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Benefits of invasive species management for terrestrial biodiversity are widely expected and promoted in New Zealand. Evidence for this is presented in policy and scientific reviews of the literature, but the robustness and repeatability of the underpinning evidence-base remains poorly understood. We evaluated the design of field-based studies assessing biodiversity responses to invasive species management in 155 peerreviewed articles published in 46 journals from 2010-2019. Each study was assessed against nine principles of experimental design, covering robustness of sampling and avoidance of bias. These principles are important in New Zealand to detect treatment effects from environmental variability driven by underlying gradients such as soil fertility, climate, and disturbance. Across all publications, about half defined the sampling universe (52%) or were unreplicated (54%), whereas most (74%) did not representatively collect data across the sampling universe. Management treatments were specified, with or without only influencing the target species, in 68% of publications. Relatively few studies quantified invasive species (15%) and biodiversity responses (27%) representatively within replicates. Initial conditions and accounting for the effects of experimental implementation were not used in 57% and 84% of publications, respectively. No publications avoided observer/analyst bias using blinding methods, despite this being widely adopted in other scientific fields. We used ordinal logistic regression to understand how these principles varied among categories of biodiversity responses and for major groups of invasive species. Our findings suggest that greater attention to experimental design principles is desirable: supported by researchers, funding agencies, reviewers, and journal editors. Greater resources are not necessarily a solution to these design issues. One alternative is undertaking fewer studies that are individually more expensive because they better adhere to experimental design principles. The challenges of meeting experimental design principles suggests a significant role for other approaches such as systematic monitoring and natural experiments, although many of the design principles we discuss still apply. Our intent in this article is to improve the robustness of future field studies for at least some principles. Robust designs have enduring value, reduce uncertainty, and increase our understanding of when, where and how often the impacts of invasive species on biodiversity are reversible. [ABSTRACT FROM AUTHOR]

Intrinsic image decomposition is the task of mapping image to albedo and shading. Classical approaches derive methods from spatial models. The modern literature stresses evaluation, by comparing predictions to human judgements (“lighter”, “same as”, “darker”). The best modern intrinsic image methods train a map from image to albedo using images rendered from computer graphics models and example human judgements. This approach yields practical methods, but obtaining rendered images can be inconvenient. Furthermore, the approach cannot explain how a one could learn to recover intrinsic images without geometric, surface and illumination models, as people and animals appear to do. This paper describes a method that learns intrinsic image decomposition without seeing human annotations, rendered data, or ground truth data. Instead, the method relies on paradigms – spatial models of albedo and of shading. Rather than finding the “best” albedo and shading for an image via optimization, our approach trains a neural network on synthetic images. The synthetic images are constructed by multiplying albedos and shading fields sampled from our models. The network is subject to a novel smoothing procedure that ensures good behavior at short scales on real images. An averaging procedure ensures that reported albedo and shading are largely equivariant – different crops and scalings of an image will report the same albedo and shading at shared points. This averaging procedure controls long scale error. The standard evaluation for an intrinsic image method is a WHDR score. Our method achieves WHDR scores competitive with those of strong recent methods allowed to see training WHDR annotations, rendered data, and ground truth data. Our method produces albedo and shading maps with attractive qualitative properties – for example, albedo fields do not suppress wood grain and represent narrow grooves in surfaces well. Because our method is unsupervised, we can compute estimates of the test/train variance of WHDR scores; these are quite large, and suggest is unsafe to rely small differences in reported WHDR. [ABSTRACT FROM AUTHOR]

Estimating the abundance and density of mountain ungulates is difficult because of rugged and remote terrain, high elevations, and rapidly changing weather. Helicopter surveys could overcome these problems, but researchers have seldom applied helicopter‐based survey methods at large spatial scales in mountain terrain. We used helicopters to count introduced Himalayan tahr (Hemitragus jemlahicus) at 117 plots, each of 4 km2, in New Zealand's Southern Alps during 2016–2019. The sampling frame was 7,844 km2 and we located the plots at the vertices of an 8‐km grid superimposed over the sampling frame (i.e., a systematic random sampling design). We conducted 3 repeat counts at each plot during summer–autumn. We used the repeat counts to estimate tahr abundance and density, corrected for imperfect detection, using a dynamic N‐mixture model for open populations. We estimated the population of tahr in the sampling frame using design‐based, finite sampling methods and model‐based inference procedures. The mean estimated density of tahr on each plot varied from zero to 31.7 tahr/km2. The mean densities of tahr varied among management units, ranging from 0.3 to 10.7 tahr/km2, and exceeded specified intervention densities in 6 of the 7 management units. The total design‐based estimate of tahr abundance in the sampling frame was 34,500 (95% CI = 27,750–42,900), with a coefficient of variation (CV) of 0.11. The corresponding model‐based estimate of total abundance was similar (34,550, 95% CI = 30,250–38,700) but was substantially more precise (CV = 0.06) than the design‐based estimate. The precision of the estimates for the individual management units was also better than that of the design‐based estimates, with CVs of <0.20 for all but 1 management unit. Our study provides a repeatable method for sampling mountain ungulates. More generally, robust estimation of abundance and density of mountain ungulates is possible by combining aerial surveys and open population models with an objective, probabilistic sampling design. [ABSTRACT FROM AUTHOR]

Deer (Cervidae) are key components of many ecosystems and estimating deer abundance or density is important to understanding these roles. Many field methods have been used to estimate deer abundance and density, but the factors determining where, when, and why a method was used, and its usefulness, have not been investigated. We systematically reviewed journal articles published during 2004–2018 to evaluate spatio‐temporal trends in study objectives, methodologies, and deer abundance and density estimates, and determine how they varied with biophysical and anthropogenic attributes. We also reviewed the precision and bias of deer abundance estimation methods. We found 3,870 deer abundance and density estimates. Most estimates (58%) were for white‐tailed deer (Odocoileus virginianus), red deer (Cervus elaphus), and roe deer (Capreolus capreolus). The 6 key methods used to estimate abundance and density were pedestrian sign (track or fecal) counts, pedestrian direct counts, vehicular direct counts, aerial direct counts, motion‐sensitive cameras, and harvest data. There were regional differences in the use of these methods, but a general pattern was a temporal shift from using harvest data, pedestrian direct counts, and aerial direct counts to using pedestrian sign counts and motion‐sensitive cameras. Only 32% of estimates were accompanied by a measure of precision. The most precise estimates were from vehicular spotlight counts and from capture–recapture analysis of images from motion‐sensitive cameras. For aerial direct counts, capture–recapture methods provided the most precise estimates. Bias was robustly assessed in only 16 studies. Most abundance estimates were negatively biased, but capture–recapture methods were the least biased. The usefulness of deer abundance and density estimates would be substantially improved by 1) reporting key methodological details, 2) robustly assessing bias, 3) reporting the precision of estimates, 4) using methods that increase and estimate detection probability, and 5) staying up to date on new methods. The automation of image analysis using machine learning should increase the accuracy and precision of abundance estimates from direct aerial counts (visible and thermal infrared, including from unmanned aerial vehicles [drones]) and motion‐sensitive cameras, and substantially reduce the time and cost burdens of manual image analysis. [ABSTRACT FROM AUTHOR]

