Wednesday, April 30, 2008

Depredation (If you're not interested in my bluebird posts, skip this)

The one thing that I looked forward to doing after work today was to make our weekly check on the bluebird box. The one thing I did not look forward to was learning the definition of a new word: Depredation - n. a predatory attack; raid. Sadly, this is what I have to report.

I was very suspicious that something was not right because I did not see either the male or the female anywhere from the time I got home around 4:45 until the time we went up to check, which was about 6:30. Thad got the ladder and I got the camera and we headed up to the garden. I had been worried that maybe they had been the victims of the cold weather last night. But, instead of finding the five tiffany jewels snug in the box, only two remained and they were on the ground below the box.

Looking inside, you would not have know that something dastardly had happened there today. After doing some research, I believe that the eggs were the victims of a house wren attack. Enemies of the bluebirds include house sparrows and house wrens among the birds. My conclusion is three-fold: 1. we do not have house sparrows in the area that I am aware of; 2. there was no evidence inside the box of blood or shell fragments; and 3. the eggs were left and not eaten which would most likely point to a bird attack. The other eggs were probably also on the ground but removed by the parents, or they could have been eaten by a mouse or other small animal before we found them.
In any case, they're gone for now. The eggs and the parents. I checked the Bluebird Forum on Nature Web and they suggest removing the nest from the box as soon as possible to encourage new nesting.

So we will once again watch for that "flash of blue" that gives our heartstrings a little tug and hope that they will not be discouraged by this and will come back to us.

I don't remember if I related the story of how they begin their nesting, humanizing the process, but here goes. The male goes out house-hunting and finds prospective nest sites. He sits atop the box and calls to his mate, twittering and flittering his wings. She comes, gives the outside a once over and then hops onto the front of the box to take a peek in. You know that she is interested if she actually jumps into the box. If not, no sale. They do this for several days it seems. You know, the process of elimination with the other houses on the market.

Then the nest building begins. He brings the grass and the needles and the feathers and puts them into the box. She goes in, and presumably, starts arranging the nest. This goes on for several days. If he brings some piece of grass or weed that is not of her liking, she brings it right out again. If you're lucky enough to be outside and near when this is going on you can hear them twittering back and forth like an old married couple: "Be careful where you put that now." "I know." "That's not going to be soft enough." "Yes it will." "I told you not to put that there." "Okay, I'll get something else dear."

Then the egg laying starts. One egg a day. In and out. Taking turns checking on the eggs. Making sure they're still there. When she's done laying, they're both responsible for making sure that they're properly incubated. There's also egg rolling to be done - got to heat all the sides. He'll stand watch in a tree or on the fence nearby, waiting to hear her call when she needs a break.

Once the hatching starts, dad will feed mom and the chicks and the story will go on and should go on. But tonight I think they are out in the woods and the conversation will be somewhat different: "Why did you leave, I said I would be right back." "You were gone so long, I was worried." "I'm sorry." "I know - I'm just so sad." ................."I know."

No comments:

Post a Comment

It's always so nice to hear from visitors. Thanks for stopping by and leaving a comment.