Miguel Ferrer

Spanish National Research Council | CSIC · Department of Ethology and Biodiversity Conservation

Studies on normal concentration of blood constituents of free-living birds are not very common. An adequate knowledge of blood chemistry is greatly recommended for those projects involving research and management of populations as far as they can be valuable for the assessment of the nutritional levels and health status of species. No previous publ...

Birds of prey frequently feature in reintroductions and the hacking technique is typically used. Hacking involves removing large nestlings from donor populations, transferring them to captivity, feeding them ad libitum. Potentially, via the hacking method, the stress of captivity and disruption of parental feeding may be detrimental. Alternatively,...

Energy infrastructure is expanding at a global scale and can represent a major threat to wildlife populations. Power lines are one of the main sources of human-induced avian mortality due to electrocution or collision, but many species use electricity pylons as a structure for nesting. Pylon nesting results in human-wildlife conflict because it can...

As mentioned in previous chapters, electrocution can occur in two ways: by contact between two conductors or, more frequently, by contact between a conductor and an earthed metallic structure (the crossarm itself or a ground wire), and birds are among the groups most seriously affected (Figures 88 and 89). Given the distance between supports, the s...

Calls for urgent action to conserve biodiversity under global change are increasing, and conservation of migratory species in this context poses special challenges. In the last two decades the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has provided a framework for several subsidiary instruments including action plans...

Birds of prey frequently feature in reintroductions and the hacking technique is typically used. Hacking involves removing large nestlings from donor populations, transferring them to captivity, feeding them ad libitum. Potentially, via the hacking method, stress of captivity and disruption of parental feeding may be detrimental. Alternatively, pro...

Avian mortality is one of the most negative impacts of wind energy. Consequently, techniques that effectively reduce avian collision rates are necessary. One of such method is the stop-turbine system, otherwise known as a Turbine Shutdown System (TSS). Here, we analyzed changes in mortality during 15 years, starting two years before the application...

The spatial variation in the strength of climate change may lead to different impacts on migratory birds using different breeding areas across a region. We used a long-term data series of White Stork ring recoveries to study the temporal and spatial variation of annual survival rates of White Stork across western Europe between 1960 and 2009 in rel...

Metalliferous mining, a major source of metals and metalloids, has severe potential environmental impacts. However, the number of papers published in international peer-reviewed journals seems to be low regarding its effects in terrestrial wildlife. To the best of our knowledge, our review is the first on this topic. We used 186 studies published i...

Parent–offspring conflict theory predicts that offspring seek to prolong the parental care period, while parents strive to shorten it as much as possible. Transition to the crèche phase in penguins involves changes in the dynamic of parental investment in chicks, and thus may be modulated by interests that benefit parent or offspring. We explored p...

Physiology can either be a product of or affect the behavior and ecology of individual animals. Blood plasma chemistry contains many components that are indicative of several aspects of a bird’s physiological state at the time of sampling. Plasma chemistry is routinely used in clinical settings. However, despite its potential application in ecologi...

Currently, there is a demand for more energy-efficient lighting sources, however, light emitted by different lighting systems differs in primary properties such as intensity, propagation direction, and wavelength spectrum, among others, and these properties may affect insect light attraction. Despite the energetic benefits of light-emitting diodes...

Historical variations (1966-2016) in the exposure to inorganic elements in raptors of South West Spain have been little studied. Therefore, uncertainty exists concerning whether environmental or anthropogenic inputs, as well as dietary strategy shift, may cause changes in exposure patterns. To address this gap, essential and non-essential inorganic...

Mixed-species colonies occur frequently, especially among seabirds, and may provide mutual benefits among associated species including antipredator advantages. The "protector" species in such associations may provide early warning signals or by aggressively defending their own nests, may expel predators from the area. We explored costs and benefits...

The most common ecological response to climate change is the shifts in species distribution ranges. Nevertheless, landscape fragmentation compromises the ability of limited dispersal species to move following these climate changes. Building connected environments that enable species to track climate changes is an ultimate goal for biodiversity cons...