When the fitness costs and benefits of sons and daughters differ, offspring sex ratio manipulation could be an important reproductive tactic. We explored the effects of environment and maternal caring ability on offspring sex to test four adaptive sex ratio modification hypotheses: the extrinsic modification hypothesis (EMH), carrying capacity hypothesis (CCH), Trivers-Willard hypothesis (TWH), and cost-of-reproduction hypothesis (CRH). The EMH and CCH propose that environmental conditions shape offspring sex ratios, directly or in interaction with maternal condition. The TWH and CRH predict a positive relationship between maternal condition and production of the costlier sex. The TWH predicts that mothers with superior caring ability should produce more of the sex that can provide the greatest fitness returns from additional maternal allocation, and the CRH proposes that females with limited caring ability should reduce fitness costs by producing the cheaper sex. Repeated measures on 83 known-age eastern gray kangaroos, polygynous marsupials with strong sexual dimorphism, revealed that offspring sex ratio was independent of per capita forage, supporting neither the EMH nor CCH, but was dependent on maternal mass, consistent with the TWH and CCH. Our results, however, cannot clearly identify the ultimate cause of the relationship between maternal mass and greater production of sons. One of the three assumptions of the TWH could not be verified, and mothers of sons suffered only marginal additional fitness costs. Sex ratios in higher vertebrates are likely not solely explained by factors dependent on maternal control. [ABSTRACT FROM AUTHOR]

Introduced ungulates are an important management issue on New Zealand's public conservation land (PCL). Ungulates are harvested by recreational and commercial hunters, with some government-funded culling. A robust monitoring system is needed to reliably report trends in occupancy and abundance, and to evaluate management effectiveness. We first describe the design and implementation of a monitoring programme enabling ungulate occupancy and relative abundances to be estimated on New Zealand's PCL. Monitoring sites are located at the vertices of an 8-km grid superimposed over PCL on North, South and Stewart/Rakiura islands (i.e. a spatially representative sampling network). At each site, intact ungulate pellets are counted on four transects radiating from a 400 m2 vegetation plot, with each 150 m transect containing 30 1-m radius plots. We next report an analysis of the first such data collected at 1346 sites during 2012-2018. Nationally, ungulate occupancy and abundance were higher at woody than at non-woody sites, and overall were higher in the North Island than in the South Island. Occupancy odds increased by 34% and 21% per annum in the North Island and South Island, respectively. Abundance (conditional on sites being occupied) increased 11% annually in the North Island, but did not change in the South Island. These increases in occupancy and abundance indicate that ungulate populations are recovering from the lows of the 1980s, likely due to reduction in both commercial harvesting and government-funded control. The data from the monitoring reported here establish a baseline against which future estimates of ungulate occupancy-abundance, and the effectiveness of management activities, can be assessed. Five-yearly remeasurements at the sites, coupled with more comprehensive recording of information on government control and commercial/recreational harvesting activities, should enable the drivers of future changes in ungulate occupancy and abundance to be better understood. [ABSTRACT FROM AUTHOR]

Life history theory predicts trade-offs in allocation between survival, maintenance, growth, and reproduction, especially when resources are scarce. Individual variation in resource acquisition can affect trade-offs, but is often unaccounted for. We quantified the fitness costs of reproduction, accounting for environmental conditions, maternal characteristics and individual variation. We analyzed 10 years of data from marked kangaroos to evaluate how reproductive allocation affected annual mass change and skeletal growth, subsequent fecundity and weaning success, and survival, accounting for maternal mass or size and forage availability. Through repeated measurements of 76–91 females, we investigated how trade-offs varied within and between individuals, assessing whether individual variation could mask population-level trade-offs. In poor environments, females that weaned an offspring lost mass. Females that nursed an offspring for > 7 months had reduced skeletal growth. Females that did not gain mass over the previous 12 months rarely reproduced, especially if they had nursed an offspring for > 7 months the previous year. Reproductive allocation had no effect on weaning success, which was very low, and did not affect maternal survival, suggesting a conservative strategy. Disentangling within- and between-individual responses revealed trade-offs within individuals, but because individuals did not vary in their responses to earlier effort, these trade-offs did not drive population trends. The interacting effects of environmental conditions, maternal characteristics and individual variation on allocation trade-offs demonstrate the importance of long-term monitoring for understanding life history variations in changing environments. [ABSTRACT FROM AUTHOR]

Exposure of scavenging wildlife to lead from ammunition is a worldwide problem for wildlife management, but there has been little research on this topic in Australia. To examine which species of scavenging birds are potentially at risk of harmful exposure to lead, we deployed camera-traps to observe avian scavenger behaviour on carcasses of non-native and native mammals shot with lead-based bullets in two different locations in Victoria. We monitored 30 Sambar Deer Rusa unicolor carcasses in temperate eastern Victoria and 48 kangaroo Macropus spp. carcasses in semi-arid north-western Victoria. At least eight avian taxa scavenged from carcasses, including Wedge-tailed Eagles Aquila audax, Little Eagles Hieraaetus morphnoides, Brown Goshawks Accipiter fasciatus, Whistling Kites Haliastur sphenurus, ravens/crows Corvus spp., and three species belonging to the family Artamidae. Fifty-six percent of all carcasses were visited by birds. Corvids visited the most carcasses and typically arrived first, whereas Wedge-tailed Eagles arrived second but individually spent more time feeding. Our results indicate that a diverse avian scavenger community consumes carcasses of shot mammals in Australia, and consequently could be exposed to lead from bullet fragments. [ABSTRACT FROM AUTHOR]

