Weekly Outdoor Report by Regional Wildlife Biologists 
Previous Reports
July 12, 2008
Birds, Birds, Birds!
In the mid 1980s, the Maine Department of Inland Fisheries & Wildlife began to integrate nongame bird management throughout what was then referred to as the Migratory Bird Project. Before this time, the Department’s accomplishments in bird conservation focused on waterfowl and American woodcock research and management, and marine wildlife studies.
Currently, in addition to their traditional gamebird work, Bird Group biologists spend a significant portion of their time on “all bird” issues, including Endangered and Threatened birds. The breadth of the Bird Group’s programmatic responsibilities involve stewardship of 223 bird species that nest in Maine, and many more that migrate through or winter in Maine. Below is a sample of MDIFW’s bird management projects.
Peregrine Falcon
The peregrine falcon has benefited greatly from federal and state partnerships in endangered species conservation. Formerly a breeding resident of coastal headlands and cliffs in mountainous regions, the species was extirpated from Maine and the entire eastern U.S. by the early 1960s. Like bald eagles and many other birds of prey, peregrines were the victims of DDE, a persistent by-product of the insecticide DDT. Decreased reproductive rates among peregrines persisted for decades, and worldwide threats of extinction coincided with eggshell thinning caused by this contaminant. Today there is no evidence of residual contaminant impacts on Maine’s re-established peregrines, but the population needs careful attention to monitor for this possibility or other related problems.
More than 35 nations have conducted programs to restore peregrine falcons. A total of 144 young peregrines produced in captive-breeding programs were successfully released at 8 different locations in Maine during the period 1984 through 1997. The Peregrine Fund, U.S. Fish and Wildlife Service, Acadia National Park, and MDIFW jointly conducted this venture using methods based upon traditional falconry techniques. Some peregrines reintroduced in Maine were encountered as breeding birds in New Hampshire, Massachusetts, and New York. Others have been documented as migrant visitors to points as far away as Cuba and Venezuela!
Despite these dramatic movements, others have returned to breed in Maine. A peregrine from the 1984 release in Baxter State Park found its way back to the same Penobscot County cliff in 1985 and reappeared in 1986 as the first adult peregrine searching for a home (and a mate) in Maine. The first pair of peregrines to reside in Maine chose a historic eyrie, Mount Kineo in Piscataquis County, as their new home in 1987. In 1988, a second pair appeared at “The Precipice,” the Acadia National Park cliff last inhabited by peregrines before their disappearance in the 1960s. Also that year, an Oxford County cliff became the first site of successful breeding by reestablished peregrines. Throughout the recent past, most peregrines breeding in Maine inhabited southern Oxford County near the state’s western border; but new peregrine eyries were found during 2007 in Cumberland County and Knox County. The first documentation of peregrine nesting in either in at least 50 years! Peregrines have inhabited a total of 26 different eyries over the last several years.
Many land managers have championed stewardship of peregrines nesting on their property: White Mountain National Forest, Maine Bureau of Parks and Lands, Seven Islands Land Co., Hancock Timberlands, and especially Acadia National Park. MDIFW and cooperating agencies manage several settings to mitigate potential recreational disturbances. Biologists can advise rock climbers where breeding peregrines are present. Hikers and rock climbers have assisted by reported peregrine sightings during their recreational pursuits. Peregrines have proven quite adaptable, and managers have successfully maintained peregrines in some high profile settings with only modest precautions.
Maine and most eastern states are now dependent mostly on state budgets for annual peregrine monitoring and management. Major increases of peregrines in the western U.S. are largely responsible for federal delisting of peregrines in 1999, but they are still recognized as Endangered Species under state jurisdictions in Maine and throughout the eastern U.S. For those who have witnessed the spectacular flight of a peregrine (whether in Baxter State Park or downtown Lewiston), it is an event not readily forgotten. Centuries of mankind’s fascination with the peregrine as the fastest-flying bird and an accomplished predator continue on!
