Surveying Tidal Marshes across the Northeastern U.S.
Surveying Tidal Marshes across the Northeastern U.S.
Field Team Members: Mo Correll, Kate Ruskin, James Style, Brian Olsen and Tom Hodgman
Point count surveys – Maine to Virginia (Intensive demographic study in Scarborough Marsh, Maine)
National Science Foundation ‘Science360’ video feature link: http://news.science360.gov/archives/20120626
Tidal marshes are ecotonal systems that dominate the transition zone between terrestrial and marine communities in eastern North America (Reinold 1977, Mitsch and Gosselink 1993). Tidal marsh is critical for absorbing the energy of ocean storms and preserving shorelines (Daiber 1986), improving water quality in bays and estuaries (Heinle and Flemer 1976, Valiela and Teal 1979, Dame et al. 1986, Valiela et al. 2000, Koch and Gobler 2009), and supplying critical habitat for wildlife. Furthermore, the shoreline of eastern North America possesses the highest level of vertebrate biodiversity and endemism of any tidal marsh region worldwide (Greenberg and Maldonado 2006).
Tidal marshes are at risk of suffering degradation and loss, and therefore are a top priority for gathering information to develop and coordinate conservation actions. Climate change may impact the unique bird assemblage found in tidal marshes by increasing the frequency (Resio and Hayden 1975, Hayden 1981) and intensity (Emanuel 1987, Knutson 1998, Bacon and Carter 1991) of storm surges. Additionally, sea-level rise is projected to result in a loss of high marsh habitat on the Atlantic Coast.
In the face of habitat degradation and loss expected to affect tidal marshes given climate change predictions, a group of academic, government, and non-profit ecologists have formed the Saltmarsh Habitat and Avian Research Program (SHARP) to gather information to aid the conservation of this ecosystem. Our project will determine each state’s responsibility for the conservation of tidal marsh bird species thus providing a platform for long-term monitoring of the tidal marsh bird community within Atlantic coastline.
Dr. Brian Olsen and his students Mo Correll, Kate Ruskin, and James Style form the University of Maine contingent of SHARP. We are leading efforts to conduct point count surveys across the entire northeastern Atlantic coast and intensively monitor sparrow populations at local breeding sites. We completed our pilot season in 2011, our results are described below.
Objective 1 – Bird Use of High Marsh Communities
Goal – To map the abundance and distribution of all bird species using high tidal marsh habitat in the northeastern U.S. during the breeding season. Led by Ph.D. student Mo Correll, the UMaine team is coordinating point count surveys of marshes spanning from New York to Maine.
Approach – We conducted bird surveys using both passive and broadcast point count methods along the coast. Point count surveys consisted of a five-minute passive period followed by a series of broadcast calls for secretive marsh birds, for a total of 8-12 minutes per point. During this time all bird species detected by sight or sound were recorded.
Results – In 2011, SHARP surveyed a total of 1660 points across the region (Figure 1). At these points, a total of 230 species were observed, including federally endangered species such as the Piping Plover. In Maine, 312 points were surveyed. SHARP focal species of concern were detected at many points (Table 1). All points will be revisited and surveyed in 2012.
Focal Species Occurrence (% points where detected) in Maine
|American Black Duck||
Objective 2 – Assessing Geographic Trends in Demography
Goal – To quantify demographic rates for Species of Greatest Conservation Need across the region via intensive study of populations in several focal areas. Ph.D. student Kate Ruskin and M.S. student James Style are leading a demographic survey of tidal marsh sparrows in Scarborough, Maine.
Approach – We established three primary areas for intensive demographic studies in Maine, Connecticut, and New Jersey, supplemented by additional sites in New Hampshire and Rhode Island. In 2012, we plan to add further sites in New York. We believe this geographic scope will provide insight into the biology of saltmarsh breeding birds, given variation in climate, vegetation communities, and other species across the region. Sampling for Saltmarsh Sparrow will be especially comprehensive as our study sites span the range of this species.
In each study area, we established three 10-25 hectare focal plots. Field crews searched each plot for nests on a regular basis. All nests were monitored in order to track nest success and to gather information on the causes of nest failure. Crews also conducted systematic mist-netting at regular intervals throughout the breeding season and targeted mist-netting to capture females that were associated with nests. All captured birds were banded, measured, and release in order to gather information on survival rates and potential factors that might affect survival.
Results – All study plots were monitored for nesting from May through August 2011. Across the different sites, we found a total of 501 nests of the six focal species. In Scarborough Marsh, we found a total of 111 nests (Table 2). In Scarborough Marsh, the crew captured and banded a total of 234 adult and 19 juvenile sparrows via mist-netting. In addition, we banded 61 Sharp-tailed Sparrow chicks from monitored nests (Table 3). We successfully collected blood samples from females associated with nests to analyze for mercury and chicks for paternity analysis. The demographic survey will continue at Scarborough Marsh and other sites across the region in 2012 and 2013.
2011 Scarborough Marsh Nesting Summary
2011 Scarborough Marsh Banding Summary
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