Seasonal variation in nest placement of Abert's Towhees
Seasonal variation in nest placement of Abert's Towhees
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阿伯特土鹬筑巢位置的季节变化
DOI：
10.2307/1367905
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
D. Finch
中科院分区：
文献类型：
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作者：
D. Finch
已知有几个气象变量会影响筑巢鸟类的热量收支（例如，Walsberg and King 1978 a，B）.这些因素包括空气温度、入射辐射、风和湿度。如果巢内的小气候不利，亲鸟可能会变得不注意，使蛋或雏鸟暴露在过热或过冷的环境中。他们可能会抛弃巢穴，他们的后代可能会死亡。为了提高成功筑巢的可能性，许多东半球的沙漠鸟类将巢安置在能够接受早晨阳光的地方（麦克莱恩，1976）。一些研究者已经证明了新大陆洞穴筑巢鸟类洞穴入口的非随机方向（Ricklefs and Hainsworth 1968，Inouye 1976，Inouye et al. 198 1），但很少有人测试非随机位置或开放巢季节之间位置变化的意义。麦克林（Maclean，1976）指出，卡拉哈里沙漠中的云雀将它们的巢穴定位为在夏季得到阴凉，在冬季得到阳光。Balda和Bateman（1970年）预测，亚利桑那州的松鸦（Gymnorhinus cyanocephalus）可能会在这个季节的第一个巢放在黄松（Pinus ponderosa）的向阳面，但它们可能会在以后的巢中随机放置。他们表明，3月份这些树木的南侧比北侧温暖30摄氏度，而且松鸦选择筑巢地点是为了获得更多热量：所有松鸦的巢穴，无论季节如何，都明显向南。我在这里报告第二个测试巴尔达和贝特曼（1970年）的假设，使用的数据，一种鸟的炎热的气候，阿伯特的Towhee（Pipilo aberti）。这种定居的物种只栖息在美国西南部的沙漠河岸地区，而移动的松鸦占据了更大的海拔和纬度范围，虽然主要在山麓和较低的山脉繁殖。由于阿伯特的Towhee巢通常暴露在更高的春季和夏季温度比松鸦，巴尔达和贝特曼的预测的第二个测试可能会显示更大的季节性变化的巢位置。这项研究是在亚利桑那州埃森伯格以北10公里的科罗拉多河印第安人保留区的蜂蜜牧豆树（Prosopis glandulosa）栖息地进行的。从1980年1月至7月，我每周花15小时（84个5小时搜索）寻找巢穴，或附近的网格研究地块20公顷。野外工作于7月结束，当时没有新的巢穴开始。
Several meteorological variables are known to influence the heat budgets of nesting birds (e.g., Walsberg and King 1978a, b). Such factors include air temperature, incident radiation, wind, and humidity. If the microclimate of the nest is unfavorable, parent birds may become inattentive, exposing eggs or nestlings to excessive heat or cold. They may then desert the nest and their offspring may die. To improve the probability of nesting successfully, many Old World desert birds place their nests so as to receive morning sunlight (Maclean 1976). Several investigators have demonstrated nonrandom orientation of hole entrances of New World cavity-nesting birds (Ricklefs and Hainsworth 1968, Inouye 1976, Inouye et al. 198 1), but few have tested for the significance of nonrandom placement or variation in placement between seasons of open nests. Maclean (1976) indicated that larks in the Kalahari Desert oriented their nests to receive shade in summer and sun in winter. Balda and Bateman (1970) predicted that Pinyon Jays (Gymnorhinus cyanocephalus) in Arizona may place first nests of the season on the sunny sides of ponderosa pines (Pinus ponderosa), but that they may orient later nests more randomly. They showed that these trees in March were 30C warmer on the south side than on the north side, and that the jays selected nest sites to gain more heat: all jay nests, regardless of season, had a significant southward orientation. I report here a second test of Balda and Bateman's (1970) hypothesis, using data for a bird of hotter climates, the Abert's Towhee (Pipilo aberti). This sedentary species inhabits only desert riparian regions of the southwestern United States, whereas the mobile Pinyon Jay occupies a greater elevational and latitudinal range, though breeding chiefly in foothills and lower mountain ranges. Because nests of the Abert's Towhee are typically exposed to higher spring and summer temperatures than those of the Pinyon Jay, a second test of Balda and Bateman's prediction may demonstrate greater seasonal variation in nest placement. The study was conducted in honey mesquite (Prosopis glandulosa) habitat on the Colorado River Indian Reservation 10 km north of Ehrenberg, Arizona. From January to July 1980, I spent 15 h each week (84 5-h searches) looking for nests on, or near a gridded study plot of 20 ha. Field work terminated in July when no new nests were started.