Time filter

Source Type

Margalida A.,Bearded Vulture Study and Protection Group
European Journal of Wildlife Research | Year: 2010

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. © 2010 Springer-Verlag.

Hernandez M.,Laboratorio Forense Of Vida Silvestre | Margalida A.,Bearded Vulture Study and Protection Group
Journal of Wildlife Diseases | Year: 2010

Normal hematologic and blood chemistry values for clinical use and age-related changes are reported as reference values for the endangered Bearded Vulture (Gypaetus barbatus). Blood samples were obtained from 21 nestlings and 26 free-living subadults and adults. No significant differences were found between subadults and adults or between sexes for any of the studied parameters. Reference ranges have been established for Bearded Vulture nestlings (less than 3 mo of age) and for free-living Bearded Vultures, with subadult and adult data combined without affecting clinical interpretation, Some reference values for the parameters reported in this study are similar to those previously described for vultures and other raptor species, although creatine Phosphokinase and lactate dehydrogenase activities were higher than those reported for birds ofprey. Significant age-related differences were identified in urea, uric acid, triglycerides, total serum protein, inorganic phosphorus, and magnesium concentrations, as well as aspartate aminotransferase, creatine Phosphokinase, lactate dehydrogenase, alkaline phosphatase, amylase, and lipase activities (P<0.05). Additionally, significant age-related differences were noted in red and white blood cell counts, packed cell volume, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, fibrinogen level, and heterophils, lymphocytes, and eosinophils (P<0.005). The results obtained from this study provide reference ranges that will be useful for evaluating the pathologic conditions and general health of Bearded Vulture populations and reveal the existence of important agerelated differences in the species. © Wildlife Disease Association 2010.

Margalida A.,University of Bern | Margalida A.,Bearded Vulture Study and Protection Group | Carrete M.,Pablo De Olavide University | Hegglin D.,Stiftung Pro Bartgeier | And 3 more authors.
PLoS ONE | Year: 2013

After the quasi-extinction of much of the European vertebrate megafauna during the last few centuries, many reintroduction projects seek to restore decimated populations. However, the future of numerous species depends on the management scenarios of metapopulations where the flow of individuals can be critical to ensure their viability. This is the case of the bearded vulture Gypaetus barbatus, an Old World, large body-sized and long-lived scavenger living in mountain ranges. Although persecution in Western Europe restrained it to the Pyrenees, the species is nowadays present in other mountains thanks to reintroduction projects. We examined the movement patterns of pre-adult non-breeding individuals born in the wild population of the Pyrenees (n = 9) and in the reintroduced populations of the Alps (n = 24) and Andalusia (n = 13). Most birds were equipped with GPS-GSM radio transmitters, which allowed accurate determination of individual dispersal patterns. Two estimators were considered: i) step length (i.e., the distance travelled per day by each individual, calculated considering only successive days); and ii) total dispersal distance (i.e., the distance travelled between each mean daily location and the point of release). Both dispersal estimators showed a positive relationship with age but were also highly dependent on the source population, birds in Andalusia and Alps moving farther than in Pyrenees. Future research should confirm if differences in dispersal distances are the rule, in which case the dynamics of future populations would be strongly influenced. In summary, our findings highlight that inter-population differences can affect the flow of individuals among patches (a key aspect to ensure the viability of the European metapopulation of the endangered bearded vulture), and thus should be taken into account when planning reintroduction programs. This result also raises questions about whether similar scenarios may occur in other restoration projects of European megafauna. © 2013 Margalida et al.

Margalida A.,Bearded Vulture Study and Protection Group | Margalida A.,University of Bern | Benitez J.R.,Linea de Geodiversidad y Biodiversidad | Sanchez-Zapata J.A.,University Miguel Hernandez | And 3 more authors.
Ibis | Year: 2012

Between 2000 and 2009 we studied the diet and breeding success of Egyptian Vultures Neophron percnopterus in southern Spain. Wild species accounted for 74.9% of prey items (n=1071) with a predominance of mammals (62.3%), followed by birds (20.8%) and reptiles (13.1%). Spatially, the diet was highly varied and not restricted to carcasses of livestock; wild Rabbits Oryctolagus cuniculus accounted for 54% of the overall remains. The spatial variability may reflect regional and local disparity in the availability of main prey. The temporal relationship between variation in trophic diversity and Vulture nesting productivity (both values showing a long-term decrease) might suggest a causal link between variation in diet and reproductive output. We hypothesize that high turnover rates could explain productivity variation as a consequence of the recruitment of less experienced individuals to the breeding population. This could in turn generate covariation between diet and reproductive output. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union.

Margalida A.,Bearded Vulture Study and Protection Group | Donazar J.A.,CSIC - Donana Biological Station | Carrete M.,CSIC - Donana Biological Station | Carrete M.,Pablo De Olavide University | Sanchez-Zapata J.A.,University Miguel Hernandez
Journal of Applied Ecology | Year: 2010

Between 1996 and 2000 the appearance of bovine spongiform encephalopathy swiftly became one of the most serious public health and political crises concerning food safety ever experienced in the European Union (EU). Subsequent sanitary regulations led to profound changes in the management of livestock carcasses (i.e. the industrial destruction of around 80% of all animal carcasses), thereby threatening the last remaining healthy scavenger populations of the Old World and thus contradicting the long-term environmental policies of the EU.2. Several warning signs such as a decrease in breeding success, an apparent increase in mortality in young age classes of vultures and an increase in the number of cases of vultures attacking and killing cattle, as well as a halt in population growth, suggest that the decrease in the availability of food resources has had harmful effects on vulture populations.3. Between 2002 and 2005, a number of dispositions to the EU regulations (2003/322/CE 2005/830/CE) enabled conservation managers to adopt rapid solutions (i.e. the creation of vulture restaurants) aimed at satisfying the food requirements of vultures. However, these conservation measures may seriously modify habitat quality and have indirect detrimental effects on avian scavenger populations and communities.4. Synthesis and applications. Conservation managers and policy-makers need to balance the demands of public health protection and the long-term conservation of biodiversity. The regulations concerning carrion provisioning need to be more flexible and there needs to be greater compatibility between sanitary and environmental policies. We advocate policies that authorize the abandonment of livestock carcasses and favours populations of wild herbivores to help to maintain populations of avian scavengers. Conservation strategies should be incorporated into new European Commission regulations, which should be effective in 2011. © 2010 The Authors. Journal compilation © 2010 British Ecological Society.

Discover hidden collaborations