote and developing regions. Using community members to collect data can provide access to a greater wealth of information than that obtained by local or foreign researchers, often at a reduced financial cost. We monitored the harvest of marine turtles at 12 major villages in Madagascar using community members as data collectors ( sous collecteurs) from each village, at a total cost of

From the time since the decline of the wild rabbit Oryctolagus cuniculus in southern Europe, various techniques and methods have been explored with a view to restoring wild rabbit populations or increasing rabbit resilience, for both conservation and game purposes. Rabbit restocking and habitat management are among the measures most often applied. Some efforts have been made to increase refuges for wild rabbits, mainly through the construction of artificial warrens. The present study evaluates the response of a wild rabbit population introduced to artificial warrens of varying sizes. This involves comparisons of the density of rabbits in the warrens, rabbit density change between seasons of low and high rabbit population density and the productivity index for large and small warrens in rabbit populations living under semi-natural conditions. Our results show that large warrens had higher rabbit abundance than had small warrens, but significantly lower rabbit density. No differences in density increase or productivity index were found with respect to warren size. The results suggest that it is preferable to build many small warrens for conservation of wild rabbit populations, but, in the event that only a few warrens are built, it is advisable that they be large. [ABSTRACT FROM AUTHOR]

Encountering cryptogenic populations that are either native or introduced is a common but underreported phenomenon in field biology. Such local species' occurrences of unknown origin hamper our understanding of species' natural distribution ranges, and pose a problem to conservation management decisions. Genetic tools are frequently used to infer the ancestry of natural or invasive populations based on spatial geographical variation. Here we describe the occurrence of cryptogenic crested newts Triturus cristatus c. 25 km away from their main range and situated in an area where an introduction has taken place half a century ago. We first verify the suitability of a coalescent-based analysis that reconstructs the number of founder individuals of a putative propagule from a source pool, based on previously published data documenting a well-known introduction (the Laysan finch on the Hawaiian archipelago). After showing the validity of the approach, we apply this analysis to the case of T. cristatus, revealing that the number of effective founders would have been of the same order as the current effective carrying capacity of the population. We thus argue that the local T. cristatus occurrence is in fact of natural origin, with the documented introduction having little or no impact to the current gene pool. The result has major implications to our understanding of the species' habitat requirements in a zone of parapatry with a closely related species. [ABSTRACT FROM AUTHOR]

Effective population size ( N) is a key determinant of genetic diversity of populations. In amphibians, the ratio effective population size/census size ( N/ N) is often very low, raising concerns for the long-term persistence of genetic diversity in isolated populations. It has been proposed that the phenomenon of 'genetic compensation' increases the ratio N/ N in small populations, but the underlying mechanisms are poorly understood. Polygyny can decrease N/ N because of the negative relationship between polygyny and N. We used genetic information (microsatellites) to evaluate the relationship between census size, polygyny and N in populations of the threatened Italian agile frog Rana latastei. We reconstructed parentage in tadpoles from nine populations with eight to 32 breeding females, using a likelihood-based method; we analysed simulated datasets with known properties to confirm the reliability of this approach in reconstructing polygyny. Furthermore, we estimated N using approximate Bayesian computation. The level of polygyny differed strongly among populations (average number of mates per breeding male: 2-6.4). Polygyny was greater in populations with larger census sizes. Moreover, variance in male mating success was larger in large populations. Effective population size increased with population size, but was negatively related to polygyny; as polygyny increased in large populations, this was associated with reduced N/ N. In polygynous species, increasing levels of polygyny in large populations may explain the low N/ N values, with important implications for the conservation of genetic diversity and for long-term population persistence. [ABSTRACT FROM AUTHOR]

Over the past few decades, amphibian populations have undergone drastic declines on a global scale. Declines in many anuran populations have been linked to the emergent skin-invasive amphibian chytrid fungus Batrachochytrium dendrobatidis ( Bd). Antimicrobial peptides in the skin are thought to act as important components of the innate immune system that may protect some species from infectious diseases. The four archaic species of Leiopelma in New Zealand are of great conservation concern and a severe population crash of Leiopelma archeyi between 1996 and 2001 has been tentatively linked with the outbreak of Bd. Here, we investigated the in vitro activity of skin secretions of six frog species in New Zealand against Bd zoospore growth. The activity of skin secretions produced by frogs in the wild varied significantly between species, with those of Le. archeyi being the most active. The skin secretions of native Leiopelmatid species showed greater Bd zoospore inhibition (31.0-71.9%) than the naturalized Litoria species (17.4-18.2%). Leiopelma archeyi has the most active peptides, even though it is the only native species with known susceptibility to Bd infections. [ABSTRACT FROM AUTHOR]

