Population dynamics of the bearded vulture Gypaetus barbatus in southern Africa

The essential features of mortality and survivorship of bearded vultures Gypaetus barbatus in southern Africa were deduced from age class plumage characteristics. The population consisted of about 204 adult pairs within a breeding range of about 35,000 sq km. Pairs bred every year and produced, on average, about 0·9 young per pair per year. Young birds made up about 37% of the population, subadults 3·5% and adults 60%. About 182 fledged young were recruited to the population each year. The proportion of young birds in the population in different areas was inversely related to the breeding density of adult birds (range 24–47%). Young bird mortality over the four years to subadult age was 87%, the survival rate of adults was 94% and the mean lifespan of birds surviving to adulthood was 21·4 years. This study demonstrates the need to understand the relationship between adult breeding density and young bird numbers in different parts of their range to accurately deduce population dynamics characteristics.     

Genetically distinct island populations of the Egyptian vulture (Neophron percnopterus)

The Egyptian vulture (Neophron percnopterus) is a species in decline throughout Europe, with the largest remaining breeding populations found in northern Spain. Iberian Peninsula populations of this species (about 1000 pairs) migrate to Africa in winter, while small populations in both the Canary and Balearic Islands (less than 40 pairs in each case) are apparently sedentary. We found that Egyptian vultures from both of these island groups were significantly differentiated from Iberian Peninsula populations (R _ST = 0.065–0.129, p = 0.000–0.007), using nine microsatellite loci isolated in a related species, the bearded vulture. The greatest degree of genetic differentiation was observed between the two island groups (R _ST = 0.279, p = 0.000). These island populations were more distinct from mainland groups than was a small sample of a well-defined separate subspecies from India (N. p. ginginianus; R _ST = 0.083–0.091, p = 0.023–0.024). This implies that these two island populations have been isolated from peninsular populations for many generations, despite the long-distance migration capabilities of the species. In constrast, populations within the Peninsula were not differentiated from one another at these microsatellite loci (R _ST = $-$0.004–0.007, p = 0.442–0.675). Introductions of Egyptian vultures from the larger northern breeding groups might therefore be appropriate in southern Spain, if necessary, but mainland birds should not be introduced to the islands if the genetic distinctiveness of these groups is to be preserved. Independent conservation plans are urgently required to protect these two island populations from extinction. This revised version was published online in July 2006 with corrections to the Cover Date.     

Isolation and characterization of 18 microsatellite loci in the Egyptian vulture (Neophron percnopterus)

We developed 18 new microsatellite loci for the endangered Egyptian vulture (Neophron percnopterus). Microsatellite loci were screened for variation in two different populations belonging to separate subspecies: the nominal N. p. percnopterus and the Canarian N. p. majorensis. Mean expected heterosygosities were respectively 0.51 and 0.46, while the mean number of alleles per locus was 4.7 and 3.9. These new markers allow further genetic studies for the endangered Canarian Egyptian Vulture.     

Phylogeography, genetic structure and diversity in the endangered bearded vulture (Gypaetus barbatus, L) as revealed by mitochondrial DNA

Bearded vulture populations in the Western Palearctic have experienced a severe decline during the last two centuries that has led to the near extinction of the species in Europe. In this study we analyse the sequence variation at the mitochondrial control region throughout the species range to infer its recent evolutionary history and to evaluate the current genetic status of the species. This study became possible through the extensive use of museum specimens to study populations now extinct. Phylogenetic analysis revealed the existence of two divergent mitochondrial lineages, lineage A occurring mainly in Western European populations and lineage B in African, Eastern European and Central Asian populations. The relative frequencies of haplotypes belonging to each lineage in the different populations show a steep East-West clinal distribution with maximal mixture of the two lineages in the Alps and Greece populations. A genealogical signature for population growth was found for lineage B, but not for lineage A; futhermore the Clade B haplotypes in western populations and clade A haplo-types in eastern populations are recently derived, as revealed by their peripheral location in median-joining haplotype networks. This phylogeographical pattern suggests allopatric differentiation of the two lineages in separate Mediterranean and African or Asian glacial refugia, followed by range expansion from the latter leading to two secondary contact suture zones in Central Europe and North Africa. High levels of among-population differentiation were observed, although these were not correlated with geographical distance. Due to the marked genetic structure, extinction of Central European populations in the last century re-sulted in the loss of a major portion of the genetic diversity of the species. We also found direct evidence for the effect of drift altering the genetic composition of the remnant Pyrenean population after the demographic bottleneck of the last century. Our results argue for the management of the species as a single population, given the apparent ecological exchangeability of extant stocks, and support the ongoing reintroduction of mixed ancestry birds in the Alps and planned reintroductions in Southern Spain.     

