Past LRC Projects
1
Black Skimmer Population Connectivity
The Black Skimmer (Rynchops niger) is a charismatic representative of coastal-nesting waterbird
communities in North America and freshwater riverine and coastal systems in South America. Skimmers are at
high risk of decline due to threats including habitat loss, human activity, and climate change throughout the
annual cycle. Microsatellite loci were used to reveal
genetic differentiation across the Americas to understand range-wide population connectivity of the Black Skimmer. This study documented a split between hemispheres with a lack of movement between North and South American populations.
2
Gull-billed Tern Dietary Plasticity
Large scale oceanic processes like the El Niño Southern Oscillation (ENSO) can have profound consequences for marine and coastal food webs. ENSO-related impacts to marine foragers has been documented for decades, and current research suggests that dietary flexibility may be a key component by which seabirds can mitigate environmental variation. While information is available for some marine foragers, there are relatively few projects assessing coastal bird responses. Our motivation for this research was to better understand how a dietary generalist in the coastal environment may respond to changes in prey food availability caused by oceanic events such as ENSO and marine heat waves, as the intensity and frequency of these events are expected to increase due to climate change.
3
American Oystercatcher Tradeoffs
American Oystercatchers are a conservation success story, but there are still gaps in knowledge about factors influencing their foraging ecology. In our study, GPS telemetry and mixed-effects models revealed that American Oystercatcher foraging behavior is shaped by a suite of factors including reproductive stage, nesting landscape, adjacent foraging habitat, tidal stage, and lunar illumination. Foraging distance decreases progressively throughout the breeding season. Significant differences in foraging distance were documented across habitats with barrier island nesting birds foraging substantially farther than marsh or dredge island birds. Oystercatchers foraged nocturnally at rates not previously documented, with tidal height and moon phase both influencing trip timing and distance. These tradeoffs suggest that a two-stage management plan is needed to increase the odds of both nesting success and brood survival.
4
Black Skimmer responses to flooding in the Peruvian Amazon
Black Skimmers typically nest in coastal environments. However, there are populations in South America
that nest along freshwater river tributaries, where they are subjected to threats from predation and flooding that differ from
coastal counterparts. We monitored Black Skimmers from a population in Manu National Park, Peru, over two breeding seasons
and compared their life history traits with those of Black Skimmer populations across the Americas. Mean clutch size, daily
nest survival rate, hatching success, and incubation period were within reported ranges. However, incubation bouts were short, provisioning rates were high, and chicks fledged about 10 days earlier than NA populations. Flooding accounted for 41%–61% of nest failures, concentrating mortality risk during early development. High food availability coupled with a tenuous nesting situation appears to select for individuals that exploit abundant food resources and maximize chick growth rates, such that a shortened growth period may
limit exposure to stage-specific
mortality influences.