Following the identification of three locations in Iran where over 24 bird-power line collision fatalities had been recorded, involving two globally Vulnerable species, bird diverters were installed. Initial results have been very encouraging, with no fatalities recorded after installation. The fitting of these relatively low-cost devices, combined...

Avian electrocutions are a global conservation problem. Power outages associated with electrocutions are problematic for electric utilities focused on delivering reliable electric power. We used contextual data, photographs, line voltage, outage type and assessments of power line components to quantify outage-causing avian electrocutions throughout...

The depopulation of rural areas by humans had marked ecological consequences on wildlife in southern Europe, which became evident fifteen years ago. Shrub and tree encroachment, and the expansion of forest birds and of the formerly persecuted mammalian ungulates and carnivores, were highlighted as the major consequences of the rural exodus in Italy...

We suggest that raptors facultatively capable of nesting either on cliffs or trees are commonly found nesting on cliffs not because of preference or scarcity of trees but rather because of intense human persecution in the past. We show that both golden and Bonelli's eagles are increasingly nesting on trees in Spain (in parallel with the low levels...

In long‐lived species, usually with deferred maturity and low release numbers, the success of conservation translocations is especially sensitive to survival and site fidelity during the prolonged establishment phase. Concurrent management actions usually implemented in threatened populations may also influence translocation‐related responses. Ther...

Natal sex‐ratio variation is a central concept in population demography. When males and females are equally costly to rear, the population sex ratio should be 1:1, but if they differ in cost, more of the cheaper sex should be produced. According the Age Dependent Sex Ratio Hypothesis, younger breeders should produce more chicks of the cheaper sex....

Bird diverter devices were developed to improve power line visibility for birds and reduce their risk of collision. However, differences in efficacy between types of devices, and in some cases conflicting results, place in question the ability of these devices to reduce collision risk to birds. Here, we investigated the efficacy of three types of f...

Mining is responsible of releasing trace elements to the environment with potential negative effects on wildlife. Traditionally, wildlife exposure assessment has been developed by analyzing mainly environmental compartments or internal tissues. Nowadays, the use of non-destructive matrices such as hair or feathers has increased. Nevertheless, its u...

The Spanish Imperial Eagle (Aquila adalberti) disappeared from Africa as a breeding species in the 1960s coincident with a general decline of their populations in the Iberian Peninsula. Because of a combination of successful conservation actions and a general change in human attitudes, the Spanish Imperial Eagle population has been increasing in Ib...

An increasing number of wildlife-vehicle collisions occur each year worldwide, which involves extensive economic costs and constitutes one of the main anthropogenic causes of animal mortality. Because of this, there is an urgent need to identify the factors leading to collision hotspots and thus implementing effective mitigation measures. By using...

Here, we provide evidence that the number of Western European ospreys wintering in the Iberian Peninsula has been increasing over nearly two decades due to a reduction of the migration distances. We compared trends in wintering and breeding populations of ospreys in the Iberian Peninsula and western Europe, respectively, and we provide a detailed d...

The aim of this study was to estimate global population trends of abundance of two endemic migratory seabird species breeding in the Mediterranean Sea, Balearic and Scopoli's shearwaters, from migration counts at the Strait of Gibraltar. Specifically, we assessed how regional environmental conditions (i.e. sea surface temperature, chlorophyll a con...

An increasing number of wildlife-vehicle collisions occur each year worldwide, which involves extensive economic costs and constitutes one of the main anthropogenic causes of animal mortality. Because of this, there is an urgent need to identify the factors leading to collision hotspots and thus implementing effective mitigation measures. By using...

With recent increases in the numbers of reintroduction projects, it has become crucial to know the main factors that allow colonization of new areas and prevent the extinction of small and reintroduced populations. Dispersal is one of the most important phenomena in population biology with consequences to the proportion of individuals that keep bre...

We used biochemical analyses of blood to quantify nutritional status and a standardized test to measure the response to a novel object (bold-shy test). Our aim was to examine the relationship between nutritional status and behavioral responses in nestlings of Black-browed albatrosses (Thalassarche melanophrys). A total of 66 nestlings from Saunders...

