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Gangoso L, Viana DS, Merchán M, Figuerola J. A new trophic specialization buffers a top predator against climate-driven resource instability. Behav Ecol 2024; 35:arae005. [PMID: 38287939 PMCID: PMC10824164 DOI: 10.1093/beheco/arae005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/22/2023] [Accepted: 01/15/2024] [Indexed: 01/31/2024] Open
Abstract
Intraspecific phenotypic variability is key to respond to environmental changes and anomalies. However, documenting the emergence of behavioral diversification in natural populations has remained elusive due to the difficulty of observing such a phenomenon at the right time and place. Here, we investigated how the emergence of a new trophic strategy in a population subjected to high fluctuations in the availability of its main trophic resource (migrating songbirds) affected the breeding performance, population structure, and population fitness of a specialized color polymorphic predator, the Eleonora's falcon from the Canary Islands. Using long-term data (2007-2022), we found that the exploitation of an alternative prey (a local petrel species) was associated with the growth of a previously residual falcon colony. Pairs in this colony laid earlier and raised more fledglings than in the other established colonies. The specialization on petrels increased over time, independently of annual fluctuations in prey availability. Importantly, however, the positive effect of petrel consumption on productivity was stronger in years with lower food availability. This trophic diversification was further associated with the genetically determined color morph, with dark individuals preying more frequently on petrels than pale ones, which might promote the long-term maintenance of genotypic and phenotypic diversity. We empirically demonstrate how the emergence of an alternative trophic strategy can buffer populations against harsh environmental fluctuations by stabilizing their productivity.
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Affiliation(s)
- Laura Gangoso
- Department of Biodiversity, Ecology and Evolution, Faculty of Biological Sciences, Complutense University of Madrid, C/Antonio Novais 12, 28040, Madrid, Spain
| | - Duarte S Viana
- Estación Biológica de Doñana, CSIC, C/Américo Vespucio 26, 41092, Sevilla, Spain
| | - Marina Merchán
- Estación Biológica de Doñana, CSIC, C/Américo Vespucio 26, 41092, Sevilla, Spain
| | - Jordi Figuerola
- Estación Biológica de Doñana, CSIC, C/Américo Vespucio 26, 41092, Sevilla, Spain
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Avilés JM, Cruz-Miralles Á, Parejo D. Colour-specific diet specialization is associated with differences in owlet weight in a polymorphic owl: influence of the trophic quality variation. Oecologia 2023; 203:181-191. [PMID: 37815597 PMCID: PMC10615958 DOI: 10.1007/s00442-023-05460-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 09/25/2023] [Indexed: 10/11/2023]
Abstract
The niche divergence hypothesis proposes that the evolution and maintenance of colour polymorphism is based on a mechanism of disruptive selection. In a trophic context, the hypothesis predicts that individuals differing in colour vary in their trophic niche, either because they differ in foraging efficiency or feed in different habitats. A major evolutionary conundrum is how these expectations are affected by variation in trophic quality. Using an owl species with colour plumage polymorphism, the Eurasian scops owl Otus scops, we examined diet and habitat segregation during reproduction in relation to plumage colouration and trophic quality. Intensive sampling revealed that trophic quality for scops owls (i.e. abundance of grasshoppers and locusts) varied more among territories than between years, but scops owls did not segregate among territories of different quality by their colouration. However, we found that sex, plumage colouration and territory differences in trophic quality explained differences in the degree of dietary specialization. Brownish males delivered a higher diversity of prey to the nest than greyish ones in high trophic quality territories. We also found that the more diverse the diet provided by males, the heavier the owlets at fledging. Our study provides evidence for a different sensitivity to trophic quality of the colour morphs with potential fitness consequences in scops owls. We highlight the importance of studying the mechanisms leading to the persistence of colour polymorphism in patchy environments, since segregation may pass otherwise unnoticed if only habitats or years with similar conditions are considered.
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Affiliation(s)
- Jesús Miguel Avilés
- Departamento de Ecología Funcional y Evolutiva, EEZA-CSIC, La Cañada de San Urbano, Almería, Spain.
