Mouse-eared Bat

Fascinating facts about the Mouse-eared Bat

• Weighing up to 45 g and stretching a 40 cm wingspan, the greater mouse-eared bat rivals a house mouse in size yet outlives most tiny mammals, with documented lifespans beyond 35 years. Its weight range overlaps 20-45 g and wingspan varies 36.5-45 cm, showing considerable size flexibility across Europe. While most Myotis live only 6-7 years, this species has been recorded at 13 years in the UK and up to 22 years in the wild, and a remarkable individual was recaptured 44 years after first being banded, highlighting an extraordinary longevity for a bat of its size.
• Unlike most bats that snatch insects on the wing, the greater mouse-eared bat hunts by listening for the faint clicks of ground beetles and moths, then gleans them from the forest floor. It only fires ultrasonic calls for navigation, not for capture, with frequencies spanning 22-86 kHz, a peak energy at 37 kHz and each pulse lasting about 6 ms. This passive listening lets it exploit prey on the ground, expanding its diet to beetles, centipedes and spiders.
• Colonies can swell to astonishing numbers: on Mallorca the bat forms groups of up to 500 individuals, while continental sites have recorded colonies exceeding 4,500 bats. In spring, individuals may travel up to 200 km to new summer sites, though most movements are around 10 km, matching the roughly 10 km activity radius recorded for the species.
• Mating occurs in autumn, and females give birth between May and June, usually to one or two pups. The newborns cling to their mothers for roughly 45 days before becoming independent, during which time mothers gather in exclusive nursery colonies that exclude males.
• Human fear can turn deadly for these bats: in March, villagers in Culden, Peru, set fire to a roost after hearing rumors that the animals spread COVID-19. SERFOR officials intervened just in time to rescue almost 200 mouse-eared bats and relocate them to a safe cave. Such attacks illustrate how misinformation fuels persecution, threatening colonies that already face habitat loss, and underscore the need for education about the ecological services bats provide, like insect control.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia
• Mongabay

At a glance

About the Mouse-eared Bat

In the fading light of dusk, the mouse-eared bat stirs, unfolding its delicate wings like a dark, leathery cloak, as it takes to the evening skies with a soft, rustling whisper. With echolocation calls that pierce the night air, this endangered creature navigates the treacherous landscape of human alteration, its remarkable adaptability a testament to the enduring will to survive in a world where its very existence is under threat. As it flits and weaves through the shadows, its large, round ears drinking in the faintest sounds, the mouse-eared bat embodies a fragile, flickering beauty that is both captivating and heartbreaking.

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