Conservation Biology Group

Threats and solutions

Published an article in the journal Bird Conservation International about the demographic evolution of the Egyptian vulture in Catalonia

A new study about the increasing population of the Egyptian vulture in Catalonia entitled "Identifying key demographic parameters for the viability of a growing population of the endangered Egyptian Vulture Neophron percnopterus" has been published in the journal Bird Conservation International. The paper explains the growth experienced by the population of this species in Catalonia and also it is carried out an Analysis of the Viability of the species to make predictions of the conservation status of the population in the future.

The Egyptian vulture population in central and eastern Catalonia has increased from 1 to 22 pairs during the period 1988-2012, and today is still growing. To explain this population increase, a series of models based on different demographic parameters (population growth rate, survival and productivity) have been designed to simulate various scenarios that could have happened in the last 20 years. One of the main conclusions of the models is that to explain the population observed growth rate, survival of adult individuals in our population should be higher than adult survival of individuals from other parts of the Iberian Peninsula (specifically the Ebro valley).

Adult Egyptian vulture in flight. Photo: Kiku Parés (Conservation Biology Group of the UB)

One possible explanation for this high adult survival would be that in our area the use of poisons is lower than in other areas of the peninsula, where poisoning is the main cause of unnatural mortality of adult individuals. However, the models also suggest that the arrival of individuals from other populations could contributed to the demographic increase, since a high adult survival is not enough to explain the population growth experienced in recent years.

Moreover, a Population Viability Analysis was carried out to predict the future of the Egyptian vulture in Catalonia under different scenarios. This analysis establishes that if conditions do not change and vital parameters of the population remain, all scenarios predict that the population will maintained or continue to grow, depending on whether immigrants are still arriving to the population or do-leave it.

This positive trend of the population of eastern Catalonia is an exception to the overall situation of the Egyptian vulture, a species classified as 'endangered' by the IUCN for its declining in a wide part of its range. For this reason, it is important to highlight that although the actual situation of the population is favorable is still susceptible and any change could cause a population decline again.

This study was carried out by the Conservation Biology Group (Joan Real, Antonio Hernández-Matías and Helena Tauler) together with expert naturalists from “Grup de Naturalistes d’Osona” (Jordi Baucells and Carles Martorell) and from Berguedà and Solsonès (Per Aymerich and Joan Santandreu).

Evolution of the number of occupied territories of Egyptian vulture in central and eastern Catalonia during 1988-2012. Source: Tauler et al., 2015

Thanks to the rest of naturalists that provided information for the study (S. Arís, J. Arrey, E. Bassols, M. Batriu, J. Bosch, J. Calaf, J. Faus, J. Fort, J. Garcia Petit, J. Gracia, P. Isern, G. Lampreave, T. Mampel, D. Mañas, J. Montserrat, A. Miño, F. Parés and A. Peris), to the Natural Parcs and institutions that participated (“Parc Natural de Montserrat”, “Parc Natural de Sant Llorenç de Munt”, “Parc Natural de la Zona Volcànica de la Garrotxa”, “Consorci dels Espais Naturals del Ripollès”), as well as the “Institut Català d’Ornitologia” to make avaliable its data base Thank to “Red Eléctrica de España” the support received and especially to Mercedes Gil Pozo her interest on the monitoring and the development of the project. Helena Tauler was supported by a predoctoral grant IRBIO-UB (APIF 2014).

For further information:
  • Tauler, H., Real, J., Hernández-Matías, A., Aymerich, P., Baucells, J., Martorell, C. & Santandreu, J. 2015. Identifying key demographicparameters for the viability of a growing population of the endangered Egyptian Vulture Neophron percnopterus. Bird Conservation International, doi:10.1017/S0959270914000392 pdf