Anthropogenic Drivers Leading to Population Decline and Genetic Preservation of the Eurasian Griffon Vulture (Gyps fulvus)

Human activities are having increasingly devastating effects on the health of marine and terrestrial ecosystems. Studying the adaptive responses of animal species to changes in their habitat can be useful in mitigating this impact. Vultures represent one of the most virtuous examples of adaptation to human-induced environmental changes. Once dependent on wild ungulate populations, these birds have adapted to the epochal change resulting from the birth of agriculture and livestock domestication, maintaining their essential role as ecological scavengers. In this review, we retrace the main splitting events characterising the vultures’ evolution, with particular emphasis on the Eurasian griffon Gyps fulvus. We summarise the main ecological and behavioural traits of this species, highlighting its vulnerability to elements introduced into the habitat by humans. We collected the genetic information available to date, underlining their importance for improving the management of this species, as an essential tool to support restocking practices and to protect the genetic integrity of G. fulvus. Finally, we examine the difficulties in implementing a coordination system that allows genetic information to be effectively transferred into management programs. Until a linking network is established between scientific research and management practices, the risk of losing important wildlife resources remains high.

Evidence of genetic structure in the wide-ranging bearded vulture (Gypaetus barbatus (Linnaeus, 1758))

BACKGROUND

The bearded vulture is sparsely distributed across a wide geographic range that extends over three continents (Africa, Europe and Asia). Restriction to high-altitude mountainous habitats, low breeding rates, lack of food and a heightened level of persecution have left many local populations severely diminished or extinct. Understanding the genetic connectivity and population structure of this threatened vulture species is critical for accurately assessing their conservation status, and for appropriately managing local populations through captive breeding programmes or translocations. Previous genetic assessments of the species were mainly focused on the European and Asian populations and included limited representation of the geographically isolated southern African population. A single mitochondrial study, which focused on the African populations of the bearded vulture, detected limited genetic differentiation between populations in Ethiopia and southern Africa, with reduced haplotype diversity in the southern Africa population. In this study, we extend the previous genetic assessments of the species by examining the phylogeography and genetic connectivity of global G. barbatus populations using a panel of 14 microsatellite loci.

RESULTS

Analyses revealed spatially correlated genetic differentiation between regional populations and low levels of gene flow between these population fragments. In contrast to the mitochondrial data, the microsatellite data support the management of genetically different populations as separate entities.

CONCLUSIONS

Low genetic diversity and geographic isolation are known to adversely affect the evolutionary potential of a species in the long-term. The high inbreeding found in the southern African G. barbatus and, to a lesser extent, the northern African populations highlights the need for conservation programmes to effectively manage populations of this species and maintain extant genetic diversity.

Genetic diversity of the Griffon vulture population in Serbia and its importance for conservation efforts in the Balkans

The Griffon vulture was once a widespread species across the region of Southeast Europe, but it is now endangered and in some parts is completely extinct. In the Balkan Peninsula the largest Griffon vulture inland population inhabits the territory of Serbia. We present, for the first time, the genetic data of this valuable population that could be a source for future reintroduction programs planned in South-eastern Europe. To characterize the genetic structure of this population we used microsatellite markers from ten loci. Blood samples were collected from 57 chicks directly in the nests during the ongoing monitoring program. We performed a comparative analysis of the obtained data with the existing data from three native populations from French Pyrenees, Croatia, and Israel. We have assessed the genetic differentiation between different native populations and determined the existence of two genetic clusters that differentiate the populations from the Balkan and Iberian Peninsulas. Furthermore, we analysed whether the recent bottleneck events influenced the genetic structure of the populations studied, and we found that all native populations experienced a recent bottleneck event, and that the population of Israel was the least affected. Nevertheless, the parameters of genetic diversity suggest that all analysed populations have retained a similar level of genetic diversity and that the Griffon vulture population from Serbia exhibits the highest value for private alleles. The results of this study suggest that the Griffon vulture populations of the Balkan Peninsula are genetically differentiated from the populations of the Iberian Peninsula, which is an important information for future reintroduction strategies.

