Evolution of High Latitude Birds
Questions addressing the mechanisms of population differentiation continue to engage and challenge evolutionary biologists including myself. Molecular markers can be used to help provide us with important insights and potential answers to this critical question and in turn advance our knowledge of the mechanisms of speciation. My research program examines how historical and contemporary ecological factors have affected patterns of genetic variation in high latitude species. I am comparing levels of genetic variation in previously glaciated and unglaciated regions to infer patterns of recolonization; and to examine the role of physical and non-physical barriers to dispersal.

Razorbills
Razorbills are one of the rarest breeding seabirds in Atlantic Canada. Little is known of the relationship between breeding and wintering areas. We are using microsatellite markers to assess population structure of breeding sites and the extent of mixing on the wintering grounds.

Collaborator: Vicki Friesen

Chickadee Hybrids
Chickadees are known to hybridize. We used molecular markers to examine the level of hybridization between mountain and black-capped chickadees in areas of sympatry and allopatry.

Collaborators: Ken Otter and Angelique Grava

Amsterdam Albatross
The Amsterdam albatross breeds in the Indian Ocean. It is currently listed as critically endangered and there are fewer than 100 birds. We are examining levels of genetic variation in this small population and comparing it to closely related species found in the Southern Ocean.

Collaborator: Henri Weimerskirch

Songbird Speciation
I used molecular markers to study phylogeography of songbirds in western North America. During the Pleistocene glaciation, it is believe that many plants and animals survived in an ice-free refugium on the northeastern tip of the Queen Charlotte Islands. I used genetic markers to determine if the morphological variation found in many of these avian species/subspecies is the result of historical isolation or postglacial colonization and subsequent genetic drift. Specifically, I am examined the role of glaciation on passerine speciation in western North America.

Collaborators: Vicki Friesen and Tony Gaston

Albatrosses Mating Systems, Phylogeography and Speciation
I studied mating systems, population structure and systematics of black-browed, grey-headed and wandering albatrosses. Using microsatellite markers, I determined that extrapair paternities were present in all three albatross species and that there was considerable interannual variation within each species. I also examined macrogeographic population structure in the three different taxa using a combination of mtDNA and microsatellite markers. Despite having similar geographic ranges, each species exhibited a different phylogenetic pattern that could be attributed to species-specific foraging patterns. Species foraging in open oceans, such as grey-headed albatrosses, showed no population structure while coastal foraging species, such as black-browed and wandering albatrosses, showed some level of population structuring. I was able to use assignment tests to examine albatross bycatch and assign birds to island groups. Genetic results showed that the recent taxonomic revisions need to be further revised. Molecular analyses show black-browed albatross from the Falkland Islands are genetically distinct from other T. melanophris and that the level of differentiation between the two species of wandering albatross in New Zealand is considerably lower than that found between other species of wandering albatross.

Supervisors: Bill Amos and John Croxall

Unravelling Dispersal Patterns in Northern Fulmars
Using mtDNA we were able to study the recent, rapid expansion of the northern fulmar in the North Atlantic. In the late 18th century, fulmars in the North Atlantic were confined to Iceland and St. Kilda off the west coast of Scotland. During the last 100 years, the fulmar population has undergone a rapid range expansion and fulmars are now found throughout the North Atlantic from Newfoundland to France. We attempted to determine if the expansion involved birds from Iceland, St Kilda or a combination of both. While levels of variation were higher in the Icelandic populations, we could not rule out the possible that St. Kilda played a role in the population expansion.

Collaborators: Mike Brooke and Bill Amos

Supervisors: Michael Smith and Andrew Trites