Otter Ecology and Conservation Dynamics

Otters are semi-aquatic mustelids that occupy a range of freshwater, coastal and estuarine environments across all continents except Australia and Antarctica. Their role as top predators links aquatic food webs and influences prey populations of fish, crustaceans and amphibians. Individuals maintain home ranges that may vary seasonally in size and overlap, reflecting resource availability and intraspecific tolerance. Habitat quality, connectivity of river corridors and riparian vegetation are critical for foraging, denning and dispersal. Populations have suffered from habitat degradation, pollution, over-exploitation of prey and direct persecution, but many species have demonstrated resilience following legal protection and restoration of aquatic networks. Contemporary conservation dynamics focus on non-invasive monitoring methods, spatially explicit density estimation, landscape-scale habitat modelling and the management of human–otter conflicts. Integrated strategies now emphasise ecological restoration, maintenance of hydrological regimes and creation of habitat corridors to support long-term population viability and ecosystem health.

Research from Nature Portfolio

A 2024 study has examined Eurasian otter densities and spatial behaviour in a Mediterranean river pool undergoing progressive drying. Using non-invasive genetic sampling of faecal deposits and spatial capture–recapture modelling, the work revealed densities up to five times higher than previously recorded in similar biogeographical regions. Movement patterns indicated extensive home-range overlap and minimal territorial aggression under conditions of resource concentration. These findings highlight the behavioural plasticity of otters in seasonal systems and underscore the importance of maintaining connectivity and minimum flow levels in regulated rivers.

Otter Ecology and Conservation Dynamics publication trend

The graph below shows the total number of articles in otter ecology and conservation dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Spraint: Otter faecal deposit used for scent-marking and non-invasive monitoring of presence.

Latrine site: Concentrated area where multiple spraints are deposited for social communication.

Spatial capture–recapture: Statistical method estimating animal density by analysing detections of individuals at spatially referenced sampling locations.

Occupancy model: Analytical framework to estimate the probability of species presence and detection across survey sites while accounting for imperfect detection.

References

1. Low signs of territorial behavior in the Eurasian otter during low-water conditions in a Mediterranean river. Scientific Reports (2024).
2. Multi-scale habitat influences sprainting and group size of a freshwater-obligate smooth-coated otter (Lutrogale perspicillata) in Tungabhadra Otter Conservation Reserve, India. Ecological Processes (2024).
3. Dietary complexity and hidden costs of prey switching in a generalist top predator. Ecology and Evolution (2020).
4. Marking behaviour and census of Eurasian otters (Lutra lutra) in riverine habitats: what can scat abundances and non-invasive genetic sampling tell us about otter numbers?. Mammal Research (2020).