Rapid population declines of Egyptian vulture (Neophron percnopterus) and red-headed vulture (Sarcogyps calvus) in India

Since the early 1990s, large and rapid population declines of three species of vulture ( Gyps spp.) endemic to south Asia have occurred on the Indian subcontinent and have led to these species being listed by IUCN as critically endangered. Evidence of rates of population decline, cause of death and toxicity is consistent with these declines being caused by poisoning of vultures through the ingestion of tissues from livestock treated with the anti-inflammatory drug diclofenac. In this paper, analysis of repeated surveys in and near protected areas widely spread across India shows that populations of two other vulture species, Egyptian vulture Neophron percnopterus and red-headed vulture Sarcogyps calvus , have also declined markedly and rapidly, but probably with a later onset than Gyps vultures in the same region. The declines continued at least up to 2003. It is recommended that these two species are considered for inclusion in the IUCN Red List and for urgent remedial conservation measures. Research is needed to determine whether or not the principal cause of these declines is diclofenac poisoning and to establish population trends in other scavenging birds in the Indian subcontinent.     

Organization and variation of the mitochondrial DNA control region in five Caprinae species

The complete mitochondrial DNA (mtDNA) control region was analyzed from five species of the subfamily Caprinae; Naemorhedus caudatus, N. goral, Capra hircus, Capricornis swinhoei, and Capricornis crispus. Among these species, the control region ranged from 1,096 to 1,212 bp in length. Our results were compatible with the scheme of three domains (ETAS, Central, and CSB) within the control region. A + T < G + C was observed in all the domains. In the Korean gorals, of the 31 variable sites in the whole control region resulting in 15 haplotypes, 27 variable sites were in the ETAS domain. We found two to three tandem repeat in all five species examined in this study, three in N. caudatus and N. goral, two in Capra hircus and C. crispus, and one in C. swinhoei, respectively. All of these repeat units include two short sections of mirror symmetry (TACAT and ATGTA). Short mirror symmetries were well-resolved among five different species, although left domain has high substitution rates. By Kimura’s two parameter method, the genetic distances between the genera Naemorhedus and Capricornis were calculated and divergence time between Naemorhedus and Capricornis may be nearly 2Myr.     

Plumage colour and feather structure of the bearded vulture (Gypaetus barbatus)

The rufous colouring on the feathers of the under parts of adult bearded vultures Gypaetus barbatus , studied by scanning electron microscopy, energy-dispersive X-ray microanalysis and X-ray diffraction analysis, is caused by an external deposit of iron oxide in the ferrihydrite state. Unstained feathers, e.g. in captive birds, are pure white. The feathers of young birds have similar coatings of iron oxide to those of adults, but because the feathers are pigmented pale to dark brown (dependent on age), the rusty colour is partly or totally obscured. The intensity of the colour in adult birds varies between individuals and within individuals with time; the more worn the feathers the more iron oxide they can hold. After heavy rainfall up to 30% of adult birds can become appreciably paler. Birds take about 6 days (range–9 days) to regain normal colouring. Iron oxide accumulates mainly in the axes of shafts and barbs, barbs and barbules and barbules and hamuli, and forms blob-like deposits at the ends of barbs and barbules on the outer layers of feathers. Iron oxide is probably acquired passively when bearded vultures come into contact with deposits in caves and on ledges on cliffs. The colour is then spread by preening. Iron oxide imparts camouflage to adult birds, but also reduces wear on the outer layer of feathers, makes feathers more rigid and probably helps control ectoparasites.     

Analysis of relatedness and determination of the source of founders in the captive bearded vulture, Gypaetus barbatus, population

Genetic relatedness among founders is a vitalparameter in the management of captivepopulations as kin structure can have asignificant effect on subsequent populationstructure. Methods for inferring relatednessfrom microsatellite markers have all beendeveloped for natural populations; theirapplicability to captive populations withunknown founder origins needs thereforetesting. We used information derived from 14microsatellites in 177 individuals and Quellerand Goodnight's approach, to estimaterelatedness in the captive bearded vulturepopulation and to test the assumption ofunrelated founders. Mean relatedness of knownparent–offspring, full-sib and half-sib pairswithin the captive population were in agreementwith theoretical distributions. Pairwiserelatedness values among the founders had amean of –0.051 (SE ± 0.007) and theirdistribution did only differ marginally fromthe one found in the natural Pyreneanpopulation. A maximum likelihood approach wasused to determine the likelihood of founderpairs to be as closely related as full-sibs orparent–offspring. These results were combinedwith data from 268 bp mitochondrial DNA controlregion sequences and studbook information. Wecould exclude a close relationship among themajority of the 36 successfully reproducingfounders. Our study therefore removesmanagement concerns about hidden problems ofinbreeding and inbreeding depression. Itdemonstrates the applicability of relatednessestimates based on microsatellite allelefrequency data even in captive populations.Furthermore, we verified studbook informationon the origin of two founders from thePyrenees, and show the value of assignmenttests based on microsatellites for deducingfounder origins and their important role infuture monitoring projects.     