Identifying landscape features and processes that facilitate the persistence of populations is particularly important for invasive mammal species, because it can focus management interventions on relatively small areas. We used camera traps to test predictions concerning the relative abundance of invading chital deer (Axis axis) on seven cattle ranches in northern Australia: that abundance of chital deer would be highest near permanent water and near homesteads, and that dingoes (Canis dingo) reduce abundance of chital deer. Distance from the nearest homestead determined deer abundance (as indexed by images per camera-day), with negligible abundance > 4 km from homesteads. In contrast, distance from homestead did not predict abundance of feral pigs (Sus scrofa), macropods, or dingoes. Abundance of chital deer also declined with increasing distance from water, as did feral pig abundance. There was no relationship between either macropod or dingo abundance and distance to water. The abundance of chital deer was unaffected by dingo abundance, but 75–100% of dingo scats collected within 1 km of homesteads contained chital deer. The high abundances of chital deer near homesteads are likely due to increased food quality or quantity, or protection from dingoes, but these hypotheses require further testing. We conclude that homesteads and permanent water are important determinants of the distribution and abundance of invasive chital deer in northern Australia (i.e. they are "invasion hubs" for this species). Our results suggest that, during the dry season, managers should survey for and attempt to control chital deer within 4 km of homesteads and within 3 km of water. [ABSTRACT FROM AUTHOR]

Estimating population abundances, densities, and interspecific interactions are common goals in wildlife management. Camera traps have been used to estimate the abundance and density of a single species, and are useful for carnivores that occur at low densities. Spatial capture–recapture (SCR) models can be used to estimate abundance and density from a camera trap array when all, some, or no individuals in the population can be uniquely identified. These SCR models also estimate locations of individual activity centers, the spatial patterning of which could provide important information about interspecific interactions. We used SCR models to estimate abundances, densities, and activity centers of each of 3 carnivore species (i.e., dingo [Canis familiaris], red fox [Vulpes vulpes], and feral cat) using photographs from 1 camera trap array in southeastern Australia during September to November 2015. Some dingoes and feral cats were uniquely identifiable and therefore, we used a spatial mark–resight model for these species. We could not uniquely identify fox individuals, however, so we used a spatial unmarked (SUN) model for this species. Our estimated dingo density was 0.06/km2. The fox (0.25/km2) and feral cat (0.16/km2) densities are within the ranges previously reported for these species in Australia. We obtained a relatively imprecise fox density estimate because we did not have detections of uniquely identifiable individuals; hence, the SUN model should be used as a last resort. We next modeled spatial dependence among the estimated activity centers for the 3 species using a spatial pair correlation function for a marked point process. Consistent with our expectations, the activity centers of dingoes and foxes were strongly negatively associated at distances of <1,000 m. Foxes and feral cats were also negatively associated at distances of <1,500 m. Surprisingly, dingoes and feral cats were positively associated at distances of >500 m, with no association evident at distances of <500 m. Our study extends the inferences that can be made from using a camera trap array and SCR methods to include spatial patterning and interspecific interactions, and provides new insights into the carnivore community of dingoes, foxes, and feral cats in southeastern Australia. © 2019 The Authors. The Journal of Wildlife Management Published by Wiley Periodicals, Inc. We used spatial capture–recapture models to estimate abundances, densities, and interspecific spatial associations of 3 carnivore species (dingo, red fox, and feral cat) using photographs from one camera‐trap array in southeastern Australia. Our methods can be used to estimate abundances, densities, and interspecific spatial associations elsewhere, providing robust information that will greatly assist managers and researchers working with wildlife communities. [ABSTRACT FROM AUTHOR]

Invasive mammalian predators commonly coexist with invasive mammalian herbivore prey. Managers often advocate controlling invasive prey in the belief that this will also reduce invasive predator abundance. Such an outcome would have desirable ecological and financial benefits, but there have been few tests of this hypothesis.We used large‐scale and long‐term monitoring data to test the prediction that invasive red fox Vulpes vulpes populations decline following control of invasive European rabbit Oryctolagus cuniculus populations in Australia. Both species severely impact natural and agricultural ecosystems, and significant resources are expended to reduce these impacts. We fitted a hierarchical state‐space model to spotlight counts of both species conducted at 21 transects between 1998 and 2015. The effects of rainfall, control activities (warren ripping and surface harbour removal), and density dependence on the population growth rates of both species were also evaluated.Control activities at 18 transects substantially reduced average rabbit abundances. Rabbit populations showed little response to rainfall, but exhibited negative density dependence and higher rates of increase during the autumn–spring interval.There was no numerical response of foxes to changes in rabbit abundance. Rather, fox populations increased rapidly after high rainfall and exhibited negative density dependence. The equilibrium abundance of foxes varied with rainfall and season, but was always <0.2 foxes per spotlight km.Synthesis and applications. We conclude that controlling rabbits to low abundances does not substantially reduce fox abundances in south eastern Australia. Rather, efforts to reduce fox abundance should directly target fox populations. Managers of invasive predator–invasive prey systems should not assume that controlling prey will, by itself, reduce predator abundances. Quantifying the numerical response is critical for understanding the likely response of predators to changes in prey abundance. We conclude that controlling rabbits to low abundances does not substantially reduce fox abundances in south eastern Australia. Rather, efforts to reduce fox abundance should directly target fox populations. Managers of invasive predator–invasive prey systems should not assume that controlling prey will, by itself, reduce predator abundances. Quantifying the numerical response is critical for understanding the likely response of predators to changes in prey abundance. [ABSTRACT FROM AUTHOR]

The Department of Conservation has implemented a Biodiversity and Monitoring Reporting System (BMRS) that estimates occupancy rates and relative abundances of introduced brushtail possums (Trichosurus vulpecula) at a representative sample of sites on public conservation land. Leg-hold traps have been used to monitor possums in the BMRS, but wax tags and chew cards have logistical and financial advantages over traps. If possum occupancy rate and/or abundance index estimates differ depending on which of the three methods are used, then correction of the estimates would be required for valid comparisons. We sampled possum occupancy rates and relative abundances using leg-hold traps, wax tags and chew cards in the BMRS sampling design at each of 54 forest and 54 non-forest sites. Possum occupancy rates estimated using each of the three detection methods were similar and hence do not require correction. Median possum abundance index values estimated from traps were lower than those estimated from wax tags and chew cards in forest, but were similar to those from wax tags in non-forest. Calibration is therefore required if possum abundance index values from either chew cards or wax tags are to be validly compared with trap catch abundance index values. We used a zeroinflated negative binomial (ZINB) model to calibrate the chew card and wax tag abundance indices with the trap catch abundance index. The ZINB model allowed us to account for structural zeros (i.e. possums were not present and therefore cannot be detected) and non-structural zeros (i.e. possums were present, but not detected by a particular method). The relationship between possum abundance index estimates from chew cards and leg-hold traps was better calibrated than that between wax tags and leg-hold traps, with the latter particularly poor in non-forest habitat. We therefore conclude that chew cards, rather than wax tags, should replace leg-hold traps for monitoring possum occupancy rates and relative abundances in the BMRS. Our ZINB model can be used to correct chew card abundance index values for valid comparison with previous trap catch abundance index values estimated using the BMRS design. [ABSTRACT FROM AUTHOR]

