It all started in the 1800's, (and not realizing the damaging affects that would occur) The House Sparrow and the European Starlings were introduced to North America. Today the bluebirds and other nest cavities birds will have to fiercely compete for nesting sites. Both the House Sparrow and the European Starlings are killers! These two non-native birds are very aggressive and will destroy nestlings and adult native birds that get in their way. And top that off, these two non-natives birds are the most abundant songbirds on the continent. Bluebirds feed mainly on insect from the ground and in the winter they depend on many kinds of wild berries for their food supply. However, the supply of wild berries decreased and the berries that remain are often stripped away quickly by large flocks of House Sparrows and Starlings. A large flock of Starlings can clear one acre on land of insects, in less than 60 seconds.
Mankind has played an even a larger role in the destruction of bluebirds. The bluebird suffered a major decline from 1920 to1970. We lost 92% of the bluebirds. Mainly due to pesticides known as DDT, Today in the name of progress, the bluebirds continue to struggle due to (man’s needs) to develop the land. Let’s look at the growth of our country; it’s been hard on the bluebirds. Large amounts of habitat have been destroyed by logging industries for business and residential developments along with progresses in manufacturing. The supply of natural nesting cavities for bluebirds and other cavity nesters has greatly been reduced.
In 1973: The Endangered Species Act was passed. Though 90% of the bluebirds vanished, they have never been placed on any Federal lists of Endangered or Threatened Species. In 1980, many people under the age of 40 had never seen a bluebird. Even today, there are still many people who have yet to encounter one.
(Man's best friends) < Dogs and Cats > cause more injuries and death to bluebirds than their natural predators. Talking to a wild life rehabilitator they confirm 90% of all injures to birds are caused by Cats and 10% by Dogs. And she will quickly reply, it’s not a cat or dog problem (It’s a People Problem!)
If that wasn't enough the bluebird must now deal with climate change; And to fully understand how birds will respond to climate change, we need to study not only how they themselves respond but how the plants and insects and other organisms that make up their habitats will respond. Bluebird eggs and nestlings cannot survive temperatures exceeding 107 degrees. And a nest boxes can reach 120 degrees or more and are at least 10 to 15 degrees higher than the outside temperature.
Over the years the bluebirds has faced a lot of challenges, and there’s more to come no doubt. Together we can make a difference, our concern and compassion to get directly involved will strengthen The Bluebird’s Perseverance.