April is such a promising month. This year it has been an exceptional month, with very little snow and some truly summery weather. Many birds are streaming northward, and with the lake free of ice, waterfowl and shorebirds are arriving daily.
Sunday, April 20, brought a broad-tailed hummingbird back to our yard and six white-faced glossy ibis to Evergreen Lake. Tuesday, April 22, brought the first chipping sparrow returning to our feeder. Wednesday, April 23, brought white-crowned sparrows, yellow-headed blackbirds and yellow-rumped warbles stopping on their way north.
April and May are the most exciting months at Evergreen Lake. Almost every day brings something new to the water, wetlands or shrubbery around the area. It is a shame to miss a morning at the lake, for you never know what you may see.
Wetland birds that show up at the lake are perhaps the most exciting. Because we have so few wetlands in this semi-arid climate, wetland birds tend to concentrate in these small areas. Birds like black-headed grosbeaks can be found many places in our miles of mixed ponderosa pine forests, but birds like a sora or an ibis may be found only in wetlands. Thus, we all tend to get excited when any of these long-legged waders appear.
Each spring a few groups of white-faced ibis appear at the lake in April and early May. They are considered to be tropical or semi-tropical birds, so our chilly spring weather is often hard on them. There are several small breeding colonies in the San Luis Valley, and they have been moving their breeding range farther north over the past 40 years. They now breed in Oregon, Wyoming, South and North Dakota, and just across the border into Canada. So we assume “our” birds are headed farther north because they do not remain here more that a few days.
The glossy ibis, Plegadis falcinellus, is practically worldwide in distribution, including the southeastern states, part of South America and parts of Europe and Africa. The white-faced ibis, Plegadis chihi, which we have here, is considered by some to be a distant species, but some scientists believe it to be just a subspecies and that the two should be lumped together as one species. Time and DNA will tell eventually, but as of now, our birds, even those that do not have a white face edging, are still considered to be white-faced glossy ibis.
No matter whether they are lumped or not, our birds are ibises. They are larger than a curlew and smaller than most herons. Their long, thin necks are held straight out in flight. Their flight is rapid and usually in a diagonal line or a V. Their nests are built on the ground in reed and cattail marshes. They are made of reed and cattail stalks piled up in a mound, 2 or more feet above water level. They lay three to five eggs, and both parents incubate and feed the young.
Crows and ravens often steal their eggs, and raccoons often destroy the nest, eating both eggs and young. In some areas where the land is overgrazed, livestock trample the nests as they wade into the wetlands in search of food. Many nesting colonies need better protection so they can breed more successfully.
Ibis are a beautiful deep chestnut color with green and purple iridescence; however, except in bright sunlight, these colors are often not seen, and they appear to be just black. Their long decurved beak makes them look like a curlew, and therefore one of their old names was black curlew. However, they are in entirely different families.
The sacred ibis of Egypt, Threskiornis aethiopica, has been extinct in Egypt for nearly a century. This ancient family is well represented in fossil records from the Eocene going back 60 million years.