Animal Conservation最新文献

Effective conservation planning is often predicated on detailed and current information about a species' geographical distribution. However, traditional sources of occurrence data (e.g., online biodiversity databases) may be insufficient for estimating the range of rare, poorly understood species that are readily misidentified. Here, we demonstrate a more holistic approach to this problem, using the poorly known glossy grass skink (Pseudemoia rawlinsoni) as a case study. We first compared the relative contribution made (to our geographical knowledge of the species) by online database records, with that of photo-substantiated records obtained via personal communication (PC). We used ecological niche modelling (ENM) to predict the species' distribution, then performed field surveys at both historical and predicted suitable sites to further clarify its occurrence. 20% of all known records came from the PC method, which resulted in 35 new sites and increased the species' area of occupancy (AOO) by 176 km². Most records obtained via PC came from the past decade, demonstrating that this method is more effective at elucidating the current distribution. ENM revealed that P. rawlinsoni has a disjunct range, and is mostly a low-elevation coastal species, with the exception of suitable habitat in parts of the high-elevation Australian Alps bioregion. The species' AOO has likely declined over recent decades owing to anthropogenic disturbance, given that 38% of the species' predicted range is now cleared agricultural land, and our field surveys failed to detect the species at 52% of historical record sites. Together, these findings provide a robust foundation of geographical knowledge on which to develop strategic conservation actions for the species.

Wolves use howls to maintain large territories, intra-pack communication and social bonding. Besides their physical presence, howls are also instrumental in creating fear and impacting foraging behaviour among the lower cascade. Anthropocene-led behavioural alteration in vocalization has been observed in a wide range of species, but the effect on wolf howl is unknown. In this context, we have studied the howling behaviour of the Indian wolf through playback surveys (n = 264) across the anthropogenic gradient. We found a disparity in their howl response – based on the distance to villages. In the low disturbed East-Maharashtra (EM), wolves mostly avoided responding to howling surveys (HS) if done within 1200 m of villages [response rate (RR) = 0.03 ± 0.021], but they did respond once it was done far from villages (>1200 m) (RR = 0.226 ± 0.075). In high human-density West-Maharashtra (WM), wolves showed high RR within 1200 m from the villages (RR = 0.148 ± 0.031). But the RR within 500 m from villages was less as howling near villages might lead to easy detection. The collared wolf data showed significantly high RR (0.635 ± 0.067) in their home-range core, but low RR if the core area was close to a village. Therefore, howling too close to a village is disadvantageous, although their tolerance for responding to HS has increased in the human-dominated landscape. The extent of the village may increase further with development, which will leave fewer areas for the wolf to defend territory with a long-range howl. The wolves might behaviourally adapt to a human-modified landscape by reducing their howling intensity. Adaptation to a fragmented habitat may save the wolves from extinction, but the repercussions of the fundamental behavioural alteration might adversely impact wolf behaviour and the ecological cascade. Whereas ecologists are mainly concerned with the extinction of species, this study highlights the vulnerability of fundamental behaviour of a keystone species attributed to human-induced contemporary evolution.

Agroforests are increasingly seen as ancillary conservation landscapes that effectively integrate production needs while sustaining biodiversity goals. The conservation potential of these land uses can be significantly improved by using evidence-based management practices. In this study, we examine the community assembly of anuran amphibians and identify vulnerable species based on their life-history traits across tea and coffee agroforests and non-agricultural forest fragments in the Anamalai Hills of India. We conducted visual and auditory encounter surveys for amphibians along streams and terrestrial habitats. A modified joint species distribution model was used to examine the drivers of species richness, community composition and species co-occurrence patterns. At the community level, mean species richness was greatest in forest fragments followed by coffee and least in tea agroforests. Community composition was associated with both land use (tea/coffee/forest) and habitat (stream/terrestrial), with the greatest composition difference between coffee and forest. Life-history traits were significant drivers of species occupancies, particularly in forests. Fast-flowing water breeding amphibians and smaller body sizes were positively associated with forest streams over coffee and tea streams. Elevation was a strong predictor of amphibian occupancy with nine species showing negative association and 14 species showing positive association. Twelve species also showed a significant positive association with the wetter year, seven of which belonged to direct-developing frogs. This suggests that even single-year declines in rainfall could have detrimental effects on populations and make these species vulnerable to climate change. The results of the study have important conservation consequences for agroforests in the Western Ghats. Stream restoration efforts across elevation gradients could significantly improve habitats for different amphibian assemblages in agroforests.

