Juan Manuel Pérez-García

Supplanting ecosystem services provided by scavengers raises greenhouse gas emissions

Global warming due to human-induced increments in atmospheric concentrations of greenhouse gases (GHG) is one of the most debated topics among environmentalists and politicians worldwide. In this paper we assess a novel source of GHG emissions emerged following a controversial policy decision. After the outbreak of bovine spongiform encephalopathy in Europe, the sanitary regulation required that livestock carcasses were collected from farms and transformed or destroyed in authorised plants, contradicting not only the obligations of member states to conserve scavenger species but also generating unprecedented GHG emission. However, how much of this emission could be prevented in the return to traditional and natural scenario in which scavengers freely remove livestock carcasses is largely unknown. Here we show that, in Spain (home of 95% of European vultures), supplanting the natural removal of dead extensive livestock by scavengers with carcass collection and transport to intermediate and processing plants meant the emission of 77,344 metric tons of CO2 eq. to the atmosphere per year, in addition to annual payments of ca.

Roles of raptors in a changing world: from flagships to providers of key ecosystem services

50 million to insurance companies. Thus, replacing the ecosystem services provided by scavengers has not only conservation costs, but also important and unnecessary environmental and economic costs.

Conserving outside protected areas: edge effects and avian electrocutions on the periphery of Special Protection Areas

Summary. Birds of prey have been, in comparison to other avian groups, an uncommon study model, mainly due to the limitations imposed by their conservative life strategy (low population density and turnover). Nonetheless, they have attracted a strong interest from the point of view of conservation biology because many populations have been close to extinction and because of their recognised role in ecosystems as top predators and scavengers and as flagship species. Today, after more than a century of persecution, and with the exception of some vultures still very much affected by illegal poisoning, many populations of birds of prey have experienced significant recoveries in many regions of Spain and the European Mediterranean. These changes pose new challenges when addressing the conservation of raptors in the coming decades. On this basis, and from a preferentially Mediterranean perspective, we have focused our attention on the need of describing and quantifying the role of these birds as providers of both regulating (rodent pest control and removal of livestock carcasses) and cultural ecosystem services. Moreover, we revisited persisting conflicts with human interests (predation of game species) and call attention to the emergence of new conflicts with a strong social and media component such as the predation on live cattle by vultures. Also, the rampant humanization of the environment determines the need for new solutions to the growing, yet scarcely explored, problem of accidents in new infrastructures such as mortality in wind farms. Finally, we explored in depth the ecological response of birds of prey to large-scale habitat changes such as urbanisation and abandonment of marginal lands that are also expected to increase in the near future. We urgently need more scientific knowledge to provide adequate responses to the challenge of keeping healthy populations of avian predators and scavengers in a rapidly changing world.

Spatial and temporal movements in Pyrenean bearded vultures ( Gypaetus barbatus ): Integrating movement ecology into conservation practice

Summary Electrocution on power lines is one of the principal problems facing raptors and other mediumand large-sized birds at the global scale. The recent European-based Spanish state legislation on avian electrocutions has focused on Special Protection Areas (SPA). Here we evaluate whether this policy has been successful, using the Community of Valencia, Spain, as a regional model. We compiled a database of 400 electrocution events from information on electrocuted birds taken into Wildlife Recovery Centres and incidents registered by the main local power company during the last decade. A small proportion (c.18%) of electrocution casualties occurred within SPA boundaries but the 5 km wide belt immediately surrounding the SPAs produced more than three times the number of avian electrocutions (c.60% of the total recorded). This was probably caused by higher densities of both power lines and susceptible birds, and higher use of the pylons for perching and roosting in the areas surrounding the SPAs. We therefore conclude that the focus on preventative measures being applied within SPAs is inefficient and that action should be targeted in these peripheral areas. Our results illustrate a classic problem of an edge effect associated with a protected area, where external human influences directly affect the persistence of protected species within reserves. Equally, they support the idea that management strategies within parks cannot be independent of the human activities surrounding them.

Effect of landscape configuration and habitat quality on the community structure of waterbirds using a man-made habitat

Understanding the movement of threatened species is important if we are to optimize management and conservation actions. Here, we describe the age and sex specific spatial and temporal ranging patterns of 19 bearded vultures Gypaetus barbatus tracked with GPS technology. Our findings suggest that spatial asymmetries are a consequence of breeding status and age-classes. Territorial individuals exploited home ranges of about 50 km2, while non-territorial birds used areas of around 10 000 km2 (with no seasonal differences). Mean daily movements differed between territorial (23.8 km) and non-territorial birds (46.1 km), and differences were also found between sexes in non-territorial birds. Daily maximum distances travelled per day also differed between territorial (8.2 km) and non-territorial individuals (26.5 km). Territorial females moved greater distances (12 km) than males (6.6 km). Taking into account high-use core areas (K20), Supplementary Feeding Sites (SFS) do not seem to play an important role in the use of space by bearded vultures. For non-territorial and territorial individuals, 54% and 46% of their home ranges (K90), respectively, were outside protected areas. Our findings will help develop guidelines for establishing priority areas based on spatial use, and also optimize management and conservation actions for this threatened species.

