In this month’s Gosforth Nature Reserve update, NHSN volunteer Christopher Wren takes us into the secret world of the reserve’s otters. Trail cameras have once again captured the fascinating courtship behaviour that could signal the arrival of a new litter later this year.
Courting Otters
The life of a female otter is pretty relentless. It takes up to a year to teach the cubs how to be otters and as soon as they have mastered it it’s time to start all over again. Unlike most other mammal species, otters are non-seasonal breeders, meaning that they can have young at any time of the year, probably because they have a year-round food supply.
The news from the reserve is that the three grown-up cubs left in early May and the resident female immediately started courting again. Courtship usually lasts for only a few days and as far as I can tell it is initiated by the female. It makes sense that the male otter is wary because if he approaches a female with cubs he is likely to be driven off. Once bitten, twice shy.
These are our two otters at the moment. First the female with a wet coat, just out of the water. Then the dog otter, all fluffy and dry.
For just a few days last month they were going around together and, as usual the female seemed to be making the running. In the next video first we see the dog otter, followed by the female. When they returned she bumped her head on the camera before running ahead to encourage him into the water.
Here is another recent video. First the female who is then joined by the dog. She is making the chuckling noises and if you listen carefully you can hear a bittern booming in the background.
Courtship can be a very noisy affair. This was the female last year. She is doing the chasing.
Here is another example of the female otter chasing the male up the bank and then enticing him back into the water.
This is the fourth May in consecutive years that the cameras have shown courtship behaviour in the otters. Here is a fairly primitive chart to show what has been happening in the 7+ years that I have been following the otters with trail cameras, starting in February 2019.
You’ll see that a pattern has emerged in the last four years with cubs (presumably) born in July (gestation is 63 days) and visible from October/November before dispersing in May as courtship begins. Although otters are non-seasonal breeders this has settled into an annual cycle. In the earlier years I didn’t have cameras in all the time and hadn’t worked out the best place to put them but even so we can see a different pattern. The courting in February 2022 was well seen on camera but presumably didn’t lead to anything as new cubs weren’t seen until November that year. This was the video from then. Eventually the female was fed up with the male’s indecision and swam off. He then left in a different direction.
Otters don’t usually breed until they are about two years old and I read that the average female only lives long enough to have two or three litters. However, otters can live for up to eight or nine years in the wild so it is obviously possible for one female to have more. If a female died or was no longer able to reproduce I would expect there to be a delay while the territory was taken over by a new female so the chart makes me wonder if our resident female is already six years old and is hoping to embark on her fifth pregnancy. If so, and if all goes well, we should expect to see new cubs on the cameras in October or November.
One other observation. None of the three recent cubs ended up larger than their mother so I suspect all three were female. You’ll see above how much larger the male otter is. A year ago both cubs were male and grew larger than their mother before leaving.
You can get more updates on local wildlife from Christopher Wren on his own TrogTrogBlog. You can discover the wildlife of Gosforth Nature Reserve here.