GEDAi at the European Vulture Conference 2023!

Dr. A. Santangeli presents his first results on the age-dependent survival probabilities of vulture in Europe and Middle East at the European Vulture Conference 2023 in Caceres, Spain. 

New publication on bird conservation and aesthetic!

Santangeli, A., Haukka, A., Morris, W. et al. What drives our aesthetic attraction to birds?. npj biodivers 2, 20 (2023).

In a shell: Understanding our relationship with other species is crucial. This study reveals that people are most aesthetically attracted to smaller birds with vivid colors and extreme ornaments. Unveiling the visual features underpinning our aesthetic attraction to birds is a critical step towards optimizing conservation

Abstract: In the Anthropocene, the era when the imprint of humans on nature is pervasive across the planet, it is of utmost importance to understand human relationships with other species. The aesthetics of nature, and of species, is one of the values that plays a role in shaping human-nature relationships. 

Birds are ubiquitous across the world. The beauty of birds exerts a powerful tug on human emotions, and bird-rich areas attract scores of eco-tourists. People naturally find some birds more beautiful or interesting than others, but we currently lack a global understanding of the specifics of what makes a species aesthetically attractive. Here, we used a global citizen-science database on bird attractiveness covering nearly all extant bird species, to show that there are specific visual features that drive our aesthetic appeal for some bird species over others. First, our aesthetic attraction is highest for smaller birds with specific, vivid colors (e.g., blue and red, and departing from brown-grey) and extreme ornaments (a long crest or tail). Second, our aesthetic attraction is highest for species with broad ranges, possibly because such species may be more familiar to us. The features that make us attracted to a particular bird strongly align with broad human visual aesthetic preferences in modern society. Unveiling the visual features underpinning our aesthetic attraction to birds is a critical step towards optimizing conservation (e.g., via conservation marketing) and education campaigns, and leverage the cultural ecosystem service potential of birds.

 

 

Shearwaters on the news!

 J.-M. Igual explains the  breeding biology of Cory's Shearwaters and the importance of long-term monitoring to identify threats. The full interview here.

New publication on gulls as seed dispersers!

Ando, H., Martín-Vélez, V., Tavecchia, G., Traveset, A., Jiménez-Martín, I., Igual, J. M., Martínez-Abraín, A., & Hervías-Parejo, S. (2023). Gulls contribute to olive seed dispersal within and among islands in a Mediterranean coastal area. Journal of Biogeography, 00, 1–9. https://doi.org/10.1111/jbi.14735 

In a shell: Gulls contributed to long-distance olive seed dispersal including different islands. Our findings indicate that gulls are relevant vectors for long-distance dispersal of large fleshy fruits in island ecosystems where specialist large frugivores are absent.

 

Photo: wikipedia.org

Abstract: Aim:To analyse the role of non-frugivorous birds on seed dispersal, seed dispersal by gulls is expected to be especially instrumental in island ecosystems, as these have a smaller subset of frugivores when compared to the mainland, and because long-distance dispersal is required for plant colonisation. Here, we investigated the seed dispersal of olives by gulls among 10 islands of the same archipelago to reveal if gulls contribute to long-distance seed dispersal including different islands, and how gulls' adaptation to domestic olives and individual differences in foraging activities affect their seed dispersal pattern.

Location:Balearic Islands in the Western Mediterranean Sea, Spain.Taxon:Yellow-legged gulls (Larus michahellis), Domestic and wild Olives (Olea europaea and O. europaea var. sylvestris).Methods:We developed seed dispersal models of the two ecotypes of olives dispersed by gulls across an archipelago, based on GPS tracking data, gut passage time and seed viability. Results:Mean dispersal distances were 7.67 (±12.48) km in wild and 12.57 (±13.08) km in domestic olives. 7.1% of wild and 8.5% of domestic olives were dispersed among islands. Among these, 8.2% of domestic seeds were transported from large to small islands where gull colonies are located, whereas wild olives were dispersed in more variable directions. Such dispersal pattern of two olive ecotypes was consistent despite the differences in dispersal distances among individuals. Gulls contributed to long-distance olive seed dispersal including different islands. The seed dispersal of domestic olives to longer distances with specific directions may facilitate colonisation and expansion of that variant if the conditions of seed deposition sites are suitable. Our findings indicate that gulls are relevant vectors for long-distance dispersal of large fleshy fruits in island ecosystems where specialist large frugivores are absent.

New publication on gulls and landfills!

Delgado, S., Tavecchia, G., Herrero, A. et al. Model projections reveal a recent decrease in a yellow-legged gull population after landfill closure. Eur J Wildl Res 69, 99 (2023). https://doi.org/10.1007/s10344-023-01723-w

 In a shell: The study reveals that the closure of local landfills leads to a decline in survival rates, especially in younger birds, ultimately causing a population decrease with continuing consequences.

Abstract: The food available in open-air landfills, one of the most common predictable anthropogenic food subsidies (PAFS), can have a profound impact on animal biodiversity. Understanding how and to what extent PAFS affect wildlife is crucial for a sustainable management of resources. Most large gulls behave as opportunistic foragers and constitute a good avian model to analyze the effect of PAFS reduction on animal populations. 

