When I first sighted this bird, it was standing with its neck outstretched so that it was not especially difficult to find. But after several minutes, it crouched down in the vegetation and I had to use my binoculars to spot it again, even though it was still in the open. When I drove by the same area several hours later, I could not find the bird again, but a Great Egret with mostly pure white plumage was easily seen.
18 May 2011
Camouflage in Birds
The plumage patterns and colors of many bird species certainly do not seem to have evolved to camouflage their presence. Indeed, these aspects of many seem to do just the opposite and flaunt their presence. On a trip to Freezout Lake near Fairfield, MT yesterday, I photographed a species that I don't see too often, and perhaps that is at least partially due to the camouflage pattern of its plumage that very closely mimics the habitat in which it is usually found. The species is the American Bittern. 
When I first sighted this bird, it was standing with its neck outstretched so that it was not especially difficult to find. But after several minutes, it crouched down in the vegetation and I had to use my binoculars to spot it again, even though it was still in the open. When I drove by the same area several hours later, I could not find the bird again, but a Great Egret with mostly pure white plumage was easily seen.
When I first sighted this bird, it was standing with its neck outstretched so that it was not especially difficult to find. But after several minutes, it crouched down in the vegetation and I had to use my binoculars to spot it again, even though it was still in the open. When I drove by the same area several hours later, I could not find the bird again, but a Great Egret with mostly pure white plumage was easily seen.
16 May 2011
New "Kid" on the Block
On my morning neighborhood walk yesterday, I encountered a single Eurasian Collared-Dove near my house. This may not sound like much but it is another chapter in the story of the amazing spread of a non-native bird species in the US, and indeed, around the world. In the 19th Century, this dove species was apparently confined mostly to its native range in sub-tropical Asia. In the early 20th Century, it began dispersing into and colonizing Europe and perhaps northern Africa. It reached Germany in the mid-1940's and Great Britain by the mid-1950's. It the mid-1970's it was apparently introduced into the Bahama Islands as part of the pet trade, and escaped into the wild there. By 1982, it was first sighted in Florida. It rapidly progressed across North America and was first reported in Montana in 1997.
On a recent trip to Nebraska and then into the SW States, I was pretty amazed to see these Eurasian Collared-Doves in essentially every small to medium-sized town we passed through. And they were easy to find. In my home stomping grounds, Helena, MT, I first observed this species in 2007, although they certainly could have been present prior to that time. And now for the first time, they are present in my neighborhood.
In the US and perhaps other areas that these doves have colonized, they are almost always associated with human habitation, needing abundant food and trees for nesting. The key to their fast spread may be their prolific breeding habits. Although they usually only lay 2 eggs per nest, they may nest 3 to 4 times per year in northern climates and up to 6 times in warmer areas. It will be interesting to see if they become established as breeders in my neighborhood. 
These birds have now reached Alaska and will likely spread into South America, if they are not already doing so. It is not known at this time whether or not they compete with native species, but they seem to be filling a niche not occupied by other species.
On a recent trip to Nebraska and then into the SW States, I was pretty amazed to see these Eurasian Collared-Doves in essentially every small to medium-sized town we passed through. And they were easy to find. In my home stomping grounds, Helena, MT, I first observed this species in 2007, although they certainly could have been present prior to that time. And now for the first time, they are present in my neighborhood.
In the US and perhaps other areas that these doves have colonized, they are almost always associated with human habitation, needing abundant food and trees for nesting. The key to their fast spread may be their prolific breeding habits. Although they usually only lay 2 eggs per nest, they may nest 3 to 4 times per year in northern climates and up to 6 times in warmer areas. It will be interesting to see if they become established as breeders in my neighborhood. 
These birds have now reached Alaska and will likely spread into South America, if they are not already doing so. It is not known at this time whether or not they compete with native species, but they seem to be filling a niche not occupied by other species.
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