Pre-release training is becoming a standard practice in conservation breeding and translocation programs for mammals and birds, but is still relatively neglected for herpetofauna, likely stemming from widespread beliefs that amphibians are “hard-wired” and are thus predicted to benefit little from experiential learning. However, experience during development can drive both morphological and behavioral modifications that could benefit post-translocation survival. Here, we developed an anti-predator training program for the endangered mountain yellow-legged frog Rana muscosa and evaluated its impact on morphometrics, developmental rates, behavior, and post-release outcomes. Using a controlled, balanced factorial experimental design, we exposed individuals at two developmental stages (tadpoles and post-metamorphic) to visual and olfactory cues from one of its principal predators, the two-striped garter snake Thamnophis hammondii. We found that exposure to predators during the tadpole stage impacted tadpole development, morphology, and behavior. However, we found no evidence that post-metamorphic behavior or post-release outcomes were influenced by tadpole predator exposure, either on its own or in interaction with post-metamorphic training treatments. Training of post-metamorphic frogs, however, yielded evidence of learning, with downstream effects on behavior and apparent survival after release into the wild. Our findings produce novel insights on the value of anti-predator training in amphibian conservation translocation programs, bolster recent evidence re-evaluating the importance of learning and developmental experience for amphibian species, and provide guidance for selecting optimal developmental windows for training.

The Indonesian archipelago, where the tropical rainforest ecosystem is home to 15% of the world's vertebrate species, has been the hardest hit by deforestation in Southeast Asia for the last decade. This situation makes ex situ conservation strategies, particularly biobanks, more important than ever to supplement in situ efforts which are becoming increasingly difficult. This study examines the status and future of biobanking implementation in Indonesian wildlife. The results show that current biobanking efforts in Indonesian wildlife are still limited, with a non-uniform distribution among taxa, sex and geographical origin. Current work is largely focused on mammals, while avifauna, reptiles and amphibians, particularly from the eastern region, are generally neglected. Cryopreservation is primarily used as a low-cost preservation method, but success rates are strongly influenced by intra- and interspecific characteristics, making the development of species-specific protocols essential. This report identifies the challenges and suggests ways to establish a national biobanking facility and collaborate with stakeholders to promote sustainable biobanking in Indonesia.

Conservation breeding programs are an increasingly important tool to help supplement declining wild populations, but captive-bred animals generally do not survive well post-release. Early life in captivity has the potential to influence growth and development, with impacts carrying over to affect survival. Understanding carry-over effects of captivity and consequences on survival is critically important for conservation efforts globally but remains poorly understood. We examined the relationship between early-life environment, physical condition, and juvenile survival of wild and captive-bred critically endangered orange-bellied parrots (Neophema chrysogaster). Using nestling growth models, we calculated a body condition index for 1,039 wild and captive-bred orange-bellied parrots hatched over six breeding seasons. Nestling body condition varied with year, provenance, and brood position. Wild nestlings had consistently higher body condition than captive-bred nestlings, and first-hatched nestlings were typically heavier than later hatched siblings. We then investigated first-year survival for 298 wild-born and captive-bred released parrots in the wild. Overall, first-year survival was 27.5%, and individual body condition was more influential than provenance in predicting survival. Our findings could be used to aid the selection of individuals for release that have the best prospects of surviving in the wild. This study addresses important questions about the post-release fitness of captive-bred animals, and our metric of assessing physical condition provides a straightforward tool for other conservation breeding programs to adapt management techniques to improve survival outcomes.