Abstract: Biological invasions by large herbivores involve the establishment of novel interactions with the receiving mammalian carnivore community, but understanding these interactions is difficult due to the large spatiotemporal scales at which such dynamics would occur. We quantified the functional responses of a native apex predator (the dingo (Canis familiaris), which includes wild dogs and their hybrids) and a non‐native mesopredator (red fox; Vulpes vulpes) to an invading non‐native ungulate (sambar deer; Cervus unicolor) in Australia. We predicted that the apex predator would exhibit a stronger functional response to increasing sambar deer abundance than the mesopredator. We used a state–space model to link two 30‐year time series: (i) sambar deer abundance (hunter catch‐per‐unit‐effort); and (ii) percentages of sambar deer in dingo (N = 4531) and fox (N = 5002) scats. Sambar deer abundance increased over fourfold during 1984−2013. The percentages of sambar deer in dingo and fox scats increased during this 30‐year period, from nil in both species in 1984 to 8.2% in dingoes and 0.5% in foxes in 2013. Dingoes exhibited a much stronger functional response to increasing sambar deer abundance than foxes. The prediction that invading deer would be utilized more by the apex predator than by the mesopredator was therefore supported. The increasing abundance of sambar deer during the period 1984−2013 provided an increasingly important food source for dingoes. In contrast, the smaller red fox utilized sambar deer much less. Our study demonstrates that prey enrichment can be an important consequence of large herbivore invasions and that the effect varies predictably with the trophic position of the mammalian carnivores in the receiving community. [ABSTRACT FROM AUTHOR]

The roles of density-dependent and density-independent factors in the dynamics of tropical large herbivore populations are poorly understood. Understanding these dynamics is particularly important if the herbivore is prey for an apex predator of conservation concern because a decline in the prey could cause the predator to decline. We tested hypotheses about the roles of density-dependent and density-independent factors in the dynamics of 2 tropical ungulates, Rusa deer (Rusa timorensis) and wild pigs (Sus scrofa), in Komodo National Park, eastern Indonesia. We counted the dung of Rusa deer and wild pigs (a validated index of abundance for these 2 species) along permanently marked transects at 10 sites over 4 islands annually during 2003-2014 to estimate ungulate abundance. Ungulates were much more abundant on the 2 larger islands compared with the 2 smaller islands, with wild pig dung completely absent from the latter. During our 12-year study, Rusa deer abundance declined slightly on Nusa Kode and Rinca islands, did not change on Komodo Island, and increased on Gili Motang Island. There was a decline in abundance of wild pigs on Komodo Island and an increase on Rinca Island. Annual variation in population growth rate was strongly density-dependent and island-specific for both species, with annual rainfall and vegetation composition being relatively unimportant. Population growth rates of Rusa deer exhibited spatial synchrony, with synchrony declining with increasing intersite distance. Our findings confirm the importance of density dependence in the dynamics of tropical large herbivore populations. However, the strength of density dependence varied between species and spatially. Declines of Rusa deer and wild pigs on the larger 2 islands, which are strongholds of the Komodo dragon, are cause for concern. Continued monitoring of ungulate populations is critical for the conservation of Komodo dragon populations in Komodo National Park. [ABSTRACT FROM AUTHOR]

Estimation of the age or age class of harvested animals is often necessary to interpret the condition and dynamics of wildlife populations. The mammalian eye lens continues to grow until death and hence the dry mass of the eye lens has commonly been used to estimate the age of mammals. The method requires the relationship between eye lens mass and age to be parameterized using individuals of known age. However, predicting age is complicated by the curvilinear relationship between eye lens mass and age. We used frequentist and Bayesian methods to predict the ages and age classes of harvested hog deer Axis porcinus from eye lens mass. Deer were tagged as calves and harvested 4-177 months later in southeastern Australia. Lenses were extracted, fixed and oven-dried. Of the five growth models evaluated, the Lord model best described the relationship between age and eye lens dry mass ( R2 = 95%). The precision of age predictions obtained using the Lord model in a Bayesian mode of inference decreased with increasing eye lens dry mass, with the size of the 95% CI equaling or exceeding predicted age for hog deer > 6 years. However, most predictions of hog deer age will have reasonable precision because few animals > 6 years are harvested. Linear discriminant analysis had high predictive power for classifying hog deer to four widely-used age classes (juvenile, yearling, prime-age and senescent). The Bayesian method is recommended for inverse non-linear prediction of age and the frequentist linear discriminant analysis method is recommended for estimating age class. We provide tables of correspondence between hog deer eye lens dry mass and predicted age and age class. Our statistical methods can be used to estimate age and age class for other mammalian species, including from other ageing techniques such as tooth eruption-wear criteria. [ABSTRACT FROM AUTHOR]

There is interest in large-scale and unbiased monitoring of biodiversity status and trend, but there are few published examples of such monitoring being implemented. The New Zealand Department of Conservation is implementing a monitoring program that involves sampling selected biota at the vertices of an 8-km grid superimposed over the 8.6 million hectares of public conservation land that it manages. The introduced brushtail possum (Trichosurus Vulpecula) is a major threat to some biota and is one taxon that they wish to monitor and report on. A pilot study revealed that the traditional method of monitoring possums using leg-hold traps set for two nights, termed the Trap Catch Index, was a constraint on the cost and logistical feasibility of the monitoring program. A phased implementation of the monitoring program was therefore conducted to collect data for evaluating the trade-off between possum occupancy–abundance estimates and the costs of sampling for one night rather than two nights. Reducing trapping effort from two nights to one night along four trap-lines reduced the estimated costs of monitoring by 5.8% due to savings in labour, food and allowances; it had a negligible effect on estimated national possum occupancy but resulted in slightly higher and less precise estimates of relative possum abundance. Monitoring possums for one night rather than two nights would provide an annual saving of NZ$72,400, with 271 fewer field days required for sampling. Possums occupied 60% (95% credible interval; 53–68) of sampling locations on New Zealand’s public conservation land, with a mean relative abundance (Trap Catch Index) of 2.7% (2.0–3.5). Possum occupancy and abundance were higher in forest than in non-forest habitats. Our case study illustrates the need to evaluate relationships between sampling design, cost, and occupancy–abundance estimates when designing and implementing large-scale occupancy–abundance monitoring programs. [ABSTRACT FROM AUTHOR]

