Pacific Black Brant Ecology
Pacific black brant are a species of international concern because of chronically reduced population size and low annual production. They are recognized by the U.S. Fish and Wildlife Service as Focal Species and pose conservation and management challenges because of their wide geographic range of breeding and wintering, sensitivity to human disturbance and over-harvest, and exclusive use of the near shore coastal zone. Mid-winter counts of populations have declined >30% over last 20 years, and recently, have approached threshold levels for cessation of sport and subsistence hunting set by the U.S. Fish and Wildlife Service. This downward trend in population size coupled with increased rates of habitat degradation and loss at primary staging and wintering areas prompted a cooperative research program between the U.S., Canada, and Mexico to identify factors limiting population size and improve management of these species. Research on black brant has focused on studies of movement, site fidelity, behavior, and habitat assessment during breeding and non-breeding (winter and migration) in Baja California and Alaska.
In recent years, efforts have been directed towards climate-induced effects and how changes in habitat (foods) and environmental conditions during non-breeding affect subsequent reproductive performance (breeding probability), fecundity and growth of this population. This project has amassed a large, multi-year data base of individual observations by season that is being used to show how survival probability varies with individual state and how climate in low latitude wintering areas can influence breeding in high latitude nesting populations.
Habitat assessments are focused on: 1) inventorying and mapping coastal (primarily intertidal) areas using state-of-the-art remote sensing techniques, 2) establishing programs to monitor spatial change in seagrass distribution, and 3) examining the morphology, phenology, and photosynthetic characteristics of seagrass populations along a latitudinal gradient.
Data and Resources
Website :: USGS Website