Populations Of Endangered Species Research Articles

The importance of including survival release costs when assessing viability in reptile translocations

Translocations to restore populations of endangered species are an important conservation tool, but a reliable diagnosis is needed to assess their success. We used capture-recapture modeling to analyze the adult apparent survival of released and resident tortoises in two translocation projects in Spain monitored for 14 and 29years. We tested if long-term survival rates differ between released and resident individuals, if survival was lower during the phase of establishment (i.e. release cost), how long acclimation lasts and if increased density due to releases affects survival. We found lower survival of released tortoises during the phase of establishment (1 to 3years) when residents were already present. After establishment, survival was very high and unaffected by density-dependence. Body condition before release was similar between recaptured and dead/missing tortoises, and did not predict establishment survival. Stochastic population viability analysis showed that success when releasing small numbers of individuals strongly depends upon adult long-term survival. Release of small second batches of tortoises was not sensitive to a growing population, regardless of its release timing. Our results highlight long-term survival as crucial in translocation projects of long-lived species, invalidating short-term (first year) survival assessment, when survival release cost does not match long-term survival. A release cost of different duration should be included in model estimation before modeling predictions. Releasing tortoises (for welfare of captive individuals or for mitigating human negative impacts) in an already established population is not recommended under most circumstances. Acclimation cost is followed by survival approaching wild counterparts. If this milestone is not achieved, the project needs to be carefully assessed to adopt other management options or should be stopped altogether.

Uncertain recovery of the North Atlantic right whale in a changing ocean.

Human activities have placed populations of many endangered species at risk and mitigation efforts typically focus on reducing anthropogenic sources of mortality. However, failing to recognize the additional role of environmental factors in regulating birth and mortality rates can lead to erroneous demographic analyses and conclusions. The North Atlantic right whale population is currently the focus of conservation efforts aimed at reducing mortality rates associated with ship strikes and entanglement in fishing gear. Consistent monitoring of the population since 1980 has revealed evidence that climate-associated changes in prey availability have played an important role in the population's recovery. The considerable interdecadal differences observed in population growth coincide with remote Arctic and North Atlantic oceanographic processes that link to the Gulf of Maine ecosystem. Here, we build capture-recapture models to quantify the role of prey availability on right whale demographic transitional probabilities and use a corresponding demographic model to project population growth rates into the next century. Contrary to previous predictions, the right whale population is projected to recover in the future as long as prey availability and mortality rates remain within the ranges observed during 1980-2012. However, recent events indicate a northward range shift in right whale prey, potentially resulting in decreased prey availability and/or an expansion of right whale habitat into unprotected waters. An annual increase in the number of whale deaths comparable to that observed during the summer 2017 mass mortality event may cause a decline to extinction even under conditions of normal prey availability. This study highlights the importance of understanding the oceanographic context for observed population changes when evaluating the efficacy of conservation management plans for endangered marine species.

Perceptions and law enforcement of illegal and legal wolf killing in Norway: organized crime or folk crime?

On 20 April 2015, five men were convicted in a Norwegian court for breaching the penal law, namely for attempting to reduce the natural population of a protected endangered species on 15 February 2014. One was also charged with having killed a wolf on 14 March 2014. The sentences were the strictest ever imposed for similar crimes in Norway, with 20 months’ imprisonment for the main offender, partly because they were charged with organized crime—an aggravating circumstance. The verdict was appealed and a new conviction made on 5 April 2016, where the prison sentences for the five convicted men were considerably reduced, the strictest from 20 to 9 months, and with the law applied differently. The state appealed the decision from the Appeal Court to the Supreme Court [Høyesterett], concerning the application of law, and there four of the men were again found guilty of attempting to reduce the population of an endangered species. These verdicts invite discussion of how such crimes should be perceived-as serious organized crime or as “folk crimes”. This article argues that either way such acts should be regarded as theriocides that breach the Animal Welfare Act and its statement that animals have intrinsic value, and further that they cannot be viewed in isolation but must be seen in the context of state policy towards large predators. The crimes are thus discussed from a green criminology perspective, concentrating on seeing these theriocides as crimes, not “only” harms.