Using individual data from a yellow-legged gull population of the Basque coast (northern Iberia) collected over a 15-year period, we estimated survival and reproductive parameters and used them to parameterize an age-structured population model to explore the effects of the local landfill closure. Local survival probability declined with time as a consequence of the progressive closure of the local landfill sites. The top-ranked models included a quadratic function of time, suggesting an acceleration of mortality during the later years, especially in juveniles, while survival in adults was linear. An effect more pronounced in first year birds than in older birds. Population models predict a decrease of the population and confirmed a greater sensitivity of the population growth rate to adult survival probability. Overall, our results suggest that the reduced carrying capacity of the system resulted after landfill closures have caused a population decline which is expected to continue in the near future.

New publication on illegal and accidental hunting!

Pérez‐García, J. M., Sebastián‐González, E., Rodríguez‐Caro, R., Sanz‐Aguilar, A., Botella, F. (2023). Blind shots: non‐natural mortality counteracts conservation efforts of a threatened waterbird”. Animal Conservation. https://doi.org/10.1111/acv.12906

In a shell: The study found that 60% of recorded mortalities of the marbled teal was due to non-natural causes, including illegal shooting. Hunters might kill marbled teals accidentally while shooting other game species. The study highlights the need to reduce illegal shootings to establish a viable population of marbled teal.

Abstract: Waterbirds are particularly affected by the high hunting pressure they face in many regions, which in some cases is compromising conservation actions for threatened species. The marbled teal Marmaronetta angustirostris is one of the most endangered waterbirds in Europe. In order to restore its population, several conservation actions have recently been undertaken, including a population reinforcement programme in Spain using captive-bred birds. With the aim of assessing the success of the reinforcement programme to establish a long-term self-sustaining population, we identified mortality causes of marbled teal, evaluated the survival of individual birds of the reinforcement programme and estimated the viability of the population under different management scenarios. 

Pohto: Wikipedia.com

We used data from wild and captive-bred individuals tracked by GPS since 2018 (n = 42) and from a mark–recapture programme initiated in 2015 (n = 297). We recovered 15 dead birds or transmitters: 20% died of natural causes, 60% of non-natural causes (including all anthropic causes) and 20% of unknown causes. Furthermore, the GPS tags of 24 birds unexpectedly stopped transmitting without any indication of malfunction, and for 66.7% of these disappeared birds, the cessation was suspected to be caused by illegal shooting. Survival during the hunting season was higher for males (31.3%) than for females (12.5%), and for the wild (50%) than for the captive-bred birds (9.4%), probably due to differences in migration patterns to North Africa. Population viability models revealed that maintaining the breeding population at the current mortality rates is only possible with a permanent release programme of captive-bred individuals, and that in order to establish a self-sustaining population, non-natural mortality would have to be reduced by at least 40%. We recommend management measures to reduce marbled teal mortality, such as limiting legal hunting to hours with clear visibility, prosecuting illegal shootings, controlling exotic predators and improving water management to reduce disease outbreaks. Some improvements can be implemented in captive-breeding programmes, such as earlier release times and incorporating anti-predator training.

A press note (in Spanish) here

New publication on the effect of protected areas!

Santangeli, A., Weigel, B., Antão, L.H. et al. Mixed effects of a national protected area network on terrestrial and freshwater biodiversity. Nat Commun 14, 5426 (2023). https://doi.org/10.1038/s41467-023-41073-4

In a shell: Only a small fraction of species benefits of protected areas and it is not linked to species traits or conservation status. This indicates that additional measures like expanding coverage, enhancing connectivity, and better management are essential to address the broader biodiversity crisis effectively.

Abstract: Protected areas are considered fundamental to counter biodiversity loss. However, evidence for their effectiveness in averting local extinctions remains scarce and taxonomically biased. We employ a robust counterfactual multi-taxon approach to compare occupancy patterns of 638 species, including birds (150), mammals (23), plants (39) and phytoplankton (426) between protected and unprotected sites across four decades in Finland. We find mixed impacts of protected areas, with only a small proportion of species explicitly benefiting from protection—mainly through slower rates of decline inside protected areas. The benefits of protection are enhanced for larger protected areas and are traceable to when the sites were protected, but are mostly unrelated to species conservation status or traits (size, climatic niche and threat status). Our results suggest that the current protected area network can partly contribute to slow down declines in occupancy rates, but alone will not suffice to halt the biodiversity crisis. Efforts aimed at improving coverage, connectivity and management will be key to enhance the effectiveness of protected areas towards bending the curve of biodiversity loss.

New publication on plastic and Storm Petrels!

Clark, B.L., Carneiro, A.P.B., [...] Sanz-Aguilar, A.,[...] Rotger, A., et al. Global assessment of marine plastic exposure risk for oceanic birds. Nat Commun 14, 3665 (2023). https://doi.org/10.1038/s41467-023-38900-z

 In a shell: Unevenly distributed plastic pollution in the ocean can impact on vulnerable marine organisms, particularly petrel seabirds. High exposed zones were found in the Mediterranean, Black Seas, Pacific oceans, South Atlantic, and Indian Ocean. We emphasize the need for international collaboration to mitigate these risks.

Photo: Y.Muzika - eBird

Abstract: Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species.  Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.