Mostrando entradas con la etiqueta recruitment. Mostrar todas las entradas
Mostrando entradas con la etiqueta recruitment. Mostrar todas las entradas

lunes, 10 de julio de 2017

Upcoming CMRR workshop 2017. Apply now !

Workshop on Capture-Mark-Recapture and -Recovery analysis 2017 : you can subscribe now!

The introductory course aims to introduce students, researchers and environmental managers to the theory and practical aspects of the analysis of capture-mark-recapture and –recovery. 
We will focus on how to estimate survival, recruitment and dispersal probabilities in natural populations.
The course is based on theoretical classes as well as practical sessions with real and simulated data.
No previous knowledge on capture-mark-recapture or capture-mark-recovery analyses is necessary.


 

If you want to subscribe send message to : g.tavecchia-at-uib.es

For more information on the program and course payment : http://populationecologygroup.blogspot.com.es/p/workshop.html

martes, 13 de septiembre de 2016

WORKSHOP ON CAPTURE-RECAPTURE AND -RECOVERY ANALYSIS, 21-25 November, Mallorca, Spain

UPCOMING WORKSHOP : WORKSHOP ON CAPTURE-RECAPTURE AND -RECOVERY ANALYSIS

21-25 November 2016, Mallorca, SPAIN

Photo: F. Sergio
The course aims to introduce students, researchers and environmental managers to the theory and practical aspects of the analysis of capture-mark-recapture and –recovery data to estimate survival, recruitment and dispersal probabilities. The course is based on theoretical classes as well as practical sessions with real and simulated data.



Information here  or contact directly  g.tavecchia-at-uib.es
 
 Dead line for registration: October 2016
Places: 20

jueves, 28 de abril de 2016

New Publication on the rescue effect in Scopoli's Shearwaters !

Sanz-Aguilar, A.; Igual, J.M.; Tavecchia, G.; Genovart, M; Oro, D. 2016. When immigration mask threats: The rescue effect of a Scopoli’s shearwater colony in the Western Mediterranean as a case study. Biological Conservation, 198, 33–36. doi:10.1016/j.biocon.2016.03.034

Photo: M. Gomila
Abstract: Populations of long-lived species are highly sensitive to increases in mortality, but a loss of breeders can be compensated for by recruitment of local individuals or immigrants. Populations maintained through immigration can be sinks, jeopardizing the viability of the metapopulation in the long term when additive mortality from anthropogenic impacts occurs. Thus, the correct identification of whether a breeding population is maintained by local recruitment or by immigration is of special importance for conservation purposes. We developed robust population models to disentangle the importance of local recruitment and immigration in the dynamics of a Western Mediterranean population of Scopoli's shearwater Calonectris diomedea showing low adult survival but stable breeding numbers. Our results show that the shearwater population is not self-maintained but rescued by immigration: yearly immigrants recruiting in the population represents ~ 10–12% of total population size. We believe that this situation may be common to other Western Mediterranean populations, currently acting as sinks. We recommend urgent demographic studies at large core colonies to evaluate the global conservation status of the species.

 
A press release of the publication has just appeared. You can read the spanish version here

miércoles, 12 de agosto de 2015

New Publication on the effect of tagging birds


Sergio, F., Tavecchia, G., Taferna, A., López Jimenez, L. Blas, J., De Stephanis, R. Marchant, T. A., Kumar, N. and Hiraldo, F. 2015 No effect of satellite tagging on survival, recruitment, longevity, productivity and social dominance of a raptor, and the provisioning and condition of its offspring. J. App. Ecol. Accepted.

Abstract:
1.The deployment of electronic devices on animals is rapidly expanding and producing leapfrog advances in ecological knowledge. Even though their effects on the ecology and behaviour of the marked subjects are potentially important, less than 10% of the studies are accompanied by an evaluation of impact, and comprehensive, long-term assessments have been few. Therefore, there is an urgent need to test for impacts, especially for tags that are heavy and deployed for long time periods, such as satellite transmitters.
Photo: F. Sergio
2.We marked 110 individuals of a medium-sized, migratory raptor, the black kite Milvus migrans, with GPS satellite tags, representing about 4% of the body mass and attached as backpacks through a Teflon harness. Tagged individuals were compared to control animals of similar sex, age and breeding status for a large number of behavioural, condition-related and ecological traits.
3.Despite a sample size 2–3-fold greater than most previous assessments that reported significant impacts, there was no detectable difference between tagged and control individuals in key vital rates such as survival probability, longevity, recruitment, age of first breeding, reproductive performance and timing of breeding.
4.Tagged and untagged kites showed similar social dominance during fights over food and a similar capability to provision nestlings, which prevented carry-over effects on the stress levels and condition of their offspring.
5.Synthesis and applications. Radio-marking studies are growing exponentially in the current “movement ecology era” and impact assessments will be ever more important. In principle, tags of up to 4% mass-load can be deployed without apparent harm on some avian soaring species, but impacts should be properly evaluated on a case-by-case basis. Resilient species for which impacts seem weak could be used as early warning systems for trials of new devices: if impacts are observed, they are likely to be even greater on more vulnerable species. Finally, individual fatalities caused by marking should be taken into serious account, but comprehensively evaluated in the light of broader population-level impacts. Future initiatives to minimize tagging impacts could include more stringent licensing criteria enforcing attendance at training courses or incorporation of impact evaluations into study designs, increased availability of training courses for tagging, and enhanced sharing of information through blogs, workshops or specialized journal sections.