A Whole-of-Society Approach to Wildlife Crime in South Africa

The recent and rapid increase in wildlife crime not only threatens the survival of significant populations of endangered species in South Africa, but also threatens regional security, the sustainability of the tourism sector and social stability of local communities. Many interventions and actions in addressing wildlife crime fail to achieve sustained impact mainly due to the complexity of the problem and the resulting multiple and simultaneous interventions needed along the short, medium and long term. Factors that contribute to the complexity of the problem are, the number of role players involved, the framing of the problem through different worldviews, the high stakes, the number of simultaneous aspects of interventions, the problem dynamics and the huge number of interactions. Different aspects of the problem are interconnected, but stakeholders are tempted to address the problem in parts (fragmentation), thus creating new problems. This dynamic facilitates situations in which decision makers find the problem too big and complex to address and they remain in a state of crisis management. Addressing the current wildlife crisis requires harmonised efforts incorporating on-the-ground cross-border cooperation and a strategic environment that balances conserving wildlife with stakeholder needs for economic growth and local, national, and regional stability. This paper explores innovative and integrated ways in mitigating the complexity of the wildlife crime problem. The approach is problem focused as opposed to discipline focused or organisation-centric. The paper also discusses the lessons learnt and the resulting preliminary set of “principles”: inclusivity of actors, different ways of being and knowing as ways of addressing fragmentation; foresight; governance, as dynamic problem solving to build capabilities; and the transforming organisational narratives as part of implementing new strategies. These “principles” form the basis of the whole-of-society approach in dealing with complexity and can be applied in future interventions that concentrate on combining operational and scientific expertise with local knowledge, through participatory learning and governance.

A Whole-of-Society Approach to Wildlife Crime in South Africa

The recent and rapid increase in wildlife crime not only threatens the survival of significant populations of endangered species in South Africa, but also threatens regional security, the sustainability of the tourism sector and social stability of local communities. Many interventions and actions in addressing wildlife crime fail to achieve sustained impact mainly due to the complexity of the problem and the resulting multiple and simultaneous interventions needed along the short, medium and long term. Factors that contribute to the complexity of the problem are, the number of role players involved, the framing of the problem through different worldviews, the high stakes, the number of simultaneous aspects of interventions, the problem dynamics and the huge number of interactions. Different aspects of the problem are interconnected, but stakeholders are tempted to address the problem in parts (fragmentation), thus creating new problems. This dynamic facilitates situations in which decision makers find the problem too big and complex to address and they remain in a state of crisis management. Addressing the current wildlife crisis requires harmonised efforts incorporating on-the-ground cross-border cooperation and a strategic environment that balances conserving wildlife with stakeholder needs for economic growth and local, national, and regional stability. This paper explores innovative and integrated ways in mitigating the complexity of the wildlife crime problem. The approach is problem focused as opposed to discipline focused or organisation-centric. The paper also discusses the lessons learnt and the resulting preliminary set of “principles”: inclusivity of actors, different ways of being and knowing as ways of addressing fragmentation; foresight; governance, as dynamic problem solving to build capabilities; and the transforming organisational narratives as part of implementing new strategies. These “principles” form the basis of the whole-of-society approach in dealing with complexity and can be applied in future interventions that concentrate on combining operational and scientific expertise with local knowledge, through participatory learning and governance.

Using relatedness networks to infer contemporary dispersal: Application to the endangered mammal Galemys pyrenaicus.

Information about the degree of contemporary dispersal is important when trying to understand how populations interchange individuals and identify the specific barriers that prevent these movements. In the case of endangered species, this can represent crucial information when designing appropriate conservation strategies. Here we analyse relatedness between individuals from different localities and use these data to infer whether dispersal occurred in recent generations. We applied this approach to the Pyrenean desman (Galemys pyrenaicus), a semiaquatic and endangered species endemic to the Iberian Peninsula. We studied this species in four primary rivers in the Iberian Range, where two ancient mitochondrial lineages are separated by a strict contact zone, suggesting the existence of complex dispersal patterns. Using next-generation sequencing, we obtained 912 SNPs from each specimen and estimated relatedness values between them. While relatedness networks were dense within each river, we found surprisingly few relationships between individuals from different rivers despite their close proximity in some cases, indicating much lower dispersal between rivers compared to dispersal within a single river. In agreement with this result, the degree of inbreeding was exceedingly high in most individuals. These data show that relatedness information can be crucial to understand the contemporary dispersal patterns and conservation status of specific populations of endangered species.

