Monday, April 28, 2008
It's Tough Out There!
This morning I heard quite a few White-throated Sparrows (Zonotrichia albicollis) singing in my backyard so they seemed to have come through this nasty weather in good shape. However, while out and about today with my students I observed something I had not seen for a while and it made me worry a bit. Around our bird feeder station I watched several Yellow-rumped Warblers (Dendroica coronata) foraging for food on the ground. With the cold temperatures and the snow we had yesterday, there are no flying insects around to speak of and I'm sure the early arriving warblers are having a hard time finding food. They are probably in the grasses looking for moths or other insects that might be immobilized by the cold.
I have seen this before. A few years ago we had a very cold spring and the long stretch of bad weather prevented birds from continuing northward. My friend Mark and I were banding birds during that time and caught several of the Yellow-rumps and Palm Warblers (Dendroica palmarum) that were hanging around. A standard piece of data we collect from each bird is it's weight. Well, a few days later we recaptured one of the birds (a Palm) and when we re-weighed it we found it had lost a significant percentage of it's body weight in just a few days. These bad weather episodes have to be really tough on these guys. Luckily, it won't take much of a temperature increase to bring out more flying insects so if the warblers have a supply of stored fat they should make it through.
If you have a suet feeder out keep watch as warblers will sometimes come in and feed on suet when there is no other source of food out there. I've even known some people who buy mealworms at the pet shop and put them out in bowls they keep warm by setting them on top of a pail of hot water.
Aren't birders just the best people????