Unknown Future: Troubles on horizon for endangered Everglades Snail Kite

This is the second in my series on how Everglades Restoration would change the wildlife and landscape of South Florida’s River of Grass: The Everglades Snail Kite population has been declining steadily since 2001, and one scientific model projection puts the species on a track towards near extinction in 2030 if conditions don’t change. That means fewer than 50 Snail Kites by as early as 2030. “The bottom line is the population is not doing well. That is not an overstatement, it is an understatement,” said UF Research Ecologist Dr. Wiley Kitchens.

(Female Snail Kite. Photo Credit: University of Florida)

Changes to the flow of South Florida’s wetlands, made worse by recent drought years, have sent this locally endemic species of snail-eating hawk into a “precarious situation,” said Kitchens, who has closely studied the Snail Kite since 1990.

I spoke to Kitchens, whose team is in the field banding Snail Kites and conducting surveys of the endangered species’ nests, in a phone interview from his University of Florida office earlier this week.

First, a glimmer of positive news: While the kites are becoming more rare in some traditional breeding areas—such as the Everglades Water Conservation Area 3-A, which spans from Tamiami Trail north to the sugar plantations of Palm Beach County—some of the birds are adapting to conditions in other locations further north where they historically have not breed. Also, officials with state and local agencies, such as the U.S. Corps of Engineers and the Florida Fish and Wildlife Conservation Commission (FWC), are cooperating and teaming up with biologists like Kitchens in an all-out effort to help the Snail Kites survive. “It’s a new dawning of managers from various agencies being engaged in trying to accommodate the kite,” Kitchens said. For instance, FWC has hired a Snail Kite coordinator; the coordinator is a former student of Kitchens.

Most importantly, many hope the proposed Everglades Restoration Plan will trigger a rebound in crucial breeding areas such as Water Conservation Area 3-A, an area where there have been only 10 new chicks born in the past four or five years, an alarming decrease from previous years.

The bad news, however, is bleak. The Snail Kite’s population has been reduced in half twice since 2000, and the kites now number less than 1,000.

A signature species of the Everglades, the Snail Kite is found in the U.S. only in south Florida. It is highly dependent on certain water levels to maintain the wetland habitats for its primary food source, the apple snail. It uses its sharply-curved beak to remove snails from their shells. The main culprit of the Snail Kites decline over the past century is a vastly-altered Everglades and the resulting greatly reduced flow of water and quality of water.

“I think the restored system will be good for the kites,” Kitchens said about proposed plans to try to return the Everglades to its natural flow, “if they are around. If things don’t improve, the kites won’t survive as a population through restoration.”

Male Snail Kite, Loxahatchee Wildlife Refuge. May 2, 2011. Photo: Roger Real Drouin

Trends compiled by University of Florida biologists using a vast array of data, such as kite lifespan, reproductive rate, and current Everglades water conditions, show a decline to a population of around 50 Snail Kites by 2045. The projection year is further reduced to 2030 if you account for conditions related to the anticipated impact of global warming, such as extreme flooding and drought. These “Population Viability” projections are based on 19 years worth of solid, objective data.

The projection is a realistic one.

“It’s our best attempt at this,” Kitchens said. “There is all kinds of uncertainty. But we have a good data base.” The better the data set, the more realistic the projection.

The indications right now look bad to Kitchens, who, along with graduate students, conducts surveys and banding trips in South-Florida locales from Water Conservation Area 3-A to the Lake Kissimmee region of Florida. The average life expectancy of Snail Kites is dropping swiftly. And fewer of the hawks are reproducing, if they even find a place to nest. Several adults have abandoned nests in extremely low water, because there is less access to a snail food supply, and predators such as raccoons can get to the nest easier.

Dr. Wiley M. Kitchens. Photo Credit: University of Florida.

In a strange twist, some kites have adapted to feeding in higher water levels, further north in the state, by relying on invasive Hydrilla plants. The birds will forage from Hydrilla for a non-native species of snails called the island apple snail. Some of Kitchens’ and his colleagues’ research has shown that the Snail Kite is now only thriving where both the non-native Hydrilla and island apple snail are present. As a result of this research, Florida Fish and Wildlife officials have eased up on their removal of Hydrilla from certain lakes and canals where a significant number of Snail Kites are present to give the endangered hawk a chance at survival. Hydrilla has its foes because it can limit boat navigation, block sunlight to other aquatic vegetation and deprive fish of oxygen.

In fact, the Snail Kite has become reliant on these two exotic species. This use of a plant and substitute snail that are not native to Florida is not considered a long-term sustainable mode of survival. A 2010 UF study suggests juvenile kites may actually starve while trying to subsist on the hard-to-handle invasive snails that are nearly twice as large as the native apple snails.

But the adapting behavior has surprised biologists, and it shows how the species is seeking different sources of food to survive.

An unknown future:

According to the National Audubon Society, “the Snail Kite may… benefit from the Comprehensive Everglades Restoration Plan, which has already facilitated the purchase of 207,000 acres, as well as attempts to create a more natural water cycle.”

However, the current fiscal climate and political uncertainty threaten to reverse plans for Everglades restoration work. There is always the possibility that only a portion of such large-scale governmental projects will ever be completed.

Even if restoration work comes to fruition, it may be too little too late.

People interested in getting involved can contact their local Audubon Society and ask for more information. Those interested can also attend future public meetings on Everglades Restoration Plans.

Here is some additional information on the Everglades Snail Kite:

U.S. Fish & Wildlife Species Profile

Audubon Watch List Snail Kite (Rostrhamus sociabilis)

Palm Beach Post article “Environmentalists say pumping from low Lake Okeechobee to irrigate farms will threaten snail kites.”

Audubon report and petition against Okeechobee water pumping

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