Assemblages of introduced taxa provide an opportunity to understand how abiotic and biotic factors shape habitat use by coexisting species. We tested hypotheses about habitat selection by two deer species recently introduced to New Zealand’s temperate rainforests. We hypothesised that, due to different thermoregulatory abilities, rusa deer (Cervus timorensis; a tropical species) would prefer warmer locations in winter than red deer (Cervus elaphus scoticus; a temperate species). Since adult male rusa deer are aggressive in winter (the rut), we also hypothesised that rusa deer and red deer would not use the same winter locations. Finally, we hypothesised that in summer both species would prefer locations with fertile soils that supported more plant species preferred as food. We used a 250 × 250 m grid of 25 remote cameras to collect images in a 100-ha montane study area over two winters and summers. Plant composition, solar radiation, and soil fertility were also determined for each camera location. Multiseason occupancy models revealed that direct solar radiation was the best predictor of occupancy and detection probabilities for rusa deer in winter. Multistate, multiseason occupancy models provided strong evidence that the detection probability of adult male rusa deer was greater in winter and when other rusa deer were present at a location. Red deer mostly vacated the study area in winter. For the one season that had sufficient camera images of both species (summer 2011) to allow two-species occupancy models to be fitted, the detection probability of rusa deer also increased with solar radiation. Detection probability also varied with plant composition for both deer species. We conclude that habitat use by coexisting tropical and temperate deer species in New Zealand likely depends on the interplay between the thermoregulatory and behavioural traits of the deer and the abiotic and biotic features of the habitat. [ABSTRACT FROM AUTHOR]

Adoption is rare in animals and is usually attributed to kin selection. In a 6-year study of eastern grey kangaroos (Macropus giganteus), 11 of 326 juveniles were adopted. We detected eight adoptions by observing behavioural associations and nursing between marked mothers and young and three more by analysing the relatedness of mothers and young using microsatellite DNA. Four adoptions involved reciprocal switches and three were by mothers whose own pouch young were known to subsequently disappear. Adoptive mothers were not closely related to each other or to adoptees but adoptive mothers and young associated as closely as did biological pairs, as measured by half-weight indices. Switch mothers did not associate closely. Maternal age and body condition did not influence the likelihood of adoption but females were more likely to adopt in years with high densities of females with large pouch young. Adoption did not improve juvenile survival. We conclude that adoptions in this wild population were potentially costly and likely caused by misdirected care, suggesting that eastern grey kangaroos may have poorly developed mother-offspring recognition mechanisms. [ABSTRACT FROM AUTHOR]

Understanding the long-term impacts of invasive mammalian browsers and granivores in mixed forests is difficult due to the many processes potentially affecting the demography of long-lived trees. We constructed individual-based spatially explicit simulation models of two mixed conifer-angiosperm forests, growing on soils of contrasting phosphorus (P) availability, to investigate how browsing by invasive red deer (Cervus elaphus scoticus) and granivory by invasive rodents (primarily house mouse Mus musculus) might alter forest dynamics. Models were parameterized with field data. Seedling growth and survival rates were estimated inside and outside deer exclosures. Seed predation rates were estimated at high and low rodent densities in mast and non-mast seeding years. For the alluvial terrace forest, which grew on P-rich soil, our model contained 15 tree species dominated by angiosperms; our model of the P-poor marine terrace forest contained seven species dominated by conifers. The two forest models were used to explore four 500-year scenarios: deer and rodents present, deer present and rodents absent, deer absent and rodents present, and deer and rodents absent. Our field studies revealed that the highest probabilities of seed predation by rodents occurred for two canopy species in mast years and in neighborhoods of high species-specific basal area, and that deer browsing had the greatest negative effects on the growth and survival rates of angiosperm seedlings. Our simulation models predicted that the presence of deer and rodents would reduce the abundances of canopy codominants, and hence total basal area, in the alluvial terrace forest. The presence of deer increased the dominance of conifers in both forests, but effects of deer and rodents were much stronger in the alluvial terrace forest. Our study revealed two emergent properties. First, rodent- and deer-induced reductions in seedling abundances did not always translate into reduced sapling and adult tree abundances. Second, when deer changed the abundance of a canopy dominant, other species were affected by altered interspecific competition. We conclude that the effects of invasive deer and rodents will be greatest in forests growing on P-rich soils. Exclusion of deer is predicted to have greater long-term effects on forest dynamics than exclusion of rodents. [ABSTRACT FROM AUTHOR]

Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on dingoes/wild dogs, foxes and the food resources they interact with. [ABSTRACT FROM AUTHOR]

Large herbivores typically have consistently high prime‐aged adult survival and lower, more variable, juvenile, and senescent survival. Many kangaroo populations undergo greater fluctuations in density compared with other large herbivores, but age‐ and sex‐specific survival of kangaroos and their response to environmental variation remain poorly estimated. We used long‐term capture–mark–recapture data on 920 individuals to investigate the survival component of eastern grey kangaroo (Macropus giganteus) population dynamics. Forage availability and population density were monitored quarterly and included as predictors of survival in Bayesian Cormack–Jolly–Seber models. Annual survival probabilities were estimated for five age classes: 0 years (juveniles), 1–2 years (subadults), 3–6 years (prime‐aged adults), 7–9 years (presenescent adults), and ≥10 years (senescent adults). Survival of juveniles varied widely during our 12‐year study, ranging from 0.07 to 0.90 for females and 0.05–0.92 for males. Subadult survival was 0.80–0.93 for females and 0.75–0.85 for males, while that of prime‐aged adults was ≥0.94 for females and ≥0.83 for males, despite large fluctuations in forage and density. The survival of presenescent adults spanned 0.86–0.93 for females and 0.60–0.86 for males. Senescent survival was variable, at 0.49–0.90 for females and 0.49–0.80 for males. Male survival was significantly lower than female survival in prime‐aged and presenescent adults, but not in other age classes. Although most of the models supported by Watanabe–Akaike Information Criterion selection included at least one environmental covariate, none of these covariates individually had a discernible effect on survival. Temporal variability in overall survival appeared mostly due to changes in the survival of juvenile and senescent kangaroos. Kangaroo survival patterns are similar to those of ungulates, suggesting a strong role of sex–age structure on population dynamics. [ABSTRACT FROM AUTHOR]

