Otters are widespread in Ireland around the coast, and along the river and lakes. They construct their home which is called a 'Holt' on the bank and the entrance is often underwater. They are nocturnal animals (usually) which means that they hunt at night. They tend to rest during the day in their well hidden homes.
Their presence is confirmed by mud slides used in play and by 'spraints' containing fish bones mainly which are deposited on a rock as a mark of territory. An expert eye identifies their site here by the luscious green grass growth on tufts where they defecated after their meal of eels, fish, frogs, small birds, rodents, insects, newts, slugs, earthworms and tadpoles. Occasionally, salmon or trout may be caught. They are accomplished swimmers and can stay under water for 4 minutes. Their underwater prey is carried ashore between teeth or clasped by forepaws appearing like human hand clasps.
The otter is still widespread throughout the country, but that numbers have fallen somewhat since the last survey in 1990-1991. More intensive monitoring surveys are now underway to provide rapid assessments of otter status at the catchment level. The main reasons for the decline are poisoning, shooting, netting on our lakes, rivers and pollution. In recent years many of the wetlands used by our toads and frogs as spawning grounds have been lost. This loss is mainly due to the harvesting of peat from our bogs, intensive farming and building development.
Ireland has the densest otter population in Europe - a 1980 study by Chapman and Chapman showed over 90% of sites surveyed positive for otter presence - and they noted that otters were common in Irish cities. The Irish population is consequently of international importance. Otters have been reported in Cork City since the 1960's but no specific survey had been carried out. In our survey, presence was reported from sightings and road casualties, and this was confirmed by the finding of spraints (otter faeces), holts (otter dens), footprints, trails, slides and rest sites.
The Eurasian otter has become extinct in much of Europe due to hunting and habitat destruction, so Ireland's otter population is of international importance. The otter is one of our oldest mammals, having been part of our fauna for at least 10,000 years.