domingo, 17 de septiembre de 2017

New publication on Tiger Mosquito range expansion !

Tavecchia, G., Miranda, M.-A., Borrás, D., Bengoa, M., Barceló, C. Paredes-Esquivel, C. and Schwarz, C. 2017 Modelling the range expansion of the Tiger mosquito in a Mediterranean Island accounting for imperfect detection   Frontiers in Zoology, 14:39-49 doi. 10.1186/s12983-017-0217-x

Abstract: Aedes albopictus (Diptera; Culicidae) is a highly invasive mosquito species and a competent vector of several arboviral diseases that have spread rapidly throughout the world. Prevalence and patterns of dispersal of the mosquito are of central importance for an effective control of the species. We used site-occupancy models accounting for false negative detections to estimate the prevalence, the turnover, the movement pattern and the growth rate in the number of sites occupied by the mosquito in 17 localities throughout Mallorca Island. Site-occupancy probability increased from 0.35 in the 2012, year of first reported observation of the species, to 0.89 in 2015. Despite a steady increase in mosquito presence, the extinction probability was generally high indicating a high turnover in the occupied sites. We considered two site-dependent covariates, namely the distance from the point of first observation and the estimated yearly occupancy rate in the neighborhood, as predicted by diffusion models. Results suggested that mosquito distribution during the first year was consistent with what predicted by simple diffusion models, but was not consistent with the diffusion model in subsequent years when it was similar to those expected from leapfrog dispersal events. Assuming a single initial colonization event, the spread of Ae. albopictus in Mallorca followed two distinct phases, an early one consistent with diffusion movements and a second consistent with long distance, ‘leapfrog’, movements. The colonization of the island was fast, with ~90% of the sites estimated to be occupied 3 years after the colonization. The fast spread was likely to have occurred through vectors related to human mobility such as cars or other vehicles. Surveillance and management actions near the introduction point would only be effective during the early steps of the colonization.

viernes, 15 de septiembre de 2017

Gull tracking on the news (2) !

José Manuel Igual speaks about the Yellow-Legged Gull study at Dragonera Natural Park to the "Mallorca Zeitung" (text in German).

lunes, 11 de septiembre de 2017

New publication on Storm Petrel population dynamics !

 Population Ecology, 59:225–238, doi: 10.1007/s10144-017-0590-5
Photo By A. Caldas (Flickr)
Abstract : Life-history traits of migratory seabirds are influenced by changing conditions at breeding and wintering grounds. Climatic conditions and predation are known to impact populations’ survival rates, but few studies examine their effect simultaneously. We used multievent capture–recapture models to assess mortality due to environmental conditions and predation in breeding European storm petrels (Hydrobates pelagicus) in two allopatriccolonies  (Mediterranean and Atlantic). Predatory mortality at the colonies showed annual variation, being around 0.05 in certain years. Mortality at sea differed between the two oceanic basins, and was lower in the Mediterranean colony [0.11, 95% CI (0.09, 0.14)] when compared to the Atlantic colony [0.18, 95% CI (0.15, 0.22)]. The Western Mediterranean Oscillation index (WeMOi)  explained 57%of the temporal variability in mortality of Mediterranean breeders. In comparison, 43% of the temporal variability in mortality of Atlantic breeders was explained by the winter St Helena index (wHIX) and El Niño-Southern Oscillation index (wENSO). Our results suggest that Mediterraneanbreeders remain in this basin for wintering where they may face lower migratory costs and more favourable environmental conditions. In contrast, Atlantic breeders’ mortality may be due to higher cost of migration, changing upwelling conditions in the Benguela current  and heavy storms over their migratory route during La Niña events. This study underlines the importance of modelling separately different causes of mortality when testing the effects of climatic covariates.

martes, 1 de agosto de 2017

New Publication on Ferreret, the Majorcan midwife toad !