Introduced pathogens are increasingly being implicated in population declines and their effects are difficult to manage. In the absence of methods to eradicate pathogens acting as threatening processes, intervention before population decline is necessary. Such an intervention requires an ability to predict when population declines will occur, and therefore, an understanding of when exposure will lead to infection, disease, death and population decline. This study investigates when pathogen exposure leads to disease for the amphibian chytrid fungus Batrachochytrium dendrobatidis, which has been implicated as a causal agent in the global amphibian decline. Susceptibility studies were conducted on two anuran species, the green and golden bell frog Litoria aurea and the striped marsh frog Limnodynastes peronii, when exposed to the fungus as either tadpoles or juveniles. Host species was found to significantly affect the outcome of exposure, with infection loads in L. aurea increasing over time and resulting in significantly lower survival rates than unexposed. By comparison, infection loads in L. peronii remained the same or decreased over time following the initial infection, and survival rates were no different whether exposed to B. dendrobatidis or not. These outcomes were independent of the life stage at exposure. Individuals with higher infection loads were not found to have lower survival rates; rather, an infection load threshold was identified where individuals with infection loads that crossed this threshold had high likelihoods of showing terminal signs of chytridiomycosis. Therefore, host species determined whether infection load crossed this threshold and the crossing of the threshold determined the incidence of disease and survival. The quantification of infection load thresholds for survival, along with the time it takes to reach them, will enable infection loads in wild populations to be related to the likelihood of disease and is the first step in the understanding and prediction of when exposure will result in population decline. [ABSTRACT FROM AUTHOR]

The endangered minnow Iberochondrostoma almacai is an endemic Iberian cyprinid with a restricted and fragmented distribution. Here, we describe the genetic structure of the species and infer its demographic history from six nuclear-encoded microsatellite loci and mitochondrial cytochrome b sequences. Genetic diversity was low (microsatellite He<0.45; mtDNA π<0.0015), and both markers resolved two groups: one from the northern Mira drainage and one from the Arade and Bensafrim drainages. The relatively low differentiation between these groups (0.09< FST<0.29; 0.31< ΦST <0.57) suggests past headwater captures and/or that populations were large until recently. The genetic diversity and differentiation estimates were compared with those for other three endangered cyprinids inhabiting similar intermittent rivers. Microsatellite data indicate a population decrease in the last 100–2400 years, probably as a result of anthropogenic disturbance. Human activities together with an intermittent flow of these rivers apparently led to local extinctions with consequent fragmentation and contraction in range. We recognize two management units corresponding to the two genetic groups identified. To maintain/increase genetic diversity, we recommend habitat restoration actions and measures to increase gene flow within and/or between the two units, under controlled reproductive programmes. Ecological experiments should be performed to ensure the success of supplementation among the two units. Moreover, the reintroductions in unoccupied drainages are suggested if further data confirm the presence of I. almacai in the recent past. [ABSTRACT FROM AUTHOR]

Like many endangered wildlife populations, the viability and conservation status of ‘southern resident’ killer whales Orcinus orca in the north-east Pacific may be affected by prey limitation and repeated disturbance by human activities. Marine protected areas (MPAs) present an attractive option to mitigate impacts of anthropogenic activities, but they run the risk of tokenism if placed arbitrarily. Notwithstanding recreational and industrial marine traffic, the number of commercial vessels in the local whalewatching fleet is approaching the number of killer whales to be watched. Resident killer whales have been shown to be more vulnerable to vessel disturbance while feeding than during resting, travelling or socializing activities, therefore protected-areas management strategies that target feeding ‘hotspots’ should confer greater conservation benefit than those that protect habitat generically. Classification trees and spatially explicit generalized additive models were used to model killer whale habitat use and whale behaviour in inshore waters of Washington State (USA) and British Columbia (BC, Canada). Here we propose a candidate MPA that is small (i.e. a few square miles), but seemingly important. Killer whales were predicted to be 2.7 times as likely to be engaged in feeding activity in this site than they were in adjacent waters. A recurring challenge for cetacean MPAs is the need to identify areas that are large enough to be biologically meaningful while being small enough to allow effective management of human activities within those boundaries. Our approach prioritizes habitat that animals use primarily for the activity in which they are most responsive to anthropogenic disturbance. [ABSTRACT FROM AUTHOR]

