Press release on landfill and birds!

A press release on birds and landfill on the White Stork paper (here) just came out here (in Spanish).

New publication on climate change and bird breeding phenology!

Mingozzi, T., Storino, P., Venuto, G., Massolo, A., Tavecchia, G., 2021. Climate warming induced a streth of the breeding season and an increase of second clutches in a passerine breeding at its altitude limits. Current Zoology, zoab029, https://doi.org/10.1093/cz/zoab029

Abstract: The increase in the average air temperature due to global warming has produced an early onset of the reproduction in many migratory birds of the Paleartic region. According to the “mismatch hypothesis” this response can lead to a decrease in the breeding output when the conditions that trigger the departure from the wintering areas do not match the availability of food resources in the breeding ground. We used 653 brooding events registered during the period 1991–2013 to investigate the link between climatic variables and individual breeding performance of a partially migratory passerine, the Rock SparrowPetronia petronia, breeding at the altitude limit of its distribu-tion.

 

Photo: Corrado Damiano

The laying date (LD) of the earliest first clutch was associated with local spring (minimum) temperatures but did not show a significant trend during the period considered. The LD of the latest first clutch had a positive and statistically significant trend, unrelated to local covariates and resulting in a longer breeding season (1.5 days/year). A longer breeding season allowed birds to produce more second clutches, which proportion increased from 0.14 to 0.25. The average breeding success was also positively correlated with the average temperature in July and with the duration of the breeding season. Contrary to expectations, the most important climate-dependent effect was a stretch of the breeding season due to a significant increase of the LD of the latest first-clutches rather than an earlier breeding onset. We show how climate changes act on bird populations through multiple paths and stress the need to assess the link between climatic variables and several aspectsof the breeding cycle.

Citizen science at Sa Dragonera Island! Saturady 24 April.

Do you like wildlife photgraphy? Suscribe for the Red Ring Challenge here and join our long-term research on the Yellow-legged gull at Sa Dragonera Island.

Take a picture of a marked gull and win an original T-Shirt. 

Presence-absence data of marked animals are extremely important as they can be used to estimate annual survival probability and movements of individuals within the breeding colony. 

The project, funded by the Spanish Ministery of Science and Education, will investigate how the management of discards from human activities influences the ecology of gulls. 

To subscribe write your name and telephone number to:

medgulls@gmail.com

 

 

 

New Publication on avian scavangers and anthropized landscapes!

Gangoso, L., Cortés-Avizanda, A., et al. 2021. Avian scavengers living in anthropized landscapes have shorter telomeres and higher levels of glucocorticoid hormones. Science of the Total Environment.146920, https://doi.org/10.1016/j.scitotenv.2021.146920  

Abstract:  Habitat anthropization is a powerful stressor affecting the health and fitness of organisms, ultimately impacting their population dynamics. In vertebrates, stressful living conditions are usually associated with elevated glucocorticoids-based responses (GCs) as well as shorter telomeres, which are in turn associated with decreased overall body condition fitness and life expectancy. However, our understanding of how habitat anthropization per se and population processes synergistically, or independently, may affect GCs and telomere dynamics in natural populations is still very limited. 

Here, we assessed the physiological footprint of habitat anthropization and conspecific density in 65 GPS-tagged Eurasian griffon vultures (Gyps fulvus) from two populations of the Iberian Peninsula. We examined how extrinsic (human footprint values and conspecifics density within individual activity areas) and intrinsic (sex and home range size) factors determine GCs deposited in feathers (CORT_f) and telomere length as proxies of overall individual condition and quality. We found strong differences in both physiological markers between populations, with higher CORT_f levels and shorter telomeres in vultures living in the northern, more anthropized area. We also found sex-specific patterns of CORT_f, with females having higher levels than males. In both sexes, telomere length decreased as the density of conspecifics increased. Previous studies in these populations have shown lower survival rates in individuals who exploit more anthropized areas, and here we show a potential physiological causal link. We highlight the existence of complex effects of chronic stress associated both with living in anthropized environments and with population-related processes likely associated to the spatial distribution of resources.

Cover!

The article by Sergio et al. 2021 on Ecological Application (here) made the cover of the last issue. Nice pic.

Well done Fabrizio!

New Publication: Don't mess with encounter probabilities!

Tavecchia, G., Gimenez, O., Choqut, R., Oro, D., Tenan, S. and Sanz-Aguilar, A. 2021.The trap of hidden processes: Why ‘quick & dirty’ methods to estimate mortality are not always good. A comment to De Pascalis et al. (2020) Biological Conservation, 109057, doi: 10.1016/j.biocon.2021.109057

CMRR models can be difficult to build and many conservation biologists are tempted to shortcut them for simpler, ‘quick & dirty’, methods, trading difficulty with the lack of precision. In some particular cases, it is a winning trade, however, in most cases, it is a very hazardous practice. The proportion of animal seen alive vs those seen dead depends, by definition, on the detection probability, p, that an animal alive is detected and on the probability, λ, that a dead animal is found or retrieved (c) and the tag reported (r), with λ = c*r. Not taking thi into acocunt would lead to biased estimates. Explore scenarios through an R shiny application provided at https://github.com/oliviergimenez/bias_recovery.

Yellow Legged Gull campaign on the starting blocks!

The Yellow-legged gull campaign is on the starting blocks. Last year it has been difficult due to the lockdown in the middle of the breeding season. This year we are ready to catch up with a new fieldwork campaign in Ibiza and some extra help. We are warming up with some press notes and radio interview.

Illustration by Pelopanton

A press note about the project here and a radio interview by Dr. Ana Sanz-Aguilar here