Bakken George S, Williams Joseph B, Ricklefs Robert E
Department of Life Sciences, Indiana State University, Terre Haute, Indiana 47809, USA.
J Exp Biol. 2002 Nov;205(Pt 22):3435-43. doi: 10.1242/jeb.205.22.3435.
Wind is a significant factor in the thermoregulation of chicks of shorebirds on the Arctic tundra. We investigated the effect of wind at speeds typical of near-surface conditions (0.1-3 ms(-1)) on metabolic heat production, evaporative cooling and thermal conductance of 1- to 3- week-old downy scolopacid chicks (least sandpiper Calidris minutilla; short-billed dowitcher Limnodromus griseus; whimbrel Numenius phaeopus). Body mass ranged from 9 to 109 g. To accurately measure the interacting effects of air temperature and wind speed, we used two or more air temperatures between 15 degrees and 30 degrees C that produced cold stress at all wind speeds, but allowed chicks to maintain normal body temperature (approximately 39 degrees C). Thermal conductance increased by 30-50% as wind speed increased from 0.1 to 3 ms(-1). Conductance in these chicks is somewhat lower than that of 1-day-old mallard ducklings of similar mass, but higher than values reported for downy capercaillie and Xantus' murrelet chicks, as well as for adult shorebirds. Evaporative water loss was substantial and increased with mass and air temperature. We developed a standard operative temperature scale for shorebird chicks. The ratio of evaporative cooling to heat production varied with wind speed and air temperature.
风是北极苔原上滨鸟雏鸟体温调节的一个重要因素。我们研究了近地表条件下典型风速（0.1 - 3米/秒）的风对1至3周龄绒羽鹬鸻科雏鸟（最小滨鹬Calidris minutilla；短嘴半蹼鹬Limnodromus griseus；斑尾塍鹬Numenius phaeopus）代谢产热、蒸发散热和热传导的影响。雏鸟体重在9至109克之间。为了准确测量气温和风速的相互作用影响，我们在15摄氏度至30摄氏度之间使用了两个或更多的气温，这些气温在所有风速下都会产生冷应激，但能让雏鸟维持正常体温（约39摄氏度）。随着风速从0.1米/秒增加到3米/秒，热传导增加了30% - 50%。这些雏鸟的热传导略低于体重相近的1日龄绿头鸭雏鸟，但高于报道的绒羽黑琴鸡和桑氏小海雀雏鸟以及成年滨鸟的值。蒸发失水量很大，且随体重和气温增加。我们为滨鸟雏鸟制定了一个标准的有效温度标度。蒸发散热与产热的比率随风速和气温而变化。
