Demographic shifts and the role of climate warming in a switch from migrant to resident life history
department or school: Forestry, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Visty, Hannah
issued: 2018-11-21T17:00:28Z
issued: 2018
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Identifying causes and consequences of variation in species life history should improve predictions about how climate and land use change will affect the demography and distribution of species in future. Sooty fox sparrows (Passerella iliaca unalaschcensis) were documented as obligate migrants, abundant in winter but with only three breeding records in coastal habitats of British Columbia and Washington prior to 1950. Because this subspecies has since established year-round resident populations in this region, I studied resident populations of sooty fox sparrows to test theory on how climate change and life history might affect the demography and distribution of a new partial migrant. I estimated demographic vital rates in one recently established resident population on Mandarte Is., BC, using color-banded birds. Annual fecundity (F) was higher than reported in migrant populations studied previously in Alaska and Newfoundland, supporting the hypothesis that residents invest more in reproduction on average than migrants within species. I also estimated high juvenile and adult overwinter survival (Sj = 0.32 ± 0.06, and Sa = 0.69 ± 0.05) and population growth (λexp = 1.61 ± 0.57), implying rapid population growth. I next tested the hypothesis that climate warming facilitated the establishment of resident populations by reducing the net benefit of migrating out of the wintering area to breed. Because resident sooty fox sparrows breed earlier and longer than migrants, I asked if climate warming during the pre-breeding period coincided with patterns of establishment by: 1) characterizing the pre-breeding climate niche of resident populations using species distribution models, occurrence data, and monthly climate records, and 2) testing if the emergence of the pre-breeding climate niche currently occupied by resident populations corresponds to the first reports of sooty fox sparrows breeding after 1920. Niche models suggest that the mild, near-shore climate niche now occup…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/67827
note: DEMOGRAPHIC SHIFTS AND THE ROLE OF CLIMATE WARMING IN A SWITCH FROM MIGRANT TO RESIDENT LIFE HISTORY by Hannah Visty B.Sc., The University of British Columbia, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) November 2018 © Hannah Visty, 2018 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis/dissertation entitled: Demographic shifts and the role of climate warming in a switch from migrant to resident life history submitted by Hannah Visty in partial fulfillment of the requirements for the degree of Master of Science in Forestry Examining Committee: Dr. Peter Arcese, Forestry Supervisor Dr. Kathy Martin, Forestry Supervisory Committee Member Dr. Andrew Trites, Zoology Additional Examiner Additional Supervisory Committee Members: Dr. Scott Wilson, Environment Canada Supervisory Committee Member iii Abstract Identifying causes and consequences of variation in species life history should improve predictions about how climate and land use change will affect the demography and distribution of species in future. Sooty fox sparrows (Passerella iliaca unalaschcensis) were documented as obligate migrants, abundant in winter but with only three breeding records in coastal habitats of British Columbia and Washington prior to 1950. Because this subspecies has since established year-round resident populations in this region, I studied resident populations of sooty fox sparrows to test theory on how climate change and life history might affect the demography and distribution of a new partial migrant. I estimated demographic vital rates in one recently established resident population on Mandarte Is., BC, using color-banded birds. Annual fecundity (F) was higher than reported in migrant populations studied previously in Ala…
has type: Thesis/Dissertation
date issued: 2019-02
is shown at: 10.14288/1.0374159
language: eng
degree discipline: Forestry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-ShareAlike 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-sa/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/67827