BREEDING ECOLOGY OF PRAIRIE NESTING SHOREBIRDS: RELATIONSHIPS WITH HABITAT, LAND USE AND PREDATORS
Date
1961
Authors
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ORCID
Type
Degree Level
Undergraduate
Abstract
Some prairie shorebird population shave declined over the past century as a result of
hunting pressure and from habitat loss due to agricultural expansion. While habitat loss and
fragmentation likely were ultimate factors contributing to these declines, an increase in nest
predation by mammalian predators within breeding habitats may potentially be aproximate
cause.
Species such as red fox, skunk, raccoon and coyote have readily adapted to intensively
farmed landscapes and resulting predation levels may have detrimental effects on
many
ground-nesting species, including shorebirds. To assess partial effects of predation on prairieĀ
nesting shorebirds in 2000 and 200I, I monitored nesting success of seven shorebird species
in intensively cultivated landscapes of southern Saskatchewan where large mammalian
predators had been removed (4 study sites) and areas without predator removal (4 sites).As
expected, removal of mammalian predators increased nest success, but the effect varied with
shorebird' species, among removal sites and between years. Interspecific differences in nest
success
may have been influenced by compensatory predation by other non-target predators,
or by differences in habitat use, body size and nest defense by incubating adults.
Another hypothesized factor affecting nesting success in shorebirds is habitat
preferences or, more
specifically, characteristics of nesting habitat, including micro-site
features. Nesting sites that reduce nest predation should be advantageous, and there is ample
evidence of non-random nest site use in shorebirds and other bird species. Therefore, I
examined nest site selection patterns at nest site (fine) and habitat patch (course) scales in
five shorebird species. At a coarse scale, I found that native pasture (willet and upland
sandpiper) and wetland margins (Wilson's phalarope)were used more often than expected
(when compared to random sites).Ata finer scale, phalarope nest site characteristics differed
significantly from those at random sites, which provides evidence that patterns in nest site
selection could result from long-term selection. However, there were no
significant
differences between successful and depredated nests, and the lack of similarity between nest
sites and successful nests further indicates little support for an ongoing refinement of nest site
selection patterns in phalaropes in response to current predation pressure.
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Degree
Master of Science (M.Sc.)
Department
Biology
Program
Biology