Habitat requirements of endangered species in a former coppice of high conservation value.

Transformation of coppices to high forests has caused fundamental changes in site conditions and a decline of many species across Central Europe. Nevertheless, some formerly coppiced forests still harbour a number of the declining species and have become biodiversity hotspots in the changing landscape. We focused on the best preserved remnant of formerly grazed and coppiced subcontinental oak forest in the Czech Republic - Dúbrava forest near Hodonín. To improve our understanding of the ecology of the declining species, we studied local habitat requirements of vascular plants most endangered at the national level. We recorded vegetation composition and sampled important site variables in plots with the largest populations of endangered species and in additional plots placed randomly across all major forest habitats. We demonstrated that sites with endangered species have a highly uneven distribution in ecological space and their species composition is often similar to open-canopy oak forests. Within this habitat, the endangered species are concentrated in places with a high light availability and high soil pH. Light-demanding species characteristic of subcontinental oak forests are the best indicators of these sites, while broadly distributed shade-tolerant and nutrient-demanding species avoid them. These results support the view that the occurrence of many endangered species in Dúbrava forest is a legacy of the long history of traditional management that kept the canopies open. The light-demanding species are now threatened by ongoing successional changes. Therefore, active conservation measures are recommended, including opening up the canopies, early thinning of young stands, control of expansive and invasive species and understorey grazing or mowing.

Surviving at the edge of a fragmented range: patterns of genetic diversity in isolated populations of the endangered giant Mediterranean limpet (Patella ferruginea)

The survival of endangered and rare species with slow growth and low dispersal capabilities critically depends on the persistence of populations within marine protected areas (MPAs). The effectiveness of MPAs at maintaining the species evolutionary potential will depend on the occurrence of self-sustaining and viable populations, harboring sufficient levels of genetic diversity. Here, individuals of Patella ferruginea Gmelin, 1791, an endangered and rare limpet endemic to the western Mediterranean, were genotyped using eight microsatellite loci. Genetic information was used to assess the occurrence of (1) self-sustaining and viable populations and (2) fine-scale spatial genetic structure within two MPAs in the north of Sardinia Island. In contrast to the literature-based expectation of two relict and declining populations, levels of genetic diversity were similar to those reported for other marine gastropods. Furthermore, the contemporary effective population size was higher than the average effective size found in populations of other endangered species. Even accounting for uncertainty, such estimates exceeded the critical threshold below which inbreeding and random genetic drift determine the loss of genetic diversity. The two populations showed different spatial genetic patterns, which might reflect the interplay between species life-history traits and topographic and oceanographic features. With regard to the conservation and management of marine resources, these results stress once more the importance of taking into account both the species life-history traits and the habitat features that can limit connectivity at small geographic scales.

Genetic monitoring of an endangered species recovery: demographic and genetic trends for reintroduced pygmy rabbits (Brachylagus idahoensis)

Monitoring demographic and genetic parameters of reintroduced populations of endangered species is essential for evaluating and informing conservation strategies to maximize the chances of a successful recovery. We applied noninvasive genetic monitoring using fecal DNA to evaluate demographic and genetic parameters as they relate to the recovery of the endangered Columbia Basin pygmy rabbit (Brachylagus idahoensis) in central Washington, United States, during the initial 3 years of a renewed reintroduction effort. We quantified post-release dispersal, apparent survival, and reproduction in the wild, and monitored the genetic diversity and composition of the released cohorts, wild surviving population, and breeding population held in large enclosures. During this study, we reintroduced 1,206 pygmy rabbits into the wild, and detected a total of 176 individuals living on or near the release area during surveys the following winters. Median dispersal distance of juveniles was 776 m, compared to 471 m for adults, and dispersal distances for juveniles decreased for rabbits released later in the release season. Survival of juveniles differed across years and was positively associated with release date, release weight (a surrogate for age), and heterozygosity. Survival of adults was similarly influenced by release day, with some evidence for a positive effect of heterozygosity. Only 14 wild-born individuals were detected during the study. Genetic monitoring was an effective way to evaluate the demographic and genetic status of the reintroduced population within a limited study area, to inform changes to the conservation strategy, and to generate a data set to address long-term research and recovery goals.