Parameterization of population viability models is a complicated task for most types of animals, as knowledge of population demography, abundance and connectivity can be incomplete or unattainable. Here I illustrate several ways in which genetic data can be used to inform population viability analysis, via the parameterization of both initial abundance and dispersal matrices. As case studies, I use three ambysomatid salamander datasets to address the following question: how do population viability predictions change when dispersal estimates are based on genetic assignment test data versus a general dispersal–distance function? Model results showed that no local population was large enough to ensure long-term persistence in the absence of immigration, suggesting a metapopulation structure. Models parameterized with a dispersal–distance function resulted in much more optimistic predictions than those incorporating genetic data in the dispersal estimates. Under the dispersal–distance function scenario all local populations persisted; however, using genetic assignments to infer dispersal revealed local populations at risk of extinction. Viability estimates based on dispersal–distance functions should be interpreted with caution, especially in heterogeneous landscapes. In these situations I promote the idea of model parameterization using genetic assignment tests for a more accurate portrayal of real-world dispersal patterns. [ABSTRACT FROM AUTHOR]

Conservation strategies for endangered species require accurate and precise estimates of abundance. Unfortunately, obtaining unbiased estimates can be difficult due to inappropriate estimator models and study design. We evaluate population–density estimators for tigers Panthera tigris in Kanha Tiger Reserve, India, using camera traps in conjunction with telemetry ( n=6) in a known minimum population of 14 tigers. An effort of 462 trap nights over 42 days yielded 44 photographs of 12 adult tigers. Using closed population estimators, the best-fit model (programcapture) accounted for individual heterogeneity ( Mh). The least biased and precise population estimate ( ( SE) [ ]) was obtained by the Mh Jackknife 1 (JK1) [14 (1.89)] in programcare-2. Tiger density ( ( SE) [ ]) per 100 km2 was estimated at 13 (2.08) when the effective trapping area was estimated using the half mean maximum distance moved (1/2 MMDM), 8.1 (2.08), using the home-range radius, 7.8 (1.59), with the full MMDM and 8.0 (3.0) with the spatial likelihood method in programdensity 4.1. The actual density of collared tigers (3.27 per 100 km2) was closely estimated by home-range radius at 3.9 (0.76), full MMDM at 3.48 (0.81) and spatial likelihood at 3.78 (1.54), but overestimated by 1/2 MMDM at 6 (0.81) tigers per 100 km2. Sampling costs (Rs. 450 per camera day) increased linearly with camera density, while the precision of population estimates leveled off at 25 cameras per 100 km2. At simulated low tiger densities, a camera density of 50 per 100 km2 with an effort of 8 trap nights km−2 provided 95% confidence coverage, but estimates lacked precision. [ABSTRACT FROM AUTHOR]

The harvest of ungulate populations is often directed against certain sex or age classes to maximize the yield in terms of biomass, number of shot animals or number of trophies. Here we examine how such directional harvest affects the effective size of the population. We parameterize an age-specific model assumed to describe the dynamics of Fennoscandian moose. Based on expressions for the demographic variance for a small subpopulation of heterozygotes Aa bearing a rare neutral allele a, we use this model to calculate how different harvest strategies influence the effective size of the population, given that the population remains stable after harvest. We show that the annual genetic drift, determined by , increases with decreasing harvest rate of calves and increasing sex bias in the harvest towards bulls 1 year or older. The effective population size per generation decreased with reduced harvest of calves and increased harvest of bulls 1 year or older. The magnitude of these effects depends on the age-specific pattern of variation in reproductive success, which influences the demographic variance. This shows that the choice of harvest strategy strongly affects the genetic dynamics of harvested ungulate populations. [ABSTRACT FROM AUTHOR]

