Avian Predation on Juvenile Salmonids in the Lower Columbia River.
Assess the magnitude of losses to avian predation of juvenile salmonids
from the Columbia River Basin that are listed under the U.S. Endangered
Species Act. Determine the distribution and size of breeding colonies of
fish-eating birds, measure diet composition, estimate consumption of juvenile
salmonids using bioenergetics modeling, quantify impact of these losses to the
demography of ESA-listed salmonid stocks from the Columbia River Basin,
and consult extensively with federal, state, and tribal resource management
agencies and other stakeholder groups on management options and the effects
of management. PI: Roby. Funding source: Department of Energy (BPA).
Caspian Tern Predation on Juvenile Salmonids in the Columbia River Estuary. Census the large Caspian tern breeding colony on Rice Island in the Columbia River estuary, measure nesting success, determine diet composition, estimate consumption of juvenile salmonids using bioenergetics modeling, and consult with resource management agencies on options for reducing the impact of Caspian tern predation on survival of ESA-listed salmonid smolts. PI: Roby. Funding source: Department of Defense (USACE). 1997-1999.
Barges as Temporary Breeding Sites to Assess Potential Colony Restoration for Caspian Terns. Test the feasibility of using barges as experimental colony sites for Caspian terns. Determine whether Caspian terns can be enticed to nest on barges and, if so, whether colonies on barges can be used to collect site-specific data on diet composition and nesting success. PI: Roby. Funding source: Department of the Interior (USGS, USFWS), Department of Commerce (NMFS), Department of Defense (USACE). 2001-2002.
Use of Pile Dikes and Jetties by Cormorants, Brown Pelicans, and Steller Sea Lions in the Columbia River Estuary. Measure the use of pile dikes, jetties, and other navigational aids in the Columbia River estuary as roosting, nesting, and haul out sites for endangered California brown pelicans, threatened Steller sea lions, and avian predators on juvenile salmonids (i.e., cormorants). Evaluate potential effects of pile dike and jetty repair, replacement, or removal on ESA-listed species and their predators. PI: Roby. Funding source: Department of Defense (USACE). 2000-2002.
A Satellite Telemetry Study of the Endangered Short-tailed Albatrosses: Oceanic Habitat Selection, Foraging Behavior, and Potential Conflicts with Long-Line Fisheries. Investigate how endangered short-tailed albatrosses respond to spatial and temporal variability in their pelagic environment, including (1) quantify the foraging range and marine habitat use during breeding and post-breeding, (2) identify environmental variables and oceanographic features that most influence at-sea distribution, and (3) identify potential conflicts with long-line fishing fleets in the North Pacific. PI: Roby. Funding source: Department of the Interior (USFWS). 2001-present.
Population Size, Productivity, and Food Habits of Seabirds Nesting on St. Lawrence Island, Alaska. Develop bioindicators of ecosystem structure and health for the Bering Sea using plankton-feeding and fish-eating seabirds nesting on St. Lawrence Island. Develop effective and reliable approaches to assessing population size, nesting success, and diet composition of seabirds. PIs: Roby and Irons. Funding source: Department of the Interior (USFWS). 2000-present.
A Review of the Nutritional Stress Hypothesis in Seabirds and Sea Lions: Effects of Diet Quality on Productivity of Apex Marine Predators. Evaluate available evidence on the role of nutritional constraints for limiting recovery of top trophic-level predators from declines that occurred following ocean regime shifts in the North Pacific Ocean during the late 1970s. Low availability of high-lipid prey may have caused a variety of piscivorous seabirds and marine mammals to decline in the subsequent two decades. PI: Roby. Funding source: North Pacific Universities Marine Mammal Research Consortium. 2001-present.
Diet Composition, Reproductive Energetics, and Productivity of Seabirds
Damaged by the Exxon Valdez Oil Spill. Assess the role of food constraints
in limiting the recovery of seabird populations injured by the Exxon Valdez
oil spill. Measure (1) diet composition of seabirds in the field, (2) energy
content of seabird prey in the laboratory, (3) energetics of nesting seabirds,
and (4) the role of various forage fish resources for limiting reproductive
success of seabird species injured by the spill. PI: Roby. Funding source:
Department of Commerce (NMFS). 1995-2001.
Effects of Diet on Growth and Development of Nestling Seabirds. Test the hypothesis that diet quality is a key limiting factor for seabird nesting success. Raise nestling seabirds in captivity on restricted diets of particular seabird prey, measure growth and development rates in relation to energy intake rates, measure energy assimilation efficiency on the various diets, and thereby assess the quality of various forage fishes as food for young seabirds. PIs: Roby and Piatt; Funding source: Department of the Interior (USGS). 1996-1998.
Pigeon Guillemot Restoration Research at the Alaska SeaLife Center. Investigate potential factors limiting recovery of Pigeon Guillemots, a seabird species damaged by the Exxon Valdez oil spill that has failed to recover, including (1) assess effects on nestling health of residual oil in food and develop nondestructive biomarkers of exposure to petroleum hydrocarbons and (2) understand how dietary factors constrain growth, development, and condition at fledging of young guillemots. PI: Roby. Funding source: Department of the Interior (USGS). 1998-2002.
Behavioral Constraints to Harlequin Duck Recovery from the Exxon Valdez Oil Spill in Prince William Sound, Alaska. Investigate the effects of crude oil ingestion on the behavior and time-activity budgets of Harlequin Ducks, a sea duck species that was damaged by the Exxon Valdez oil spill and has failed to recover. Test the hypothesis that chronic ingestion of sublethal doses of weathered crude oil increases energy requirements and foraging times of Harlequin Ducks. PI: Esler. Co-PI: Roby. Funding source: Department of the Interior (USGS). 2000-present.
Effects of Low-altitude Jet Aircraft Overflights on Nesting Success of Threatened
Peregrine Falcons. Determine the impact of military jet overflights on the nesting
success of Peregrine Falcons in interior Alaska. Quantify the behavioral responses
of nesting Peregrine Falcons to jet overflights, determine those overflight
characteristics most responsible for variation in falcon response, assess the
relationship between behavioral response and subsequent nesting success, and measure
the noise dose/productivity response relationship. PI: Roby. Funding source:
Department of Defense (USAF). 1994-1999.
Effects of Disturbance on Roosting Behavior of Endangered California Brown Pelicans in the Columbia River Estuary. Investigate the impact of anthropogenic and natural disturbances on the behavior and size of the night-time roost of California Brown Pelicans on East Sand Island in the Columbia River Estuary, the largest pelican roost in the Pacific Northwest and an incipient breeding colony. PI: Roby. Funding source: Department of Energy (BPA). 2001-present.