Charlie Todd, Wildlife Biologist, Bangor
Freshwater Marshbirds
The Maine Outdoor Heritage Fund sponsored a series of marsh bird surveys as part of the Ecoregional Survey Project conducted by MDIFW. A total of 137 wetlands were surveyed for marshbirds in the southern, central, eastern, and northwestern portions of the state. Based on these surveys, MDIFW identified several marshbird species that warranted management concern because they are uncommon, have limited distributions, or show evidence of population decline. Also, three marshbird species support hunting seasons (i.e., Virginia rail, sora, common snipe), and population data are required for harvest management. The least bittern, common moorhen, American coot, and pied-billed grebe were found in relatively few wetlands during these surveys. All are considered rare or uncommon, and the hunting season for the common moorhen has been closed because of low numbers.
Least bittern and American bittern populations also may be declining. Least bitterns were not found recently in a few wetlands where they have been present in the past. American bitterns were encountered less frequently in southern than northern Maine, suggesting that population declines in southern parts of New England also may be occurring in southern Maine. Population trend data are important for managing hunted species, to identify significant population declines in game and nongame species, and to provide a basis for conservation actions.
Information on population trends for marshbirds is sparse throughout the northeastern U. S., because these species are inconspicuous, often widely dispersed, and difficult to routinely monitor. However, we have a unique opportunity to measure long-term population trends in Maine because there are data available from two separate marshbird surveys; the first conducted during 1989-90 and the second from 1998-2000.In 2005, we began a project to resurvey most of these wetlands to determine 15+-year trends in wetland occupancy and relative abundance of marshbird species. We also examined short-term trends (approximately 5-8 years) by resurveying about 20 sites that were originally visited during the 1998-2000 ecoregional surveys. We focused our efforts on the least bittern, American bittern, pied-billed grebe, common moorhen, Virginia rail, sora, common snipe, American coot, and marsh wren, but data for other wetland species was recorded. A graduate student from the University of Maine led the fieldwork for this project.
Survey crews revisited 75 wetlands during spring and summer. Each site was visited on at least 3 occasions. Virginia Rail was the most frequently encountered target species. Based on our preliminary data and comparisons with earlier surveys, we observed a significant increase in the number of wetlands occupied by American Bitterns and Virginia Rails, yet a significant decline in the number of wetlands occupied by Least Bitterns. We found no change in wetland occupancy by Pied-billed Grebes or Soras.
An assessment of habitat use by American Bitterns, Virginia Rails, Soras, Pied-billed Grebes, and Least Bitterns is nearly complete. In brief, based on preliminary data analyses, Least Bitterns, Virginia Rails, and Soras prefer wetlands with substantial components of emergent vegetation, Pied-billed Grebes are strongly associated with large wetlands that contain a high proportion of open water. American bitterns prefer shrub wetlands, but will nest in wetlands that are dominated by emergent vegetation as well. This work is being supported by Outdoor Heritage Funds, the Loon Conservation Plate Funds, the University of Maine, and the Maine Cooperative Fish and Wildlife Research Unit.
Thomas P. Hodgman, Wildlife Biologist, Bangor
Rusty Blackbird
The Rusty Blackbird (Euphagus carolinus) is a wetland-breeding blackbird of the boreal regions of northern North America. Formerly considered common, it has shown dramatic declines in numbers during the past century, with these declines accelerating since 1970. The cause of this continent-wide decline is not clear, although experts suggest several anthropogenic factors, including draining and conversion of wetlands in their wintering range, wetland acidification leading to declines of invertebrate prey, and disturbance from landscape changes. However, none of these hypotheses clearly account for both the magnitude and prolonged duration of this decline. During recent Ecoregional Surveys, sponsored in part by the Maine Outdoor Heritage Fund, MDIFW conducted roadside surveys of nearly 200 wetland sites in northwestern Maine. They found breeding Rusty Blackbirds at only 18 locations, and some of these were of just single singing males.
In late 2005, MDIFW began a study that involves a baseline inventory of the current geographic distribution and abundance of Rusty Blackbirds in Maine. These data will be used to a) examine the validity of state and regional population targets and b) to make recommendations for an effective monitoring program for this species on their breeding grounds. We also will compare current records with past distributional information to evaluate whether the species’ well-documented decline has a) effected its distribution in Maine, and b) if populations show fidelity to known breeding locations. Finally, we will assess a) how habitat selection in Maine differs from that reported from elsewhere in North America, and b) compare habitat features at currently occupied breeding sites with other seemingly suitable potential breeding sites in the state, to test hypotheses on why this species has declined and what habitat management options exist to aid in its recovery.