Impacts of canine distemper virus infection on the giant panda population from the perspective of gut microbiota

The recent increase in infectious disease outbreaks has been directly linked to the global loss of biodiversity and the decline of some endangered species populations. Between December 2014 and March 2015, five captive giant pandas died due to canine distemper virus (CDV) infection in China. CDV has taken a heavy toll on tigers and lions in recent years. Here, we describe the first gut microbiome diversity study of CDV-infected pandas. By investigating the influence of CDV infection on gut bacterial communities in infected and uninfected individuals and throughout the course of infection, we found that CDV infection distorted the gut microbiota composition by reducing the prevalence of the dominant genera, Escherichia and Clostridium, and increasing microbial diversity. Our results highlight that increases in intestinal inflammation and changes in the relative abundances of pathogen-containing gut communities occur when individuals become infected with CDV. These results may provide new insights into therapeutics that target the microbiota to attenuate the progression of CDV disease and to reduce the risk of gut-linked disease in individuals with CDV. In addition, our findings underscore the need for better information concerning the dynamics of infection and the damage caused by pathogens in panda populations.

Distribution Pattern and State of Coenotic Population of <i>Tulipa lehmanniana</i> Merckl. in Kyzylkum Desert Conditions (Uzbekistan)

The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa lehmanniana Merckl. is given. Within the western part of the area (Kyzylkum desert) in different ecological and phytocenotic conditions, 8 coenotic populations of the species were identified. Based on the number of organism and population traits, the current state of coenotic populations of the species was evaluated. It was revealed that the vast majority of coenopopulations are in pessimal state. Coenopopulation only growing on the eastern part of the mountain Kuljuktau was assessed as optimal.

SNP discovery and characterisation in White Rhino (Ceratotherium simum) with application to parentage assignment.

The white rhino is one of the great success stories of modern wildlife conservation, growing from as few as 50-100 animals in the 1880s, to approximately 20,000 white rhinoceros remaining today. However, illegal trade in conservational rhinoceros horns is adding constant pressure on remaining populations. Captive management of ex situ populations of endangered species using molecular methods can contribute to improving the management of the species. Here we compare for the first time the utility of 33 Single Nucleotide Polymorphisms (SNPs) and nine microsatellites (MS) in isolation and in combination for assigning parentage in captive White Rhinoceros. We found that a combined dataset of SNPs and microsatellites was most informative with the highest confidence level. This study thus provided us with a useful set of SNP and MS markers for parentage and relatedness testing. Further assessment of the utility of these markers over multiple (> three) generations and the incorporation of a larger variety of relationships among individuals (e.g. half-siblings or cousins) is strongly suggested.

Створення Чорнобильського біосферного радіоекологічного заповідника як втілення біотехнології відновлення зони відчуження

Мета: cтаття присвячена збереженню унікальної території, яка має унікальне поєднання лісів, боліт, ставків і земель. Наразі дана територія стала радіоекологічним полігоном. Можливе створення біосферного заповідника на основі території зони відчуження, а також існуючих територій та об'єктів національного природно-заповідного фонду. Методи: оцінки на основі картографічної інформації та прогнозного визначення ступеня погіршення територій. Результати: поліпшення управління існуючих і нових територій зони відчуження, шляхом створення однієї великої природоохоронної території в регіоні. Посилення контролю за популяціями рідкісних і зникаючих видів. Обговорення: запропонована попереднє функціональне зонування біосферного заповідника в межах відповідних адміністративних районів.

Specific alleles at immune genes, rather than genome-wide heterozygosity, are related to immunity and survival in the critically endangered Attwater's prairie-chicken.

