Bats are nocturnal mammals known for their ability to echolocate, yet all bats can see, and most bats of the family Pteropodidae (fruit bats) do not echolocate – instead they rely mainly on vision and olfaction to forage. We investigated whether echolocating bats, given their limited reliance on vision, have poorer spatial resolving power (SRP) than pteropodids and whether tongue click echolocating fruit bats differ from non-echolocating fruit bats in terms of visual performance. We compared the number and distribution of retinal ganglion cells (RGCs) as well as the maximum anatomical SRP derived from these distributions in 4 species of bats: Myotis daubentonii, a laryngeal echolocating bat from the family Vespertilionidae, Rousettus aegyptiacus, a tongue clicking echolocating bat from the family Pteropodidae, and Pteropus alecto and P. poliocephalus, 2 non-echolocating bats (also from the Pteropodidae). We find that all 3 pteropodids have a similar number (≈200,000 cells) and distribution of RGCs and a similar maximum SRP (≈4 cycles/degree). M. daubentonii has fewer (∼6,000 cells) and sparser RGCs than the pteropodids and thus a significantly lower SRP (0.6 cycles/degree). M. daubentonii also differs in terms of the distribution of RGCs by having a unique dorsal area of specialization in the retina. Our findings are consistent with the existing literature and suggest that M. daubentonii likely only uses vision for orientation, while for pteropodids vision is also important for foraging.
Brain Behav Evol

中文翻译：

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回声定位和非回声定位蝙蝠的视网膜神经节细胞地形和空间分辨能力。

蝙蝠是夜间活动的哺乳动物，以其回声定位能力而闻名，但所有蝙蝠都能看到，大多数翼足科蝙蝠（果蝠）不会回声定位 - 相反，它们主要依靠视觉和嗅觉来觅食。我们调查了回声定位蝙蝠，鉴于它们对视觉的依赖有限，是否具有比翼足类动物更差的空间分辨能力 (SRP)，以及舌点击回声定位果蝠在视觉表现方面是否与非回声定位果蝠不同。我们比较了 4 种蝙蝠的视网膜神经节细胞 (RGC) 的数量和分布以及源自这些分布的最大解剖 SRP：Myotis daubentonii，一种来自 Vespertilionidae 和Rousettus aegyptiacus的喉部回声定位蝙蝠，一只舌尖回声定位蝙蝠来自 Pteropodidae，以及Pteropus alecto和P. poliocephalus，2 只非回声定位蝙蝠（也来自 Pteropodidae）。我们发现所有 3 种翼足类动物都具有相似的数量（≈200,000 个细胞）和 RGC 的分布以及相似的最大 SRP（≈4 个周期/度）。M. daubentonii 的RGC 比翼足类少（约 6,000 个细胞）和稀疏，因此 SRP 显着降低（0.6 个周期/度）。M. daubentonii在 RGC 的分布方面也有所不同，因为它在视网膜中有一个独特的背侧区域。我们的发现与现有文献一致，并表明M. daubentonii可能只使用视觉来定位，而翼足类动物的视觉对于觅食也很重要。
大脑行为进化