Life on the booming grounds: eggs

I went out with Mike the other day to measure and weight the eggs. First when we reach the nest site we had to wait for the hen to leave her nest in the morning to feed. After we heard that her signal is away from the nest we moved in and collected her eggs from the nest. A typical hen usually lays around 10-13 eggs. Using a caliper Mike calls out the length and width while I input the data into a computer program. We weighed the eggs and compared it to the measurements to determine its estimated hatch time. It is scientifically proven that a grouse (chicken-like bird) egg will lose about 15% of its mass everyday-it is developing and converting yolk into body mass-by using a formula we can estimate when the eggs will hatch. The first batch of eggs (a clutch of 13 eggs in the Duncan pasture) are estimated to hatch on April 21st or 22nd. We filmed, took pictures of the vegetation, spread fire ant poison and took a GPS point of the nest site. The hen will remain on her nest all day except in the morning and afternoon to feed. A couple of days before the estimated hatch date we will visit the nest site to monitor the status of the eggs. When we find out that the eggs are hatched, depending whether if it is a good year for insects or not, we will go out at night and place a brood box (kinda like a mesh cage) on top of the hen and her new chicks. The brood box is used to keep the females and chicks in a single location for protection- the hen and her chicks will be fed caught insects in the brood box during the daytime every 2 hours until they are mature. When they are ready we will capture and place radio collars on the chicks.

*new pictures and update!* (4/15/11)
It was my turn again this morning to go out with Mike and measure eggs. We went to a double nest site (two nests in one fence area) in the Duncan pasture. We waited for about an hour before the first hen left her nest in search of food, a couple of minutes later the second one flew off. Both nests had 10 eggs each (20 total eggs), although one was dented (probably from when the hen flushed from her nest)- we collected the damaged egg and will use it for nutrient analysis. The other eggs are good and the estimated hatch dates are for April 29th and 30th. Here are some pictures.