Pinya, S., Tavecchia,G. and Valentín Pérez-Mellado, V. Population model of an endangered amphibian: implications for conservation management  Endangered Species Research, 34: 123–130,

Abstract: Amphibian populations are declining worldwide, but for many taxa, robust estimates
of demographic parameters to assess population state or trends are scarce or absent.
robust estimates of adult apparent survival of the endemic Majorcan midwife toad Alytes muletensis using individual capture-recapture data collected over 4 yr in a 60 m2 cistern. Moreover, we combined the vital rates into a stage-structured population model to estimate the ex pected longterm growth rate of the population. Apparent survival estimates of males and females were similar (0.737 ± 0.042 and 0.726 ± 0.045, respectively) indicating that the egg-carrying behavior of males, typical of this species, does not reduce its survival probability. We found evidence of a low local survival of juveniles compared with adults, most likely due to permanent dispersal. Adult population size estimation provided higher tadpole:adult ratios than previously reported for this endangered species, suggesting an overestimation of the previous adult population size. Model projections suggested a stable population, since λ, the expected asymptotic growth rate of the population, was close to 1.00.

Full text here

lunes, 24 de julio de 2017

Shearwaters at night : the video !

Camera-traps reveal the territorial behaviour of nesting Cory's Shearwater.
Stay tuned for more videos

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 :

For more information on the program and course payment :

miércoles, 5 de julio de 2017

Storm Petrel Day ended

Photo D. Revenga
Storm Petrel Day at Benidorm Island ended. It ws a good occasion to meet other research teams and set monitoring protocole and collaborative research. Press note (in Spanish) and nice pictures by D. Revenga here. All is ready for the next 25 years!
B Massa & A Sanz (Photo: D. Revenga)

martes, 27 de junio de 2017

Gull tracking on the news!

Photo: G. Tavecchia
GSM/GPS data are generating a growing interest in gulls' feeding strategy. A new article by E. Soto in the newspaper El Mundo (here) has just been published on the monitoring of Yellow-legged Gulls at Dragonera. Long-distance tracks and daily feeding strategies are on the spot. Thank also to the help of T. Muñoz from the GOB (Grup Balear d'Ornitologia I Defensa de la Naturalesa)

sábado, 24 de junio de 2017

Storm Petrel Days at Benidorm Island

The 29-30th of June the Natural Park of Sierra Gelada organizes the European Storm Petrel Day at Benidorm to mark the 25 years of populaiton monitoring. 
Special guest: Dr A. Sanz-Aguilar, who contributed to more than half of the period. 

martes, 20 de junio de 2017

New Publication on Spoonbill population dynamics!

Tenan S, Fasola M, Volponi S, Tavecchia G. Conspecific and not performance-based attraction on immigrants drivescolony growth in a waterbird. J Anim Ecol. 2017;00:1–8.

  1. Local recruitment and immigration play an important part in the dynamics and growth of animal populations. However, their estimation and incorporation into open population models is, in most cases, problematic. We studied factors affecting the growth of a recently established colony of Eurasian spoonbill (Platalea leucorodia) and assessed the contribution of local recruits, i.e. birds born in the colony, and immigrants, i.e. birds of unknown origin, to colony growth.
  2. We applied an integrated population model that accounts for uncertainty in breeding state assignment and merges population surveys, local fecundity and individual longitudinal data of breeding and non-breeding birds, to estimate demographic rates and the relative role of recruitment and immigration in driving the local dynamics. We also used this analytical framework to assess the degree of support for the ‘performance-based’ and ‘conspecific attraction’ hypotheses as possible mechanisms of colony growth.
  3. Among the demographic rates, only immigration was positively and significantly correlated with population growth rate. In addition, the number of immigrants settling in the colony was positively correlated with colony size in the previous and current year, but was not correlated with fecundity of the previous year.
  4. Our results suggest that the variation in immigration affected colony dynamics and that conspecific attraction likely triggered the relevant role of immigration in the growth of a recently formed waterbird colony, supporting the need of including immigration in population analysis.
You can see press release (in Italian) following the links belows:

miércoles, 14 de junio de 2017

The mistery of the route to the Cantabric Sea solved!