The negative effects of inbreeding on fitness are serious concerns for populations of endangered species. Reduced fitness has been associated with lower genome-wide heterozygosity and immune gene diversity in the wild; however, it is rare that both types of genetic measures are included in the same study. Thus, it is often unclear whether the variation in fitness is due to the general effects of inbreeding, immunity-related genes or both. Here, we tested whether genome-wide heterozygosity (20 990 SNPs) and diversity at nine immune genes were better predictors of two measures of fitness (immune response and survival) in the endangered Attwater's prairie-chicken (Tympanuchus cupido attwateri). We found that postrelease survival of captive-bred birds was related to alleles of the innate (Toll-like receptors, TLRs) and adaptive (major histocompatibility complex, MHC) immune systems, but not to genome-wide heterozygosity. Likewise, we found that the immune response at the time of release was related to TLR and MHC alleles, and not to genome-wide heterozygosity. Overall, this study demonstrates that immune genes may serve as important genetic markers when monitoring fitness in inbred populations and that in some populations specific functional genes may be better predictors of fitness than genome-wide heterozygosity.

Role of New Nature Reserve in Assisting Endangered Species Conservation - Case Study of Giant Pandas in the Northern Qionglai Mountains, China.

The creation of nature reserves is the most direct way to save endangered species populations and their habitat. Development of the giant panda (Ailuropoda melanoleuca) nature reserve network in China was initiated in the 1960s, though the effort to create new reserves boomed considerably after the year 2000. Given this rapid development of protected areas in panda habitats, and the potential conflicting interests between conservation administrations and local economic development, it is essential to assess the role of new nature reserves in the overall giant panda conservation effort and reserve network. We utilized data from national giant panda surveys conducted in 2000 and 2012 to compare the size, spatial use, and distribution of panda populations, as well as the habitat suitability and connectivity in the Northern Qionglai Mountains between the two survey years. Our results show that although the total giant panda population in the study area did not change remarkably, local changes did occur. Most notably, the population in Wolong Nature Reserve declined by 27.3% (N = 39) and the population in Caopo Nature Reserve increased by 71.4% (N = 29) over the 12-year study period. We also found habitat suitability and availability decreased in both Wolong (12.4%) and Caopo (7.4%), but that the relative density of giant pandas declined (19.2%) and increased (84.6%) at each site, respectively. The distance between centers of high IUA were more distant in 2012 (14.1±1.9km) than that in 2000 (6.1±0.9km; t = -7.4, df = 5, p = 0.001), showing a scattered spatial pattern. Habitat availability decreased by 42% within the corridor between the two reserves, however panda occurrences in the corridor increased 24.6%. Compared to the total number of encounters, the proportion of the corridor increased 45.76%. Our results show the importance and success of the newly established Caopo to the conservation of giant pandas, and how crucial it is to identify and repair reserve corridors. Furthermore, we propose criteria for future nature reserve network management and investment, which is applicable for other endangered species conservation practices.

Non-indigenous populations of endangered species: control and conservation

Non-indigenous populations of endangered species: control and conservation

Extent and reasons for meadows in South Bohemia becoming unsuitable for orchids

Decline in wet grasslands, which in the past resulted particularly from the intensification of agriculture, was accompanied by the loss of a lot of populations of organisms, including protected and endangered species of plants and animals associated with these habitats e.g. terrestrial orchids. The survival of populations of many species of European orchids is strongly dependent on appropriate site management, especially regular mowing or grazing. In addition, humans can negatively affect the persistence of orchid populations in various ways, such as conversion of orchid meadows into building areas, dams, roads etc. or the intensive use of fertilizers and contamination of areas by fertilisers from nearby fields. Comparison of historical data with the present distribution of orchids can reveal a lot about the main reasons for the decline in this endangered group of plants. Here we present an extensive study of the persistence of 192 historical orchid sites in South Bohemia, with particular reference to the 5 commonest species of orchids, Anacamptis morio, Dactylorhiza majalis, Epipactis helleborine, Epipactis palustris and Platanthera bifolia. We show that the most abundant species at the sites studied was Dactylorhiza majalis. E. palustris, A. morio and P. bifolia are currently not present at any of the historical localities for these species. Considering more recent history, the situation regarding orchid localities in South Bohemia is not critical, but the fate of these species should be closely monitored. The majority of this loss is due to the cessation of mowing of the sites. Thus more attention should be paid to the management of the existing sites. During this study, some new sites were discovered.

