Avian Use of Northeast Creek and Bass Harbor Marsh in Acadia National Park 2001-2002

Wilson, Paul; Longcore, Jerry; Sauer, John; Anderson, Karen

Field Work: April - October 2001 and March - August 2002. Note: Field work spanned both lands 'owned' by the NPS at the time of the study, lands within the legislated fee boundary of the park but not 'owned' at the time of the study, and areas outside the legislated fee boundary of the park. Following from abstract: 'We surveyed avian communities of two estuarine-influenced wetlands, Bass Harbor Marsh (BHM) and Northeast Creek (NEC), located on Mount Desert Island, Maine. We ascertained community composition of avifauna, relative abundance of species, and seasonal distribution of species in these wetlands during 2001 and 2002. Our intent was to determine which marsh habitats were especially valuable for species diversity, which supported high breeding densities, and which supported regionally uncommon species. Our findings address management interests and identify those areas of these wetlands that are the most ecologically valuable as bird habitat. Some unprotected, but quality wetland habitat areas may be appropriate for acquisition by Acadia National Park (ANP), National Park Service (NPS).' 'Our surveys located 152 species of which 123 species were located in Bass Harbor Marsh and 135 were recorded in Northeast Creek. Sixty-two species were determined to be confirmed, possible, or probable breeders, whereas 90 were non-breeders. Bass Harbor Marsh contained 47 confirmed, possible, or probable breeding species and 75 non-breeding species, and Northeast Creek contained 53 confirmed, possible, or probable breeding species and 82 non-breeding species. Species richness of breeders was not different between BHM and NEC for 2001 but was different in 2002. Species richness was significantly higher in NEC as compared with BHM during 2002. Similarly, species richness was significantly higher in NEC in 2002 as compared with NEC in 2001. Maximum diversity and evenness were similar between years and marshes. Based on point count data, we present relative abundance of species for both marshes. Ascertainment of breeding was primarily based on data collected during point count surveys unless nests were located. In both wetlands we detected greater density and diversity of breeding species in forested habitat (i.e., forested wetland and forested upland) and shrub-dominated habitats than species breeding in other wetland habitats. Counts of individual breeders were high in grassland-like, forested, and shrub-dominated habitats. Regionally common wetland breeding species (e.g., Common Yellowthroat (Geothlypis trichas), Yellow Warbler (Dendroica petechia), Swamp Sparrow (Melospiza Georgiana)) were detected in higher abundance than regionally less common wetland breeders (e.g., Virginia Rail (Rallus limicola), Piedûbilled Grebe (Podilymbus podiceps)). Regionally uncommon species nesting in the wetlands included Least Bittern (Ixobrychus exilis), Nelson's Sharp-tailed Sparrow (Ammodramus nelsoni), and Northern Harrier (Circus cyaneus). The Virginia Rail was a possible breeder. Duck productivity was lower than expected, although American Black Duck (Anas rubripes) and Mallard (Anas platyrhynchos) were common nesting species. Two species listed as Maine state or federal endangered or threatened birds were recorded during the survey. The Bald Eagle (Haliaeetus leucephalus), a Maine state endangered and federally threatened species, was a rare species in BHM and an uncommon species in NEC. Peregrine Falcon (Falco peregrinus) (Maine state endangered and federally delisted) was a rare species in NEC.' (See external holding link for full report.) /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/Bass Harbor Marsh/Northeast Creek

Avian Use of Northeast Creek and Bass Harbor Marsh in Acadia National Park 2001-2002

Series