Subject: [Tweeters] Varied Thrush on the Palouse, part 2
Date: Jan 9 12:10:42 2005
From: Kelly Cassidy - lostriver at completebbs.com


Here on the Palouse, the winter so far has been relatively mild. Most days, the temperature has reached at least 29 F. At 29 F, some of the apples on the ground, especially the dark-colored ones, are a little mushy. The birds that eat fruit can find apple bites without much ice. The creek a couple hundred feet away has running water to drink. Animals in winter generally avoid eating ice unless they are desperate for water. Ice takes too many precious winter calories to defrost.



A couple weeks ago, I posted about a Varied Thrush in the yard. Apples seemed to form the core (bad pun, ha ha) of his diet. I've seen the Thrush (or a Varied Thrush that I assume is the same bird) most days since, whenever I have had time to watch for him. Yesterday morning was sunny. I heard the creaky winter version of the Varied Thrush song from the creek, where I think he visits to get a drink. The creek vegetation is utterly dominated by Reed Canary Grass, so it is not prime Varied Thrush foraging ground.



Yesterday was Saturday. I was home most of the day and searched diligently for the Thrush. I didn't see him. Instead, an aggressive Robin was trying to guard the apples. The Robin swooped at Flickers when the Flickers came in for a brief apple snack. Neither the Flickers nor the Magpies were fazed by the Robin, but I suspect he had more luck at driving the Thrush away. Later, I saw two male Robins sparring in the yard near the apples.



This morning, the two male Robins seemed to have staked out apple territories. I haven't seen the Varied Thrush since Friday morning. The appearance of the Robins could be ominous for the Thrush. In a few days, a mass of bitterly cold air is forecast, with temperature lows in the single digits and highs in high teens/low twenties on Wednesday and Thursday. To survive those temperatures with very little available food, the Thrush will need a good store of fat. There isn't much for the Thrush to eat except for the apples. There are some snowberries which have so far stayed soft all winter. They must have either a high lipid or low water content. Nothing has shown any interest in eating the snowberries, but they are in the open where the Thrush may be reluctant to go. The juniper berries don't have as much water as the apples, but when I sampled one on a recent cold day, it was icy. I don't know if they can supply enough calories to overcome the cost of eating ice.



A few days ago, I was thinking the Varied Thrush was home free for the winter, but he may have to try for a warmer climate or starve.



Kelly Cassidy

Pullman WA