Population collapse of the Egyptian fruit bat on Cyprus (2005–2022): evidence for the roles of roost disturbance and reduced food availability likely associated with climate change

Insular bat populations are particularly vulnerable to human disturbance and environmental change, yet long-term demographic data remain scarce. The Egyptian fruit bat ( Rousettus aegyptiacus ) is the only native fruit bat in Europe, with Cyprus harbouring one of its most isolated populations. We analysed long-term monitoring data from 21 roosts surveyed between 2005 and 2022 to quantify population trends and evaluate the roles of roost accessibility and food availability. Population trends were estimated using log-linear TRIM models, while generalized linear mixed models tested whether trends differed between roosts with contrasting accessibility. Commercial fruit production was analysed as a proxy for food availability. The population declined from approximately 7200 individuals in 2005 to about 1050 in 2022, corresponding to an overall decline of 85.4% and an average annual decrease of 8.8%. Trend analyses identified three phases: a rapid decline (2005–2011), a slower decline (2012–2017), and a partial recovery after 2018. Colonies in easily accessible roosts declined significantly faster than those in less accessible roosts, indicating that human disturbance likely contributed substantially to the population collapse. Commercial fruit production also declined markedly during this period, coinciding with exceptional drought on Cyprus. Our results suggest that roost disturbance was a major driver of the decline, whereas reduced food availability, likely associated with increasing aridity and climate-driven changes in agricultural production, further contributed to population losses. Our findings highlight the need for strict protection of roosts and suggest that securing food and water resources may represent an important complementary conservation measure.