Penrose is 'otterly' amazing

Otters faced years of decline during the 1960s and 70s in Cornwall as their habitats became threatened by poorly kept and polluted waterways. Recent reports suggest that otters may be making a return to Penrose and the ranger team have recently been using secret cameras to monitor the elusive mammal as its populations show signs of recovery.

History of otters at Loe Pool

The English/ Cornish otter population declined significantly during the 1960s and 1970s due to the effects of certain pesticides, for example, DDT. More locally, Loe Pool was suffering from eutrophication and algal blooms during the summer months. During surveys carried out in 1977 and in 1986 no signs of otter were found and as such, otters were thought to be extinct from Loe Pool. However, during the 1991-94 survey, signs of otter were found and ever since then we believe the population to be slowly recovering and recolonising the Loe.

Current state of otter population at Penrose

Evidence of otters, and otters themselves, have been spotted by National Trust staff, volunteers and visitors sporadically over the past 20 years. In 2016 we decided to find out more about these enigmatic nocturnal residents and invest in a wildlife cam, thanks to funding from Banrock Station. Having investigated the best place for it, based on the presence of spraint (otter poo), we installed the motion activated camera and left it to do its work. After leaving it in place for 2 weeks, we took the memory card and waited impatiently for the files to download. Video after video showed reeds blowing in the wind, a mouse, and a heron going about their business so we didn’t hold out much hope. Then on the last video we couldn’t believe our eyes when were treated to an otter’s bottom disappearing away from the camera. The camera has been up and running for several months now and we’ve had several visits from the same otter, who we believe to be a male. Soon after that our camera caught footage which shows an otter having a wee! Please see the video at the top of this page!

Work to improve habitat

The reappearance of otters at Loe Pool mirrors the national increase in the population. We have seen a dramatic improvement in water quality largely thanks to the work of the Loe Pool Forum, who are a partnership of organisations headed up by the National Trust, founded in 1996. We no longer see toxic algal blooms in the summer and healthier fish and amphibian populations provide an ample food source for otters. The large expanse of open freshwater with adjoining river, wetlands, reed-beds, and bank-side scrub and trees make Penrose theoretically ideal for otters. Having said that, we wanted to give them that extra helping hand so in autumn 2016 with the help of our local volunteer team we built a man-made otter holt, used for breeding and lying-up, out of logs and brash. Volunteers are continuing to help manage the wet woodland habitat, through coppicing and installing leaky dams, which will have a beneficial effect on the ecology of the whole area. 

Volunteers working at Penrose dam building
Volunteers help build a dam at Penrose
Volunteers working at Penrose dam building
A volunteer group at Penrose

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Want to get involved? Our volunteers work across the property with whatever time they can spare doing a variety of tasks.