The location and use of warrens is a key factor in the population dynamics of the European rabbit Oryctolagus cuniculus L., which can influence stability and persistence in the long term. Within the species' original distribution range, its numbers have declined sharply in recent decades, which is a serious problem for the conservation of Mediterranean ecosystems. Artificial warrens are commonly used to bolster rabbit populations and the characterization of natural warrens in those areas might improve their efficiency. In this study, we use binomial generalized linear models to identify the factors associated with the location and use of warrens in a low-density area and we evaluate the effect of including the spatial structure of the data in the model. In addition, we generate a map that predicts the most suitable areas for artificial warrens. Contrary to what was expected, habitat variables are only secondary factors, and the location and use of warrens is influenced mainly by spatial factors, such as proximity to nearby warrens. Furthermore, the aggregated spatial pattern of warrens suggests that, at the local scale, for example, the hunting estate, intra-specific interactions might be playing a primary role in these low-density populations. To identify the most suitable sites for artificial warrens and, thereby, improve the efficiency of artificial warren building for conservation purposes, information about spatial structures should be included in models predicting natural warrens of European rabbits. [ABSTRACT FROM AUTHOR]

The feline leukemia virus (FeLV) is a retrovirus that affects domestic cats all over the world. Its pathogenic effects generally include anemia, immunosuppression or tumors. Dissemination over populations is linked to cat sociality, because the virus is transmitted by direct contact. Although the domestic cat is its common host, FeLV infection has also been described in some wild felids. In the Iberian lynx Lynx pardinus, some sporadic FeLV infection cases have been reported since 1994, but an outbreak with the involvement of several animals has never been described until now. During spring 2007, an FeLV outbreak hit the Doñana (SW Spain) population. The infection rapidly spread throughout the densest subpopulation throughout Doñana. Infected animals showed very acute anemic disease, most of them dying in <6 months. To avoid FeLV dissemination, a control program was carried out that included removal of viremic lynxes, vaccination of negative individuals and reduction of the feral cat population. The program was implemented both in Doñana and in Sierra Morena populations. In Doñana, around 80% of the total lynx population and 90% of the outbreak focus subpopulation were evaluated. Seven out of the 12 infected individuals found died and two reverted to latency; the remaining viremic animals have been kept in captivity. The outbreak appears to have been successfully confined to the subpopulation where the virus appeared and no more cases have been found since August 2007. In the larger Sierra Morena population, 8% of the lynx population was surveyed. Thirty-four uninfected Iberian lynxes were vaccinated at least once. The FeLV prevalence was found to be 27% in the Doñana population and 0% in the Sierra Morena population. [ABSTRACT FROM AUTHOR]

The consequences of inbreeding in small isolated populations are well documented, yet populations are often managed in isolation to avoid irreversibly mixing genetic lineages and to maintain the historic integrity of each population. Three remaining populations of Whitaker's skink ( Cyclodina whitakeri) in New Zealand, remnants of a once wider distribution, illustrate the conflict between this genetic goal (separate management of populations) with the more tangible and immediate threats of small population size and inbreeding. Middle and Castle Islands harbour populations of C. whitakeri and have been separated from each other and from the mainland for ∼10 000 years. The single mainland population at Pukerua Bay is extremely small, declining and deemed a high priority for management. We sequenced a 550 bp region of mitochondrial DNA (mtDNA,ND2) and genotyped animals from all three populations at 13 microsatellite loci. The population of C. whitakeri at Pukerua Bay showed marked differences from the island populations at both mtDNA (unique, fixed haplotype) and microsatellite loci ( FST∼0.20), and private alleles were detected at a high frequency (24% of all alleles). However, we attribute this pattern to an historic genetic gradient coupled with rapid genetic drift. Further, animals in captivity show genetic signatures of both Pukerua Bay and island populations, despite the goal to maintain a pure Pukerua Bay stock. The mixed genetic stock in captivity provides an opportunity for the addition of skinks from Middle Island to evaluate the risks of further population hybridization, including the disruption of potential local adaptation, while mitigating the risks of inbreeding. [ABSTRACT FROM AUTHOR]