Microsatellite genotypes of the South African Cape vulture, Gyps coprotheres

Across the globe, vulture species are experiencing major population declines. A key factor for the long-term persistence of these endangered species is the maintenance of genetic diversity patterns within wild populations. The datasets presented in this descriptor includes microsatellite genotypes of 605 Cape vultures (Gyps coprotheres) drawn from across the southern African distribution of the species. Microsatellites are useful in quantifying genetic diversity at the population level. Populations of the endangered Cape vulture are currently monitored by conservation agencies and the data presented here can be used as an important baseline for future population genetic monitoring.

Development of microsatellite loci for two New World vultures (Cathartidae)

Objective

Use next-generation sequencing to develop microsatellite loci that will provide the variability necessary for studies of genetic diversity and population connectivity of two New World vulture species.

Results

We characterized 11 microsatellite loci for black vultures (Coragyps atratus) and 14 loci for turkey vultures (Cathartes aura). These microsatellite loci were grouped into 3 multiplex panels for each species. The number of alleles among black vulture samples ranged from 2 to 11, and 3 to 48 among turkey vulture samples.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4295-z) contains supplementary material, which is available to authorized users.

Low genetic diversity and shallow population structure in the endangered vulture, Gyps coprotheres

Globally, vulture species are experiencing major population declines. The southern African Cape vulture (Gyps coprotheres) has undergone severe population collapse which has led to a listing of Endangered by the IUCN. Here, a comprehensive genetic survey of G. coprotheres is conducted using microsatellite markers. Analyses revealed an overall reduction in heterozygosity compared to other vulture species that occur in South Africa (Gypaetus barbatus, Necrosyrtes monachus, and Gyps africanus). Bayesian clustering analysis and principal coordinate analysis identified shallow, subtle population structuring across South Africa. This provides some support for regional natal philopatry in this species. Despite recent reductions in population size, a genetic bottleneck was not detected by the genetic data. The G. coprotheres, however, did show a significant deficiency of overall heterozygosity. This, coupled with the elevated levels of inbreeding and reduced effective population size, suggests that G. coprotheres is genetically depauperate. Given that genetic variation is considered a prerequisite for adaptation and population health, the low genetic diversity within G. coprotheres populations is of concern and has implications for the future management and conservation of this species.

Inbreeding and endangered species management: is New Zealand out of step with the rest of the world?

There is growing evidence that inbreeding can negatively affect small, isolated populations. This contrasts with the perception in New Zealand, where it has been claimed that native birds are less affected by inbreeding depression than threatened species from continental regions. It has been argued that New Zealand's terrestrial birds have had a long history of small population size with frequent inbreeding and that this has 'purged" deleterious alleles. The rapid recovery of many tiny and inbred populations after introduced predators have been controlled, and without input from more genetically diverse populations, has further supported the view that inbreeding is not a problem. This has led to a general neglect of inbreeding as a factor in recovery programs for highly endangered species such as the Black Robin (Petroica traversi) and Kakapo (Strigops habroptilis). We examined the reasons for this situation and review the New Zealand evidence for genetic purging. Complete purging of the genetic load and elimination of inbreeding depression are unlikely to occur in natural populations, although partial purging may be more likely where small populations have become inbred over an extended period of time, such as on small isolated islands. Recent molecular data are consistent with the view that island endemics, including New Zealand's threatened birds, have low genetic variation and hence have possibly gone through longer periods of inbreeding than threatened species from continental regions. Nevertheless, results from recent field studies in New Zealand indicate that, despite the opportunity for purging, inbreeding depression is evident in many threatened species. Although inbreeding depression has not prevented some populations from recovering from severe bottlenecks, the long-term consequences of inbreeding and small population size--the loss of genetic variation--are potentially much more insidious. The degrees to which genetic factors reduce population viability generally remain unquantified in New Zealand. Although minimizing ecological risks (e.g., preventing reinvasion of islands by mammalian predators) will continue to receive high priority in New Zealand because of their much larger impacts, we advocate that genetic considerations be better integrated into recovery plans.