Chapters 1 - U.S. Fish and Wildlife Service

Chapter 4
stems is pulled over and entwined above the nest, hiding the nest completely from above. The
surrounding tall cordgrass provides cover and also allows the nest to float upwards in place
during a high tide. A ramp of dead cordgrass stems leads from the platform down and along
the ground.
Light-footed clapper rails inhabit coastal marshes from the Carpinteria Marsh in Santa Barbara
County, California, to Bahia de San Quintin, Baja California, Mexico. It is believed that most salt
marshes along the coastline at one time supported clapper rails. However, recent census data
indicate that less than 50 percent of the coastal wetlands in California are currently occupied.
Southern California’s largest subpopulation of these rails, located in the Upper Newport Bay, has
been successfully reproducing since 1980. In contrast, the second and third largest subpopulations
at Tijuana Marsh and Seal Beach NWR are known to have undergone significant and
episodic decreases in their numbers.
Destruction of coastal wetlands in southern California has been so extensive that many estuaries
where light-footed clapper rails were once abundant have been reduced to remnants. Although
salt marsh habitat loss, degradation, and fragmentation are the leading threats to these rails, they
are also threatened by disturbance, diseases, contaminants, and predation by coyotes, feral cats,
crows, raptors, and other avian predators. The light-footed clapper rail was federally listed as
endangered in 1970.
The Light-footed Clapper Rail Recovery Plan, approved in 1985 (USFWS 1985b), outlines the
actions that if implemented will make possible consideration of reclassification of this subspecies to
threatened status. The recovery objective for the light-footed clapper rail is to increase the
breeding population in California to at least 800 pairs by preserving, restoring, and/or creating
approximately 10,000 acres of adequately protected, suitable managed wetland habitat consisting
of at least 50 percent suitable marsh vegetation in at least 20 marsh complexes. Recovery Plan
strategies specific to Anaheim Bay (Seal Beach NWR) include:
Restore tidal action to surrounding uplands;
Determine causes of elevational differences between Anaheim Bay and Upper Newport
Bay, investigate feasibility of corrective actions;
Develop fringing freshwater marsh and create nest hummocks;
Enhance Spartina vigor;
Control pollutants/debris;
Identify and resolve water quality problems;
Coordinate with vector control personnel;
Establish and monitor permanent vegetation transects in Anaheim Bay; and
Obtain information on the biology of the rail and its ecosystem to enhance recovery,
including investigating factors limiting rail population size in Anaheim Bay.
The first clapper rail count available for the Refuge was conducted in the early 1970s and resulted
in an estimate of 100-200 individual birds within Anaheim Bay (Wilbur 1974). Annual counts on the
Refuge began in 1979 and call counts conducted throughout the bird’s U.S. range were initiated in
1980. The results of spring call counts and high tide counts for the Refuge from 1980 to 2005 are
provided in Figure 4-14. In 2007, 32 rails were documented during the fall high tide count, and the
spring call count detected eight breeding pair, four single birds, and one advertising male
(Hoffman 2008). In 2008, 20 rails were documented during the fall high tide count, while the 2008
spring call count identified only one breeding pair (Hoffman 2009). In 2009, 50 rails were
documented during the fall high tide count, while the 2009 spring call count detected 12 breeding
pairs. Breeding pair estimates for the Refuge between 1980 and 2008 are provided in Table 4-9.
4-64 Seal Beach National Wildlife Refuge