|4/24/2014 9:45:00 AM|
Pretty in White-
by Don ReimerFor delicate beauty and elegance, it's hard to match members of the heron/egret family. Snowy Egrets have returned to Weskeag Marsh for the summer season, and a roaming pair of Cattle Egrets recently passed through Rockland. Although superficially similar in appearance, these two egret species hold major differences in lifestyle and geographical origins.
Snowy Egrets are pure white, with a slender black bill and yellow lores - the area between the eye and bill. Bright-yellow feet are apparent in flight, such that they're also known as "the bird with the golden slippers." Snowies use a characteristic manner of feeding as they wade through water, jiggling their legs and yellow toes against the bottom to stir up aquatic prey. Approaching the northern terminus of breeding range, a small Snowy colony exists on mid-coastal offshore islands. If we were to coin a simple term to designate the Snowy's migratory pathways, it might be "Out of Florida."
Cattle Egrets are an entirely another story. Their historical origins might aptly be described as "Out of Africa." If you've ever watched an African nature film, you are probably familiar with Cattle Egrets. They are the chunky white birds perched on the bare backs of water buffalo on the vast savannah plains. What is an African-based species doing in Rockland, Maine, you ask?
According to ornithologist Louis Bevier, prior to 1930 Cattle Egrets were largely restricted to southwest Europe and Africa. By the late '30s, they had established a foothold in Guyana, South America. Unlike other species such as European Starlings and House Sparrows that were introduced into North America, these pioneering egrets arrived unaided by man or machine (in a few instances, birds have accidentally traveled here aboard cargo ships).
A nonstop 3,000-mile ocean crossing is obviously a daunting task for any bird that relies on powered flight for an intercontinental journey. One favoring factor in these crossings may be the global wind patterns that flow in a westerly direction below the Equator.
By 1941-42 Cattle Egrets had expanded into North America. Single birds were photographed at Lake Okeechobee, Florida, in 1952, and later that same spring at Wayland, Massachusetts. One egret landed on a boat off the Grand Banks, Newfoundland, that year, and expansion continued into the 1950s.
Cattle Egrets first bred in New England during 1971 (Connecticut), and their regional peak was probably the late 1970s to early 1980s, when even Maine saw some limited nesting. Their decline from the mid-Atlantic to upstate New York started by the late 1980s, and now they appear to be extirpated as a breeder in New England. There were four birds reported in South Thomaston during July 2006, which was the highest count in the state since 1999. These birds nest in nearly all 50 states and have been recorded from Newfoundland to Alaska.
Cattle Egrets are slightly smaller than Snowies, with a straight dagger-like orange bill, relatively short legs and a short, thick neck. Cinnamon-colored feather patches on the head, breast and back are a diagnostic field mark. This egret often assumes a characteristic hunched posture as they lean forward to pursue prey. This is definitely a terrestrial species that stalks insects, earthworms and small mammals in pastures and fields, seldom entering water. As the name implies, they are often found at the feet of grazing livestock, taking advantage of insects dislodged by the moving cattle. They are known to follow plowing farm tractors as well. Now, that's being resourceful!
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