Seabird Monitoring and Response to Independence Day Fireworks Displays at Two Locations within Oregon Islands National Wildlife Refuge, Oregon.

摘要

Oregon supports 1.3 million seabirds of fifteen species, with 393 breeding colonies distributed along all parts of the coast. The majority of colony sites are located within Oregon Islands and Three Arch Rocks National Wildlife Refuges (NWR), which are designated as Wilderness Area. Seabirds play an important role in the marine ecosystem and their populations must be protected and closely monitored. Seabirds are extremely sensitive to human disturbance and single disturbance events can cause mortality of eggs and young or result in colony abandonment by adults. One source of disturbance that has been little studied is the impact of large-scale celebratory fireworks near seabird colonies, which can occur during a critical period (July) of the seabird nesting season. In this study, we examined potential responses and effects on local seabird population abundances (daily counts) and reproductive success from commercial Independence Day fireworks displays at two locations within Oregon Islands NWR including Pirate Cove Rock, Depoe Bay, Lincoln County and rocks adjacent to Coquille Point, Bandon, Coos County, Oregon. The study area consisted of two treatment sites: Pirate Cove Rock and Coquille Point Seabird Colony Complex; and two reference sites: Yaquina Head Seabird Colony Complex and Gregory Point Seabird Colony Complex. We conducted daily counts of six seabird species and monitored nests of Brandts cormorants, double-crested cormorants, pelagic cormorants, western gulls, and black oystercatchers from land vantage points. We also conducted aerial photographic surveys to document numbers of nests and nest fate for each colony. In addition, we examined bird behavior prior to and during the fireworks display using night-vision camera equipment that recorded night-time still-frame and video images.