Ph.D. Defense!

Noelia Hernandez Muñoz defended successfully her Ph.D. titled "Effects of environmental stochasticity on life history parameters of marine top predators" supervised by Prof. D. Oro.   Well done Noelia !


You can find Noelia's published work here

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.

G.E.P. at the Percy FitzPatrick Institute & SEEC

Ana Payo-Payo, from the GEP, has visited the Percy FitzPatrick Institute of African Ornithology  and the Centre for Statistics in Ecology, the Environment and Conservation (SEEC) at Cape Town (South Africa) with a fellowship from the Spanish Ministry of Education. During the 2-month visit at the FitzPatrick and SEEC Ana explored SouthAfrican wildlife and worked with Prof. P. Ryan and Prof. R. Altwegg on the application of multievent and state-space models on seabird populations.

New Publication on Storm Petrel Ecology!

Ramírez, F., Afan, I., Tavecchia, G., Catalán, I. A., Oro, D. and Sanz-Aguilar, A. 2016 Oceanographic drivers and mistiming processes shape breeding success in a seabird. Proceedings of the Royal Society B. Doi: 10.1098/rspb.2015.2287

Photo: M. Gomilla

Abstract: Understanding the processes driving seabirds' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.

Official press release (Spanish) here

New publication on foraging range and colony size in seabirds

Jovani, R,; Lascells, B.; Garamszegi, L. Z.; Mavor, R.; Oro, D.Colony size and foraging range in seabirds. Oikos DOI: 10.1111/oik.02781

We tested “Ashmole’s halo” hypothesis of food depletion around colonies using a phylogenetic comparative study of 43 species of seabirds (28,262 colonies). We confirmed that foraging range imposes a ceiling on the maximum colony size of seabird species. 

Abstract:The reasons for variation in group size among animal species remain poorly understood. Using “Ashmole's halo” hypothesis of food depletion around colonies, we predict that foraging range imposes a ceiling on the maximum colony size of seabird species. We tested this with a phylogenetic comparative study of 43 species of seabirds (28,262 colonies), and investigated the interspecific correlation between colony size and foraging ranges. Foraging range showed weak relationships with the low percentiles of colony size of species, but the strength of the association increased for larger percentiles, peaking at the maximum colony sizes. To model constraints on the functional relationship between the focal traits, we applied a quantile regression based on maximum colony size. This showed that foraging range imposes a constraint to species' maximum colony sizes with a slope around 2. This second-order relationship is expected from the equation of the area of a circle. Thus, our large dataset and innovative statistical approach shows that foraging range imposes a ceiling on seabird colony sizes, providing strong support to the hypothesis that food availability is an important regulator of seabird populations.

You can read the philosophy behind “Colony size and foraging range in seabirds” in Oikos blog, by Roger Jovani

New Publication on Scopoli's Shearwater!

Hernandez, N., Genovart, M., Igual, J.-M. and Oro, D., 2015 The influence of environmental conditions on the age pattern in breeding performance in a transequatorial migratory seabird. Forntiers in Ecology and Evolution.http://dx.doi.org/10.3389/fevo.2015.00069

 Abstract: Several studies of marine top predators, above all of seabirds, have analyzed the effects of either individual age or environmental fluctuations on reproduction; nevertheless, little is known about the age patterns in breeding performance in a variable environment.

Photo: Pedro Trejo (c)

To investigate the simultaneous influence of age and environmental conditions on laying dates and egg volumes, we tested different climate and food availability indices in a transequatorial migratory seabird using female data from a 23-year study. Our results show an improvement in breeding parameters with age (i.e., earlier laying dates and greater egg volumes) but no pattern of senescence in older age groups. The best models showed an interaction of time and age in breeding performance, i.e., the age pattern of breeding performance changed each year likely as a result of environmental variability.
Nevertheless, climatic indexes used here explained part of that annual variability: NAO and SOI index accounted for 24 and 20% of deviances in laying dates and egg volume, respectively. Part of that unexplained variability might be related to other processes such as intermittent breeding and the individual quality of breeders, which were not assessed in our study.

Scopoli's Shearwater campaign

Photo: P. Arcos

The annual campaign on the ecology of  the Scopoli's Shearwater Calonectris diomedea has started with the first breeding pairs at the colony. We will assess laying date, breeding success and collect individual data on presence-absence of marked birds. The hard work will end in September, when the newborns will leave for their first trans-equatorial migration. Check the publications by the GEP to learn more on this incredible bird here .

Still growing...PhD at the GEP

Enrique Real Garcías joined the GEP for a Ph.D. supported by the MINECO. He will deal with the difficult task of estimating fishery induced mortality of seabirds. His challenge will be to couple bycatch data, seabird surveys and capture-recapture data to estimate the mortality caused by fishery. The project will be developed in collaboration with the Balearic Center of Oceanography (IEO). Welcome Enrique.

YLG 2015 campaign ended today

 

The Yellow Legged gull campaign ended today with twenty-seven gulls marked, two surveys and eighty clutches measured along the path to the Llebeig lighthouse. Thank to everyone who helped. Eleanor Falcons have just arrived, time for us to go. 

See you next year!

Kick-off meeting of the EU-project MINOUW

 Palma, 13-16 April 2015

 The GEP is involved in estimating the effect of discard reduction on seabird population dynamics

Yellow-legged gull campaign on the blocks!

The 2015 campaign on Yellow-legged gull at Dragonera Natural Park is on the blocks.   First visits for some digit-scoping in search of marked  birds.

Seminar this Wednesday !

