Laurie Hall
Characterizing the dispersal patterns and social system of Marbled Murrelets (Brachyramphus marmoratus) using microsatellites
The Marbled Murrelet (Brachyramphus marmoratus) is an endangered seabird
in the state of California and is listed as a threatened species in
the U.S. and Canada (USFWS 1997, Piatt et al. 2007). Marbled Murrelet
populations have declined due to harvesting of old-growth forests, oil
spills, gillnetting, declines in prey availability, and increases in
nest predators (Peery et al. 2004a, Becker and Beissinger 2006, Peery
et al. 2006a, Becker et al. 2007). Tagging and demographic studies have
been unable to clearly describe the dispersal patterns and social system
of Marbled Murrelets, and previous genetic studies have found little
population genetic structure throughout the species range, making management
of this species challenging. This study will perform genetic population
assignments and relatedness tests for birds from the central
California
population to characterize the social system and dispersal patterns
of Marbled Murrelets. Genetic data from 14 microsatellite markers will
be analyzed in combination with demographic and morphological information
to identify migrant birds and compare differences in the number of migrants
among seasons, age classes, and genders. In addition, genetic data will
be used to examine reproductive skew and pair-bonding in Marbled Murrelets.
This information will improve management planning and facilitate conservation
efforts for this species.
Additional Activities and Research Interests
Adaptive genetic diversity of Marbled Murrelets
(Brachyramphus marmoratus)
The current proposal to remove Marbled Murrelets (Brachyramphus marmoratus)
from the federal threatened species list is based, in part, on the lack
of population genetic structure detected at presumed neutral genetic markers
such as mitochondrial DNA, nuclear introns, and microsatellites. We propose
to characterize adaptive genetic variation in Marbled Murrelet populations
from Alaska to California using the major histocompatibility complex (MHC).
MHC markers are functional genes involved in immune response that are
thought to be influenced by selection pressures and may diverge rapidly
even for large populations. We hypothesize that Marbled Murrelets will
have high genetic diversity within the MHC region examined and that genetic
differentiation among murrelet populations will occur at a finer scale
than detected previously with neutral markers.
Identifying the origin of Marbled Murrelets
recovered from a San Francisco Bay oil spill
Three
oiled Marbled Murrelets were recovered dead in Marin County, California
during the San Francisco Bay Oil Spill in November 2007. Murrelets disperse
on the order of several hundred kilometers from nesting areas in the fall,
so the breeding population of origin for these birds is unknown. We propose
to use genetic markers to identify the population provenance for the oiled
murrelets to help guide oil spill mitigation and habitat restoration efforts
in the region.
Centennial-scale declines in the genetic diversity of Marbled Murrelets
Population genetic methods provide a valuable tool for characterizing
the demographic history of rare or threatened species when field-based
monitoring studies are costly and time consuming.
In
this study, we used genetic bottleneck tests based on modern samples and
comparisons of modern versus historic levels of genetic variation to test
for declines in a small, geographically isolated population of Marbled
Murrelets.
Publications
Peery, M. Z., Hall, L. A., Bérubé, M. Selas, A., and Palsbøll, P. J. In review. Centennial declines in the genetic diversity of Marbled Murrelets. Conservation Genetics.
Peery, M. Z., Beissinger, S. R., House, R. H., Bérubé,
M., Hall, L. A., Selas, A., and Palsbøll, P. J.
In press. Characterizing source-sink dynamics with genetic parentage assignments.
Ecology.
Contact me: lhall@mlml.calstate.edu
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