| 1. |
- Beausoleil, Marc Olivier, et al.
(author)
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Where did the finch go? Insights from radio telemetry of the medium ground finch (Geospiza fortis)
- 2022
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In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 12:4
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Journal article (peer-reviewed)abstract
- Movement patterns and habitat selection of animals have important implications for ecology and evolution. Darwin's finches are a classic model system for ecological and evolutionary studies, yet their spatial ecology remains poorly studied. We tagged and radio-tracked five (three females, two males) medium ground finches (Geospiza fortis) to examine the feasibility of telemetry for understanding their movement and habitat use. Based on 143 locations collected during a 3-week period, we analyzed for the first time home-range size and habitat selection patterns of finches at El Garrapatero, an arid coastal ecosystem on Santa Cruz Island (Galápagos). The average 95% home range and 50% core area for G. fortis in the breeding season was 20.54 ha ± 4.04 ha SE and 4.03 ha ± 1.11 ha SE, respectively. For most of the finches, their home range covered a diverse set of habitats. Three finches positively selected the dry-forest habitat, while the other habitats seemed to be either negatively selected or simply neglected by the finches. In addition, we noted a communal roosting behavior in an area close to the ocean, where the vegetation is greener and denser than the more inland dry-forest vegetation. We show that telemetry on Darwin's finches provides valuable data to understand the movement ecology of the species. Based on our results, we propose a series of questions about the ecology and evolution of Darwin's finches that can be addressed using telemetry.
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| 2. |
- Camacho, Carlos, et al.
(author)
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Leucistic plumage as a result of progressive greying in a cryptic nocturnal bird
- 2022
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- Leucism, broadly defined as the lack of melanin pigmentation, occurs in many animal species. Most studies on leucism and other colour aberrations are based on opportunistic observations or small cross-sectional samples, thus limiting our ability to produce reliable results and test theoretical predictions. This study combines cross-sectional and longitudinal data collected in 2016–2020 from a population of red-necked nightjars (Caprimulgus ruficollis). The goals of the study are (i) to investigate sex and age effects on partial leucism, (ii) to separate within-subject effects (progressive greying) from between-subject effects (selective disappearance), and (iii) to examine differences in body mass, structural size, and life span between leucistic and non-leucistic individuals. The probability of leucism in nightjars increased from juveniles to adults at similar rates in males and females. Our longitudinal analysis and life-span comparisons indicated a minor contribution of selective disappearance to age-related changes in leucism, but rather suggested that the loss of melanin from feathers can be attributed to progressive greying in ageing adults. Body mass and size were consistently smaller (5% and 1.5%, respectively) in leucistic than in non-leucistic nightjars, although the reason for this difference remains unclear. Our study sheds light on the sources and mechanisms of variation in leucism in natural populations and its relationship with important life-history traits, such as life span.
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