- Unidad Asociada (CSIC): Ecología en el Antropoceno, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
| | - Ángel Cruz-Miralles
- Departamento de Anatomía, Biología Celular y Zoología, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - Deseada Parejo
- Departamento de Ecología Funcional y Evolutiva, EEZA-CSIC, La Cañada de San Urbano, Almería, Spain
- Unidad Asociada (CSIC): Ecología en el Antropoceno, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
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Koskenpato K, Lehikoinen A, Morosinotto C, Gunko R, Karell P. Regional variation in climate change alters the range-wide distribution of colour polymorphism in a wild bird. Ecol Evol 2023; 13:e10311. [PMID: 37470029 PMCID: PMC10352091 DOI: 10.1002/ece3.10311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/20/2023] [Accepted: 06/26/2023] [Indexed: 07/21/2023] Open
Abstract
According to Gloger's rule, animal colouration is expected to be darker in wetter and warmer climates. Such environmental clines are predicted to occur in colour polymorphic species and to be shaped by selection if colour morphs represent adaptations to different environments. We studied if the distribution of the colour polymorphic tawny owl (Strix aluco) morphs (a pheomelanic brown and a pale grey) across Europe follow the predictions of Gloger's rule and if there is a temporal change in the geographical patterns corresponding to regional variations in climate change. We used data on tawny owl museum skin specimen collections. First, we investigated long-term spatiotemporal variation in the probability of observing the colour morphs in different climate zones. Second, we studied if the probability of observing the colour morphs was associated with general climatic conditions. Third, we studied if weather fluctuations prior to the finding year of an owl explain colour morph in each climate zone. The brown tawny owl morph was historically more common than the grey morph in every studied climate zone. Over time, the brown morph has become rarer in the temperate and Mediterranean zone, whereas it has first become rarer but then again more common in the boreal zone. Based on general climatic conditions, winter and summer temperatures were positively and negatively associated with the proportion of brown morph, respectively. Winter precipitation was negatively associated with the proportion of brown morph. The effects of 5-year means of weather on the probability to observe a brown morph differed between climate zones, indicating region-dependent effect of climate change and weather on tawny owl colouration. To conclude, tawny owl colouration does not explicitly follow Gloger's rule, implying a time and space-dependent complex system shaped by many factors. We provide novel insights into how the geographic distribution of pheomelanin-based colour polymorphism is changing.
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Affiliation(s)
- Katja Koskenpato
- Bioeconomy Research TeamNovia University of Applied SciencesEkenäsFinland
- Finnish Museum of Natural History, The Helsinki Lab of OrnithologyUniversity of HelsinkiHelsinkiFinland
- Present address:
Department of Forest Sciences, Faculty of Agriculture and ForestryUniversity of HelsinkiHelsinkiFinland
| | - Aleksi Lehikoinen
- Finnish Museum of Natural History, The Helsinki Lab of OrnithologyUniversity of HelsinkiHelsinkiFinland
| | - Chiara Morosinotto
- Bioeconomy Research TeamNovia University of Applied SciencesEkenäsFinland
- Department of BiologyLund UniversityLundSweden
- Present address:
Department of BiologyUniversity of PadovaPadovaItaly
- Present address:
National Biodiversity Future Center (NBFC)PalermoItaly
| | - Ruslan Gunko
- Bioeconomy Research TeamNovia University of Applied SciencesEkenäsFinland
- Department of BiologyUniversity of TurkuTurkuFinland
| | - Patrik Karell
- Bioeconomy Research TeamNovia University of Applied SciencesEkenäsFinland
- Department of BiologyLund UniversityLundSweden
- Present address:
Department of Ecology and GeneticsUniversity of UppsalaUppsalaSweden
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Becciu P, Séchaud R, Schalcher K, Plancherel C, Roulin A. Prospecting movements link phenotypic traits to female annual potential fitness in a nocturnal predator. Sci Rep 2023; 13:5071. [PMID: 36977731 PMCID: PMC10050157 DOI: 10.1038/s41598-023-32255-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Recent biologging technology reveals hidden life and breeding strategies of nocturnal animals. Combining animal movement patterns with individual characteristics and landscape features can uncover meaningful behaviours that directly influence fitness. Consequently, defining the proximate mechanisms and adaptive value of the identified behaviours is of paramount importance. Breeding female barn owls (Tyto alba), a colour-polymorphic species, recurrently visit other nest boxes at night. We described and quantified this behaviour for the first time, linking it with possible drivers, and individual fitness. We GPS-equipped 178 female barn owls and 122 male partners from 2016 to 2020 in western Switzerland during the chick rearing phase. We observed that 111 (65%) of the tracked breeding females were (re)visiting nest boxes while still carrying out their first brood. We modelled their prospecting parameters as a function of brood-, individual- and partner-related variables and found that female feather eumelanism predicted the emergence of prospecting behaviour (less melanic females are usually prospecting). More importantly we found that increasing male parental investment (e.g., feeding rate) increased female prospecting efforts. Ultimately, females would (re)visit a nest more often if they had used it in the past and were more likely to lay a second clutch afterwards, consequently having higher annual fecundity than non-prospecting females. Despite these apparent immediate benefits, they did not fledge more chicks. Through biologging and long-term field monitoring, we highlight how phenotypic traits (melanism and parental investment) can be related to movement patterns and the annual potential reproductive output (fecundity) of female barn owls.
