RESEARCH | ecol-evol

RESEARCH PROJECTS

Avian demography under one million years of climate change

We use full-genome sequence data from hundreds of bird species to evaluate demographic change in the face of climate change and human expansion over the past million years. This project, funded by the Danish Research Council, involves a consortium of researchers from universities, museums, and genomic centers around the world. Ongoing results from this work inform our understanding of how biodiversity will respond to current and ongoing environmental challenges, allowing us to make more realistic demographic predictions to help stem global biodiversity loss.

Illustration by Jon Fjeldså

The relative effects of genetic and individual variation versus habitat quality on fitness

Much of our past and ongoing research focuses on disentangling the effects of habitat quality versus genetic and among-individual variation on measures of fitness. To address this topic, we primarily rely on the long-term study population of song sparrows (Melospiza melodia) on Mandarte Island (British Columbia, Canada), which has been monitored continuously since 1975.

Each year, every nesting attempt on this small island is located and all offspring are banded and followed until independent from parental care. This effort over the past four decades allows for highly detailed estimates of both habitat preference and habitat quality. Because all individuals in this resident population are monitored over their lifetime, we are able to accurately measure variation in individual fitness and use the detailed pedigree to determine the heritability of fitness traits.

Long-term demographic monitoring of huntable waterfowl in Europe

Our group works with inter-governmental organizations and NGOs to estimate abundance and help set sustainable harvest levels for key huntable goose and duck species in Europe. This highly-collaborative work involving national researchers, wildlife managers, and policy advisors also allows us to address practical research questions related to detection probability in wildlife counts, migratory flyway delineations, and the effects of climate change on population trends and harvest potential over time.

The effects of polyandry on population relatedness structure and inbreeding

Our more theory-focused work centers on estimating the effects of female multiple mating (‘polyandry’) on the potential for inbreeding in wild populations. The widespread occurrence of polyandry in nature suggests some intrinsic benefit to this behaviour, despite its obvious costs. However, we have very little empirical basis on which to consider how the evolutionary dynamics of mating systems could be influenced by the effects of polyandry on population-wide relationship structures (Figure) and the resulting potential for inbreeding.

Developmental-based variation in sexual signals

Many animals use conspicuous visual and vocal displays in both courtship and territorial interactions, as such displays often act as signals of individual genetic and/or phenotypic quality. However, we have only a limited understanding of how the information conveyed through such signals changes when displays themselves develop or change over an individual’s lifetime.

Our work on this topic has so far focused on the delayed maturation of sexual signals in the American redstart (Setophaga ruticella), a migratory warbler with dramatic age-based differences in male plumage colouration. Using populations on both the breeding grounds (Queen’s University Biological Station, Ontario, Canada) and wintering grounds (Font Hill Nature Preserve, Westmoreland Parish, Jamaica), we found that a more adult-like appearance may signal a juvenile male’s competitive ability for high-quality resources during both stages of the annual cycle. We further uncovered developmental differences in the mate-attraction song of male redstarts, indicating that males of this species exhibit delayed song maturation as well as delayed plumage maturation.

Natural history and miscellany

We enjoy conducting research on a variety of topics related to natural history and wildlife conservation, and have formed great collaborations with people who feel the same way. This has led to a number of fun studies on diverse subjects such as evidence-based conservation area design, predation on passerines living in gull colonies, the effects of highways as barriers to mammal movement, and how ecologists can effectively target their research audience. Please see our publications page for more information.