Sunday, April 8, 2012

Lets Build a Bird Nest
Part 1

It turns out what I thought was a sparrow is actually a House Finch. They are very common across the US and you will probably see them at the next bird feeder you come across.

Female and male House Finch... (plagiarized pic from internet)
From their activity today it would appear they decided on the open air model of bird nests. Not surprising as there is a shortage of the ones with walls and a roof.

It's very entertaining to watch them come and go with nesting material. It was actually comical when the female tried and put some twigs of a tumble weed into her nest. The weed seems to act like Velcro and half of what she brought wound up on the ground after sticking to her soft under-feathers. They are very busy as I write this retrieving bits and pieces of grass, feathers, debris of unknown origin.

All this family bliss is not without it's challenges. There is an interloper!  A House Sparrow (not to be confused with the House Finch) has eyes on this nesting site also. The sparrow is a bit bigger than the finch but the finches seem to make more noise when the sparrow approaches. I have observed the sparrow actually sitting in the finch nest while they are foraging for nest material... maybe the sparrow is trying out the feel, like someone shopping for a new car.

When the finches return to find the sparrow they of course get all atwitter and so far the sparrow has not considered the site worth fighting over.

The picture to the right is the bird nest under construction. Hanging over the front-right of the nest is some the tumble weed I mentioned. I'm sure the nest will look quite different in a few hours if the number of trips the pair are making is any indication of progress.

I will try and post updates of my observations of the finch family and their home making and hopefully their new family.  As I write this I'm trying to figure out how to get my web cam positioned for more clandestine observations.
The following information is from Wikipedia about the house finch:

Nests are made in cavities, including openings in buildings, hanging plants, and other cup-shaped outdoor decorations. Sometimes nests abandoned by other birds are used. Nests may be re-used for subsequent broods or in following years. The nest is built by the female, sometimes in as little as two days. It is well made of twigs and debris, forming a cup shape, usually 1.8 to 2.7 m (5.9 to 8.9 ft) above the ground.

During courtship, the male will touch bills with the female. He may then present the female with choice bits of food, and if she mimics the behavior of a hungry chick, he may actually feed her. The male also feeds the female during the breeding and incubation of both eggs and young, and the male is the primary feeder of the fledgelings (who can be differentiated from the females by the pin feathers remaining on their heads).

The female lays clutches of eggs from February through August, two or more broods per year with 2 to 6 eggs per brood, most commonly 4 or 5. The egg laying usually takes place in the morning, at the rate of one egg per day. The eggs are a pale bluish green with few black spots and a smooth, somewhat glossy surface. In response to mite infestation, the mother finch may lay one gender of egg first, which increases the chances of the young finches' survival. The female incubates the eggs for 12 to 14 days. Shortly after hatching, she removes the empty eggshells from the nest. The hatchlings are pink with closed eyes and tufts of fluffy down. The female always feeds the young, and the male usually joins in. The young are silent for the first seven or eight days, and subsequently start peeping during feedings. Initially, the mother carries fecal sacs out of the nest, but when the young become older, she no longer carries them all away, allowing droppings to accumulate around the edge of the nest. Before flying, the young often climb into adjacent plants, and usually fledge at about 11 to 19 days after hatching. Dandelion seeds are among the preferred seeds fed to the young.

House Finches are aggressive enough to drive other birds away from places such as feeders.

1 comment:

Daniel Bruckner said...

While I'm by no means an open endorser of violence, a nice finch vs sparrow battle sounds intriguing. I'll have to do some research before I decide who to wager on.