There is much interest in understanding how anthropogenic food resources subsidise carnivore populations. Carcasses of hunter-shot ungulates are a potentially substantial food source for mammalian carnivores. The sambar deer (Rusa unicolor) is a large (≥150 kg) exotic ungulate that can be hunted throughout the year in south-eastern Australia, and hunters are not required to remove or bury carcasses. We investigated how wild dogs/dingoes and their hybrids (Canis lupus familiaris/dingo), red foxes (Vulpes vulpes) and feral cats (Felis catus) utilised sambar deer carcasses during the peak hunting seasons (i.e. winter and spring). We placed carcasses at 1-km intervals along each of six transects that extended 4-km into forest from farm boundaries. Visits to carcasses were monitored using camera traps, and the rate of change in edible biomass estimated at ∼14-day intervals. Wild dogs and foxes fed on 70% and 60% of 30 carcasses, respectively, but feral cats seldom (10%) fed on carcasses. Spatial and temporal patterns of visits to carcasses were consistent with the hypothesis that foxes avoid wild dogs. Wild dog activity peaked at carcasses 2 and 3 km from farms, a likely legacy of wild dog control, whereas fox activity peaked at carcasses 0 and 4 km from farms. Wild dog activity peaked at dawn and dusk, whereas nearly all fox activity occurred after dusk and before dawn. Neither wild dogs nor foxes remained at carcasses for long periods and the amount of feeding activity by either species was a less important predictor of the loss of edible biomass than season. Reasons for the low impacts of wild dogs and foxes on sambar deer carcass biomass include the spatially and temporally unpredictable distribution of carcasses in the landscape, the rapid rate of edible biomass decomposition in warm periods, low wild dog densities and the availability of alternative food resources. [ABSTRACT FROM AUTHOR]

ABSTRACT Failure to account for dependencies among observers in multiple-observer capture-recapture studies will lead to biased inference yet methods that account for dependencies are poorly developed. We combined hierarchical capture-recapture models and finite sampling theory to infer population abundance of koala ( Phascolarctos cinereus) in the 5,812-ha Mount Eccles National Park, southeastern Australia. We used plot replication to build a Bayesian hierarchical model of koala sightings by multiple observers. Given the number of koala present on a plot, we modeled counts of koala by a multinomial log-linear model with interaction terms to account for between-observer dependencies. We modeled total numbers using a Poisson log-linear model with covariate and random effects. We estimated the number of koala as 1.9 koala/ha (95% CI = 1.6, 2.4). We found evidence of between-observer interactions, highlighting the importance of having at least 3 observers in multiple observer studies. © 2014 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on activity recognition when multiple views are available. In the literature, this is often performed using two different approaches. In the first one, the systems build a 3D reconstruction and match that. However, there are practical disadvantages to this methodology since a sufficient number of overlapping views is needed to reconstruct, and one must calibrate the cameras. A simpler alternative is to match the frames individually. This offers significant advantages in the system architecture (e.g., it is easy to incorporate new features and camera dropouts can be tolerated). In this paper, the second approach is employed and a novel fusion method is proposed. Our fusion method collects the activity labels over frames and cameras, and then fuses activity judgments as the sequence label. It is shown that there is no performance penalty when a straightforward weighted voting scheme is used. In particular, when there are enough overlapping views to generate a volumetric reconstruction, our recognition performance is comparable with that produced by volumetric reconstructions. However, if the overlapping views are not adequate, the performance degrades fairly gracefully, even in cases where test and training views do not overlap. [Copyright &y& Elsevier]

We report on the use of semiconductor optical amplifier (SOA) gain compression for achieving intensity noise reduction in light from an incoherent broadband source, running at high data rate of 10 Gb/s in a narrow spectrum-sliced high-intensity channel of 20 GHz (~0.16 nm) bandwidth, in order to improve quality of performance in future spectrum-sliced systems. Data have been collected on the performance of a single SOA as noise reducer at various input powers and biases. Improvements of ~20 dB in the relative intensity noise, together with commensurate improvements in both signal-to-noise ratio and quality factor, have been achieved at a nominal 0 dBm of power inserted into the SOA at 0.15 A bias. The overall results obtained herein give designers a knowledge of the best SOA operating conditions required, particularly in terms of bias and input power, in order to achieve a desired intensity noise reduction, and thus an overall system performance improvement, while still obtaining some signal gain from the SOA as well. [ABSTRACT FROM AUTHOR]

Due to the intrinsic long-tailed distribution of objects in the real world, we are unlikely to be able to train an object recognizer/detector with many visual examples for each category. We have to share visual knowledge between object categories to enable learning with few or no training examples. In this paper, we show that local object similarity information--statements that pairs of categories are similar or dissimilar--is a very useful cue to tie different categories to each other for effective knowledge transfer. The key insight: Given a set of object categories which are similar and a set of categories which are dissimilar, a good object model should respond more strongly to examples from similar categories than to examples from dissimilar categories. To exploit this category-dependent similarity regularization, we develop a regularized kernel machine algorithm to train kernel classifiers for categories with few or no training examples. We also adapt the state-of-the-art object detector to encode object similarity constraints. Our experiments on hundreds of categories from the Labelme dataset show that our regularized kernel classifiers can make significant improvement on object categorization. We also evaluate the improved object detector on the PASCAL VOC 2007 benchmark dataset. [ABSTRACT FROM AUTHOR]

The exploitation ecosystems hypothesis (EEH) proposes that 1) plant biomass reflects the primary productivity of an ecosystem modified by the regulating effect of herbivory, and 2) herbivore abundance reflects the productivity of plants modified by the regulating effect of predation. Primary productivity thus determines the number of trophic levels in an ecosystem and the extent to which bottom-up and top-down regulation influence the biomass ratios of adjacent and non-adjacent trophic levels (i.e. trophic cascading). We constructed an interactive model of plant (pasture), herbivore (red kangaroo Macropus rufus) and predator (dingo Canis lupus dingo), a system in which trophic cascades have been suggested to occur, and used it to test the effects of increasing stochastic variation in primary productivity and dingo culling on predictions of the EEH. The model contained four feedback loops: the predator-herbivore and herbivore-plant feedback loops, and the predator and plant density-dependent feedback loops. The equilibrium conditions along the primary productivity gradient reproduced the three zones of trophic dynamics predicted by the EEH, plus an additional zone at productivities above which the maximum density of a predator is achieved due to social regulation: that zone is characterized by increasing herbivore density and decreasing plant biomass. Culling dingoes produced trophic cascades that were strongly attenuated at primary productivities below which the maximum density of dingoes was attained. Results were robust to uncertainty in kangaroo off-take by dingoes and to the efficacy of dingo culling, but prey switching by dingoes from red kangaroos to reptiles would weaken trophic cascades. We conclude that social regulation of carnivores has important implications for expression of the EEH and trophic cascades, and that attenuation of trophic cascades increases with increasing stochasticity in primary productivity. Our model also provides a framework for understanding the conditions in which dingo-mediated trophic cascades might be expected to occur, and generates testable predictions about the effects of higher dingo densities (e.g. by stopping culling or reintroduction to former range) on kangaroo and pasture dynamics. [ABSTRACT FROM AUTHOR]