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Affiliation(s)
- Paolo Becciu
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
| | - Robin Séchaud
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Agroecology and Environment, Agroscope, Reckenholzstrasse 191, 8046, Zurich, Switzerland
| | - Kim Schalcher
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Céline Plancherel
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Alexandre Roulin
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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Ratajc U, Lourenço R, Espín S, Virosta PS, Birrer S, Studler D, Wernham C, Vrezec A. The importance of population contextual data for large-scale biomonitoring using an apex predator: The Tawny Owl (Strix aluco). THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 860:160530. [PMID: 36574555 DOI: 10.1016/j.scitotenv.2022.160530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/17/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Top predators are often used as sentinel species in contaminant monitoring due to their exposure and vulnerability to persistent, bioaccumulative and, in some cases, biomagnificable contaminants. Some of their ecological traits can vary in space and time, and are known to influence the contamination levels and therefore information on ecological traits should be used as contextual data for correct interpretation of large-scale contaminant spatial patterns. These traits can explain spatiotemporal variation in contaminant exposure (traits such as diet and dispersal distances) or contaminant impacts (traits such as population trend and clutch size). The aim of our research was to review the spatial variation in selected contextual parameters in the Tawny Owl (Strix aluco), a species identified by the COST Action European Raptor Biomonitoring Facility as one of the most suitable candidates for pan-European biomonitoring. A considerable variation in availability of published and unpublished contextual data across Europe was found, with diet being the most extensively studied trait. We demonstrate that the Tawny Owl is a suitable biomonitor at local scale but also that taking spatial variation of other contextual data (e.g. diet) into account is necessary. We found spatial gaps in knowledge about the species ecology and biology in Southern Europe, along with gaps in certain population parameters (e.g. population trends) in several countries. Based on our findings, we proposed a minimal recommended scheme for monitoring of population contextual data as one of the first steps towards a pan-European monitoring scheme using the Tawny Owl.
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Affiliation(s)
- Urška Ratajc
- Department of Organisms and Ecosystems Research, National Institute of Biology, SI-1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, SI-1000 Ljubljana, Slovenia.
| | - Rui Lourenço
- MED Mediterranean Institute for Agriculture, Environment and Development & CHANGE Global Change and Sustainability Institute LabOr Laboratory of Ornithology, IIFA, University of Évora, Pólo da Mitra, 7006-554 Évora, Portugal
| | - Silvia Espín
- Area of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus Espinardo, 30100 Murcia, Spain
| | - Pablo Sánchez Virosta
- Area of Toxicology, Faculty of Veterinary Medicine, University of Murcia, Campus Espinardo, 30100 Murcia, Spain
| | - Simon Birrer
- Swiss Ornithological Institute, CH-6204 Sempach, Switzerland
| | | | - Chris Wernham
- British Trust for Ornithology (Scotland), Unit 15 Beta Centre, Stirling University Innovation Park, Stirling FK9 4NF, Scotland, UK
| | - Al Vrezec
- Department of Organisms and Ecosystems Research, National Institute of Biology, SI-1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, SI-1000 Ljubljana, Slovenia; Slovenian Museum of Natural History, SI-1000 Ljubljana, Slovenia
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