Importance of Long-Term Studies to Conservation Practice: The Case of the Bearded Vulture in the Pyrenees

Abstract

Detailed, long-term scientific studies are necessary for conservation purposes, but with the main handicap to have the continual economic support required for them. Behavioural and conservation biology studies need long-term projects to achieve robust data, but managers, administrations and policy-makers need, in most cases, immediate results. Here I show several examples of the research obtained from a long-term study in one of the most threatened species in Pyrenean mountains, the bearded vulture (Gypaetus barbatus), highlighting the importance of such long-term research. The results show how long-term studies are necessary to identify conservation problems, to understand demographic changes on populations and priorities to apply conservation measures. The study's findings allowed the identification of the negative density-dependent effects on fecundity, the lack of recolonization of new territories outside the current distribution area and the increase in polyandrous trios, suggesting an initial optimal habitat saturation. From a management point of view, the studies show that supplementary feeding sites (SFS) can have detrimental effects on fecundity but increases pre-adult survival. Also, illegal poisoning is increasing, and the demographic simulations suggest a regressive scenario in population dynamics if this factor is not eliminated. More recently, anthropogenic activities through human health regulations that affect habitat quality can suddenly modify demographic parameters. The results obtained about changes in nest-site selection, mating system and demographic parameters can only be achieved through long-term studies, A. Margalida

The role of age of first breeding in modeling raptor reintroductions

“…It is well known that density dependence affects several relevant parameters in population dynamics (Ferrer & Donazar, 1996), including mortality which increases when density increases (e.g., through increasing rates of territorial disputes and fighting among breeders or increasing juvenile starvation), productivity which increases when density decreases, and age of first breeding which decreases when density decreases (Ferrer & Bisson, 2003;Morandini, Benito, Newton, & Ferrer, 2017;Newton, 1998). Variation in productivity is usually included in simulation models but variation in the age of first breeding is largely ignored in PVAs (Antor et al, 2007;Bretagnolle, Inchausti, Seguin, & Thibault, 2004;Evans et al, 2009;Margalida, 2017;Margalida, Colomer, Oro, Arlettaz, & Donázar, 2015;Naveda-Rodríguez, Vargas, Kohn, & Zapata-Ríos, 2016;Radovic & Mikuska, 2009). Nevertheless, in most reintroduction programs a lower than expected age of first breeding was reported (Evans et al, 1999(Evans et al, , 2009Muriel, Ferrer, Casado, Madero, & Calabiug, 2011;Muriel, Ferrer, Casado, & Pérez Calabuig, 2010;Sarrazin, Bagnolinp, Pinna, & Danchin, 1996;Woods et al, 2007) showing that age of first breeding decreases as predicted in a low-density situation.…”

“…In this way, we are greatly overestimating the extinction risk. Unfortunately, this seems to be the prevalent practice in most of the published papers on this topic taking age of first breeding is a fixed value typical of populations at medium to high density (Antor et al, 2007;Bretagnolle et al, 2004;Evans et al, 2009;Margalida, 2017;Margalida et al, 2015;Naveda-Rodríguez et al, 2016;Radovic & Mikuska, 2009).…”

The High Mountain Conservation in a Changing World

“…They attain a high symbolic value both for the scientific community and the population in general. Correct management of these species requires accurate knowledge of their behaviour that needs to be based on long-term research plans (Margalida 2017). Nature reserves are the appropriate scenario for sustaining this type of studies.…”

A decade of proboscis monkey (Nasalis larvatus) population monitoring in Balikpapan Bay: Confronting predictions with empirical data

“…Over the last few decades, it has been shown that longer‐term studies of wildlife populations are of increasing scientific and conservation management importance (Kappeler et al, 2012; Margalida, 2017; Pelton & Van Manen, 1996). This is particularly true of taxa with long life spans such as many species of primates, which require several years of research to adequately document their life histories (Chapman et al, 2017).…”