The Workshop on capture-mark-recapture-recovery analyses has ended. It has been very interesting to know abut new exciting systems, marking methods, ecological questions and above all to meet new colleagues. We learned about turtles, shearwaters, voles, goose, vulture, penn shells..etc..
Thanks for coming!
The next workshop in 2018, last week of November, as always!
lunes, 4 de diciembre de 2017
domingo, 26 de noviembre de 2017
|Photo:José Marques, ZéMarkS|
Tracking data have showed the large scale movements of this species outside the breeding season. They have also revealed the opportunistic strategy in long-distance movements.
The long distance movements before and within the winter period indicate that wintering populations are likely to be made by birds of multiple origins. An important information to plan management actions, such as culling at wintering areas.
domingo, 19 de noviembre de 2017
martes, 7 de noviembre de 2017
Real, E., Oro, D., Martinez-Abrain, A., Igual, J.-M., Bertolero, A., Bosch, M.and Tavecchia, G., 2017. Predictable anthropogenic food subsidies, density-dependence and socio-economic factors influence breeding investment in a generalist seabird Journal of Avian Biology, 48: 001–009
Abstact: Recent European policies on the ban of fishing discards and the closure of open-air landfills are expected to reduce predictable and abundant food resources for generalist seabirds. In order to forecast the consequences of this reduction on seabird breeding investment it is important to understand whether diverse anthropogenic foraging resources act synergistically or not and whether their influence is mediated by density-dependent mechanisms.
To assess these effects at large spatio-temporal scale, we measured mean egg volume as a proxy of breeding investment in ca 5000 three-egg clutches of the yellow-legged gull Larus michahellis from 20 colonies of the Western Mediterranean, located both along European and African coasts. In European gull colonies, egg volume increased with the availability of fishing discards and landfills in the vicinity of the colony. However, the landfill effect was weaker than the effect of fishing discards, probably due to the lower quality of waste as food for gulls. In contrast, none of the anthropogenic food subsidies influenced egg volume in African colonies, likely due to socio-economic differences (i.e. a much lower availability and predictability of both discards and waste food. Finally, results showed that the positive association between fishing discards and open-air landfills on egg volume was mediated by negative density-dependent mechanisms probably related to an increase in competition for food.
miércoles, 25 de octubre de 2017
Jaume Badia is joining the GEP for his Master’s degree project in Animal Ecology at the University of Lund, Sweden. Jaume work will focus on the conservation maeasures to protect the Egyptian Vulture at Fuerteventura (Canary Islands) under the direction of Ana Sanz-Aguilar and in collaboration with the Estacion Biologica e Doñana (CSIC).
miércoles, 27 de septiembre de 2017
Tavecchia, G., Oro, D., Sanz-Aguilar, A., and Béchet, A. 2017. The multidimensional value of long-term individual.based studies: more than lots of data. Avocetta 41: 19-21
With the present rate of biodiversity loss and the profound effects of global changes, population and conservation ecologists face new questions. Many of these are related to how fast individuals can adapt to the strength and pace of environmental variability and can only be answered using individual data collected over long-term (Long Terms Individual Based Studies). Beside this undoubted scientific value, a 20 – 30 years study is likely to have trained several generations of scientists, fostered collaborations between a large number of research institutes and promoted public awareness on scientific themes and wildlife conservation problems. With current public systems providing funds for 3 to 4 years, it is increasingly difficult to initiate and maintain a long-term individual based study. As a consequence, many field studies end before time, without reaching the number of years or the amount of data needed to meet current scientific challenges and to demonstrate their educational value.Here, we argue that the value of LTIBS is multidimensional and it grows steadily with time. How and when does a long-term field study become important? [..] continue reading here
This text is in honor of Dr. Alan Roy Johnson (1941-2014, Photo), Dr. Heinz Hafner (1940-2003) and other pioneers of LTIBS. By focusing the attention on the multidimensional value of LTIBS we aimed to pay a tribute to them and to those people who, thanks to their passion, personal sacrifices and tenacity are keeping these projects alive.