The tick Ixodes uriae is an ectoparasite widely distributed among seabirds throughout circumpolar regions, usually associated with seabird colonies. Nevertheless, potential effects of infestations, especially in chicks, are not well documented. In this article, we studied factors associated with probability and intensity of infestations in Black-br...

• The present biodiversity crisis has led to an increasing number of reintroduction programs, and this conservation method is likely to be increasingly used in the future, especially in the face of climate change. Many fundamental questions in population ecology are focused on the mechanisms through which populations escape extinction. • Population...

Hematological studies concerned with the determination of normal values of blood parameters in animals have been increasing. However, studies on normal concentration of blood constituents of free-living birds still are not very common, and less than 5% of the species of birds have been analyzed, mostly in captivity. Avian hematology has been used i...

Animal-vehicle collisions have become a serious traffic safety issue. Collisions have steadily increased over the last few decades, as have their associated socio-economic costs. Here, we explore the spatial and temporal patterns of animal-vehicle collisions reported to authorities in the province of Seville, southern Spain. Most animal-vehicle col...

Species involved in animal-vehicle collisions reported to authorities in the province of Seville (Spain) in the years 2014 and 2015. Collision data were provided by the Provincial Directorate of Traffic of Seville (DGT). (PDF)

Distribution of dog-vehicle collisions in Andalusia. Collisions are shown in relation to (a) the month and (b) night-light levels used as a proxy of the distance to urban areas (see main text for further details). Black color indicates points without night-light whereas white color shows points with the highest night-light levels. The inset map ind...

This is work I presented at the 3rd International Congress on Bird Migration and Global Change, the results of which we described in Ardea.

Power lines are one of the mortality factors of mammals. There are some records of electrocuted large mammals such as elephants and leopards in India, deer and cougars in the USA. In this paper, we report some records of electrocuted mammals in Iran. In March 2015, two striped hyenas, Hyaena hyaena (Linnaeus, 1758) and three red foxes Vulpes vulpes...

Magnitude, composition and spatiotemporal patterns of vertebrate roadkill at regional scales: a study in southern Spain. Although roadkill studies on a large scale are challenging, they can provide valuable information to assess the impact of road traffic on animal populations. Over 22 months (between July 2009–June 2010, and April 2011–March 2012)...

Western Osprey was extinct in Portugal, mainland Spain and Turkey in the 1990s. In the Mediterranean region only a few small breeding populations (about 100 breeding pairs). After divers projects a reintroduction than 20 pairs now breed in Spain. Ospreys breeding in Europe mainly winter in sub-Saharan Africa, except for some individuals, whose numb...

Collision with turbines at wind farms is expected to have a greater impact on birds at particular sites where high concentrations of individuals occur, such as migration bottleneck areas. The Strait of Gibraltar (southern Spain) has long been recognized as the most important bottleneck in western Europe for soaring bird migration. Moreover, this ar...

The global potential for wind power generation is vast, and the number of installations is increasing rapidly. We review case studies from around the world of the effects on raptors of wind-energy development. Collision mortality, displacement, and habitat loss have the potential to cause population-level effects, especially for species that are ra...

In this chapter, we present the results of several flight campaigns carried out in 2015 and 2016 using multirotor Unmanned Airborne Vehicles (UAVs) over Slender-billed Gull (Chroicocephalus genei) colonies in the Doñana Nature Space, south west Spain. The images were taken at different times during the breeding season. The requirements for the flig...

The Osprey (Pandion haliaetus) is an emblematic example of conservation. Currently, the species is progressively recovering in population size and range after dramatic reductions as a consequence of human persecution and the use of pesticides in the nineteenth and twentieth centuries. Here, we analysed the population trend and productivity in relat...

Supplementary feeding is a common practice to raise reproductive output in raptors and other species; nevertheless, its application in conservation has only recently been discussed critically. Here, we analyse the effect of supplementary feeding in territorial raptors, taking advantage of two long-term datasets for the Spanish imperial eagle (Aquil...

Effects of natural and artificial light on the nocturnal behaviour of the wall gecko. In the present study, we evaluated the effects of nocturnal light level (i.e. lunar phase and artificial lighting) on the activity of wall geckos (Tarentola mauritanica) of different ages in an anthropic environment. Data on individual behaviour were collected by...

