Biology subjects

Taylor, L. U.

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

10 recordsLinked to original sources

bioRxiv2026

Burrow disturbance, renovation, and collapse in a cavity-nesting seabird

Researcher disturbance can alter the behavior, survival, and breeding success of wildlife, with effects that are especially well-documented in waterbirds. Anecdotal reports suggest that disturbance can even cause cavity-nesting species to alter the structure of their nests. We used a long-term study of a burrowing seabird, the Leach's Storm-Petrel (Hydrobates leucorhous), to ask whether storm-petrels renovate existing burrows and whether such renovation is related to a history of researcher disturbance. Our study was conducted at the Bowdoin Scientific Station on Kent Island, New Brunswick, Canada, where in 2024 we measured the burrow architecture of 363 burrows, including length and structure for occupied and unoccupied burrows both inside and outside a long-term study site with consistent research activity. Of these, 150 burrows had been measured in 2006, allowing for direct longitudinal comparison of burrow architecture. Nearly all burrows changed in length over the 18-year study period (mean absolute change = 20.8 cm +- 18.2 SD). A linear model revealed two contrasting processes of burrow length change: more frequently occupied burrows grew longer, whereas initially longer burrows shortened towards mean burrow length (~50 cm) through collapse. Occupied burrows inside the long-term study site were on average 34% longer and significantly more complex than burrows adjacent to the site, suggesting that researcher disturbance directly or indirectly reshapes burrows. Overall, these results show that storm-petrel burrows are shaped by cycles of renovation and subsequent collapse that may be exacerbated by human disturbance. Given ongoing population declines in storm-petrels and other cavity-nesting seabirds, this study emphasizes the need to balance scientific research with minimizing disturbance, particularly in long-term studies.

ecology↗

bioRxiv2026

Scheduling problems and the energetics of biparental care in a model of imperiled seabirds

For organisms with biparental care, successful reproduction hinges on coordination between partners. Seabirds face an extreme coordination challenge because parents must schedule nest attendance on land with long-distance foraging trips at sea. We present a computational model of incubation schedules for a vulnerable seabird, the Leachs Storm-Petrel (Hydrobates leucorhous). Using only simple energetic rules and parameters, the model recapitulates natural incubation rhythms, exposes a tradeoff between parent energy and egg attendance, and predicts severe reproductive failure in harsh environments. Incubation primarily fails through "schedule breakdown" -- a single point in the season when both parents spend too long foraging and the egg dies from cold. The resilience of the developing offspring to neglect is thus a fundamental adaptation to the uncertainties of biparental care. These results raise new alarms about the indirect causes of reproductive failure in sensitive marine species and provide theoretical foundations for the evolutionary ecology of scheduling behaviors.

ecology↗

bioRxiv2025

An Experimental Study of Social Signaling through Delayed Plumage Maturation in a Colony-Nesting Seabird

Delayed development is a widespread evolutionary strategy that can reduce competition among highly social animals. Many seabirds exhibit delayed plumage maturation, in which young birds spend years in visually distinct predefinitive plumages before attaining the definitive plumage of adults. Previous work hypothesized that predefinitive plumages may function to reduce aggression towards young, predefinitive seabirds at breeding colonies, an idea known from other lineages of birds as the status signaling hypothesis. We tested this hypothesis with visual stimulus experiments at a breeding colony of American Herring Gulls (Larus smithsonianus). We presented painted models of four diYerent plumage classes (first-cycle predefinitive gull plumage, third-cycle predefinitive gull plumage, definitive gull plumage, and a Canada Goose as a control) and measured the aggressive responses of breeding adults at their nests. Breeding gulls responded with significantly less frequent, lower, and slower aggression toward the first-cycle and control plumages compared to the definitive plumage. There were no significant diYerences in response towards the third-cycle plumage. These results oYer support for a status signaling hypothesis, indicating that substantial, mottled brown plumage--as worn by first-cycle gulls--reduces aggression from breeding adults in colonies or foraging flocks. Future research can investigate how immature seabirds--including third-cycle gulls--may combine plumage, posture, and behavior to shift the dynamics of social behavior at breeding colonies.

animal behavior and cognition↗

bioRxiv2025

Global monitoring of wildlife mortality through participatory science in near-real time

Detection of wildlife mortality events is critical for timely conservation and natural resource management. We present an open-source, web-based decision support tool that queries, aggregates and summarizes participatory science data from iNaturalist to monitor mortality events worldwide. We demonstrate the effectiveness of this approach using four case studies spanning taxonomic, spatial, and temporal scales. In Canada and the United States, high peaks of bird mortality coincided with zoonotic risk during avian influenza outbreaks. Across Latin America, we detected 75 mortality events of critically endangered species. In California, recorded mammal mortality was associated with human infrastructure, including proximity to roads, and to a lesser extent, the human footprint. Mortality of pumas (Puma concolor) was detected across nine countries, highlighting the need for international cooperation to conserve mobile species. Our tool enables resource managers to flag emerging threats and empowers participatory scientists to monitor and integrate mortality records for conservation.

ecology↗

bioRxiv2025

Developmental evolution of social signals in the delayed plumage maturation of manakins (Aves: Pipridae)

Avian plumage maturation involves replacing feathers, via discrete molts, until reaching an iteratively-regenerated definitive plumage. In most birds, this process takes about one year. In the Neotropical lekking manakins (Pipridae), males of most species exhibit delayed plumage maturation (DPM), passing through drab predefinitive plumages for two or three years before reaching a bright, sexually dimorphic, definitive plumage. We used a phylogenetic analysis to investigate the evolutionary history of DPM in manakins. Our unique comparative dataset derived characters from a graph structure representing the developmental schedules of individual, colorful plumage patches. We traced the origin of one-year DPM to the ancestor of sexually dichromatic Piprinae manakins, followed by three separate origins of prolonged, two-year DPM, plus one subsequent extension to three-year DPM. Consistent with social signaling hypotheses, prolonged DPM evolved to reveal and maintain signals of young male status. This interspecific pattern sheds light on the sociosexual development of lekking birds, a topic usually restricted to autecological field studies. By detailing heterochronic dynamics in manakin plumage evolution, we also show how the iterative regeneration of characters like bird feathers, insect instars, mammalian antlers, and angiosperm flowers can create multiple distinct levels of developmental homologies among bodies, sexes, and species.

evolutionary biology↗

bioRxiv2025

Prebreeding populations and the importance of life history for conserving the world's imperiled seabirds

Seabird conservation often focuses on nestlings and breeding adults. Yet imperiled seabird populations also contain prebreeders, including juveniles and subadults, that wait several years before breeding at colonies. We use previously-published data on reproductive and survival rates for 84 species to quantify the conservation relevance of prebreeding seabirds. We find, first, that prebreeders average about half of seabird populations (median 47.4%, range 11.2%-66.7%). Second, while seabird population growth is much more sensitive to adult survival than prebreeder survival, human-driven changes may shift the importance of prebreeders for future population stability. Third, lowering the breeding age is a powerful, but underexplored, route to increasing population growth. Managing prebreeders could thus play a key role in protecting seabirds. This task may require answering fundamental questions about the behavior of young birds. Broadly, we suggest that life history characteristics (e.g., breeding age) actively shape both obstacles to, and opportunities for, successful conservation.

ecology↗

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↗