in Staffordshire river
Original from BBC News
Otter video 'very good news' for Staffordshire river
The Riverwatcher Camera System is triggered by a motion sensor.
Other footage gathered includes some of a pike using the camera tunnel as an ambush point. Ms Devoy said: "The presence of a top predator on a river in the Midlands is very good news... when you consider the pressures and challenges that the wildlife in these areas have to face on a daily basis." The agency said the camera, which is fitted with a motion sensor, allows them to assess fish movements and populations. Otters are nocturnal and have a territory of up to 40km (25 miles). Populations are usually estimated by monitoring droppings and footprints. The UK otter population has been slowly recovering after almost dying out in the 1970s, thanks mainly to environmental improvements and legal protection.
David Gregory-Kumar Science & Environment correspondent, BBC News.
We know otter numbers are increasing but we tend to base this on two pieces of evidence.