Tracking data offered a first breakthrough to solve the mystery of the route to the Cantabric Sea.   
Yellow-legged gulls from the Balearic islands have been regularly seen in the Cantabric coast, but the route to Northern Spain was a mystery. Do they fly around the Iberian peninsula or throught the Ebro valley ? Do they use the Ebro river as a landmark? Do they reach the Cantabric sea from France? 
Last year preliminary data provided a first piece of the puzzle when a gull moved North following the Ebro river to Zaragoza. However the radio failed at the end of the summer and the route to the Cantabric sea along the Ebro river was not proved. This summer tracking data deliver the solution to the mystery, showing what is likely to be the main route to the Cantabric Sea: the Ebro valley. Interestingly, the route seems to pass north of the river and through the Basque Mountains at Estella. To be continued....

martes, 30 de mayo de 2017

Yellow Legged Gulls: new tracks !

A Yellow Legged gull marked as a breeder in Dragonera Island (Balearic archipelago) moved North to Barcelona. It continued the journey to Narbonne. Will it move up the Canal Du Midi or move to Camargue ? Place your bet.

To be continued....

lunes, 15 de mayo de 2017

Visiting G.E.P.

Alvaro Luna, from the Estacion Biologica de Doñana (CSIC),  is visiting the GEP lab for few weeks. Alvaro is working in Argentina on a long-term monitoring project on the Burrowing Owl Athene cunicularia. Under the direction of A. Sanz-Aguilar, he will compare the natal dispersal patterns of birds born in rural and urban areas. Welcome Alvaro!

viernes, 5 de mayo de 2017

Ph.D. defense !

Ana Payo-Payo from the GEP has defended her Ph.D, supervised by Prof. D. Oro, at the University of Barcelona. Well done Ana and Congratulations! (Next challenge : the Antartica, more information here)!

sábado, 29 de abril de 2017

GSMs reveal movements of gulls between large islands

With the help of T. Muñoz from the GOB we equipped four breeding Yellow Legged gulls with GPS/GSM devices at Dragonera Regional Park.  The first tracks reveal unexpected large movements of one male between the main islands Mallorca and Ibiza.  More to come.

viernes, 14 de abril de 2017

Prof. Oro on PAFS

Prof D. Oro interviewed by the national newspaper EL PAIS speaks about PAFS (Predictable Antrhopogenic Food Subsidies) and their role in animal ecology here.
Photo: G. Weinert (from

Check also the revision published by him and the GEP in Ecology Letters here.

viernes, 7 de abril de 2017

Intership at the GEP

Flore Mias, from the University of Toulouse, has joined the GEP for a 3-months intership. She will be investigating the movement pattern of the Balearic Wall Lizard. 
Welcome, Flore.

jueves, 23 de marzo de 2017

New publication : surviving at high elevation !

Bastianelli, G., Tavecchia, G., Meléndez, L. Seoane, J., Obeso, J. R. and Laiolo, P. 2017.
Surviving at high elevations: an inter- and intra-specific analysis in a mountain bird community Oecologia doi:10.1007/s00442-017-3852-1

Abstract: Elevation represents an important selection agent on self-maintenance traits and correlated life histories in birds, but no study has analysed whether life-history variation along this environmental cline is consistent among and within species. In a sympatric community of passerines, we analysed how the average adult survival of 25 open-habitat species varied with their elevational distribution and how adult survival varied with elevation at the intra-specific level. For such purpose, we estimated intra-specific variation in adult survival in two mountainous species, the Water pipit (Anthus spinoletta) and the Northern wheatear (Oenanthe oenanthe) in NW Spain, by means of capture–recapture analyses. At the inter-specific level, high-elevation species showed higher survival values than low elevation ones, likely because a greater allocation to self-maintenance permits species to persist in alpine environments.
Photo :
At the intra-specific level, the magnitude of survival variation was lower by far. Nevertheless, Water pipit survival slightly decreased at high elevations, while the proportion of transient birds increased. In contrast, no such relationships were found in the Northern wheatear. Intra-specific analyses suggest that living at high elevation may be costly, such as for the Water pipit in our case study. Therefore, it seems that a species can persist with viable populations in uplands, where extrinsic mortality is high, by increasing the investment in self-maintenance and prospecting behaviours.

