Born in a culvert: reproductive notes on Mimon cozumelae (Chiroptera: Phyllostomidae) during road construction in southeastern Mexico

Reproductive notes on Mimon cozumelae

Abstract

The reproductive cycle in bats is closely synchronized with resource availability and may be particularly sensitive to anthropogenic disturbance during energetically demanding stages such as mating, pregnancy, and lactation. In human-modified landscapes, road culverts can provide suitable roosting conditions for bats; however, evidence of their use as mating and maternity roosts remains limited. We documented the reproductive stages of the threatened bat Mimon cozumelae over a one-year period (August 2024 - July 2025) in a road culvert in southeastern Mexico undergoing structural modifications as part of an active road-widening project. Monthly daytime inspections were conducted through direct observations, photographic records, and camera-trap monitoring to assess reproductive stages and associated behaviors. We did not detect any evidence of reproductive stages such as copulation, lactation, or juvenile development between September and April, a period when construction activities included pipe installation, headwall construction, paving, and related infrastructure works. Reproductive stages were documented from May to July, when copulatory events, males with erect penises, lactating females carrying pups, and volant juveniles were observed despite ongoing construction activities associated with the completion of the road-widening project, including road-lighting activation. Despite prolonged disturbance associated with construction activities, the colony continued to inhabit the culvert throughout the study period, suggesting consistent use of this anthropogenic structure under sustained disturbance. These observations provide evidence of multiple reproductive stages of M. cozumelae in a road culvert during active infrastructure development and suggest that road culverts may provide suitable conditions for bats during sensitive reproductive stages. Our observations highlight the ecological importance of road culverts as potential mating and maternity roosts for bats in human-modified landscapes. Recognizing the ecological value of these structures during infrastructure planning can help mitigate impacts on bat populations.