Based on a survey of 327 wetlands, Rusty Blackbirds were observed in only 19 (5.8 percent) wetlands. In comparison, during 2001-2002 Ecoregional Surveys, 187 wetlands were surveyed for Rusty Blackbirds yielding 18 (10 percent) observations. Of the 18 observations made during 2001-2002, 14 of those sites were recently re-sampled and produced only a single Rusty Blackbird observation.
We also thoroughly re-sampled 21 atlas blocks (the area encompassed by a 7.5’ topographic quadrangle), where Rusty Blackbirds had been reported previously by the Maine Breeding Bird Atlas. Only 5 of these 21 blocks produced observations of Rusty Blackbirds. Results of this resampling effort suggest both a population decline and a range contraction. Further surveys will be needed to confirm these findings.
An unexpected outcome of our surveys was our ability to locate Rusty Blackbird nests. We found seven nests among the 19 sites and monitored each nest periodically and confirmed that 100 percent successfully fledged young. We collected habitat data around each nest to better understand nest site selection by this species in northern Maine. We anticipate further surveys, nest searches, and habitat measurements, plus if sufficient birds can be captured, we will attach radiotransmitters to a few birds to monitor their movements and better understand their habitat use. This work is being supported by Outdoor Heritage Funds, Loon Conservation Plate Funds, Pittman Robertson Funds, and the University of Maine.
Thomas P. Hodgman, Wildlife Biologist, Bangor
Sharp-tailed Sparrow
Two species of sharp-tailed sparrows occur in Maine saltmarshes. Saltmarsh Sharp-tailed Sparrows (Ammodramus caudacutus) occur from the Penobscot Bay area southward, whereas Nelson’s Sharp-tailed Sparrow (A. nelsoni) occur coastwide.
Partners in Flight lists the Saltmarsh Sharp-tailed Sparrow as a “species of continental importance for the U.S.” and among a small number of watch list species in need of immediate conservation action due to multiple threats across their entire range. Saltmarsh Sharp-tailed Sparrows are recognized as a Priority 1 Species of Greatest Conservation Need in Maine’s Wildlife Action Plan and are considered a Species of Special Concern in Maine. The subvirgatus subspecies of Nelson’s Sharp-tailed Sparrow is nearly endemic to Maine and the Maritimes, where their range is disjunct from the two other subspecies in North America. Nelson’s Sharp-tailed Sparrow likely warrants Special Concern status in Maine.
Both species complete their entire life cycles within estuaries, nesting just a few centimeters above ground in tidal marshes. Oil spills, therefore, threaten both local populations and their habitats. Additionally, high levels of mercury in the blood of Sharp-tailed Sparrows, rising sea levels, and habitat degradation threaten populations. Despite similar appearance and habitat use, Saltmarsh Sharp-tailed Sparrows have much higher blood mercury levels than Nelson’s suggesting differences in food habits. Understanding differences in diet between these species would begin to illuminate differences in habitat use that could be used to help mitigate for habitat damaged during an oil spill and could provide a critical link to understanding the pathways of mercury uptake for sharp-tailed sparrows.
Specifically, diet information may help explain why Saltmarsh Sharp-tailed Sparrows accumulate mercury at an alarming rate, while Nelson’s, feeding in the same marsh do not.
The Department has undertaken a study to 1) determine diet of nestlings of both species of sharp-tailed sparrows, 2) determine intraclutch, age-specific, and temporal differences in diet, 3) examine abundance (i.e., availability) of different insect taxa within habitat types in the high marsh, and 4) examine relationships between adult sparrow habitat use and diet of nestlings. This study was catalyzed by two significant opportunities. First, 68 dead nestlings were collected during a previous graduate study. Nestlings died as a result of tidal flooding of their nests; the key cause of nest loss among these species. Second, an intern at the Wells National Estuarine Research Reserve has expertise in identification of insects and insect parts and an interest in gut analysis. This work is being supported by the U. S. Fish and Wildlife Service, the Maine Oil Spill Contingency Fund, and Loon Conservation Plate Funds.