lunes, 20 de marzo de 2017

Lizard spring campaign: tomorrow !

Lizard spring 2017 campaign is on the starting blocks. Tomorrow : first day, first island. This year we begin a collaborative research with the LIE-EBD at the Estacion Biologica de Doñana and Dr. Laura Baldo from the University of Barcelona. New exciting data are waiting for us.
Photo: G. Tavecchia

lunes, 13 de marzo de 2017

Ph.D., FPU and INTERSHIP with the G.E.P. 2017/2018

Are you interested in joining our research or developing your own one within the G.E.P ?

We regularly supervise Ph.D., Master projects and intership experiences on several issues related to Population Ecology of different species. Our main research lines at the moment are:
Life-history adaptations of island lizards.
Population Ecology of seabirds.
The influence of human activities on life-history tactics of birds.
Population Viability Analysis of vulnerable and endangered species. 
At present we do not have fellowships to offer, but if you have a Ph.D. grant or thinking to write a FPU project with the G.E.P. please contact us

miércoles, 8 de marzo de 2017

Shortlisted for Homeward Bound Project 2018 !

Ana Payo-Payo from the G.E.P. has been shortlisted for the Homeward Bound Project 2018.  The Homeward Bound Project (here for more details) "Mother nature needs her daugthers" is a groundbreaking initiative and outreach for women, set against the backdrop of Antarctica.

Ana releases this week an interview about her personal experience and the situation of women in science at Beleopolis (article by E. Soto) here

sábado, 4 de marzo de 2017

Yellow Legged Gull campaign on the starting blocks

The Yellow Legged Gull 2017 campaign at Dragonera Naural Park is on the starting blocks. We have received two nice pics from C. Loske of a newly marked gull (top) and an old one (bottom), respectively. Thank you Carl !

viernes, 17 de febrero de 2017

New Publication on colonization in social species !

Payo-Payo, A., Genovart, M., Sanz-Aguilar, A., Greño, J.L., García-Tarrasón, ., Bertlero A. and Oro, D., Colonisation in social species: the importance of breeding experience for dispersal in overcoming information barriers. Scientific Report. doi:10.1038/srep42866

Abstract: Studying colonisation is crucial to understand metapopulations, evolutionary ecology and species resilience to global change. Unfortunately, few empirical data are available because field monitoring that includes empty patches at large spatiotemporal scales is required.
We examine the colonisation dynamics of a long-lived seabird over 34 years in the western Mediterranean by comparing population and individual data from both source colony and the newly-formed colonies. Since social information is not available, we hypothesize that colonisation should follow particular dispersal dynamics and personal information must be crucial in decision making. We test if adverse breeding conditions trigger colonisation events, if personal information plays a role in colonisation and if colonisers experience greater fitness. Our results show a temporal mismatch between colonisation events and both density-dependence and perturbations at the source colony, probably because colonisers needed a longer prospecting period to compensate for the lack of public information. Colonisers were mostly experienced individuals gaining higher breeding success in the new colony. Our results highlight the demographic value that experienced individuals can have on metapopulation dynamics of social long-lived organisms.

lunes, 13 de febrero de 2017

GEP at the International Day of Women and Girls in Science 2017

Dr. Ana Sanz-Aguilar and Ana Payo-Payo from the GEP have participated a the International Day of Women and Girls in Science 2017 to "achieve full and equal access to and participation in science for women and girls, and further achieve gender equality and the empowerment of women and girls".
From "Ultima Hora"

A nice initiative and a good occasion to explain Science to the new generations. 

