15.8 Concluding Remarks
Scientists and managers generally work at different timescales (Linklater 2003).
Managers often need to respond quickly to immediate problems, whereas scientists
can sometimes take years to generate appropriate information. This is the case of
the bearded vulture in the Pyrenees, a species at which administrations invested
substantial economic and human resources in recovering their populations. As our
results show, long-term studies are necessary to identify conservation problems, to
understand demographic changes on populations and priorities to apply conservation measures. Thanks to the long-term studies, we identified a saturation in the
region of optimal habitat for the species, reflected in negative density-dependent
effects on fecundity (Carrete et al. 2006a), the lack of recolonization and expansion
beyond the current range of new territories (Margalida et al. 2008a) and the increase
in polyandrous trios (Carrete et al. 2006b). Also, supplementary feeding sites
(SFS) can have detrimental effects on fecundity (Carrete et al. 2006a), despite
increasing pre-adult survival (Oro et al. 2008; Margalida et al. 2014b). Thus, as a
management action, SFS should be moved into peripheral areas. In this sense, the
recent network of protection areas for the feeding of necrophagous species of
European interest (PAFs) suggests that these areas may be more efficient for
breeders than for floaters, whose home ranges can be considerably larger
(Margalida et al. 2016; Morales-Reyes et al. 2017). In the case of bearded vultures,
the overlap of core areas (k50%) of breeders with PAFs reached 90.6%, while the
overlap was only 64.2% for floaters (Morales-Reyes et al. 2017). The long-term
monitoring has revealed how illegal poisoning, the most important non-natural
mortality factor (Margalida 2012), is increasing over time and the demographic
simulations suggest a regressive scenario in population dynamics if this factor is not
eliminated (Oro et al. 2008). Anthropogenic activities through human health regulations that affect habitat quality can also suddenly modify demographic parameters (Margalida et al. 2014c). Our findings suggest a delay in laying dates and a
regressive trend in clutch size, breeding success and survival following the policy
change. Finally, the recent approved veterinary use of diclofenac in Spain
(Margalida et al. 2014c) can threaten the scavenger guild community. This new risk
requires a programme of monitoring of non-steroidal anti-inflammatory drug contamination of ungulate carcases available to vultures and of moribund and dead
obligate and facultative avian scavengers would be needed to be confident that a
damaging level of contamination is not present (Green et al. 2016). The ecosystem
services provided by vultures (Moleón et al. 2014; Morales-Reyes et al. 2015) and
the conservation of biodiversity implies that managers and policy-makers need to
balance the demands of public health protection and the long-term conservation of
biodiversity.
Acknowledgements Thanks to the coauthors of different papers in which this chapter has been
based: J. Bustamante, M. Carrete, J.A. Donázar, R. Heredia, F.J. Hernández, M.A. Colomer,
D. Oro and M. Romero-Pujante. To Generalitat de Catalunya and Ministry of Environment for the
continuous support funding this research. Special thanks to J. Bertran, D. García, R. Heredia,
15 Importance of Long-Term Studies to Conservation …
375
Scientists and managers generally work at different timescales (Linklater 2003).
Managers often need to respond quickly to immediate problems, whereas scientists
can sometimes take years to generate appropriate information. This is the case of
the bearded vulture in the Pyrenees, a species at which administrations invested
substantial economic and human resources in recovering their populations. As our
results show, long-term studies are necessary to identify conservation problems, to
understand demographic changes on populations and priorities to apply conservation measures. Thanks to the long-term studies, we identified a saturation in the
region of optimal habitat for the species, reflected in negative density-dependent
effects on fecundity (Carrete et al. 2006a), the lack of recolonization and expansion
beyond the current range of new territories (Margalida et al. 2008a) and the increase
in polyandrous trios (Carrete et al. 2006b). Also, supplementary feeding sites
(SFS) can have detrimental effects on fecundity (Carrete et al. 2006a), despite
increasing pre-adult survival (Oro et al. 2008; Margalida et al. 2014b). Thus, as a
management action, SFS should be moved into peripheral areas. In this sense, the
recent network of protection areas for the feeding of necrophagous species of
European interest (PAFs) suggests that these areas may be more efficient for
breeders than for floaters, whose home ranges can be considerably larger
(Margalida et al. 2016; Morales-Reyes et al. 2017). In the case of bearded vultures,
the overlap of core areas (k50%) of breeders with PAFs reached 90.6%, while the
overlap was only 64.2% for floaters (Morales-Reyes et al. 2017). The long-term
monitoring has revealed how illegal poisoning, the most important non-natural
mortality factor (Margalida 2012), is increasing over time and the demographic
simulations suggest a regressive scenario in population dynamics if this factor is not
eliminated (Oro et al. 2008). Anthropogenic activities through human health regulations that affect habitat quality can also suddenly modify demographic parameters (Margalida et al. 2014c). Our findings suggest a delay in laying dates and a
regressive trend in clutch size, breeding success and survival following the policy
change. Finally, the recent approved veterinary use of diclofenac in Spain
(Margalida et al. 2014c) can threaten the scavenger guild community. This new risk
requires a programme of monitoring of non-steroidal anti-inflammatory drug contamination of ungulate carcases available to vultures and of moribund and dead
obligate and facultative avian scavengers would be needed to be confident that a
damaging level of contamination is not present (Green et al. 2016). The ecosystem
services provided by vultures (Moleón et al. 2014; Morales-Reyes et al. 2015) and
the conservation of biodiversity implies that managers and policy-makers need to
balance the demands of public health protection and the long-term conservation of
biodiversity.
Acknowledgements Thanks to the coauthors of different papers in which this chapter has been
based: J. Bustamante, M. Carrete, J.A. Donázar, R. Heredia, F.J. Hernández, M.A. Colomer,
D. Oro and M. Romero-Pujante. To Generalitat de Catalunya and Ministry of Environment for the
continuous support funding this research. Special thanks to J. Bertran, D. García, R. Heredia,
15 Importance of Long-Term Studies to Conservation …
375