Biology subjects

Taylor, L. U.

Publications and source records attributed to Taylor, L. U..

4 recordsLinked to original sources

bioRxiv2024

Seabird and sea duck mortalities were lower during the second breeding season in eastern Canada following the introduction of Highly Pathogenic Avian Influenza A H5Nx viruses

H5N1 clade 2.3.4.4b viruses have caused significant mortality events in various wild bird species across Europe, North America, South America, and Africa. In North America, the largest impacts on wild birds have been in eastern Canada, where over 40,391 wild birds were reported to have died from highly pathogenic avian influenza (HPAI) between April and September 2022. In the year following, we applied previously established methods to quantify total reported mortality in eastern Canada for a full year October 2022, to September 2023. In this study, we (i) document the spatial, temporal and taxonomic patterns of wild bird mortality in the 12 months that followed the mass mortality event in the summer of 2022 and (ii) quantify the observed differences in mortality across the breeding season (April to September) of 2022 and 2023. In eastern Canada, there was high uncertainty about whether 2023 would bring another year of devastating HPAI-linked mortalities. Mortalities in the breeding season were 93% lower in 2023 compared to 2022 but encompassed a more taxonomically diverse array of species. We found that mortalities in the fall and winter (non-breeding season) were dominated by waterfowl, while mortalities during the spring and summer (breeding season) were dominated by seabirds. Due to a low prevalence of HPAI among the subset of tested birds, we refrained from broadly attributing reported mortalities in 2023 to HPAI. However, our analysis did identify three notable mortality events linked to HPAI, involving at least 1,646 Greater Snow Geese, 232 Canada Geese, and 212 Northern Gannets. This study emphasizes the ongoing need for H5NX surveillance and mortality assessments as the patterns of mortality in wild populations continue to change.

ecology↗

bioRxiv2024

Strengths and limitations of using participatory science data to characterize a wildlife mass mortality event

Large participatory science (i.e., "community science" or "citizen science") platforms are increasingly used at every level of ecological and conservation research, including disease monitoring. Here, we used a comprehensive, ground-truthed mortality dataset to judge how well participatory science data from iNaturalist represented the magnitude, taxonomic, temporal, and spatial patterns of waterbird mortality associated with a mass mortality event following the incursion of Highly Pathogenic Avian Influenza in eastern Canada in 2022. The iNaturalist dataset was effective at identifying species with high mortality (especially Northern Gannets, Morus bassanus), along with the time period and spatial regions with high concentrations of avian deaths. However, iNaturalist data severely underestimated the magnitude, overestimated the taxonomic breadth, and poorly represented the full geographic scope of disease-related deaths. Our results suggest iNaturalist can be used to identify the species, timing, and location of relatively high mortality in situations where no other information is available, and to supplement conventional sources of data. However, iNaturalist alone can neither quantify the magnitude nor pinpoint the mechanisms of mortality and therefore is not a viable substitute for comprehensive mortality assessments.

ecology↗

bioRxiv2023

Social context and the evolution of delayed reproduction in birds

One puzzling feature of avian life histories is that individuals in many different lineages delay reproduction for several years after they finish growing. Intraspecific field studies suggest that various complex social contexts--such as cooperative breeding groups, nesting colonies, and display leks--result in delayed reproduction because they require forms of sociosexual development that extend beyond physical maturation. Here, we explicitly propose this hypothesis and use a full suite of phylogenetic comparative methods to test it, analyzing the evolution of age at first reproduction (AFR) in females and males across 963 species of birds. Phylogenetic regressions support increased AFR in colonial females and males, cooperatively breeding males, and lekking males. Continuous Ornstein-Uhlenbeck models support distinct evolutionary regimes with increased AFR for all of cooperative, colonial, and lekking lineages. Discrete hidden state Markov models suggest a net increase in delayed reproduction for social lineages, even when accounting for hidden state heterogeneity and the potential reverse influence of AFR on sociality. Our results support the hypothesis that the evolution of social contexts reshapes the dynamics of life history evolution in birds. Comparative analyses of even the most broadly generalizable characters, such as AFR, must reckon with unique, heterogeneous, historical events in the evolution of individual lineages.

evolutionary biology↗

bioRxiv2023

Adolescent gulls have the opportunity for social development at breeding colonies

Most seabirds delay reproduction for multiple years. The long-standing ecological hypothesis is that seabirds delay reproduction until they pass a foraging efficiency threshold. This foraging development hypothesis is puzzling for seabirds with progressive delayed plumage maturation, such as American Herring Gulls (Larus argentatus smithsonianus). Young American Herring Gulls pass through a distinct series of predefinitive plumages in their early years, suggesting a process of adolescence rather than a binary switch between energetic immaturity and maturity. Drawing on facts from both colonial seabirds and tropical lekking birds, I propose an additional life history hypothesis: young gulls undergo a phase of social development--rather than foraging development alone--during which time predefinitive plumages function as signals that reduce the costs of social engagement at breeding colonies. I tested one facet of the hypothesis: predefinitive gulls have an opportunity for social development at colonies before breeding. A unique prediction is that predefinitive gulls are common at breeding colonies, socially engaged, and not breeding. I conducted counts, quantitative tests of territoriality and conflict, and qualitative behavioral observations of American Herring Gulls at two northwest Atlantic breeding colonies in the summer of 2022. Results supported all three prediction criteria. Birds in an advanced predefinitive plumage stage were common at colonies (2.0-5.8% of census) even while birds in earlier plumage stages were nearly absent (generally <1% of census). These predefinitive birds were socially engaged while loafing on--and losing fights in--foreign territories. Yet only one out of hundreds of predefinitive birds held a territory or nest. This phenomenon suggests the social conditions of breeding colonies can set the stage for social development that, in turn, sets the stage for life history and plumage evolution.

evolutionary biology↗