Date of Award

11-25-2024

Publication Type

Thesis

Degree Name

M.Sc.

Department

Biological Sciences

Keywords

Arctic Passerine, Climate Change, Mismatch, Phenology, Snow Bunting, Songbird

Supervisor

Oliver Love

Supervisor

François Vézina

Abstract

Snow Buntings (Plectrophenax nivalis) are an Arctic-breeding cold-adapted songbird currently suffering from large population declines within the context of rapid environmental change. The goal of my thesis was to examine whether Snow Buntings can keep pace with the degree of climate change currently facing the Arctic. Specifically, we first examined whether Snow Buntings can phenologically adjust laying decisions to keep pace with climate change. We then studied the fitness consequences for phenological mismatches between Snow Buntings and arthropod prey by comparing how indices of temporal and biomass mismatch predicted offspring number and quality. To examine these questions, we used a long-term dataset (2007-2019) supplemented by two years of my own research (2022-23) from Qikiqtakuluk (East Bay Island), Nunavut to relate variation in environmental conditions and arthropod abundance to bunting lay date, clutch size, and success outcomes (e.g., fledging success and quality). In Chapter 2, we found that: i) Snow Buntings are extremely responsive to changes in temperature, ii) they rely on cues just days before investment in reproduction to time laying, and that iii) certain individuals can initiate laying at lower temperatures and therefore lay earlier than expected. In Chapter 3, we found that while a widely-used temporal mismatch index did not predict variation in breeding success, females timing breeding so that the peak of nestling demand matched higher arthropod biomass levels fledged the greatest number of offspring. However, neither the temporal nor biomass mismatch indices predicted fledgling quality. Together, these results are the first evidence of an Arctic breeding bird showing an adaptive response to climate change. For the first time, this thesis provides unique insight into the adaptive capacity of this Arctic passerine birds and suggests this species currently has the plasticity necessary to adapt to a rapidly changing Arctic.

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