This species has been recorded from coastal boulder field caves with stable cool temperatures and access into native palm woodland or marsh habitat (Gerlach 2004, Joubert 2004, Gerlach and Taylor 2006). It appears to need boulder caves with horizontal ceilings; low, stable temperatures; and clear cave flyways not obscured by vegetation (Gerlach and Taylor 2006). The species has been recorded in various locations across the southwest coast of Mahé as well as on Silhouette. Foraging sites have been identified away from known roosts on both islands and include forested areas, roads, marshes and estuaries as well as coastal disturbed habitats (Bambini et al. 2006, Barbastella Echology and Protect Paradise Seychelles 2023, Bristol 2023). Abandoned roosts have been recorded from all four islands in the species’ historical distribution (Burgess and Lee 2004).

The species is known to feed predominantly on Lepidoptera, Coleoptera and Diptera with an apparent increased reliance on Coleoptera during the breeding season (Gerlach 2008). 

Pups have been observed between November and April in 1977-1980 (Nicoll and Suttie 1982) and more recently in May 2015 (R. Bristol pers. comm. 2015) as well as July 2023 (B. Lewis pers. comm. 2023), suggesting a changing or protracted breeding season that may be due to climate change.

This insectivorous bat is endemic to the Seychelles and is currently found from 0-100 m asl on the islands of Silhouette and Mahé (Gerlach 2004, Bristol 2023). It is considered to be extinct on La Digue and Praslin where it was last seen in 1979 and 1997 respectively (Bambini et al. 2006). A single record is known from Sainte-Anne where it is believed to be a vagrant (G. Rocamora pers. comm. 2021). There are four threat-based locations at the four known roosts sites. Acoustic transects conducted inland and on the North Coast have not yielded any additional records (Bambini et al. 2006).

The species’ extent of occurrence (EOO) is 218 km² was calculated by minimum convex polygon around the species' extant range. The area of occupancy (AOO) is 16-164 km², with the minimum calculated with a 2x2 km grid over the four known roosts and the maximum from the species' extant range. Currently, the number of locations, AOO, and EOO are not thought to be declining or undergoing extreme fluctuations.

There are several ongoing species-specific conservation interventions for the species. The La Passe cave roost on Silhouette, home to the largest subpopulation, lies just within the boundaries of Silhouette National Park and receives additional protection and management there, but the other three known roosts are not located in protected areas and are on private land. Although the roosts of this species are legally protected (Seychelles Ministry of Agriculture, Climate Change, and Environment 2014), there are major developments planned near the three unprotected roosts. Although C. seychellensis is a trigger species for Key Biodiversity Areas (KBA), the three known roosts that lie outside of Silhouette National Park are not yet recognized as KBAs. There are ongoing education programs with local stakeholders and there is increasing public awareness of the state of the species in schools, to the public, and in the media. 

Compliance and enforcement of protective regulations would benefit the species as it is imperative that all known roosts are protected from planned developments and that, where appropriate, historic roosts receive protection for potential future use. Further, degraded foraging habitats should be protected and restored. On Silhouette, invasive rat and cat populations are controlled in the immediate vicinity of the roost, yet very little management is being undertaken near the known roosts on Mahé. Invasive plants and animals need to be eradicated across the species’ range, especially at all known and extant roosts. Understanding the factors behind the strong fluctuations in numbers between roost counts is important. If it is due to the dispersion to other, unknown roosts, those need to be located and monitored. If other factors are at play, those should be identified and studied to understand their potential long-term effects on the population. 

Additional research is needed to locate additional roosts and explore if the subpopulations on Silhouette and Mahé are connected through dispersal. Periodic monitoring of La Digue and Praslin where the species was extirpated 1979 and 1997, respectively (Bambini et al. 2006) is prudent on the chance the species can recolonise those islands. It is also important that more research is undertaken to better understand the feeding and breeding ecology of this species.