Retrospective analysis of causes of death in mountain pygmy-possums (Burramys parvus) at Healesville Sanctuary, Victoria, Australia.

Identification and characterisation of deaths is important for the veterinary management of both wild and captive animals. It is especially important as a tool for monitoring health and disease within populations of endangered species for which little information on morbidity and mortality is known. Investigations into the causes of death and other important necropsy findings were made in a captive population of the critically endangered mountain pygmy-possum (Burramys parvus). Necropsy records from January 2000-December 2013 were reviewed for all possums that had lived and died at Healesville Sanctuary (n = 48). The average age of death of possums in this population was 4.7 years. The most common histological change in mountain pygmy-possums was varying degrees of chronic progressive kidney disease (n = 17). Of these cases, eight animals (47%) had histological changes suggesting the kidney disease was the likely cause of death. Other causes of death included neoplasia (n = 5), necrotising pancreatitis (n = 4), pneumonia (n = 2), reproductive disease (n = 2) and trauma (n = 2). No cause of death was able to be identified in 33.3% (n = 16) of cases. Hepatic lipidosis (n = 5), pneumonia (n = 2) and degenerative joint disease (n = 2) were the most common comorbidities found. Progressive renal disease, often with secondary metastatic mineralisation, appears to be a significant cause of mortality in captive mountain pygmy-possums and further investigation into its pathophysiology, antemortem diagnosis and treatment is warranted.

Marshes as "Mountain Tops": Genetic Analyses of the Critically Endangered São Paulo Marsh Antwren (Aves: Thamnophilidae).

Small populations of endangered species can be impacted by genetic processes such as drift and inbreeding that reduce population viability. As such, conservation genetic analyses that assess population levels of genetic variation and levels of gene flow can provide important information for managing threatened species. The São Paulo Marsh Antwren (Formicivora paludicola) is a recently-described and critically endangered bird from São Paulo State (Brazil) whose total estimated population is around 250–300 individuals, distributed in only 15 isolated marshes around São Paulo metropolitan region. We used microsatellite DNA markers to estimate the population genetic characteristics of the three largest remaining populations of this species all within 60 km of each other. We detected a high and significant genetic structure between all populations (overall F ST = 0.103) which is comparable to the highest levels of differentiation ever documented for birds, (e.g., endangered birds found in isolated populations on the tops of African mountains), but also evidence for first-generation immigrants, likely from small local unsampled populations. Effective population sizes were small (between 28.8–99.9 individuals) yet there are high levels of genetic variability within populations and no evidence for inbreeding. Conservation implications of this work are that the high levels of genetic structure suggests that translocations between populations need to be carefully considered in light of possible local adaptation and that remaining populations of these birds should be managed as conservation units that contain both main populations studied here but also small outlying populations which may be a source of immigrants.

Assessment of microsatellite and SNP markers for parentage assignment in ex situ African Penguin (Spheniscus demersus) populations.

Captive management of ex situ populations of endangered species is traditionally based on pedigree information derived from studbook data. However, molecular methods could provide a powerful set of complementary tools to verify studbook records and also contribute to improving the understanding of the genetic status of captive populations. Here, we compare the utility of single nucleotide polymorphisms (SNPs) and microsatellites (MS) and two analytical methods for assigning parentage in ten families of captive African penguins held in South African facilities. We found that SNPs performed better than microsatellites under both analytical frameworks, but a combination of all markers was most informative. A subset of combined SNP (n=14) and MS loci (n=10) provided robust assessments of parentage. Captive or supportive breeding programs will play an important role in future African penguin conservation efforts as a source of individuals for reintroduction. Cooperation among these captive facilities is essential to facilitate this process and improve management. This study provided us with a useful set of SNP and MS markers for parentage and relatedness testing among these captive populations. Further assessment of the utility of these markers over multiple (>3) generations and the incorporation of a larger variety of relationships among individuals (e.g., half-siblings or cousins) is strongly suggested.