Blood chemical reference values and variations in them in long-lived endangered birds are of metabolic, veterinary, ecological and/or taxonomic interest. In the present study, we for the first time provide such reference values and test the influence of sex, age, and nest location on up to 11 plasma values in nesting black-browed albatrosses (Thala...

We investigated juvenile dispersal strategy of a territorial long-lived species with deferred maturity, the Spanish imperial eagle, Aquila adalberti. Here we used a reintroduction programme as an experimental approach to test separately predictions of the two hypotheses about natal philopatry: social attraction and local experience. We determined t...

We investigated the distribution of juvenile dispersal distances of a territorial long-lived species with deferred maturity, the Spanish imperial eagle (Aquila adalberti). Here we used a reintroduction program as an experimental approach to test predictions of different hypotheses about the distribution of juvenile dispersal distances: competition...

Capsule: In Black-browed Albatrosses Thalassarche melanophris nutritional condition is correlated between parents and their offspring. Aims: To test resource allocation hypotheses analysing the relationship between parental and offspring nutritional condition. Methods: We measured blood chemistry parameters related with nutritional condition in 24...

The aim of this study was to assess the exposure and potential effects of the toxic elements released by the Aznalcollar spillage on the fecundity of the booted eagle (Hieraetus pennatus) population of Doñana National Park. We measured As, Cd, Cu, Pb, Zn, Sb and Tl levels in the blood of 24 individuals after the accident and also used data of repro...

Many threatened species in Europe have been expanding their distributions during recent decades owing to protection measures that overcome historical human activity that has limited their distributions. Range expansion has come about via two processes, natural expansion from existing range and reintroductions to new ranges. Reintroductions may prov...

Reintroductions have been increasingly used for species restoration and it seems that this conservation tool is going to be more used in the future. Nevertheless, there is not a clear consensus about the better procedure for that, consequently a better knowledge of how to optimize this kind of management is needed. Here we examined the dynamics of...

A growing body of work shows that climate change is the cause of a number of directional shifts in the spring phenology of migratory birds. However, changes in autumn phenology are less well studied and their consistency across species, as well as their association with population trends, remains uncertain. We investigate changes in the autumn migr...

. To provide an easy and reliable work tool to identify the sex of individuals, adult Black-browed Albatrosses (Thalassarche melanophrys) (n = 31) were weighed and measured, and the sex determined using DNA analyses. Stepwise discriminant analysis showed upper bill depth and weight to be the best predictor variables for sex determination. This mode...

Our goal in this study was to identify age- and population-specific responses to climate change in the autumn migration phenology of a long-lived bird species, the white stork Ciconia ciconia, at the macroscale of its entire migration route in western Europe. We used a 40 yr data series of ring recoveries of adult (>1 yr) and juvenile (<1 yr) white...

While alteration of the migratory habits of birds is widely regarded as one of the most evident ecological effects of climate change, studies reporting shifts in migration phenology for long-lived, long-distance migrants have been few. Using time series of count data collected in southern Spain during autumn migration, we examined the magnitude and...

The transient stage prior to definitive recruitment, known as juvenile dispersal, is thought to be under great evolutionary pressure and subject to a trade-off between associated costs and long-term benefits for fitness. Conspecific attraction has been shown to be an adaptive mechanism driving dispersal behaviours that may lead to negative density-...

Migration monitoring may allow us to detect population trends over large geographic areas because the pattern of change in migrant counts may be expected to follow the pattern of change in population size. We analysed recent regional European population trends of migratory soaring birds from rates of change in migration counts over the Strait of Gi...

Migration is a significant event in the annual cycle of many avian species. During migration birds face many challenges, including unfamiliar foraging and refuge habitats, resulting in a much higher rate of mortality during migration than during other seasons of the year. Weather may significantly affect a bird’s decision to initiate migration, the...

While alteration of the migratory habit of birds is widely regarded as one of the most evident ecological effects of climate change, studies reporting shifts in migration phenology for long-lived, long-distance migrants have been few. We set forth to analyze the effects of local and regional weather conditions on the migration counts and evaluate t...