Caffeine expectancy, explicit and implicit memory performance among female nursing students: a placebo-controlled quasi-experimental study.

Droughts are globally increasing in frequency, duration and intensity (Trenberth et al., ; Xu et al., ). Drought endangers the survival of wildlife, because animals can die of dehydration, starvation, wildfire or human–wildlife conflict (Abrahms et al., ; Wato et al., ). Survival of wildlife in an increasingly dry climate depends on (i) the ability to behaviourally adapt to drought, and (ii) whether effective conservation measures are taken in case behavioural adaptation does not suffice. To develop conservation measures that aid wildlife survival and prevent human–wildlife conflict, it is important to understand if and how animals alter their behaviour during drought. Although it is well established that drought threatens wildlife survival, little is known about the connection between drought and wildlife behaviour. In particular, existing research on wildlife behaviour in relation to drought typically does not consider the timescale and the intensity of the drought (Slette et al., ; but see West et al., ). Yet, the effect of drought on resource availability strongly depends on the timescale at which the drought occurs. Drought starts upon a prolonged lack of rainfall (meteorological drought), but as drought persists, vegetation declines and crop yields drop (agricultural drought), and ultimately water levels of lakes, rivers and groundwater decline (hydrological drought) (Van Loon, ). The intensity indicates whether drought conditions are within normal climate variability, such as during annually recurring dry seasons, or fall outside of normal climate variability (Slette et al., ). This difference is important since animals may be prepared for predictable dry seasons but not for the increasingly frequent, long and intense droughts expected in the coming decades (Slette et al., ;Trenberth et al., ; Xu et al., ). For example, droughts or subsequent wildfires could cause animals to look for shelter in human‐dominated areas, potentially leading to human–wildlife conflict (Abrahms et al., ). At larger spatio‐temporal scales, climate change may disrupt long‐distance movements such as seasonal migration, because the timing of resource availability along the migration route shifts (Kubelka et al., ). Thus, accounting for drought timescale and intensity is expected to help in understanding how animals behave in a changing climate. The African elephant () is an ecosystem engineer known for its large‐scale movements that allow seed dispersal over long distances (Coverdale et al., ; Poulsen et al., ). Yet, the African elephant is endangered because of climate change and conflict with humans (Black et al., ). In Southern Africa, which has the largest elephant population in the world, severe droughts occurred in 2023 and 2024 and will become more frequent over the 21st century (Black et al., ; Schlossberg & Chase, ; UNCCD, ; Xu et al., ). Drought causes elephant mortality because elephants starve, dehydrate or get stuck in muddy waters (UNCCD, ; Wato et al., ). Moreover, drought increases the risk of human–elephant conflict, in the first place because humans and elephants compete for limited resources (Abrahms et al., ; Mariki et al., ), but also because measures to prevent human–elephant conflict may be less effective during drought (King et al., ).