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Bird Surveys Overview

Many wetlands within the Great Lakes basin have been destroyed or highly degraded by human activities over the past century. As the amount of marsh habitat has declined, so too have the populations of several marsh bird species dependent on these habitats for various stages of their life cycle. Among this group of bird species that rely on marshes for breeding are Virginia Rail, Common Moorhen, American Bittern and Sora. The presence of these ?focal? marsh bird species is recognized as an important indicator of marsh health, so long-term marsh bird monitoring is important for tracking the ecological integrity of marshes. Marsh bird monitoring data collected by MMP volunteers contribute toward wetland conservation and management initiatives at a variety of spatial scales across the Great Lakes basin.  

To conduct marsh bird surveys, volunteers:

  • Survey two times per year between mid-May and early July, with at least 10 days between each survey.
  • Survey either during the morning or the evening. However, survey routes that are established for morning surveys must always be surveyed in the morning, and vice versa for routes established for evening surveys. Morning surveys can begin as early as 30 minutes before sunrise and must be completed by 10:00 am. Evening surveys can begin as early as four hours before sunset and must be completed by the onset of darkness. All surveys occur when the weather conditions are warm and dry with little wind. Detection of marsh birds is strongly associated with season, time of day and weather.
  • Establish monitoring stations at least 250 m (275 yards) apart. Unlike amphibian surveys, stations cannot be placed back-to-back, because playing the Marsh Bird Broadcast CD (see below) might artificially increase the number of marsh birds present in marsh habitat behind the surveyor by drawing them in from adjacent areas. This would therefore bias the result.
  • Conduct surveys using a fixed-distance, 100 meter (110 yard) radius semi-circular sampling station area. However, certain ?focal? marsh bird species (see below) are recorded using an unlimited distance semi-circular sampling area. 
  • Complete a 15-minute survey at each station.  The survey begins with a 5-minute silent listening (passive) period, followed by a 5-minute call broadcast period (using the Broadcast CD) to elicit calls of the normally secretive Virginia Rail, Sora, Least Bittern, Common Moorhen, American Coot and Pied-Billed Grebe, and ends with another 5-minute silent listening period.
  • Record, during the 15-minute survey period:
    • All ?focal? species seen or heard within an unlimited-distance semi-circular area
    • All other bird species heard and/or seen within the 100 m station boundaries;
    • Aerial foragers observed foraging within the 100 m station boundaries;
    • All non-focal species observed flying through or outside the 100 m station boundaries (tallied separately).

Focal Marsh Bird Species

Certain marsh bird species require specific habitat conditions (e.g., minimum marsh size, plant community diversity) in order to meet their functional needs, such as breeding and foraging. These species tend to be less tolerant of human disturbances, and so their presence and abundance in a marsh is often indicative of the quality of that marsh. For this reason, these species are often specially targeted within bird monitoring programs, and are called ?Focal Species?. These species tend to show the greatest apparent population declines among all marsh birds, so it is important to continue monitoring their long-term population trends to gauge the effectiveness of broad-scale regulation and conservation policies. Their sensitivity to habitat change also makes them good indicators of the success of regional or site-specific wetland habitat management activities.

By recording Focal Species separately from all other bird species during your MMP surveys, you are improving the MMP?s ability to accurately report the status and long-term population trends of these vulnerable birds.

The Marsh Monitoring Program Focal Species are:

American Bittern (AMBI)
American Coot (AMCO)
Black Rail (BLRA)
Common Moorhen (COMO)
King Rail (KIRA)
Least Bittern (LEBI)
Pied-Billed Grebe (PBGR)
Sora (SORA)
Virginia Rail (VIRA)

For more information about the Marsh Monitoring Program marsh bird survey protocol, please contact:

 Kathy Jones
 Ontario Volunteer Coordinator
Bird Studies Canada
P.O. Box 160
Port Rowan, ON, N0E 1M0
Phone: (519) 586-3531 ext. 124 or (888) 448-2473 (toll-free)
Fax: (519) 586-3532

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