Being able to accurately estimate the persistence time of populations of endangered plants and animals is central to conservation biology and is of considerable importance in informing land-use decisions. Genetic deterioration (due to inbreeding and random genetic drift) and environmental deterioration (e.g. climate change, pollution and introduced species) clearly contribute to population extinction, however, considerable recent evidence suggests that interactions between genetic deterioration and environmental stress are ubiquitous. The importance of these interactions for potentially reducing persistence times has not been quantified and has not been taken into account by major conservation organizations. Using a computer simulation, we determined that including reasonable estimates of the inbreeding–environment interaction reduces persistence times by 17.5–28.5% (mean=23%) for a wide range of carrying capacities, assumptions concerning the number of lethal equivalents and different regimes for the frequency and magnitude of the stressful environment. We note that the proportional decrease in persistence time with inclusion of the interactions becomes larger (i.e. the interaction becomes more important) as absolute time to extinction gets larger. Thus, inclusion of the interaction is important and surprisingly may be most needed when populations are of intermediate size and are considered relatively safe from environmental and genetic stresses acting independently. [ABSTRACT FROM AUTHOR]

Refuge populations of Cyprinodon macularius and Cyprinodon eremus, the extant members of the endangered desert pupfish complex, have been maintained for up to 33 years in semi-natural refuges. We examined the success of the refuge program in maintaining diversity at four microsatellite DNA loci in 24 refuge populations of C. macularius and six of C. eremus that include, respectively, seven and four lineages representing original translocations from the wild. These lineages have been maintained with essentially no inoculations of genetic material from the wild and, except for one refuge, no intermixing of lineages. Comparison with wild-source populations showed marked declines in diversity within local refuges and within lineages, but relatively minor declines for the composite of all refuge populations for each species. In genetic makeup, the refuge populations generally clustered by lineage, indicating significant genetic drift early in lineage history. The results indicate that, with relatively minor adjustments in management, the refuge program can successfully preserve a large portion of the wild genetic diversity in the desert pupfish complex. [ABSTRACT FROM AUTHOR]

The spread of game ranching in southern Africa provides opportunities for the reestablishment of populations of endangered wild dogs extirpated by livestock ranchers. However, this potential has not been realized, partly because of negative rancher perceptions. Some ranchers believe that wild dogs impart costs by killing wildlife that could be utilized consumptively. Others complain that wild dogs make ungulates ‘skittish’ and cause local reductions in prey densities while denning. We compared the skittishness and density of prey species inside and outside the denning home ranges of nine wild dog packs in Zimbabwe. Wild dogs had no impact on prey skittishness, but prey species did occur at lower densities inside denning home ranges. In some scenarios, and particularly on fenced game ranches, wild dogs could cause prey population declines during denning. On small game ranches, the use of fences as a tool by wild dogs during hunting can increase the proportion of large prey species in their diet by up to 11 times, and thus increase the minimum area required to support that diet. In addition, game fencing is typically permeable to wild dogs but not their prey, preventing the recovery of prey populations through the natural influx of prey animals into the denning area following departure of the dogs. Wild dogs could thus impose significant financial costs to game ranchers hosting denning packs. Our findings emphasize the importance of promoting the formation of conservancies, where neighbouring landowners remove boundary fences to create larger contiguous wildlife areas. [ABSTRACT FROM AUTHOR]

Organisms often face a higher risk of local extinction in fragmented than in continuous habitat. However, whether populations are affected by reduced size and connectivity of the habitat or by changes in habitat quality in fragmented landscapes remains poorly investigated. We studied the regional distribution and microhabitat selection of the lacertid lizard Psammodromus algirus in a fragmented landscape where the existence of deciduous and evergreen woodlands brought about variation in habitat quality. Lizards never occupied any fragment smaller than 0.5 ha. However, above that limit fragment size no longer predicted lizard occurrence, which was explained by woodland type instead, with lizards being more frequently found in deciduous than in evergreen woodlands. Lizards selected microhabitats that had structural features favouring thermoregulation, foraging and predator avoidance, and we identified better conditions for thermoregulation and food acquisition in deciduous than in evergreen woodlands. Our results support the idea that variation in habitat quality can sometimes override the effect of habitat fragmentation on animal populations. We consider the implications of our study for the conservation of Mediterranean lizards, discussing our results in a broader context framed by previous studies conducted in nearby areas. [ABSTRACT FROM AUTHOR]

