Thursday, June 9, 2011

The hatch

With the cooler and wetter weather we have had this spring I've been getting a lot of calls from hunting partners and other chukar hunters wondering what I think the hatch will be like. I, like every other chukar hunter, am very interested in what conditions make for the best survival of nests and babies. I have incubated and raised pheasant, chukar, huns and quail and know what changes in temperature, humidity and other factors can do during this artificial process for survival of chicks. I graduated from the great Boise State University (Boise State College at that time) with a minor in biology. I spend much more time in the field than the average guy. With that, I can say I don't know diddly squat about the hatch. But I have my beliefs so here goes.
Once in a while mother nature throws us a curve. But she is pretty forgiving. All creatures have basic instincts for survival and upland birds are no different. They do not no how to read a calendar so have no idea of what day they should start nesting. Certain weather patterns and conditions get the ball rolling.
Chukar eggs take 23 days to incubate. The hen will lay an egg a day or every other day until she is ready to sit the nest. Each day after laying the egg she covers the nest for protection. She does not sit on the nest until the final egg is down. Like in artificial incubation process the egg must be stored at a cooler temperature until incubation begins. By covering the eggs she is regulating the temperature. When she has laid the last egg she sits on the nest constantly beginning the 23 day incubating process. She gets off the nest only to turn the eggs occasionally and to eat and drink. Mother nature has given her the instinct to know she must keep the eggs at a constant temperature in order for them to hatch. In the artificial process that temperature is 99.5 degree. If you let the temperature fluctuate too much or not turn the eggs survival is compromised.
So here is where my theory comes in. The mother knows she needs help keeping the eggs warm during the times she is not on the nest. If the temperature is too cool she will put off laying eggs until it begins to warm. On years like this year upland birds may nest two to four weeks later than normal years. My guess is the majority of the birds will hatch between June 15 and July 1 this year instead of June 1 to June 15.
The curve ball I was speaking of is when we get that early false spring. We have two or three weeks of above normal temperatures which start the laying process followed by a big cool down and wet weather. The chicks are then hatched at a vulnerable time and survival will be tough. Also, eggs are more vulnerable to these conditions because the hen must get off the nest now and then to eat and the egg temperature may drop too much. In this case the eggs have been lost. In both cases the hen will renest especially if she has just lost the nest, but the clutch will be smaller.
This year's spring has been cool from the start and has warmed slowly. So, as I stated earlier, I think we will start seeing chicks running around in the next week or two. I've spent many hours in the chukar hills and my observations tell me that chukars are still sitting. But the only positive scientific explanation I can give is my HOPE for another banner chukar year.


jc said...

Great post. I really appreciate this kind of information and the opportunity to learn it.

larry szurgot said...

Thanks jc. I was out today and found some more evidence that I think shows we're in for a good hatch barring any more really bad weather and will be posting about it real shortly.