PHOTOS: The beautiful thieves of Market Lake
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ROBERTS — Its 8-inch bill open, a great egret recently harvested a young frog in a swift spearing motion.
The bird also wanted minnows for breakfast. It walked slowly in the shallow near the bank of Pond No. 3 on the Market Lake Wildlife Management Area, picking up its black feet without causing ripples in the early morning glassy water. As it neared an aquatic weed patch where minnows were rising for bugs, the egret slowly inched its way toward the minnows until the belly feathers would touch the surface.
Motionless, neck spring-loaded in an “S” curve, it would wait for a minnow to make the fatal mistake of coming too close to the surface. It never missed.
After apparently getting full, it walked up the dike and flew off, buzzing a patch of bulrushes. Another great egret joined it in flight. Off they flew to the east side of the deep marsh, where they appeared to have some young.
“I don’t know if they nested here this year or not,” said Josh Rydalch, the manager of the Market Lake WMA. “They have been here all year, but I have not paid that much attention to them.”
For many years, great egrets were rare in Idaho except for their migration through Market Lake, Mud Lake and the Chester Wetlands during September. Sixteen of these elegant birds were at these shallow water impoundments last year. Decades ago, they were overhunted for their white plumes to decorate women’s clothing, and an estimated 95 percent of these beautiful birds were killed. It is believed that there were 1,000 to 1,500 pairs in the United States in 1912, but those numbers increased to an estimated to 180,000 pairs by 2005.
The last study done in Idaho was in 1994 when 26 pairs nested in Idaho, all in the southern part of the state. The closest documented pair to the Upper Snake River Valley were at American Falls Reservoir.
The great or common egrets usually nest in mixed colonies with herons like the great blues. Egrets like any type of water: ponds, canals, lakes, streams and especially freshwater in the summer. During this summer this pair appeared to be following great blue herons from the canal to the grassland.
Like herons, these large egrets use flimsy nests that are basically platforms. Males will pick the nesting area and perform a series of female-attracting antics before they become a couple for the season. While nesting, both parents incubate the eggs and feed the young.
One of the most interesting aspect of their nesting is that if one of the eggs is bad or falls out of the nest, the female will lay a replacement egg. It appears they can count – maybe it is new math that for birds.
When great egrets migrate through areas where small herons are, the larger birds become bullies, stealing food from the smaller ones. Snowy egrets and black-crowned herons are often the victims of these burglaries. Great egrets learn this habit early — in the nest the young steal from each other. Most birds steal when food is scarce, but it appears to be a hatched-in behavior and way of life for great egrets.
These thieving birds feed on basically anything that swims, scurries, flies or floats near them using their large, strong yellow bills to spear or crush their prey.
Now that the adult great egrets are protected from their only predator, humans, they should continue to expand their nesting area to the Upper Snake River Valley. Watch for them, and you may see some exciting shows.