The ultimate goal of the Mexican gray wolf Canis lupus baileyi captive management program is reintroduction of healthy individuals into wild habitats. To this end, zoo population managers work to provide not only for the physical well-being but also for the genetic health of these animals. However, the very limited genetic founder base, exacerbated by breeding within three distinct lineages, resulted in very high coefficients of inbreeding. Because support for measurable levels of inbreeding depression in the captive wolf population, as defined by reductions in common fitness measures such as juvenile survival or reproductive success, has been weak, we investigated the potential effects on male reproductive capacity. We analyzed semen samples from wolves from all three lineages and compared them with samples from subsequent lineage crosses and from generic gray wolves. We not only found a significant effect of inbreeding on sperm quality but we related both inbreeding and sperm quality to reproductive success. Samples from male offspring of lineage crosses, with inbreeding coefficients of zero were similar in quality to those from generic gray wolves. However, samples from a limited number of offspring from back-crosses were of extremely poor quality. Although it is reassuring that sperm quality was so much improved in male offspring of lineage crosses, the concomitant reduction in inbreeding coefficient does not eliminate the potentially deleterious alleles. Our results demonstrate that sperm quality is an important indicator of fertility and reproductive success in Mexican wolves. In addition, our data lend further support to the presence of inbreeding depression in this taxon. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop simple and inexpensive methods for monitoring wildlife populations in resource-poor countries. List-based methods have been advocated as simple yet potentially useful biodiversity monitoring tools, and systems have recently been launched in a number of countries to collect species lists. We attempt to advance the use of systematic list-based monitoring by (1) suggesting improvements to the way in which list reporting rates are calculated; (2) assessing the extent to which degrading effort-corrected measures of abundance into simple species lists results in loss of information on population trends; (3) comparing long-term trends in list reporting rates with population trends from a wholly independent monitoring scheme. Daily species lists of birds were derived from regular trapping at a nature reserve in southern England. Most species showed a strong correlation across years between the proportion of lists on which they occurred, adjusted for list length (adjusted list reporting rate; ALRR), and an effort-corrected measure of abundance (captures per unit effort; CPUE). ALRR revealed almost as much about annual variation in abundance as CPUE for all but the most frequently captured species. Long-term (>20 years) trends in ALRRs at the nature reserve were positively correlated with UK national population trends recorded over the same period by an independent, labour-intensive monitoring scheme that counted birds at a large number of widely spread sites. Our results support previous claims that simple species lists could generate data useful for monitoring long-term population trends, particularly where such lists are collected systematically. However, further research on the efficiency of list reporting rates relative to more sophisticated methods is necessary, before list-based methods can be advocated for dedicated monitoring schemes in resource-poor regions. [ABSTRACT FROM AUTHOR]

Many wildfowl species are declining and 34 out of 159 extant species are globally threatened, some of which are the subject of specific conservation programmes. Here we investigate which factors predict declining population trends across 154 species of Anseriformes. First we show that there are proportionately fewer declining wildfowl populations in North America, Europe and Australasia than in south and central America, Africa and Asia. Second, we use phylogenetic comparative analyses to test whether population size, global range size and ecological, life-history and sexually-selected traits predict population trends. We also consider anthropogenic threats, and human impacts within the breeding and non-breeding ranges of species. Using phylogenetically independent contrasts we show that small population size and small global ranges are the most important intrinsic factors that predispose wildfowl species to declining populations. Many wildfowl are hunted but, contrary to expectation, hunting did not influence population trends. Declining populations were associated with high International Union for the Conservation of Nature (IUCN) threat category, although the relationship is not very strong ( r=0.134, n=129 contrasts) possibly because the IUCN criteria integrate population size, range size and an assessment of threat. Two extrinsic factors were significant predictors of population declines: the increase in area of agricultural land within a species' range (an indirect measure of wetland loss), and the total number of different threat processes such as habitat loss and pollution that threaten a species. Taken together, our results strongly suggest that both anthropogenic threats and intrinsic ecological factors are influencing population declines in wildfowl. [ABSTRACT FROM AUTHOR]

