Koparde Pankaj, Mehta Prachi, Mukherjee Shomita, Robin V V
Division of Conservation Biology Sálim Ali Centre for Ornithology and Natural History Coimbatore India.
Manipal Academy of Higher Education Manipal India.
Ecol Evol. 2019 Mar 26;9(8):4864-4874. doi: 10.1002/ece3.5086. eCollection 2019 Apr.
The nested pattern in the geographical distribution of three Indian owlets, resulting in a gradient of endemicity, is hypothesized to be an impact of historical climate change. In current time, the Forest Owlet is endemic to central India, and its range is encompassed within the ranges of the Jungle Owlet (distributed through South Asia) and Spotted Owlet (distributed through Iran, South and Southeast Asia). Another phylogenetically close species, Little Owl which is largely Palearctic in distribution, is hypothesized to have undergone severe range reduction during the Last Glacial Maximum, showing a postglacial expansion. The present study tests hypotheses on the possible role of Quaternary climatic fluctuations in shaping geographical ranges of owlets.
We used primary field observations, open access data, and climatic niche modeling to construct climatic niches of four owlets for four periods, the Last Interglacial (120-140 Ka), Last Glacial Maximum (22 Ka), Mid-Holocene (~6 Ka), and Current (1960-1990). We performed climatic niche extent, breadth, and overlap analyses and tested if climatically suitable areas for owlets are nested in a relatively stable climate.
Climatically suitable areas for all owlets examined underwent cycles of expansion and reduction or a gradual expansion or reduction since the Last Interglacial. The Indian owlets show significant climatic niche overlap in the current period. Climatically suitable areas for Little Owl shifted southwards during the Last Glacial Maximum and expanded northwards in the postglaciation period. For each owlet, the modeled climatic niches were nested in climatically stable areas.
The study highlights the impact of Quaternary climate change in shaping the present distribution of owlets. This is relevant to the current scenario of climate change and global warming and can help inform conservation strategies, especially for the extremely range-restricted Forest Owlet.
三种印度小猫头鹰在地理分布上呈现嵌套模式，形成了特有性梯度，据推测这是历史气候变化的影响。当前，林斑小鸮是印度中部特有的物种，其分布范围包含在丛林小鸮（分布于南亚）和纵纹腹小鸮（分布于伊朗、南亚和东南亚）的分布范围内。另一种在系统发育上相近的物种——纵纹腹小鸮，其分布主要在古北区，据推测在末次盛冰期经历了严重的分布范围缩减，之后在冰后期出现扩张。本研究检验了第四纪气候波动在塑造小猫头鹰地理分布范围方面可能发挥的作用的假设。
我们利用原始野外观察、开放获取数据和气候生态位建模，构建了四种小猫头鹰在四个时期（末次间冰期（约120 - 140 ka）、末次盛冰期（约22 ka）、中全新世（约6 ka）和当前（1960 - 1990年））的气候生态位。我们进行了气候生态位范围、宽度和重叠分析，并检验了小猫头鹰的气候适宜区域是否嵌套在相对稳定的气候中。
自末次间冰期以来，所有被研究的小猫头鹰的气候适宜区域都经历了扩张和缩减的循环，或者是逐渐扩张或缩减。印度的小猫头鹰在当前时期显示出显著的气候生态位重叠。纵纹腹小鸮的气候适宜区域在末次盛冰期向南转移，并在冰后期向北扩张。对于每一种小猫头鹰，模拟的气候生态位都嵌套在气候稳定的区域。
该研究突出了第四纪气候变化对塑造当前小猫头鹰分布的影响。这与当前的气候变化和全球变暖情况相关，有助于为保护策略提供信息，特别是对于分布范围极其有限的林斑小鸮。
