Otter - Lutra lutra

Physical Characteristics & Habitat: 
Otter (Lutra lutra) are a large member of the mustelid family along with badger, pine marten, stoat, and weasel. They are semi-aquatic mammals with a 'dog-like face', elongated body and long tapered tail (fig. 1). Otter occur in two broad habitats - freshwater (rivers & lakes), and coastal (coastline & estuary) (Couzens et al, 2017). Around 50% of Scottish population are coastal otters, which feed almost exclusively on fish and crustaceans in the sea (NatureScot, 2024). Coastal otters tend to be diurnal, active during the day. One key sign that otters are in an area is their distinctive droppings called 'spraint', usually placed on prominent sites near water. Fresh spraint is typically dark in colour with its smell described as smeet/musky like Jasmine tea, or fishy - often consisting of fish bones or shells (Couzens et al, 2017).

Range & Distribution:
There are an estimated 8000 otters in Scotland (NatureScot, 2024). A 2011-12 survey across Scotland found otter present in 92% of sites surveyed, indicating that they are a widespread species (Findlay, Alexander & Macleod, 2015) (fig. 2). Due to the abundance of fish and crustacean in the inshore waters, coastal otters have small home ranges (4-5km of coastline) compared to freshwater otters (up to 32km for males, 20km for females) (NatureScot, 2015). 

Factors Affecting Otter:
Otter are particularly vulnerable to road collisions. Otter are also impacted by water quality and levels of pollution, alongside coastal development. Fishing pressures such as commerical eel fishing or 'creeling' for crustaceans can affect prey availability (NatureScot, 2015).

Conservation Status: 
UK Biodiversity Action Plan: Priority Species (BRIG, 2007)
Scottish Biodiversity List: Priority Species (NatureScot, 2020)
Otter are a European protected species under the Habitats Regulations 1994.In the North East of Scotland, the River Dee is designated a Special Area of Conservation for its otter population, alongside freshwater pearl mussel and atlantic salmon (NatureScot, 2005).

Conservation Efforts: 
In the 1950s otter were found to be suffering steep population decline across the UK, attributed to high levels of organochlorine pesticide pollution (e.g. dieldrin). Following bans on the use of these pesticides in the 1980s, otter have made a dramatic recovery and are now found all across the country (Sainsbury et al, 2019).
Mammals are typically underrecorded - any sightings of otter along Scotland's East coast should be submitted to NESBReC (details below).