Workshop on Capture-Recapture and -Recovery at MUSE ended

The Workshop on Capture-Recapture and -Recovery at MUSE in collaboration with Dr. S. Tenan ended last Friday. It has been a very nice and interesting meeting with data on wolves, migratory birds, wild boards, gulls... surrounded by Trento mountains. Thank you all and thank to Simone for organizing this. The next workshop is scheduled in Mallorca this November.

viernes, 27 de enero de 2017

New Publication on Storm Petrels !

Hernández, N., Oro, D and Sanz-Aguilar, A., Environmental conditions, age and senescence differentially influence survival and reproduction in the Storm Petrel. 2017. Journal of Ornithology. Volume 158, pp 113–123. DOI: 10.1007/s10336-016-1367-x

Abstract: Demographic parameters in wild populations are expected to be shaped by individual covariates and environmental variability. Thus, the understanding of the effects of age and/or environmental conditions on variability in vital rates is of special importance in ecological and evolutionary studies. Early age-related improvements in survival and reproduction and later declines due to senescence are expected, above all in long-lived species. Survival in these species is predicted to be a more conservative parameter than reproduction, thereby giving rise to less temporal variability. We studied age-dependent patterns of survival and breeding success in a long-lived seabird, the Mediterranean Storm Petrel Hydrobates pelagicus melitensis, and the additive influence of individual heterogeneity and environmental climatic variables using 22 years of individual-based data (1993–2014). The North Atlantic Oscillation index (NAO) and sea surface temperature (SST) were selected as proxies of environmental conditions in both breeding and wintering areas. Our results show that vital rates improved with age for both survival and breeding success. A slow effect of senescence at older ages was detected for breeding success, whereas models did not disentangle the occurrence or the absence of actuarial senescence. Reproduction was also influenced by the age of first observed reproduction: at the same age, more experienced birds that recruited earlier had a higher breeding success than less experienced ones. Breeding success (but not survival) also showed great temporal variability in accordance with theoretical predictions. Neither the NAO nor the SST explained this variability, probably because petrels feed on lower trophic levels than most pelagic seabirds and other physical features such as river runoffs and winds may be involved, as well as other environmental stressors such as predation by sympatric gulls.

miércoles, 11 de enero de 2017

New publication on Egyptian vulture demographic parameters!

Sanz-Aguilar, A., Cortés-Avizanda, A., Serrano, D., Blanco, G., Ceballos, O., Grande, J.M., Tella, J.L., Donázar, J.A.: Sex- and age-dependent patterns of survival and breeding success in a long-lived endangered avian scavenger. Scientific Report, 7 2017 Article number 40204, doi: 10.1038/srep40204

 Abstract. In long-lived species, the age-, stage- and/or sex-dependent patterns of survival and reproduction determine the evolution of life history strategies, the shape of the reproductive value, and ultimately population dynamics. We evaluate the combined effects of age and sex in recruitment, breeder survival and breeding success of the globally endangered Egyptian vulture (Neophron percnopterus), using 31-years of exhaustive data on marked individuals in Spain. 

Photo: J. Bas

Mean age of first reproduction was 7-yrs for both sexes, but females showed an earlier median and a larger variance than males. We found an age-related improvement in breeding success at the population level responding to the selective appearance and disappearance of phenotypes of different quality but unrelated to within-individual aging effects. Old males (≥8 yrs) showed a higher survival than both young males (≤7 yrs) and females, these later in turn not showing aging effects. Evolutionary trade-offs between age of recruitment and fitness (probably related to costs of territory acquisition and defense) as well as human-related mortality may explain these findings. Sex- and age-related differences in foraging strategies and susceptibility to toxics could be behind the relatively low survival of females and young males, adding a new concern for the conservation of this endangered species.