Golawski Artur, Kasprzykowski Zbigniew, Al Sariri Thuraya Said
Siedlce University of Natural Sciences and Humanities, Faculty of Exact and Natural Sciences, Prusa 14, 08-110 Siedlce, Poland.
Ministry of Environment and Climate Affairs of Oman, PO. Box 323, Muscat, Oman.
Saudi J Biol Sci. 2020 Jun;27(6):1462-1466. doi: 10.1016/j.sjbs.2020.04.019. Epub 2020 Apr 19.
In situations of restricted food supply, the trophic niches of closely-related species of animals should be separate. For sit-and-wait hunters, such as shrikes, this is associated with competition for food and hunting sites. In the present study, the foraging behaviour of two shrike species - Red-tailed Shrike and Red-backed Shrike was studied in a desert habitat in Oman. The fieldwork was carried out in September 2019, during the peak migration of these birds. Their behaviour was recorded in detail during 30-minute observation bouts. A General Linear Mixed Model with logit link function and binomial error variance was used to compare their behaviour. The type of perch and its height did not differ between them, but there were significant differences in their use of look-out posts only in the mean duration of a single perching event, which was more than twice as long in Red-backed Shrike. No differences in prey size were found between the species and hunting success (the ratio of successful attacks to all attacks) was similar in both (RtS-RbS: 46 vs. 61%). Dietary diversity was twice as great in Red-tailed Shrike as in Red-backed Shrike, but in general, their diets did not differ very much. Dietary overlap between the species at this level of prey identification was 92%. This absence of differences in some aspects of behaviour and diet may be due to the similarity of the two species, above all their same body size, and even the possibility of hybridization. If the species compared are so similar due to body size, behaviour and evolutionary relationship their food niches may overlap.
在食物供应受限的情况下，亲缘关系相近的动物物种的营养生态位应该是分开的。对于诸如伯劳等坐等型猎手来说，这与对食物和狩猎地点的竞争有关。在本研究中，对两种伯劳——红尾伯劳和红背伯劳在阿曼的沙漠栖息地中的觅食行为进行了研究。实地调查于2019年9月这些鸟类的迁徙高峰期进行。在30分钟的观察时段内详细记录它们的行为。使用具有logit连接函数和二项式误差方差的广义线性混合模型来比较它们的行为。它们所栖息的栖木类型及其高度没有差异，但仅在单次栖息事件的平均持续时间方面，它们对瞭望点的使用存在显著差异，红背伯劳的单次栖息事件平均持续时间是红尾伯劳的两倍多。在猎物大小方面未发现物种间存在差异，并且两种伯劳的狩猎成功率（成功攻击次数与总攻击次数的比率）相似（红尾伯劳 - 红背伯劳：46% 对 61%）。红尾伯劳的饮食多样性是红背伯劳的两倍，但总体而言，它们的饮食差异不大。在这种猎物识别水平下，两个物种之间的饮食重叠率为92%。在行为和饮食的某些方面不存在差异，可能是由于这两个物种相似，首先是它们相同的体型，甚至存在杂交的可能性。如果所比较的物种由于体型、行为和进化关系而如此相似，那么它们的食物生态位可能会重叠。