G.E.P. seminar this Wednesday (25/03/2015) by Noelia Hernandez Muñoz: "Age-dependent vital rates in the Storm Petrel at Benidrom". Seminar Room (second floor, h10.00). Apologizes for the change. Photo. by A. Sanz

GEP on Frontiers' Facebook

The article by D. Oro on Seabirds and climate: knowledge, pitfalls and opportunities has been highlighted on Frontiers' Facebook !!! here

 

See also the other articles in the Research Topic on Seabirds and Climate edited by Dr. M. Frederiksen

New publication on Sea Ice and Penguins

Ballerini, T., Tavecchia, G., Pezzo, F., Jenouvrier, S. and Olastroni, S. 2015 Predicting responses of the Adélie penguin population of Edmonson Point to future sea ice changes in the Ross Sea. Frontiers in Ecology and Evolution. doi: 10.3389/fevo.2015.00008 

Atmosphere-Ocean General Circulation Models (AOGCMs) predict changes in the sea ice environment and in atmospheric precipitations over larger areas of Antarctica. These changes are expected to affect the population dynamics of seabirds and marine mammals, but the extent of this influence is not clear. We investigated the future population trajectories of the colony of Adélie penguins at Edmonson Point, in the Ross Sea, from 2010 to 2100. To do so, we incorporated the relationship between sea ice and demographic parameters of the studied colony into a matrix population model. Specifically, we used sea ice projections from AOGCMs and a proxy for snowfall precipitation. Simulations of population persistence under future climate change scenarios showed that a reduction in sea ice extent (SIE) and an increase in precipitation events during the breeding season will drive the population to extinction. However, the population growth rate estimated by the model was lower than the population growth rate observed during the last decades, suggesting that recruits from other colonies maintain the observed population dynamics at Edmonson Point. This local “rescue” effect is consistent with a metapopulation dynamic for Adélie penguins in the Ross Sea, in which neighboring colonies might exhibit contrasting population trends and different density-dependent effects. In the hypothesis that connectivity with larger source colonies or that local recruitment would decrease, the sink colony at Edmonson Point is predicted to disappear.

Read also a newspaper note at "Repubblica.it"

New publication on seabirds !

Steigerwald, E., Igual, J.-M., Payo-Payo, A., and Tavecchia G. Effects of decreased anthropogenic food availability on an opportunistic gull: evidence for a size-mediated response in breeding females Ibis in press

Photo: G. Tavecchia

Some opportunistic vertebrates exploit, and may largely rely upon, food generated by human activities. Better understanding the influence of this additional anthropogenic food on species’ ecology would inform sustainable waste management. In the Balearic Archipelago of Spain, closure of an open-air landfill site provided an experimental setting to measure the effect of removing anthropogenic food on the average body mass, breeding parameters and body condition of opportunistic Yellow-legged Gulls Larus michahellis. After landfill closure there was a significant decline in the average body mass of breeding females and males (-10.4% and -7.8%, respectively), in average egg volume (-4.8%), and a shift in the modal clutch size from 3 to 2 eggs. Body condition decreased after landfill closure in both sexes. In breeding females, the drop in body weight was greater for birds with a low body size index. The differential response to a reduction of anthropogenic food between small and large birds suggests that food of anthropogenic origin contributes to temper the effects of natural selection, making the long-term demographic effects of changes in food supply difficult to predict.

New Publication !

Oro, D. 2014. Seabirds and climate: knowledge, pitfalls, and opportunities. Frontiers in Ecology and Evolution. doi: 10.3389/fevo.2014.00079

Foto: P. Arcos

As a physical driver of ecosystem functioning, it is not surprising that climate influences seabird demography and population dynamics, generally by affecting food availability. However, if we zoom in ecologically, seabirds are in fact very heterogeneous, ranging in size from very small to very large species (with a
difference of more than two orders of magnitude in body weight), from planktivorous forms to predators of large fish and squid, from benthic to pelagic, from species with small foraging ranges to species feeding throughout the whole circumpolar region, and from resident species (at a spatial mesoscale) to trans-equatorial migrating seabirds that travel large distances across several oceanographic systems. Due to this high variability and the difficulty in obtaining direct reliable estimates of long-term food availability, global climatic indices have been extensively used in studying seabird demography and population dynamics. However, the use made by researchers of these indices has certain conceptual and methodological pitfalls, which I shall address in this review. Other factors, such as anthropogenic impacts (including oil-spills and interaction with fisheries), may further alter or confound the association between climate and seabird demography. These pitfalls and environmental noise, together with the inability to incorporate resilience, may bias our predictions regarding the future impact of global warming on seabirds, many of which have vulnerable populations.

Seabirdstagram in action!

Seabirdstagram, the recently created free mobile App tool to facilitate the transfer of information on by-catch events, starts giving the first images of seabirds at sea!!

Find below the first image received and the location of the event.

And the map...

Many thanks to the fisherman who used the app!!!

Collaboration between researchers and fishermen surely will be a major step towards a better knowledge and Conservation of the Seas.

Fledgling !!

It is time for young Scopoli´s shearwater to leave their nests. 

They will go to the open ocean, for the first time, and possibly they will be back to breed in 4 to 7 years. 

Have a nice journey !!!!

More GEP !

Capitan Q...y las pardelas.  Manolo and Ana introducing Scopoli's Shearwater to Capitan Q

SeaBirdstagram:  Los vigilantes de Aves Marinos  by E. Soto

The Population Ecology Group ON AIR !

18th-19th of August at "Informatiu Vespre" y "Balears Fa Ciencia" with E. Culat- IB3Radio:

• 20h00 José-Manuel Igual: Seabirdstagram and the monitoring of seabird populations (min35)
• 11h00 Alejandro Martinez-Abrain: Evolution Underwater (form min42)
• 12h00 Ana Bonilla and Giacomo Tavecchia: Introducing Seabirdstagram (min8)
• 13h00 Samuel Pinya : the Ferret in Mallorca (min3)
• 13h45 A new monologue by Ana Payo (min48)