It is now two years since I started following the local otters with my trail cameras. It has been a fascinating experience - I have learnt a lot about otters and I have had a lot of opportunity to adapt and develop the recording techniques and improve my video editing. The otters have been pretty co-operative as well. When I first started they were occasionally spooked when the infrared light came on but they very soon got used to it. They usually sniff the cameras as they pass, perhaps to check it was just me, and, on one memorable occasion, the cub knocked the camera into the stream and chased it under water.
After centuries of persecution, inland otters are mainly nocturnal in the UK. Daytime sightings on the cameras have been infrequent but there have been more recently, perhaps because I have put the cameras in better positions. When they have appeared in the day the video quality has been very good. The videos have improved over the two years as my technique has evolved.
The culvert has been the most profitable monitoring place because it is pinch point for the otters as they travel from one part to another of their territories. There are technical challenges as I have to climb down into the stream as well as keeping a close eye on the water level and the weather forecast. The culvert camera was the first to find new cubs in 2019 and 2020.
Recent recordings on the bank have been fascinating. It is much better seeing the otters out of the water because we get a better look at them and can see more of their behaviour. The route up the bank connects the water to the reed beds but is also a favourite sprainting site where they can leave a smelly message and see who has been there before.
The cameras have identified unusual or even unique behaviour. Examples that come to mind are the mother trying to pick up the (large) cub by its nose, an otter breaking through the ice, and an otter eating frogs in the culvert.
The cameras have also recorded a variety of calls, showing otters can be vocal even though they are mainly solitary. The very first video recorded a cub chatting to its mum. Since then I have picked up a snort (alarm), mother and cub calling for each other when separated, a cub piping for its mother, a dog's mating call, and probably several others.
Here is a video I didn't get round to posting before of an otter attacking a heron (out of shot) in pitch dark at 3 o'clock in the morning. You can see it was trotting down the bank and suddenly accelerated, presumably because it saw the heron was there. I am not sure whether the heron was fishing in the dark or roosting but it certainly got a nasty surprise, even though it sounds as if it got away.
My trail camera monitoring started in February 2019 and immediately found a mother and two almost full-grown cubs. By March 2019 the cubs had gone and I saw only solo otters until two cubs appeared on 11 September 2019. They stayed around with the mother until January 2020. Then single otters until a new cub on 28 June 2020. This one stayed until mid January 2021 and now there are single otters again.
Otters are said to be non-seasonal breeders and to breed on average once every 18 months. The pregnancy lasts about nine weeks. The cubs emerge from the natal holt at about 12 weeks of age and start to follow their mother around from about five or six months. They stay with her until about a year of age but this varies with the local habitat and the food supply (they probably mature faster if there is plenty of food to catch).
My local otters seem to be producing new cubs every year. Of course, I can't tell if it the same mother or whether a new, already pregnant, female has moved into the territory but it does suggest there is plenty of food around.
When I started two years ago I was setting the cameras every now and then, for a few days a month, but now there are at least two in place all the time. I have also gradually learnt where are the best places to find them. It will be interesting to see what happens this year.
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