Andrés de la Cruz

Universidad de Cádiz | UCA

The expansion of renewable energy production, especially wind power, is one of the cornerstones of our strategy for mitigating climate change. However, there is growing concern about the impacts of this energy source on biodiversity. In particular, very little is known about the impact on groups of fauna such as bats, which are especially sensitive...

The expansion of renewable energy production, especially wind power, is one of the cornerstones of our strategy for mitigating climate change. However, there is growing concern about the impacts of this energy source on biodiversity, and a need to develop tools to adequately assess this impact and mitigate its effects. In particular, very little is...

Understanding how fisheries influence seabird distribution is critical in the development of sustainable fisheries management. Species distribution models were applied to analyse the influence of the fishing footprint, discards, and oceanographic factors on seabird attendance patterns to trawlers in the Gulf of Cádiz. More than 30 species of seabir...

The biology of the Cinereous Vulture Aegypius monachus is well known across its breeding range, and the species’ dispersal and movements throughout Europe are widely recorded. However, the ecology of this vulture south of the Mediterranean Sea has been overlooked, probably owing to the belief that the presence of Cinereous Vultures in North Africa...

Some migratory seabird populations have declined sharply in recent decades. Monitoring their migratory movements from strategic locations provides a useful tool to understand their phenology and estimate their population sizes. During the autumn 2020 and spring 2021 migration periods, we conducted a total of 183 hours of counts of two auk species,...

Quantifying factors that influence marine predator distributions is essential to understanding the current and future change in marine biodiversity. Here, we test whether marine predator distribution relates to prey, or is better predicted by other specific habitat features. We examine the correlation between spatial distribution of three seabird s...

The worldwide decline of seabird populations due to the combined effects of global and regional changes is creating immense challenges for managers and conser-vationists. Predicting population responses to proposed management strategies could provide the most effective tools to prevent, halt and reverse ongoing declines. System dynamic modelling fr...

The Red Sea Flyway is the most important route for soaring birds migrating between Eurasia and Africa. The Bab el-Mandeb strait in Djibouti is the narrowest water crossing of the Red Sea and as such, acts as a critical migratory bottleneck at the entrance point into the Horn of Africa. Despite the global significance of this flyway, very limited ob...

1. Spatial modelling is an important research tool to improve our knowledge about the distribution of wildlife in the ocean. Using different modelling techniques (MaxEnt and a generalized linear mixed model), a predictive habitat suitability model was developed for one of the most threatened seabirds in the world: the Balearic shearwater, Puffinus...

The expansion of marine protected areas in pelagic areas has been crucial to achieve sufficient protection of the oceans. However, there is still some controversy about whether these protected areas actually cover the vital areas for some species. We investigate the summer distribution of the critically endangered Balearic Shearwater and its overla...

We conducted bird surveys (consisting of area searches, mist-netting and road counts) throughout diverse habitats in Djibouti between 23 August and 20 September 2017. We report here on several notable sightings, including the first of Semi-collared Flycatcher Ficedula semitorquata and what is potentially the first breeding record of Lesser Flamingo...

The Balearic Shearwater Puffinus mauretanicus is considered one of the most threatened seabirds in the world, with the breeding population thought to be in the range of 2,000–3,200 breeding pairs, from which global population has been inferred as 10,000 to 15,000 birds. To test whether the actual population of Balearic Shearwaters is larger than pr...

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...

The Balearic Shearwater Puffinus mauretanicus is considered one of the most threatened seabirds in the world, with the breeding population thought to be in the range of 2,000–3,200 breeding pairs, from which global population has been inferred as 10,000 to 15,000 birds. To test whether the actual population of Balearic Shearwaters is larger than pr...

This study examines the responses to human presence of the most abundant shorebird species in an important coastal migration staging area (Los Lances Beach, southern Spain). Long-term census data were used to assess the relationship between bird abundances and human densities and to determine population trends. In addition, changes in individual bi...

Análisis y contextualización de las observaciones de Paiño de Wilson en el Estrecho de Gibraltar en 2011, y su relación con la presencia de Orcas.

The Balearic Shearwater Puffinus mauretanicus is considered the most threatened seabird in Europe, based on a prediction of extinction within 3 generations in average. Such prediction was computed in 2004, based on a population estimate of 2,000 breeding pairs at that time. However, the breeding population has been recently updated to 3,193 pairs....

The Lesser Spotted Eagle (LSE) migrates to its winter quarters via the eastern Mediterranean corridor. During 1998 to 2009, 47 LSEs have been registered in the Strait of Gibraltar during a monitoring program of bird migration. All observations were made between 6 August to 12 October (mean 16 September, median 12 September). Of thirteen age-identif...

Rüppell’s Vulture Gyps rueppellii is an endemic from a relatively narrow belt of arid sub-Saharan Africa. This species has suffered a population decline in most of its distribution area, mainly in West Africa. Generally, it is considered as non-migratory, although daily foraging movements of up to 150–200 km have been recorded. However, in the last...

The Migres Programme, formed by the Department of the Environment of the Andalusian Regional Government and coordinated by the Migres Foundation, includes long term cenusing of seabirds through the Straits of Gibraltar (Migres Marinas). Here the preliminary results of the project are given. Nearly 40 species of seabirds have been detected in the St...

During the spring of 2008 we detected in the Strait of Gibraltar the unusual presence of several species of raptors that typically migrate through the oriental flyway. The standardized records, obtained by systematic observations, and considering others not under specific monitoring protocols, total 14 birds of four different species: seven Red-foo...

RESUMEN Se muestra el método de análisis de los cronotipos para caracterizar las comunidades migratorias de aves en un ámbito geográfico concreto. Estos cronotipos son grupos de especies cuyas fenologías de paso son más parecidas entre sí de lo que cabría esperar por azar. A modo de ejemplo, se muestra la aplicación de este análisis a los datos del...

SUMMARY The results are given of intensive censusing of Balearic Shearwaters Puffinus mauretanicus during post breeding migration through the Strait of Gibraltar. A total of 12.270 Balearic Shearwaters were counted exiting the Mediterranean to the Atlantic in the course of 239 hours watching between 25 May and 9 July 2007 (approximately 35.7% of da...

Migres Program is a project, whose key objective is the long-term scientific monitoring of the migratory patterns of birds in the Strait of Gibraltar. This project is financed by the Regional Government of Andalucía and coordinated by Migres Foundation. This article contains the different monitoring campaign carried out on 2009: postnuptial soaring...

Autumn bird migration is well known across the Strait of Gibraltar, southern Spain. However, spring migration at the Strait is both one of the most spectacular and unknown natural phenomenon. Due to this reason we started a project on 2007 with the objective to design and conduct a long term monitoring program to study the spring soaring bird migra...

Censusing seabirds from coastal areas requires reliable estimates of bird numbers and the distances of the birds from the coastline. Logistical constraints make visual estimation of distances the only feasible method in many studies. We tested the accuracy of visually estimated offshore distances of six migratory seabird species in the Strait of Gi...

We studied the visible migration of small diurnal migrants (Passeriformes and related orders) in the Strait of Gibraltar during 2008 through a net- work of fixed observatories, using a constant effort methodology. The vis - ible diurnal migration in the Strait of Gibraltar is dominated by finches, swifts, swallows and house martins, bee-eaters and...

During the spring of 2008 we detected in the Strait of Gibraltar the unusual presence of several species of raptors that typically migrate through the oriental flyway. The standardized records, obtained by systematic observations , and considering others not under specific monitoring protocols, total 14 birds of four different species: seven Red-fo...