Catry I.,University of Lisbon |
Catry I.,University of East Anglia |
Franco A.M.A.,University of East Anglia |
Rocha P.,ICNF PNVG Institute Conservacao da Natureza e Florestas Parque Natural do Vale do Guadiana |
And 5 more authors.
PLoS ONE | Year: 2013
Among birds, breeding numbers are mainly limited by two resources of major importance: food supply and nest-site availability. Here, we investigated how differences in land-use and nest-site availability affected the foraging behaviour, breeding success and population trends of the colonial cavity-dependent lesser kestrel Falco naumanni inhabiting two protected areas. Both areas were provided with artificial nests to increase nest-site availability. The first area is a pseudo-steppe characterized by traditional extensive cereal cultivation, whereas the second area is a previous agricultural zone now abandoned or replaced by forested areas. In both areas, lesser kestrels selected extensive agricultural habitats, such as fallows and cereal fields, and avoided scrubland and forests. In the second area, tracked birds from one colony travelled significantly farther distances (6.2 km ±1.7 vs. 1.8 km ±0.4 and 1.9 km ±0.6) and had significant larger foraging-ranges (144 km2 vs. 18.8 and 14.8 km2) when compared to the birds of two colonies in the extensive agricultural area. Longer foraging trips were reflected in lower chick feeding rates, lower fledging success and reduced chick fitness. Availability and occupation of artificial nests was high in both areas but population followed opposite trends, with a positive increment recorded exclusively in the first area with a large proportion of agricultural areas. Progressive habitat loss around the studied colony in the second area (suitable habitat decreased from 32% in 1990 to only 7% in 2002) is likely the main driver of the recorded population decline and suggests that the effectiveness of bird species conservation based on nest-site provisioning is highly constrained by habitat quality in the surrounding areas. Therefore, the conservation of cavity-dependent species may be enhanced firstly by finding the best areas of remaining habitat and secondly by increasing the carrying capacity of high-quality habitat areas through safe nest-site provisioning. © 2013 Catry et al.
Parejo S.H.,University of Murcia |
Parejo S.H.,CSIC - Institute of Natural Products and Agrobiology |
Royuela J.B.,Brunel University |
Rodriguez-Luengo J.L.,University of California at Santa Cruz |
And 5 more authors.
Environmental Science and Policy | Year: 2015
The Portuguese government has awarded islands with more protection statutes than continental ecosystems, so it seems to recognise the exceptional biodiversity of the insular regions. However, the effectiveness of these protection statutes is questionable since, in most cases, no measures are taken to guarantee the protection against invasive alien species (IAS). This study reviews the current legislative framework addressing IAS at national, regional and local levels. Information on ecological and socio-economic impacts of IAS was used to analyse whether regional laws covering island ecosystems are ensuring the protection of their biodiversity. We detected some weakness in the Portuguese legislation: IAS are not the main focus, inconsistent terminology, vectors not targeted, a few diversity of ecosystems covered, no coordination of actions and no enforcement of management plans. In addition, the uniqueness of biodiversity on Macaronesian islands is not protected by the regional legislation. Although some non-indigenous species introduced on islands are currently threatening the integrity of their fragile ecosystems and the socio-economic spheres, they are not considered as IAS. A stronger strategic framework to address the overall impacts of IAS is required mainly in these Macaronesian islands whose one of the most imposing threat is the presence of these introduced species. © 2015 Elsevier Ltd.
Hervias S.,University of Murcia |
Hervias S.,CSIC - Institute of Natural Products and Agrobiology |
Oppel S.,Royal Society for the Protection of Birds RSPB |
Medina F.M.,CSIC - Institute of Natural Products and Agrobiology |
And 5 more authors.
Journal of Zoology | Year: 2014
Populations of feral (not owned by humans) and domestic cats Felis catus coexist in most inhabited islands, and they have similar impacts on native species. Feral cats are generally believed to vary their diet according to prey availability; however, no previous studies of diet have tested this hypothesis on insular ecosystems with a limited range of available prey. Because domestic cats kill prey independently of hunger, the spatial extent of their impact on wildlife will be influenced by home-range size. In this study, we combined dietary information with cat movements to assess the impacts of feral and domestic cats on island biodiversity. We quantified the diet of cats from scat samples collected across one year and tested whether diet varies by season. The abundance of main prey categories was also estimated to document seasonal variation in prey availability for cats. Finally, we tracked domestic cats by global positioning system units in all four seasons to examine whether home-range patterns varied seasonally. The diet of cats constituted three prey groups (rodents, birds and invertebrates), and the seasonal variation in consumption of each taxon matched the seasonal variation in prey availability, thus supporting the generalist behaviour of cats on oceanic islands. Roaming behaviour varied among individuals and across seasons, but could not be explained by availability of prey. Unconfined cats had larger home-ranges than confined cats, but most domestic cats strayed <1km from home. Thus, confinement of domestic cats might reduce the spatial extent of cat impact on native prey populations on oceanic islands. © 2013 The Zoological Society of London.
Parejo S.H.,University of Murcia |
Ceia R.S.,University of Coimbra |
Ramos J.A.,University of Coimbra |
Sampaio H.L.,Portuguese Society for the Study of Birds SPEA |
Heleno R.H.,University of Coimbra
European Journal of Forest Research | Year: 2014
The last remains of native laurel forest in the Azores are highly threatened by the spread of invasive plants. Because landslides are very frequent in these islands, conservation of native laurel forest requires knowledge of the patterns of bird-dispersed seed rain into forest gaps. We monitored 78 seed traps over 1 year to investigate (1) the role of perches in attracting avian dispersers into gaps, (2) temporal patterns in the dispersal of exotic and native seeds, (3) how seed rain affects vegetation establishment in gaps at different distances from the native forest and (4) whether the caloric content of fruits could explain the number of seeds dispersed. Perches were highly effective in concentrating avian seed dispersal. While some native fruits are produced all year-round, most exotic plants set fruits during the main peak of the native fruit production (August-November). Most seeds recovered from the traps were native, and native seed rain inside the native forest was higher than in gaps. However, deposition of exotic seeds was not affected by distance from native forest. Seed dispersal frequencies monitored by seed traps and by faecal analysis were correlated with each other, but not with fruit caloric content, suggesting that other factors are more important that the nutritional value in predicting avian fruit choice. Forest restoration activities should take into consideration that seed dispersal decreases sharply beyond 100 m from native forest and the attractive potential of perches to direct natural seed dispersal into forest gaps. © Springer-Verlag Berlin Heidelberg 2013.