Myoglobin as a conservation-relevant predictor of short-distance flight capacity in Neotropical forest birds

Some forest-dwelling tropical bird species are unable or unwilling to fly even a few hundred meters across habitat discontinuities, restricting connectivity of isolated populations in fragmented landscapes. Experimental evidence for flight limitation has reliably predicted occurrence across archipelagoes of habitat fragments varying in their distance from potential source populations. Mechanistic explanations for large differences in flight capacity of tropical birds, even over remarkably short distances, have not been tested. We evaluated myoglobin concentration in pectoralis muscles and hearts of eight Neotropical species for which experimental evidence revealing a wide range of flight abilities exists. We found a strong positive relationship between myoglobin concentration in the pectoralis muscles, but not hearts, and average over-water flight distance during dispersal-challenge experiments. The approximately 2.5-fold difference in pectoralis myoglobin concentration is directly asso...部分森林栖息的热带鸟类物种，即便仅需飞越数百米的生境断裂带，也无力或不愿飞行，这限制了破碎化景观中孤立种群的连通性。已有关于飞行受限的实验证据，可可靠预测在与潜在源种群距离各不相同的生境碎片群岛中，此类受限现象的出现情况。即便飞行距离极短，热带鸟类的飞行能力也存在显著差异，但其背后的机制性解释尚未得到验证。本研究针对8种新热带界鸟类（Neotropical species），检测了其胸肌（pectoralis muscles）与心脏中的肌红蛋白（myoglobin）浓度；这类物种的飞行能力差异已通过实验证据得到充分揭示。本研究发现，胸肌中的肌红蛋白浓度（而非心脏中的）与扩散挑战实验（dispersal-challenge experiments）中测得的平均跨水面飞行距离呈显著正相关。胸肌肌红蛋白浓度约2.5倍的差异，直接与……