Frequent or scarce? Damage to flight-enabling body parts in bats (Chiroptera)

New reports of morphological anomalies in leaf-nosed bats (Chiroptera: Phyllostomidae) from Colombia

Morphological anomalies in bats are rarely reported. We present new reports of three types of morphological anomalies (chromatic, wing, and ear) from specimens in a biological collection and from individuals captured during field sampling. We recorded piebaldism on seven individuals from six species: Carollia perspicillata, Glossophaga commissarisi, Hsunycteris thomasi, Phyllostomus elongatus, and Trachops cirrhosus from Guaviare collected in 2022, and Tonatia saurophila from Casanare collected in 2020. These represent three new reports for the continent (P. elongatus, G. commissarisi, and H. thomasi). We also recorded the broken digits anomaly on two individuals from two species: Platyrrhinus sp. and Sturnira sp. from Chocó collected in 2019. In addition, we found one case of the absence of pinnae and tragus in C. perspicillata from Santander collected in 2018; an absence not previously reported in bats. We encourage researchers to report their observations of bats with morphological anomalies, as this information could be useful in estimating occurrence rates and addressing questions about its effects on populations.

Seasonal challenges of tropical bats in temperate zones

To examine the challenges faced by free-ranging Rousettus aegyptiacus living at the northern edge of their distribution, we performed a retrospective analysis of 2196 clinical cases reported by a bat rescue NGO over a period of 36 months, from throughout Israel. All cases of injured bats were evaluated and categorized according to date, place, sex, age, and etiology of the morbidity. The data analysis revealed an increase in all types of morbidity during the wintertime, with more than two-fold the number of cases per week compared to in the summer, over three consecutive years. Moreover, we found that the number of abandoned pups peaked during spring and summer, when adult morbidity is minimal. We characterized two prominent types of previously undescribed morbidities in R. aegyptiacus. We also employed GPS tracking to monitor the movement and foraging of dozens of bats, and to examine the potential correlates of elevated winter morbidity. Our results suggest that it is mainly harsh weather that drives the observed winter morbidity, with food limitations playing a minor-role. We hypothesize that R. aegyptiacus, of tropical origin, is facing major seasonal survival difficulties near the northern edge of its distribution, probably limiting its spread further northwards still.