Thomas P. Hodgman, Wildlife Biologist, Bangor
Northeast Coordinated Bird Monitoring Partnership
In the Northeast, dozens of state, federal, and nongovernmental organizations operate hundreds of bird monitoring programs. Results have been used to guide conservation, research, and management actions throughout the region. Although some effort at alignment has been made in recent years, most programs operate independently. The lack of coordination has resulted in redundant data collection, inconsistent field protocols, and occasionally flawed survey designs. Meanwhile, several high-priority species and habitats receive little or no monitoring attention. A coordinated approach is needed to better address bird conservation and management issues in our region.
In response, state, federal, and non-governmental organizations have teamed up to develop a coordinated approach to monitoring bird abundance, distribution, and demographics in the thirteen states of the Northeast (CT, DE, MA, MD, ME, NH, NJ, NY, PA, RI, VA, VT, WV). The Northeast Coordinated Bird Monitoring Partnership was formed to develop and implement a regional bird monitoring framework that will assist state wildlife departments, federal natural resource agencies, and other organizations in improving the coordination and effectiveness of their monitoring efforts. This initiative will catalogue existing bird surveys, build consensus on monitoring priorities, and develop and implement needed new programs in the northeast. It will draw on bird conservation plans and state wildlife action plans to identify key management issues that can be addressed through monitoring. Annual workshops will afford opportunities for coordination among existing surveys, while enabling program biologists to consult with leading statisticians on matters of survey design and analysis. The project’s website www.nebirdmonitor.org will provide easily accessible resources for coordinating bird surveys across the region, including an innovative data management system. This system, to be administered by the Avian Knowledge Network at the Cornell Lab of Ornithology, will feature a secure data archive, owner-specified access, and several options for data display and analysis. By providing new tools and collaborative opportunities, the partnership will help build the fundamental basis for science-based bird conservation in the Northeast.
Implementation is already underway in Maine. A pilot project begun in New Hampshire to monitor Whip-Poor-Wills has been expanded into Maine and other states in the northeast. Furthermore, Maine’s successful owl monitoring program has been modified by adding Northern Saw-whet Owls surveys to the newly implemented Whip-Poor-Will survey. This simple change both expands owl monitoring beyond Maine and more efficiently uses volunteers on both surveys.
Efforts are underway to solidify funding for monitoring mountain birds, begin coordinated monitoring for marshbirds, and design a program for monitoring Rusty Blackbirds. The Northeast Coordinated Bird Monitoring Partnership is made possible by a 3- year multi-state grant of Pittman Robertson Funds. Participation in project implementation is supported with Loon Conservation Plate Funds.
Thomas P. Hodgman, Wildlife Biologist, Bangor
Least Tern
Least terns are the smallest of four species of terns that nest along the coast of Maine. These Endangered birds nest on the same sandy beaches used by piping plovers in southern Maine. Nesting colonies of least terns in Maine are monitored and protected by biologists from the Department of Inland Fisheries and Wildlife, Maine Audubon, and Rachel Carson National Wildlife Refuge. During the recent past, the statewide population has fluctuated from 39 pairs at 3 sites in 1982, to 157 pairs at 5 nesting beaches in 2004. Since 1979, total productivity in Maine has ranged from 12 to 123 young fledged annually. In 2005, least terns nested on Stratton Island in Saco Bay for the first time, as well as on Western beach, which had been nourished the previous winter from dredge spoils from the Scarborough River. Western beach had not been occupied by least terns since the 1980s.
The erratic productivity of these birds in Maine can be attributed to human-related disturbances such as destruction of nests or young by humans and their pets or from predators such as crows, gulls, foxes, skunks, and raccoons, which are attracted to heavily used beaches because of food items and other bits of garbage left behind by beach-goers. Terns are also faced with challenges from natural events (e.g., tides, storms) and habitat alteration from coastal development.
Production of chicks in the last decade likely has not been sufficient to maintain the population. Management of least terns in Maine includes placing fencing and signs around nesting colonies and predator control. Public education, to inform recreational beach-goers and local residents about the conservation needs of least terns, is another important management activity. MDIFW and Maine Audubon have developed management recommendations for each of the nesting beaches to aggressively confront predation and disturbance problems. Funding for this work comes from the Outdoor Heritage Fund; Loon Plate and Chickadee Check-off funds; hunting license and permit revenues; and excise taxes on sporting arms, handguns, ammunition, and archery equipment (Pittman-Robertson Fund).
Lindsay Tudor, Wildlife Biologist, Bangor