Abstract: Forest management decisions are characterised by a high level of uncertainty because responses reflect a range of interacting ecological processes. Faced with this situation, modelling can be a useful tool for characterising that uncertainty and for predicting its impacts on management decisions. In the adaptive management paradigm, different model structures are essentially hypotheses of system behaviour that are formulated to encapsulate structural uncertainty about the system. Here we report upon the initial stages of a management-scale experiment designed to increase our understanding of the effects of deer control on forest ecosystems in New Zealand. Using a modelling approach based on fuzzy cognitive maps (FCM) we were able to formalise expert knowledge and explore how growth rates of tree seedlings would respond to lower deer densities, with or without responses by other plants in the forest understorey. Alternative models predicted that the response of seedling growth and biomass in small (16m2) plots used in the experiment were dependent on hypotheses about the strength of plant competition for soil nutrients and moisture which, in turn, were conditional on light availability in the plot. To learn about which model best may describe the system, we used recently proposed methods in Approximate Bayesian Computation (ABC) to perform model selection and inference using a simulated data set generated from one of our candidate models. Using a novel Markov chain Monte Carlo algorithm together with ABC model selection on our simulated data we show that these procedures provide reliable model selection and parameter inference and hence, should be suitable for confronting our candidate FCM models with data collected at the end of the experiment. [Copyright &y& Elsevier]

n important technique in cultural heritage preservation is multispectral acquisition, where one recovers a detailed spectral record of a painting using carefully calibrated lighting. This is difficult to do with frescoes, because it is hard to recover the spatial variation in light intensity that results from factors like the imaging setup and the curvature of the fresco. We introduce a new formulation of the lightness problem applied to images of pictorial artworks. The problem is different from the conventional lightness problem, because artists often paint the effects of light, so the albedo field contains a component that mimics an illumination field. Our method distinguishes between physical illumination and painted shading through spatial frequency effects and dynamic range considerations. We evaluate our method using multispectral images of paintings, where the physical illumination field is known. Our method produces estimates of the illumination intensity field that compare very well with the known ground truth, and outperforms other state-of-the art lightness recovery algorithms. For frescoes, ground truth is not available, but we show that our method produces consistent results, in the sense that the illumination functions estimated on the image and on (some of) its subimages are very similar on the overlap. We show our method produces qualitatively good color corrections for images of frescoes found on the web. [ABSTRACT FROM AUTHOR]

Estimating diet is often an important step in understanding and managing the impacts of ungulates, particularly for non-native species, but there is uncertainty about whether rumen contents should be assessed using macroscopic or microhistological methods or both. Introduced sambar deer (Cervus unicolor) have a large and increasing distribution in south-east Australia, and there is concern about their impacts on native and non-indigenous plant species. We estimated the diets of 102 sambar deer harvested during 2007-2009 using macroscopic and microhistological rumen analysis techniques. We identified 105 plant species in the diets of sambar deer, 61 identified with both techniques and 22 identified only macroscopically or only microhistologically. Rumen species richness was 70% greater using the microhistological technique. Estimates of taxonomic (i.e., monocot and dicot) and functional (i.e., fern, shrub-tree, forb, climber, grass, and grass-like) group composition by the 2 techniques were similar. Shrubs-trees dominated the diet (macroscopic, 49.7%; microhistological, 52.7%), followed by grasses (macroscopic, 22.7%; microhistological, 17.5%) and ferns (macroscopic, 20.6%; microhistological, 22.2%). We identified 9 non-indigenous plant species, 2 of which we identified using only the microhistological technique. We detected seeds of the weed blackberry (Rubus fruticosus aggregate), sometimes in large amounts, only with the macroscopic technique, whereas we detected foliage of that species with both techniques. Both techniques classified sambar deer as an intermediate mixed feeder closer to a concentrate selector-browser than a bulk and roughage feeder. However, both techniques detected seasonal differences in the percentages of taxonomic and functional groups in the diet; sambar deer were more grazers in autumn and more browsers in spring. Our results indicate that both macroscopic and microhistological techniques may need to be used when it is important to identify plant species in the diet, as is often the case for non-native ungulates. However, either technique can be used to estimate broader taxonomic and functional diet composition, including feeding type. [ABSTRACT FROM AUTHOR]

Predicting the current and potential distributions of established invasive species is critical for evaluating management options, but methods for differentiating these distributions have received little attention. In particular, there is uncertainty among invasive species managers about the value of information from incidental sightings compared to data from designed field surveys. This study compares the two approaches, and develops a unifying framework, using the case of invasive sambar deer Cervus unicolor in Victoria, Australia. We first used 391 incidental sightings of sambar deer and 12 biophysical variables to construct a presence-only habitat suitability model using Maxent. We then used that model to stratify field sampling, with proportionately greater sampling of cells with high predicted habitat suitability. Field sampling, consisting of faecal pellet surveys, sign surveys and camera trapping, was conducted in 80 4-km grid cells. A Bayesian state-space occupancy model was used to predict probability of suitable habitat from the field data. The Maxent and occupancy models predicted similar spatial distributions of habitat suitability for sambar deer in Victoria and there was a strong positive correlation between the rankings of cells by the two approaches. The congruence of the two models suggests that any spatial and detection biases in the presence-only data were relatively unimportant in our study. We predicted the extent of suitable habitat from the occupancy model using a threshold that gave a false negative error rate of 0·05. The current distribution was the suitable habitat within a kernel that had a 99·5% chance of including the presence locations pooled from incidental sightings and field surveys: the potential distribution was suitable habitat outside that kernel. Several discrete areas of potential distribution were identified as priorities for surveillance monitoring with the aim of detecting and managing incursions of sambar deer. Synthesis and applications. Our framework enables managers to robustly estimate the current and potential distributions of established invasive species using either presence-only and/or presence-absence data. Managers can then focus control and/or containment actions within the current distribution and establish surveillance monitoring to detect incursions within the potential distribution. [ABSTRACT FROM AUTHOR]