Breeding site selection by bearded vulture (Gypaetus barbatus) and Eurasian griffon (Gyps fulvus) in the Caucasus

Occupied and unoccupied sites of bearded vulture Gypaetus barbatus and Eurasian griffon Gyps fulvus were located in the Caucasus (mainly Georgia). Habitat variables related to nest-site characteristics, climate, terrain, human disturbance and food availability were used to construct predictive models of vulture breeding site selection by using a geographic information system (GIS), logistic regression and Bayesian statistical inference. The probability of bearded vulture occupancy of a cliff ledge that was safe from climatic adversity, human disturbance and predation was positively correlated with the following variables measured within a 20-km radius of the ledge: mean elevation, mean slope, the percentage of open areas, mean distance to roads, number of globally threatened wild goats Capra cylindricornis, C. caucasica and C. aegargus , and annual biomass of dead livestock. The probability of such a cliff ledge being occupied by Eurasian griffon was negatively correlated with annual rainfall at the ledge and positively correlated with the percentage of open areas and annual biomass of dead livestock within 20 km of the ledge. Provided that GIS coverage of the habitat variables is available, these models can be of help in various areas of the Caucasus and elsewhere to predict possible nest occurrence areas, and highlight sites where vultures may occur in the future if the population grows because of conservation or other activities.     

Supplementary feeding during the chick-rearing period is ineffective in increasing the breeding success in the bearded vulture (Gypaetus barbatus)

One of the most widespread tools in the conservation of scavenger species is the provision of supplementary food. However, scientific studies on its effectiveness have been rarely conducted. Here, we present the first results of an experimental specific supplementary feeding programme applied from hatching to 45–60 days, aimed at increasing the breeding success of an obligate brood reducer, the threatened bearded vulture Gypaetus barbatus. We tested its effectiveness in the Spanish Pyrenees, the locale of the most important population of this species in the European Union, in which a regressive trend in breeding parameters has been observed in recent years. We compared the breeding success in nests with supplementary food to non-supplemented control nests. Supplementary food did not significantly increase global breeding success (supplemented nests, 0.793 ± 0.193 chicks per pair with eggs hatched vs non-supplemented nests, 0.771 ± 0.185) or the individual breeding performance of the territories (supplemented period, 0.712 ± 0.307 vs non-supplemented period, 0.642 ± 0.311). The similar values obtained suggest that the specific supplementary feeding programme applied during the chick-rearing period is apparently ineffective at increasing breeding success. The results suggest that, at least in the study area, factors that provoke breeding failure after hatching continue to operate independently of the supplementary feeding programme. Although more research on this subject is required, these preliminary conclusions should be taken into account by managers in order to optimise the investment of economic resources and to better prioritise the future establishment of alternative conservation actions.     

Parent-offspring Conflict during the Post-fledging Period in the Egyptian Vulture Neophron percnopterus (Aves,Accipitridae)

Egyptian vultures were studied during their post-fledging dependence period in northern Spain in order to detect if there were parent-offspring and sibling tensions during the transition of young to independence. The frequency of parental feedings and the frequency of movements of the parents towards their young decreased during the post-fledging period, especially in its final part. At the same time, the frequency of movements and of aggression by the young towards their parents increased. Aggression by adults to their young was not observed. Siblings disputed feedings, but there was no other evidence for sibling conflict. The results suggest that parent-offspring and sibling conflict exists and that its development is broken by the departure of young on migration. Some behavioural traits of adults (maintenance of distance from young and of intensity of nest-defence, tolerance of young during foraging trips through the home range) do not accord with parent-offspring conflict perhaps because they are related to factors other than family tension.     

Breeding biology and success of the Bearded Vulture Gypaetus barbatus in the eastern Pyrenees

We present data from an extensive study of Bearded Vulture Gypaetus barbatus breeding biology in the Pyrenees from 1992 to 1999. Average laying date was 6 January (range 11 December to 12 February, n  = 69) with no significant differences between years. Eighty per cent of clutches were of two eggs ( n  = 20) and average incubation was 54 days (range 52–56, n  = 14). Hatching occurred on average between 21 February and 3 March (range 5 February–7 April) and the first and last chicks fledged in 21–27 May and 20 July, respectively. The average chick age at fledging was 123 days (range 103–133, n  = 20). Bearded Vulture density increased significantly during the study period. Breeding success and productivity declined apparently as a consequence of the increase in the percentage of breeding failures during incubation and chick rearing, most during the hatching period. The factors that may determine breeding failure and the decline in breeding performance are analysed and management recommendations for more effective conservation measures are discussed.     

