Monitoring programs are an important part of responsible management. Only through knowledge of the status and trends of a species, and the habitats in which it occurs, can managers take appropriate actions. Migratory birds nest throughout North America, with some species nesting as far north as the high Arctic. In late summer and fall, many species migrate south for the winter. Some North American species winter in South America, while others only go as far south as the southern USA, Mexico, or Central America.
Information such as population size and trend, geographical distribution, annual breeding effort, the condition of their breeding and wintering habitats, and for hunted species, the number of hunters and the anticipated harvest, is needed for proper management.
Monitoring efforts are numerous and varied, and are undertaken by a wide variety of organizations. The Office of Migratory Bird Management undertakes a number of surveys in conjunction with the U.S. Fish and Wildlife Regional Offices, the Canadian Wildlife Service, and State and Provincial wildlife-management agencies. Some of these are listed below, along with other surveys by other organizations. The list is neither inclusive nor exhaustive, but merely identifies a number of surveys that are of national interest.
The Migratory Bird Harvest Information Program (HIP) is a method by which your state wildlife agency and the U.S. Fish and Wildlife Service (Service) are developing more reliable estimates of the number of all migratory birds harvested throughout the country.
In July a portion of the lines surveyed in May during the Breeding Waterfowl Survey are surveyed to obtain information on duck production. These counts yield measures of duck production and give an idea of the timing of nesting chronology for the year, assess water body abundance, and result in a qualitative assessment of July habitat conditions. The July brood counts are not adjusted for visibility bias and thus provide only a relative index rather than a direct estimate. The July Duck Production Survey is helpful in predicting the number of ducks to be expected during the Fall hunting season.
Prairie Pothole (Credit: USFWS)
May Breeding Waterfowl and Habitat Survey
Each May and June the Canadian Wildlife Service and the U.S. Fish and Wildlife Service survey breeding waterfowl from the north-central U.S. throughout Canada and Alaska. Survey biologists estimate numbers and species from airplanes flown along transects. A portion of the transects are then surveyed from the ground by biologists who census all waterfowl. The ground census corrects for birds not counted by the aerial team. This survey is the most extensive wildlife survey in the world, and its results are a major factor used in setting annual duck-hunting regulations. Excellent survey data exist in the form of graphs for mallards, gadwall, American wigeon, green-winged teal, blue-winged teal, northern shoveler, northern pintail, redhead, canvasback, and scaup.
Mourning Dove Call-Count Survey
The Mourning Dove Call-Count Survey was developed to provide an index to population size and to detect annual changes in mourning dove breeding populations in the U.S. The survey consists of numerous routes throughout the U.S., which are surveyed in late May and early June. The resulting estimates of relative abundance and population trends comprise the principal information used in the annual setting of mourning dove hunting seasons.
Mourning Dove Survey (Credit: USFWS)
Many geese and ducks can't be counted in the spring and summer on breeding areas because they either can't be surveyed using airplanes or they nest in remote and inaccessible Arctic areas. Abundance indices for these species are obtained from surveys on wintering areas. Most of these surveys are targeted at specific species or populations. A nationwide effort to survey all waterfowl is conducted annually in January. This, the Midwinter Survey, provides information on population trends for some species, distribution on the wintering grounds, and habitat use.
Woodcock Singing-Ground Survey
The Woodcock Singing-Ground Survey exploits the conspicuous courtship
display of the male woodcock. The survey consists of numerous routes
in the eastern half of the U.S. and Canada, which are surveyed in the
spring. Counts of singing male woodcock along the routes provide an
index to woodcock abundance, and are used to estimate woodcock population
trends for states, provinces, management regions, and the continent.
The survey is the major source of information considered in the annual
setting of woodcock hunting seasons.
The Christmas Bird Count (CBC) was initiated by the National Audubon Society in 1990 and has been sponsored annually by that organization ever since. Although designed primarily for fun and recreation, the CBC also provides valuable information on status and population trends of selected species. For a detailed look at the information provided by the CBC, go to the CBC Home Page.
Bird Banding Lab
Every year the U.S. Fish and Wildlife Service, the Canadian Wildlife Service and State and Provincial wildlife management agencies band about 300,000 migratory game birds. Management agencies, ornithological institutions, researchers, and private individuals also band approximately 700,000 nongame birds annually. These banded birds and their recoveries are an important data source used in the management of migratory birds. The Bird Banding Laboratory (BBL) of the U.S. Geological Survey and the Banding Office of the Canadian Wildlife Service jointly manage the bird-banding program in North America. Analysis of banding data allows calculation of important population parameters such as survival rates and harvest rates.The calculation of harvest rates is one of the most important uses of banding data. Annually, 87% of all recoveries reported to the BBL are from waterfowl. However, of all the banded birds recovered by hunters, only 30-40% are reported to the Banding Laboratory. Given the tremendous cost associated with the banding effort and the reliance on banding as an essential management and research tool, the loss of data associated with this low band-reporting rate is regrettable. The Service and the BBL have undertaken efforts to increase the number of bands reported. A new address was inscribed on bands several years ago; this address includes a zip code ensuring that the Postal Service routes recoveries to the BBL. In 1996, the effort to increase the number of bands reported will expand. A new toll-free telephone number to report band recoveries is now available. Bands, with the new number, were placed on an experimental group of birds in 1995 and efforts have been expanded in 1996. For more information on reporting band recoveries, link to the band recovery information page.
The Breeding Bird Survey (BBS), a roadside survey designed to monitor population trends of land birds, was initiated by the Fish and Wildlife Service on an experimental basis in 1976. In the mid-1980s, the BBS became an operational survey coordinated by the Office of Migratory Bird Management. In 1993, the BBS was transferred to the newly created National Biological Survey and at present is part of the U.S. Geological Survey, Biological Resources Division, the research arm of the Department of the Interior. Check out the BBS Home Page for information on status and trends of more than 250 species.
Colonial waterbirds include a wide variety of species that nest in colonies, ranging from freshwater wading birds such as herons and egrets to seabirds such as murres and puffins. Numerous colonial waterbird surveys have been conducted since the early 1970s by various Federal, State, and private agencies. However, little effort has been made to standardize the collection and storage of the data. Recommendations for a standard monitoring protocol are found at the colonial-nesting waterbird site. The ultimate goal is to develop a national database.
The ISS was organized by the Manomet Observatory in 1974 to gather standardized information on the numbers of shorebirds congregating at migratory stopover sites in the spring and fall. You can read a detailed or view the 1995 report.
This monitoring scheme, developed by the Institute for Bird Populations, provides demographic information such as young/adult ratios and adult survivorship for a variety of small land birds. Its goal is to assess the underlying causes of bird population trends detected by surveys such as the Breeding Bird Survey. The Fish and Wildlife Service provided funding for the initial development of MAPS. Check out the MAPS site for a detailed description of the program and a recent report.
Monitoring with Checklists
Many bird species are regular migrants through the continental United States but, because they nest at high latitudes or winter in the tropics, are not well covered by any of the existing bird-monitoring schemes. To fill that void, the Migration Monitoring Council has developed a protocol for monitoring bird population changes using checklists.
April 11, 2012