1. Many species of wildlife are harvested for sale but there are few time-series analyses of the factors determining the number of animals harvested. Economic theory predicts that price paid per animal is likely to be an important determinant of the harvest, but prices paid for alternative activities could reduce the harvest, and environmental factors such as rainfall could either constrain or enhance the harvest. 2. About 1 million feral goats Capra hircus L. are commercially harvested annually in the semi-arid rangelands of Australia, and there is much interest in how the harvest can be maximized so that the environmental impacts of the goats are minimized. 3. We developed 27 candidate models to explain monthly variation in the numbers of feral goats commercially harvested in Western Australia during July 1988 to June 2003. We fitted linear AR(1) models to the first 89 months of data and used Akaike's Information Criterion corrected for small sample size to identify the model(s) with substantial support. We then evaluated how much variation in the latter 88 months of the time series each model explained. 4. Almost 2·9 million feral goats were harvested in the study period. The two models with substantial support accounted for 70·5% and 70·6% of variation in the number of feral goats harvested during the first 89 months and 64·6% and 66·7% of variation in the subsequent 88 months. The models both included month of harvest and negative effects of rainfall in both the month of harvest and the previous month. One of the models also included a strong positive effect of the Australian Consumer Price Index-adjusted average price paid per feral goat on the number of feral goats harvested, and this model had the most support when fitted to the entire time series. 5. Synthesis and applications. This is the first study to demonstrate how both an environmental factor (rainfall) and an economic factor (average price paid per animal) can influence the size of a commercial wildlife harvest. Whilst managers can seldom modify environmental factors, our results suggest that the size of a wildlife harvest can be manipulated by altering the economics of the harvest. [ABSTRACT FROM AUTHOR]

We describe a method of representing human activities that allows a collection of motions to be queried without examples, using a simple and effective query language. Our approach is based on units of activity at segments of the body, that can be composed across space and across the body to produce complex queries. The presence of search units is inferred automatically by tracking the body, lifting the tracks to 3D and comparing to models trained using motion capture data. Our models of short time scale limb behaviour are built using labelled motion capture set. We show results for a large range of queries applied to a collection of complex motion and activity. We compare with discriminative methods applied to tracker data; our method offers significantly improved performance. We show experimental evidence that our method is robust to view direction and is unaffected by some important changes of clothing. [ABSTRACT FROM AUTHOR]

Dempster-Shafer (DS) theory provides a solution to fuse multisensor data, which are presented in a hypothesis space comprising mutually exclusive and exhaustive propositions and their unions. The fusion result is a description of the proposition with the values of support, plausibility, and uncertainty interval. However, in some applications, numerical values of a continuous function, instead of a Boolean value or a proposition, are expected. In this paper, a scheme based on DS reasoning and locally weighted regression is proposed to fuse the data obtained from the nondestructive inspections of aircraft lap joints for the estimation of the remaining thickness. The proposed approach uses a pairwise regression that is optimized by the DS method when multiple inputs are involved. The scheme is evaluated with the experiments on fusing conventional eddy current and pulsed eddy current data obtained from aircraft lap joint structures for the characterization of hidden corrosion. [ABSTRACT FROM AUTHOR]

1. Koala Phascolarctos cinereus populations sometimes exhibit eruptive dynamics, increasing to peak abundance and then crashing to low abundance. This dynamic is considered unacceptable because koalas die from starvation and food trees are killed by defoliation. There is concern that such dynamics may be occurring at a number of sites in south-eastern Australia. The only management option is fertility control of females. 2. We constructed a simulation model of koalas interacting with their food supply (manna gum Eucalyptus viminalis) in Mount Eccles National Park, Victoria, Australia. The amount of manna gum leaves consumed changed the survival and fecundity rates of koalas, and the amount of leaves removed changed the survival and transition rates of manna gums. 3. Without fertility control the koala population was predicted to increase to peak abundance within 10–18 years before crashing. The predicted dynamics of manna gum were more variable but abundance increased in most simulations for up to c. 5 years before declining to c. 25% of peak abundance within 20–30 years and then increasing subsequently. The maximum rate of koala population decline was an important determinant of the interaction between koalas and manna gum. 4. The best management strategy that was analysed involved estimating the number of unsterilized females in the population annually and then sterilizing a variable number to maintain a population of 1000 koalas: this strategy generated the least decline in manna gum at a consistently low cost. However, there was a delay between imposing fertility control and consequent reduction in koala abundance because of high adult female survival rates. Hence manna gum was predicted to decline for 5–10 years before increasing. 5. Synthesis and applications. Our results highlight important time-lags between implementing fertility control, reducing the abundance of a herbivore with high survival rates and subsequent changes in the abundance of its food supply. Our model is useful for understanding how controlling ‘overabundant’ herbivores impacts upon the dynamics of both the herbivore and its food supply. [ABSTRACT FROM AUTHOR]

As the requirements on the accuracy of nondestructive testing and evaluation are increasing, multiple nondestructive evaluation (NDE) methods are often employed to increase the reliability and reduce the uncertainty of the testing and evaluation. The need to process and analyze data from multiple sources uses the technique named data fusion, which has been growing rapidly in the NDE community in recent years. This paper reviews the progress in NDE data fusion techniques and examines the mathematical fusion algorithms, which include but are not limited to optimization methods, multiresolution approaches, heuristic methods, probabilistic methods, and scientific visualization. In the light of recent applications in NDE data fusion, important issues in handling the acquired data and applying the fusion algorithms are identified and discussed. A generic framework to apply the NDE data fusion process is described. The study on fusion of advanced NDE and sensor techniques opens up prospects for the diagnostic and prognostic health monitoring applications in the future. [ABSTRACT FROM AUTHOR]

Although fecal pellet counts have been widely used to index changes in deer abundance in forests, few studies have modeled the relationship between the indices and deer density. We examined the relationships between 3 fecal pellet indices (total pellets, pellet groups, and pellet frequency) and the density of deer (primarily red deer [Cervus elaphus scoticus]) in 20 enclosures in the North and South islands of New Zealand. In each enclosure we estimated the 3 indices on 30 randomly located 150-m transects, with each transect having 30 circular plots of 3.14 m². We developed 4 candidate models (1 linear and 3 nonlinear) to describe the relationship between the indices and deer density. We used a Bayesian analysis to account for uncertainty in the estimates of deer abundance and to facilitate fitting models that included random transect effects. The 4 models explained the relationship between the 3 indices and deer density similarly well. The slopes of the linear relationships between the 3 indices and deer density were positive. Our results suggest that fecal pellet counts may be useful indices of deer abundance. [ABSTRACT FROM AUTHOR]

Abstract: Experiments have been carried out to determine the viability of using nondestructive testing (NDT) techniques to detect active fretting processes and detect the presence of fretting damage on the faying surfaces of aircraft fuselage joint structures. A number of small specimens representing an element of an aircraft fuselage joint were subjected to fatigue, monitored during loading and inspected after loading, to determine the ability of various NDT techniques to detect fretting damage. These specimens were composed of two sheets of Al 2024-T3 fastened together with rivets, and the fretting damage expected to occur on hidden surfaces of this structure. [Copyright &y& Elsevier]