Egyptian Vultures Neophron percnopterus and Ostrich Struthio camelus eggs: the origins of stone-throwing behaviour

Experiments were carried out on wild and hand-reared Egyptian Vultures to investigate the origins of the stone-throwing this species uses to break into Ostrich eggs. There was no evidence of cultural transmission for stone-throwing through copying experienced birds. A naïve captive-reared bird threw stones once an Ostrich egg had been linked with a food reward. The origins of aimed stone-throwing are probably related to the unaimed throwing of small eggs, since the actions are similar, and all tested birds strongly preferred to throw rounded or egg-like stones, rather than jagged ones, at Ostrich eggs.     

Generation of VNTRs and heteroplasmy by sequence turnover in the mitochondrial control region of two elephant seal species

We describe an unusual repetitive DNA region located in the 3′ end of the light (L)-strand in the mitochondrial control region of two elephant seal species. The array of tandem repeats shows both VNTR (variable-number tandem repeat) and sequence variation and is absent from 12 compared mammalian species, except for the occurrence in the same location of a distinct repetitive region in rabbit mtDNA and a similar repeat in the harbor seal. The sequence composition and arrangement of the repeats differ considerably between the northern elephant seal (Mirounga angustirostris) and the southern species (M. leonina) despite an estimated divergence time of 1 MY (based on an mtDNA-RNA gene and the nonrepetitive control region). Analysis of repeat sequence relationships within and between species indicate that divergence in sequence and structure of repeats has involved both slippagelike and unequal crossingover processes of turnover, generating very high levels of divergence and heteroplasmy. Presented at the NATO Advanced Research Workshop onGenome Organization and Evolution, Spetsai, Greece, 16–22 September 1992     

First cases of polygyny for the Bearded Vulture Gypaetus barbatus in the central Pyrenees

We report the first cases of polygyny for the Bearded Vulture Gypaetus barbatus in the central Pyrenees, Spain. Although polyandry is frequent in the study area (31.8% of all reproductive units in 2016), we only observed the occurrence of three cases of polygyny over the period 1994–2017. Polygyny in Bearded Vultures is possibly a consequence of habitat saturation.     

Breeding behaviour of the Bearded Vulture Gypaetus barbatus: minimal sexual differences in parental activities

Monogamous biparental care is expected to occur when opportunities for extra-pair copulations are rare, and both parents are required to raise the chick. Bearded Vultures Gypaetus barbatus fulfill these conditions. Contributions by male and female Bearded Vulture to nest building, nest defence, incubation, nest attendance and chick feeding were studied over five years in eight pairs from the Pyrenees [Catalonia, northeast Spain). Overall, the sexes show equal investment, although the degree of parental effort developed differs depending on the specific activities. During pre-laying, males were significantly more active than females in supplying material to the nest and in territorial defence behaviour, which increased (in both sexes) as the season advanced. Incubation was shared equally both by day and by night. During chick-rearing, the nest was attended by both sexes and the presence of both parents at the nest decreased in parallel with the growth of the chick. Activities related to chick feeding were also equally divided. These results are discussed in the context of female selection of mates and the particular ecology of this species.     

Structure,DNA sequence variation and phylogenetic implications of the mitochondrial control region in horseshoe bats

There have been few studies of the structural and evolutionary characteristics of the mitochondrial control region (CR) in rhinolophids, yet this could have important consequences for the interpretation of phylogenetic relationships within this group. Here we sequenced and analyzed the CR of 37 individuals from 12 Rhinolophus species, including 2 species from GenBank. The length of the CR ranged from 1335 to 1514 bp, and the base composition was very similar among species. The CR of horseshoe bats, like that of other mammals, could be subdivided into a central conserved domain (CD) and two flanking variable domains, extended termination associated sequences (ETAS), and conserved sequence blocks (CSB). Besides the common conserved blocks (ETAS1, ETAS2, F-B boxes, CSB1, CSB2 and CSB3) found in 3 domains, an ETAS2-like and a CSB1-like element were also detected in the ETAS and CSB domains, respectively, in all individuals. Notwithstanding a short tandem repeat (11 or 13 bp) between CSB1 and CSB2 in all specimens, the base composition, copy number and arrays are all variable. A long tandem repeat (79 bp) was only identified in the ETAS domain in one individual of R. pusillus. Phylogenetic reconstructions based on the CR sequences indicated that the molecular phylogenetic relationships among some Rhinolophus species were inconsistent with the results of phenetic analyses, but similar to phylogenetic constructions using cytochrome b. An unidentified species R. sp and 3 species from the philippinensis-group that were clearly morphologically different comprised a monophyletic group, which could have resulted from morphological independent evolution.