Evaluation of the network of protection areas for the feeding of scavengers in Spain: from biodiversity conservation to greenhouse gas emission savings

Species occurrence and community structure are strongly influenced by multiple factors like habitat selection, species movement capabilities, competition, or conspecific and heterospecific attractions. More specifically, in waterbird communities, previous studies have identified the importance of environmental and structural characteristics of wetlands for their occupation and use. However, the effect of the surrounding landscape configuration remains unknown. In this article, we use a large network of artificial irrigation ponds to evaluate the importance of pond features in comparison to the effect of landscape and spatial configuration on the community at three different spatial scales. Our results show that landscape configuration has relatively little influence on structure of the waterbird community. Pond features were by far the most important variables to describe waterbird abundance and richness. At the species level, we detected differences in habitat preferences relating to species-specific ecological requirements. Our results highlight the importance of using a multiscale approach to understand and predict richness and abundance in waterbird communities. Our findings emphasize the need to maintain high-quality ponds to enhance their suitability for use as breeding and foraging sites.

Safety in numbers? Supplanting data quality with fanciful models in wildlife monitoring and conservation

Summary Protected areas are one of the most common strategies for wildlife conservation worldwide. However, their effectiveness is rarely evaluated. In Europe, after the outbreak of bovine spongiform encephalopathy, a restrictive sanitary regulation (EC 1774/2002) prohibited the abandonment of dead livestock in extensive farming (extensive livestock) in the field, which led to negative consequences for scavengers. As an attempt to mitigate this negative impact, a new regulation was approved (EC 142/2011) to allow farmers to leave extensive livestock carcasses in the so-called “Protection areas for the feeding of necrophagous species of European interest” (PAFs). Our general aims were to quantify (i) the proportion of breeding distribution of targeted scavenger species overlapping PAFs; (ii) the extensive livestock carrion biomass available inside PAFs; (iii) the proportion of breeding distribution of non-targeted scavenger species falling within PAFs; (iv) the overlap between the home range of vultures and PAFs, as well as the extent to which vultures move through different administrative units; and (v) the savings in greenhouse gas (GHG) emissions in relation to the pre-PAF scenario. After assessing the status of PAF implementation in every region of peninsular Spain, we analysed the large-scale spatial information of extensive livestock carrion availability and scavenger breeding distribution, movement data of GPS-tracked vultures, and the annual GHG emissions associated with the transport of livestock carcasses. Most regions established PAFs in their territories, although design criteria were variable. The breeding distribution of targeted species was better represented within PAFs than that of non-targeted species. The extensive livestock carrion biomass potentially available for scavengers within PAFs represented 34.9% of the annual extensive livestock biomass generated in peninsular Spain. The overlap between the home range of GPS-marked vulture populations and PAFs ranged between 63.4 and 100%. The Minimum Convex Polygon of these and other GPS-tracked vulture populations in peninsular Spain encompassed 3–14 Spanish regions and 1–4 countries. Post-PAF there was a potential reduction of ca. 55.7% of GHG emissions compared to pre-PAF. Synthesis and applications. The implementation of the new sanitary regulation by means of areas for the feeding of scavengers could mean an important improvement in scavenger conservation and a noteworthy reduction of greenhouse gas emissions: in Spain, extensive livestock carrion availability might increase 33,474 t/year, and 43,344 t of CO2 eq. might be saved annually. However, we identified some gaps related to the distribution of endangered facultative scavengers. Moreover, given that vultures are highly mobile organisms, the design and management of these feeding areas should be coordinated at both the supra-regional and supra-national scales. This article is protected by copyright. All rights reserved.

Effects of Renewable Energy Production and Infrastructure on Wildlife

Ecologists and conservation biologists seem increasingly attracted to sophisticated modelling approaches, sometimes at the expense of attention to data quality and appropriateness of fieldwork design. This dissociation may lead to a loss of perspective promoting biological unrealities as conclusions, which may be used in conservation applications. We illustrate this concern by focusing on recent attempts to estimate population size of breeding birds at large scales without any explicit testing of the reliability of the predictions through comparison with direct counts. Disconnection of analysts from “nature” can lead to cases of biological unrealities such as that used here to illustrate such trends. To counter this risk, we encourage investment in well-rounded scientists or more collaborative, multi-disciplinary teams capable of integrating sophisticated analyses with in-depth knowledge of the natural history of their study subjects.

Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula

The high levels of human demands of resources—from food to space and energy—are one of the main drivers of global change and are causing large negative impacts on ecosystems functioning worldwide (Vitousek et al. 1997). Global change components range from climate change to habitat destruction, species invasions, pollution and eutrophication. Although these factors can produce ecosystem changes independently, the final descent is often driven by synergistic processes. The resulting amplifying feedbacks can be disconnected from the original driver of change, leading to a state shift in the biosphere with unexpected consequences (Barnosky et al. 2012). Climate change seems to have taken prominence over other drivers of global change, leading to larger funding and attention with respect to other major components of global change (Verissimo et al. 2014).

Wildfires as collateral effects of wildlife electrocution: An economic approach to the situation in Spain in recent years

The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo) in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70’s. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus). In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species’ demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species’ pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals on the species genetic makeup or that such signals have been eroded by the rapid demographic recovery experienced by the species in recent years.