Saturday, April 02, 2011

South Florida - Great For Bird Watching

Wading Birds Plentiful In Conservation Areas This Year

CLEWISTON, FL. -- Extremely dry conditions that have created a water shortage for some have been a boon for wading birds so far this nesting season.

Endangered wood storks, spoonbills, white ibis and great egrets have begun nesting in the Everglades Water Conservation Areas in numbers representing a significant increase from the start of last wading bird season, South Florida Water Management District (SFWMD) scientists reported this week.

Endangered wood stork nests numbered 1,050 while white ibis nests were counted at 10,000. No nests were observed for either of these species in the conservation areas in March 2010. Spoonbill nesting increased to 200 nests from only 20, and great egret nests increased to 7,180 from 130.

There are typically two adult birds per nest.Tens of thousands of birds have been seen foraging in Water Conservation Area 3 in Broward and Miami-Dade counties. All together, scientists observed 18,430 nests at the beginning of the wading bird nesting season this March in the conservation areas compared to only 150 nests seen during the same time in 2010.

Scientists attribute this early success to water levels that are currently optimal for wading birds because their food supply of crayfish and other small fish are massing in smaller areas as the land dries out. This concentration makes for easier foraging with less energy expended. Recent SFWMD research has also made a major contribution to determining optimal water depths for wading birds.

"A key goal of Everglades restoration is to restore natural water conditions that will help re-establish an adequate food supply for wildlife across the Everglades," said SFWMD Executive Director Carol Ann Wehle. "This will more permanently support the return of successful wading bird nesting colonies."

Optimal hydrologic conditions also led to a 2009 breeding season that was exceptionally good for wading birds in South Florida, with a most noteworthy improvement for the federally endangered wood stork at the time.

While the new nesting numbers are encouraging, scientists noted that water levels may be falling too fast to maintain large populations. Birds tend to abandon nest sites and nestlings when food becomes scarce. Nestlings that manage to fledge will have a limited food supply.

Extensive dry conditions may also lead to a significant decrease in apple snail populations, which are the primary food source of the endangered Everglades snail kite.

District scientists will continue to monitor wading birds and their nesting colonies in the Water Conservation Areas throughout the season.

No comments:

Post a Comment