Bird counts down sharply near Rookery Bay since Hurricane Wilma hit in 2005 - PHOTOS

Greg Kahn/Staff
A little blue heron flies over the water near Tigertail Beach on Marco Island on Nov. 26, 2011.

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Greg Kahn/Staff A little blue heron flies over the water near Tigertail Beach on Marco Island on Nov. 26, 2011.

From 1974 through 2005, the fluctuating counts in the Marco Bay area were generally along an upward trend. Since then, the numbers have dropped by more than 50 percent, returning to where they were when Below started the counts.

— Ted Below has been counting coastal waterbirds near Marco Island since 1973, thousands of them on an average census trip.

Lately, though, Below says he hasn't been counting as high along one of the 20-mile routes he takes every other week through one of Southwest Florida's most important bird nesting and roosting sites.

From 1974 through 2005, the fluctuating counts in what he calls the Marco Bay complex generally were along an upward trend. Since then, the numbers have dropped by more than 50 percent, returning to where they were when Below started the counts.

Below, an avian ecologist and former Rookery Bay National Estuarine Research Reserve warden, has only guesses about the cause but worries that an explosion in human use of the coast has finally pushed waterbird populations too far.

"The big problem is we've changed it all," he said.

The Marco Bay complex counts take in the ABC Islands north of Marco, two mangrove island rookeries in Rookery Bay and shorebird nesting and resting spots at Sand Dollar Island off Tigertail Beach on Marco Island.

The drop spans numerous species, including brown pelicans, white ibis, herons, cattle egrets, willets, sandpipers and terns.

In 2005, the year Hurricane Wilma tore through mangrove rookeries on its way to an October landfall at Cape Romano, Ted Below counted an annual average of 4,000 birds per count at the Marco Bay complex. By 2010, that was down to 1,800 birds. The trend is continuing this year, with the annual average per count at 1,400 birds as of last week.

In 2005, the year Hurricane Wilma tore through mangrove rookeries on its way to an October landfall at Cape Romano, Below counted an annual average of 4,000 birds per count at the Marco Bay complex. By 2010, that was down to 1,800 birds. The trend is continuing this year, with the annual average per count at 1,400 birds as of last week.

Below's numbers show that 19 of the 29 species he counts as part of the Marco Bay project have declined, a drop of about 66 percent.

The same pattern holds true for sundown counts Below and a team of volunteers conduct at mangrove islands where birds flock to spend the night.

At the ABC Islands, monthly sundown counts show 64 percent of the species have declined. A twice-monthly count at the Rookery Bay mangrove islands shows 89 percent of the species have declined.

Below said it is an oversimplification to pin all the blame for the decline on damage to mangrove trees from Hurricane Wilma.

At the ABC Islands, monthly sundown counts show 64 percent of the species have declined. A twice-monthly count at the Rookery Bay mangrove islands shows 89 percent of the species have declined.

The counts include a drop in the number of some birds at Sand Dollar Island, an important nesting spot.

Nesting numbers jumped there with the formation of a lagoon that held lots of food. As the beach becomes increasingly grown up with vegetation, it has crowded out some nesters, Below said.

Black skimmers bucked the trend last summer with a huge year at Sand Dollar Island, which had some 1,000 skimmer nests.

The Florida Shorebird Alliance, a program of the Florida Fish and Wildlife Conservation Commission, aims to avoid human conflicts with nesting shorebirds at places like Sand Dollar.

Local Audubon groups, Friends of Tigertail and the city of Marco Island have teamed for the past summers to train volunteers to teach beachgoers to stay away from nesting or resting shorebirds.

"Nothing like a little downy chick to melt your heart," Collier County Audubon Society policy advocate Brad Cornell said.

Roosting spots on mangrove islands also are susceptible to disturbance from motorboats and kayaks that get too close, Below said.

"It's kind of like you're going to bed and have a freight train going through every five minutes," Below said.

Researchers suspect the problem may run deeper, all the way to the base of the estuary food chain.

Estuaries depend on just the right amount of water at just the right time to maintain a balance of saltwater and freshwater needed to produce food — baby fish, crustaceans and mollusks — for coastal birds to eat.

A system of canals dug to drain Rookery Bay's watershed for development has altered that timing, but exactly what that has meant for the food chain remains largely unknown.

"It's an important research question," Cornell said.

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maverick1 writes:

Pythons are eating the eggs

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