06/26/2002 Env Bd Packet - Laserfiche WebLink

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A great blue heron catches a fish on the Rice Creek chain of lakes, where herons have nested since 1945. For the past two years, the heron colony at Lake Peltier has abandoned its rookery prematurely, and its hatchlings did not survive. New ordinances in Lino Lakes and Centerville aim to protect the herons, which have returned to nest again this year. Although such a mass abandonment during the height of nesting season is unprecedented, the summer of 2000 was not the first time the heron colony had been displaced from the Rice Creek chain of lakes —and it would not be the last. As many as 400 herons returned to nest at Lake Peltier in the spring of 2001 —but in June they once again abandoned the rook- ery. "A bird catastrophe of this magnitude is hard to assess," says Hawkins. Many unanswered questions remain. For two seasons now, the colony has produced no surviving young, and no one knows what the ultimate effect of these losses might be. Nor does anyone know where the herons went after they left the rookery, or whether they might one day decide to abandon Lake Peltier for good. In many ways, the forested island on Lake Peltier may represent a last stand for the herons that have endured both natural disasters and human expansion into their habitat. For two seasons now, the colony has produced no surviving young, and no one knows what the ulti- mate effect of these losses might be. Great blue herons first began to inhab- it Lake Peltier in small numbers in 1989. Today's colony, which has declined in pop- ulation to about 200 birds, is believed to have assembled from the remnants of two earlier colonies that were displaced from nearby lakes. Beginning in 1945, a colony of hun- dreds of herons nested on Rice Lake, south of Lake Peltier. These birds were displaced in the early 1990s by residential develop- ment and the opening of a nearby golf course, according to Joan Galli, a nongame wildlife specialist with the Minnesota DNR. A second heron colony inhabited Howard Lake, north of Lake Peltier, and once numbered 550 nests. The Howard Lake colony suffered severe losses during a wind storm in 1987 that downed nest trees and killed many young birds. The colony never recovered from the storm's devasta- tion and relocated to Lake Peltier. "The herons have retreated — literally and figuratively —to islands of habitat that are remote from human disturbance," says Galli. "They're very precariously situated. There isn't any lakeshore they can go to, because it's all developed. Their options are more and more limited as we expand our residential occupancy of this world." Today, the Lake Peltier heron rookery is one of only nine in the seven -county metropolitan area and is the second largest. Its birds fly up to 20 miles away to feed in ponds and marshes and along lake shores. "All the herons and egrets that citi- caurimmd ru? p.4