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Biology subjects

Moller, A. P.

Publications and source records attributed to Moller, A. P..

3 recordsLinked to original sources

Host space, not energy or symbiont size, constrains feather mite abundance across passerine bird species

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constraints symbiont populations. We parameterized metabolic theory equations to predict how bird species body size and the body size of their feather mites relate to mite abundance according to four potential energy (microbial abundance, uropygial gland size) and space constraints (wing area, number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance from 26,604 birds of 106 passerine species, using phylogenetic modelling and quantile regression. Feather mite populations were strongly constrained by host space (number of feather barbs) and not energy. Moreover, feather mite species body size was unrelated to their abundance or to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.

ecology↗

Urban birds' flight responses were unaffected by the COVID-19 shutdowns

The coronavirus disease 2019 (COVID-19) pandemic dramatically altered human activities, and, during shutdowns. Here, we evaluated whether urban birds from five countries changed their tolerance towards humans during the COVID-19 shutdowns. We collected 6369 flight initiation distance estimates for 147 bird species and found that human numbers in parks (at a given hour, day, week or year - before and during the COVID-19 shutdowns) had a little effect on birds tolerance of approaching humans. Apart from the actual human numbers in the area (hourly scale), the effect of human activity at other temporal scales centered around zero. The results were similar across countries, for most species or when we restricted our analyses only to species sampled both before and during the COVID-19 shutdowns. As expected, the level of daily human presence in parks (measured by Google Mobility Reports) correlated negatively with the stringency of governmental restrictions (a weekly proxy for human presence) and was overall lower during COVID-19 shutdowns than during the post-shutdown year (2022). Our results highlight the resilience of birds to changes in human numbers on multiple temporal scales, the complexities of linking animal fear responses to human behavior, and the challenge of quantifying both simultaneously in situ.

animal behavior and cognition↗

Pangenomics provides insights into the role of synanthropy in barn swallow evolution

Insights into the evolution of non-model organisms are often limited by the lack of reference genomes. As part of the Vertebrate Genomes Project, we present a new reference genome and a pangenome produced with High-Fidelity long reads for the barn swallow Hirundo rustica. We then generated a reference-free multialignment with other bird genomes to identify genes under selection. Conservation analyses pointed at genes enriched for transcriptional regulation and neurodevelopment. The most conserved gene is CAMK2N2, with a potential role in fear memory formation. In addition, using all publicly available data, we generated a comprehensive catalogue of genetic markers. Genome-wide linkage disequilibrium scans identified potential selection signatures at multiple loci. The top candidate region comprises several genes and includes BDNF, a gene involved in stress response, fear memory formation, and tameness. We propose that the strict association with humans in this species is linked with the evolution of pathways typically under selection in domesticated taxa.

genomics↗