Identifying conservation actions to recover threatened species can be challenging due to many ecological uncertainties. For example, major threats to a species' conservation are commonly known or suspected, but the specific impacts on population or metapopulation dynamics can be uncertain. This is frequently the case with emerging infectious diseases, including chytridiomycosis, a global driver of amphibian population declines caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans. While these diseases are known to cause amphibian declines and extirpations, the mechanisms of their landscape-scale spread are still largely unknown. Such uncertainty can lead to inaction which may jeopardize timely recovery of a species. Decision analysis is a pragmatic approach to making transparent and defensible decisions while dealing with uncertainties. We investigated whether optimal actions aimed at recovering boreal toad (Anaxyrus boreas boreas) metapopulations in the southern Rocky Mountains are robust to the unknown dynamics of Bd spread using value of information and regret analyses. Value of information is a decision-analytic tool for calculating the value of new information in terms of performance on management objectives, while regret measures the cost of acting under incorrect information. We further conducted a stochastic sensitivity analysis to identify the relative effects of metapopulation parameters on system dynamics. We found optimal actions were robust to the unknown dynamics of Bd spread. While boreal toad breeding occurrence is highly sensitive to Bd distribution, the optimal decision is not. Resolving the unknown dynamics of Bd spread would lead to a minimal gain of less than one breeding toad subpopulation at the end of 50 years, given the currently available management actions. Applying a decision-analytic framework coupled with value of information and regret analyses can help frame how uncertainties affect decisions in a way that empowers decision makers.

Dogs Canis lupus familiaris, among canids, have emerged as the most successful predators and facultative scavengers, and have prevented other carnivores from approaching human habitats through intraguild competition. Over time with increasing population and livestock predation, they have become a matter of concern for pastoralists. The present study was conducted to understand the patterns of free-ranging dogs' predation on livestock and wildlife, from 2015 to 2017 in Changthang Wildlife Sanctuary (CWLS), Ladakh, India. Information was collected on (a) dog populations in 10 sites using polygon search in Spatially Explicit Capture-Recapture framework and block count, (b) their diet using scat analysis (n = 205) and (c) perceptions of pastoralists towards dogs through questionnaire-based interviews (n = 210). Dog densities varied between 10 and 310 individuals/100 km² and were high in and around human habitations. A major part of their diet constituted of livestock (74.29%) and wild species (13.06%). Among wild prey species, birds (4.49%), lagomorphs (3.67%), rodents (2.45%) and Tibetan wild ass (1.63%) had high occurrence in dog diet. The local people admitted that dogs pose a threat to livestock and wildlife. As unowned free-ranging dogs harm livestock and wildlife, about 40% of the respondents had negative perceptions towards them. The perception varied with occupation and pastoralists were more negative than non-pastoralists (P < 0.001). We suggest that effective mechanisms need to be identified or developed to manage dog populations in ecologically and economically sensitive areas to minimise the threats and safeguard the endangered wildlife and local livelihoods.

Large European carnivores are generally considered forest animals. However, there are a number of interacting factors that may have different impact on the availability and suitability of habitat for individual species. Felids, because of their stalking hunting mode, are habitat specialists requiring a heterogeneous environment, making them specifically vulnerable to habitat disturbance. The Eurasian lynx (Lynx lynx), despite protection in many European countries, has a surprisingly limited range. To explain environmental factors that affect its distribution, we undertook habitat selection and habitat suitability analyses at the macrohabitat and microhabitat scales, based on lynx occurrence and environmental data in Poland. Since the species occurs in two populations, one of which inhabits lowland and the other mountainous area, we modelled habitat suitability separately in both areas and then extrapolated it for the whole country scale. The lynx selected forests with medium undergrowth density in the lowlands and highly rugged terrain in the mountain areas—a proxy of stalking cover. Habitat suitability modelling performed at the macrohabitat scale identified around 110 000 km² of habitat available from which 55 700 km² was classified as high quality including large tracts of forests in western Poland that are beyond the natural range of the lynx. However, the microhabitat model built by including stalking cover variables, decreased high-quality habitats to only 33% of the area designated at the macrohabitat scale. This model is largely consistent with the current distribution of lynx in Poland. This suggests that the simplified internal structure of forests (lacking understory cover) may act as a hindrance to increasing the distribution of lynx populations and helps to explain its limited range in the Central European lowlands. This research suggests that the microhabitat structure may play the crucial role in the effective conservation of the Eurasian lynx.