Photo by Jeanette Parker

Photo by Jeanette Parker

In 2013, Ecostudies conducted a pilot study that implemented the first ever standardized marsh bird surveys in Everglades National Park. Secretive marsh birds are among the most inconspicuous group of birds in North America, in part, because they inhabit emergent wetlands characterized by dense vegetation and they vocalize infrequently.

In Everglades, this group of birds had never been adequately surveyed by any previous sampling effort. Like other wildlife in the region dependent on wetlands, they undoubtedly have been impacted by wetland alteration. However, they also appear vulnerable to new threats, most notably through direct predation by pythons. Rails and their close relatives, which comprise the majority of marsh bird diversity, are consumed by pythons more than any other bird group. Results from this study provided the first description of the abundance and distribution of marsh birds in Everglades National Park and recommendations for develop a long-term monitoring plan for this secretive group of birds in South Florida.

Key Findings

  • King and Clapper Rails were the most abundant species, followed by Pied-billed Grebe, Purple Gallinule, Limpkin, Least Bittern, and Common Moorhen.
  • We did not detect a relationship between bird abundance and water depth, but abundance did vary substantially among the 5, 2-week survey periods from 1 May to 15 July 2013.
  • The largest number of detections for all species was in the 1-minute segment when the call broadcast was played, indicating call-broadcasts were important for improving detectibility of these secretive birds.
  • We suggest marshbirds could serve as an important measure to evaluate effects of management, including restoration.  We recommend a power analysis be conducted to evaluate the ability to detect long-term trends in abundance as part of a long-term monitoring program.
  • We also suggest future work consider investigating patterns of marsh bird abundance and habitat use in the non-breeding season, a time when marsh bird diversity is substantially higher than in the breeding season.

Reports

Slater, G. L. 2015. Monitoring secretive marshbirds in Everglades National Park: A pilot study.  Final Report to Everglades National Park.{PDF}

Project Supporters

Inventory and monitoring of secretive marsh birds

An emergent freshwater marsh in Everglades National Park. Photo by Jeanette Parker

Inventory and monitoring of secretive marsh birds

Ecostudies technician, Jeanette Parker, capturing a python on a marshbird transect. Marshbirds are consumed by pythons more than any other bird group.

Inventory and monitoring of secretive marsh birds

A limpkin in an open wetland in Everglades National Park.