Autumn’s wind will soon blow cold, and yet late October and November bring some of the best birding of the year. Hawk watchers climb ridges to watch for the fall push of large buteos, and of even fancier birds: Northern Goshawks and Golden Eagles. On the coast, November has been branded “rarity season,” and for good reason, for this when many western vagrants are found.
So bitter temperatures shouldn’t stop the birding fun, but they sure can do just that if the birder is not dressed properly. I’ve found that the first layer of clothing (the one next to the skin) is often the most important line of defense against cold. There are two reasons for this. The first is that a snug-fitting but NOT tight first layer traps a stationary layer of air against your skin. That air is warmed by your body, and, well, you feel warm.
The second reason the first layer is most important has to with moisture, or rather getting rid of it. Taking our hike to the hawk lookout as an example, while hiking up you get warm and perspire, and when you get to the top and meet the 20 MPH northwest wind, you are chilled immediately because moisture is a great conduit for heat, in this case away from your body.
Good first layer garments wick moisture away from the skin. Cotton is not a good first layer, and in fact I recommend avoiding cotton for cold weather wear period - not underwear, not socks, not t-shirts. Cotton will absorb water and hold it against your skin, and you can forget about being warm if that happens.
The most important layers are the first, in this case a set of medium weight Thermax underwear from Cabela’s and wool Ultimax socks. A fleece button up turtleneck sweater is an ideal complement. Note that if you try to wear a wool sweater over synthetic undergarments, you are setting yourself up for static electric shock formed when the garments rub together.
There are a variety of material and trade names for moisture wicking garments - for example, polypropylene, Capilene (Patagonia’s trade name), Thermax and MTP (Cabela’s trade names), Techwick (Eastern Mountain Sports trade name). Most of these come in several thicknesses, from light to “Expedition Weight.” It might be tempting to go for the thickest stuff you can get, but I don’t recommend it, because there is such a thing as too warm, when you sweat so much that the wicking material can’t keep up. Since you can’t exactly take your inner most garments off in the field, you’re stuck for the day with the underwear you choose. I own expedition weight garments but I have almost never needed them while birding (I use them primarily for deer hunting from a stationary position).
Make sure, whatever material or weight you choose, that your first layer is neither tight nor loose. Snug is just right, tight enough to keep the material next to the skin but loose enough to allow freedom of movement and free circulation. For a second layer shirt, I much prefer designs with a zip-turtleneck or a button top, so they can be opened when it starts getting warmer or if I’m active. Also make sure the sleeves can be rolled up, for the same reason. Top off your second layer with a fleece sweatshirt, add a good pair of socks, and you’re ready to go for those November rarities.