Small or decreasing populations call for emergency actions like, for example, captive breeding programs. Such programs aim at rapidly increasing population sizes in order to reduce the loss of genetic variability and to avoid possible Allee effects. The Lesser Kestrel Falco naumanni is one of the species that is currently supported in several captive breeding programs at various locations. Here, we model the demographic and genetic consequences of potential management strategies that are based on offspring sex ratio manipulation. Increased population growth could be achieved by manipulating female conditions and/or male attractiveness in the captive breeders and consequently shifting the offspring sex ratio towards more female offspring, which are then used for reintroduction. Fragmenting populations into wild-breeding and captive-breeding demes and manipulating population sex ratio both immediately increase the inbreeding coefficient in the next generation (i.e. decrease Ne) but may, in the long term, reduce the loss of genetic variability if population growth is restricted by the number of females. We use the Lesser Kestrel and the wealth of information that is available on this species to predict the long-term consequences of various kinds of sex-ratio manipulation. We find that, in our example and possibly in many other cases, a sex-ratio manipulation that seems realistic could have a beneficial effect on the captive breeding program. However, the possible long-term costs and benefits of such measures need to be carefully optimized. [ABSTRACT FROM AUTHOR]

Barbary red deer Cervus elaphus barbarus from three areas in Tunisia ( n=30) were analysed for genetic variability at 13 microsatellite loci and 680 bp of the mitochondrial control region. Barbary red deer, the only African deer taxon, are presently confined to a small area along the Tunisian–Algerian border and underwent a severe bottleneck in the middle of the 20th century with, on the Tunisian side, possibly only seven animals left. The genetic data showed signs of inbreeding and reflected the bottleneck event. Variability was on the lower end of the range previously reported for red deer (number of haplotypes=two, observed and expected heterozygosity 0.46 and 0.78, respectively) but not as low as might have been feared in view of the population's demographic history. The three sampling sites – among them the reserve at El Feidja from which, apart from Algerian immigrants, all extant Tunisian red deer originate – did not show any sign of genetic differentiation. The Tunisian red deer can thus probably be considered a single, genetically homogeneous population. Implications for management and conservation of the genetic findings are discussed. [ABSTRACT FROM AUTHOR]

Inbreeding resulting from severe population bottlenecks may impair an individual's immune system and render it more susceptible to disease. Although a reduced immune response could threaten the survival of highly endangered species, few studies have assessed the effect of population bottlenecks on immunocompetence. We compared the counts of leucocytes and external, blood and gastrointestinal parasite loads in two populations of the endemic New Zealand robin Petroica australis to assess the immunocompetence of birds in a severely bottlenecked population relative to its more genetically diverse source population. Despite similar parasite loads in both populations, robins in the severely bottlenecked population showed lower counts of both total leucocyte and total lymphocyte numbers. When the immune system was experimentally challenged using the phytohaemagglutinin skin test, robins in the severely bottlenecked population exhibited a significantly lower immune response than the source population, suggesting that birds passing through a severe bottleneck have a compromised immunocompetence. Our results confirm that severe bottlenecks reduce the immune response of birds and highlight the need to avoid severe bottlenecks in the recovery programmes of endangered species. [ABSTRACT FROM AUTHOR]

Owing to increasing population trends and facultative predatory habits, large gulls have been identified as significant agents of change in the alteration of many ecological communities. Often, they are perceived as negatively impacting the population trends of most sympatric waterbirds. Consequently, culling programs have been implemented to remove adults, chicks and eggs intensively. Here, we review the interactions recorded in the literature between the yellow-legged gull Larus michahellis and 10 sympatric waterbirds in the Mediterranean region, all threatened and classified as species of conservation concern. We also used 177 long-term population trends derived from previous studies to study the population dynamics of these species and the culling effort performed. We show that gulls negatively affected survival, fecundity, foraging ecology and nesting habitat availability for many species. However, the annual population growth rates of most sympatric waterbirds showed positive values, even at sites where culling has yet to be initiated and local yellow-legged gull populations are large and increasing. Our results suggest clearly that population increase has not been exclusive of yellow-legged gulls, especially at the regional level. Yet, growth rates of both yellow-legged gulls and sympatric waterbirds were positively associated. Strikingly, the population extinction rate was similar between colonies of yellow-legged gulls and those of sympatric species. Thus, evidence exists to state that the success of gull control programs is relatively low in the long term. We recommend that conservation agencies heed several basic principles of population and community ecology before initiating control, for instance that (1) yellow-legged gulls have bred historically with other bird species and have likely developed defensive mechanisms against this predator and (2) populations of large gulls are regulated by density-dependent mechanisms in both space and time. Incoming European environmental policies on fishing discards and rubbish management should control more naturally and efficiently the density of large gulls and the composition of seabird communities in the long term. [ABSTRACT FROM AUTHOR]