ECOLOGICAL ASPECTS OF THE REPRODUCTIVE BIOLOGY OF EASTERN KINGBIRDS: GEOGRAPHIC COMPARISONS'
ECOLOGICAL ASPECTS OF THE REPRODUCTIVE BIOLOGY OF EASTERN KINGBIRDS: GEOGRAPHIC COMPARISONS'
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东方王鸟生殖生物学的生态学方面：地理比较
DOI：
10.2307/1937213
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
M. T. Murphy
中科院分区：
文献类型：
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作者：
M. T. Murphy
分别于 1979 年和 1980 年对美国纽约 (NY) 和堪萨斯州 (KS) 繁殖的东部霸王鸟 (Tyrannus tyrannus) 的生态进行了地理比较。重点放在地点内部和地点之间繁殖参数的变化与季节和天气的关系。与地理比较相叠加的是 1980 年堪萨斯州的严重干旱。两个种群的产蛋高峰均在 6 月第一周结束时达到，最典型的窝产数为 3。离合器尺寸的季节性下降也几乎相同。离合器尺寸差异不显着。纽约州的鸡蛋明显大于堪萨斯州的鸡蛋。这种差异与成人的体型或每年的天气变化无关。蛋量与环境变量（日期和温度）的相关性很弱，但在气温低于平均水平的几天后，产蛋就会中断。在纽约州，蛋质量随着产蛋顺序的增加而增加，但在堪萨斯州则减少。这显然反映了堪萨斯州产蛋雌性的压力状况。堪萨斯州的孵化时间显着缩短，可能是由于气温较高，因为纽约州的气温与孵化时间呈反比关系。堪萨斯州较小的鸡蛋尺寸也可能导致孵化期较短。雏鸟的生长相对缓慢，尽管质量差异很大（纽约的鸡蛋更重），但生长速度几乎相同。纽约州的绝对跗骨生长也显着更大，但堪萨斯州的第九初级发育显着更大。两个种群的雏鸟期长度与初生长度呈负相关。强调 KS 的初级发育（筑巢成功率较低），而强调 NY（饥饿更频繁）的质量增加，通过权衡来平衡捕食者（KS）和饥饿（NY）的损失来讨论。两个种群的生长都与巢的大小呈负相关，但在堪萨斯州，生长也与日期呈负相关，即季节变化可能与干旱有关。纽约州的生产力更高，但两个种群的每次筑巢尝试均未超过 1.5 只雏鸟。由于父母对雏鸟后的强烈照顾，两个种群的雏鸟死亡率都接近于零。天气对王鸟的繁殖生物学有重要影响，但大多数性状的地理差异很小。因此，王鸟的繁殖不太适应不同地点之间平均天气条件的差异。偶尔出现的恶劣天气可能会妨碍针对当地条件的狭隘专业化。因此，王鸟最能被描述为“赌注对冲”物种。生长和繁殖模式与基于其他空中食虫动物的假设和独立得出的预测相匹配，从而为最近的一些关于生活史进化的预测提供了支持。
A geographic comparison of the ecology of Eastern Kingbirds (Tyrannus tyrannus) breeding in New York (NY), and Kansas (KS), USA, was conducted in 1979 and 1980, respectively. Emphasis was placed on relating variation in reproductive parameters, both within and between sites, to season and weather. Superimposed on the geographic comparison was a severe drought in KS in 1980. In both populations egg laying peaked at the end of the 1 st wk of June, and modal clutch size was three. Seasonal declines in clutch size were also nearly identical. Clutch size differences were not significant. Eggs were significantly larger in NY than in KS. The difference was not related to either adult size or annual variation in weather. Egg mass was only weakly correlated with environmental variables (date and temperature), but interruptions in laying followed days of below-average temper- atures. Egg mass increased with the order of laying in NY, but decreased in KS. This apparently reflected the stressful conditions for laying females in KS. Incubation was significantly shorter in KS, probably due to warmer air temperatures since an inverse relationship was found between air tem- perature and incubation length in NY. Smaller egg size in KS may also have contributed to the shorter incubation period. Nestling growth was relatively slow, and despite large mass differences (eggs were heavier in NY) growth rates were nearly identical. Absolute tarsus growth was also significantly greater in NY, but development of the ninth primary was significantly greater in KS. Nestling period length was inversely correlated with primary length in both populations. Emphasis on primary de- velopment in KS, where nest success was lower, vs. mass gain in NY, where starvation was more frequent, is discussed in terms of tradeoffs to balance losses to predators (KS) and starvation (NY). Growth was negatively correlated with brood size in both populations, but in KS also with date, i.e., seasonal changes probably related to the drought. Productivity was greater in NY, but in neither population did it exceed 1.5 fledglings per nesting attempt. Mortality of fledglings is near zero in both populations due to intense postfledging parental care. Weather has important influences on the breeding biology of kingbirds, yet geographic variation in most traits was small. Hence, kingbird reproduction is not highly adapted to differences in average weather conditions between the sites. Occasional periods of severe weather probably preclude narrow specialization to local conditions. Kingbirds are therefore best characterized as a "bet-hedging" species. Patterns of growth and reproduction match hypothetical and independently derived predic- tions based on other aerial insectivores, thus providing support for several recent predictions for life history evolution.