At last, on Jun 12, shortly after sunrise, I obtained an observation which allows me to conclusively confirm there is an otter living nearby our town (its range might even extend into the town).
The otter was crossing shallow rapids at first where it wriggled in a manner that suggested the otter was perhaps taking advantage of the fish whose passage across the shallows is greatly obstructed.
The shallows consist of a layer of rocks (plus some woody debris) covered with about 5 – 20 cm of water (variable depth along the channel width which is that of ca. 5 metres).
The shallows are also elongated (up to 5 metres in one spot but mostly 1 – 2 metres), and even smaller fish struggle to swim across.
Interestingly, beavers cross the shallows very smoothly despite being large and hardly having enough of depth to support their ‘keel line’.
I should believe that an otter could also swim across smoothly unless there was an opportunity to engage in some hunting activity.
I believe the fish that the otter had encountered on its way escaped back upstream, and the otter dove in pursuit (it did not appear, however, that the otter had changed its intended course due to the fishing attempt and the fish was just a coincidental side-maneuver to crossing the shallows).
The otter emitted plenty of bubbles at that point which suggests that its mouth was maybe open and it was trying to catch the fish in its teeth.
Typically, I have read that otters submerge to eat their prey and the otter, indeed, surfaced but it exhibited no eating activity. Perhaps the hunt was not successful after all.
At this point, the otter partly climbed out on the shore and I could clearly appreciate its body shape as well as the shape of its tail.
As my previous observation indicated (Otter observation (May 22, 2024) – an otter hunting ducklings?), it was not a very large individual although it was definitely a grown up (not an otter cub born this year).
It has to be the same individual I observed earlier, and this observation was, once more, ca. 0.5 km upstream from the area of the previous sighting and mere 100 metres from the site of the first sighting (At last – an otter in our town? (Apr 28, 2024)).
I believe it is a young but mature female, and if it is a female, a male will probably settle here, as well, if he has not yet.
Cubs might also be on their way at least next year (if not this year).
I am not certain what the otter’s intents were in approaching the shore but it did not stay there.
Perhaps a fish was being eaten if it was so tiny that it requested no additional activity but that of chomping it down (without handling it with paws).
The otter returned into water and it swam for about 2 metres when it decided to dive again although I cannot tell why.
There is a beaver den which the otter had to pass by and perhaps the otter wished to avoid being noticed by the beavers in case they were watching or sniffing.
The water is quite murky there and slipping by quietly would be a feat that is achievable.
Water probably also conceals scent, especially, as the stream flows parallel to the otter’s movement and there are no eddies in that spot that would whirl the water from the side of the river where the otter was swimming against the side of the river where the beaver den is located.
At this point, the otter emitted no bubbles and it was impossible to track its path underwater from the observation spot above.
Accordingly, I assume that the bubbling belongs with hunting activity while a stealthy dive is achieved without any bubbles.
This could be useful to determine what the otter is doing below the water while it cannot be seen.
I am very glad there is a female otter in this area, and I cannot wait when the male shows up (not to mention cubs, of course).
My suspicion is that the female localizes rather downstream from the site where I observed her twice perhaps because the water, during summer, is extremely shallow upstream and only very tiny fish live there.
While otters choose medium-sized fish perhaps on the tiny side rather than massive side, currently, these niblets might be too small.
Besides, if the female is with cubs (which is possible), she might need to feed on larger fish.
Why then travel downstream at all?
After some half a kilometre of perhaps fish-poor range, there are some deeper waters surrounded by a relative wilderness which could produce invertebrates for the fish to feed upon.
I wonder if this individual is somewhat aggravated by the patchy distribution of resources along the river as there are some 200 – 500 m long stretches of ‘fishy water’ exchanged by at least 500 m stretches of shallows.
Still, as observed, the otter opportunistically hunts smaller fishes on the rapids and such shallow rapids which are found here and there (where fish are conspicuous, confused and impeded in their movement) could offset the costs of travelling.
Perhaps the female is also exploring the range and determining where it might be most profitable to settle.
The downstream portion suffers heavy disturbance and much riparian vegetation has been cleared very recently there.
If the female was travelling upstream during early hours when otters cease their activity, she might have a resting site there already.
My other observation with this individual taking the same direction also occurred after dawn.
However, I suppose that mothers would center their activities near the natal den.
As this otter, I believe spends a great part of its nights downstream but sometimes travels upstream near dawn, perhaps the female does not have cubs and uses her relative freedom of movement to hunt in the most profitable areas at night when disturbance level is low while returning to less suitable foraging grounds during day where, meanwhile, it is possible to rest in wilderness.
I wonder where she will choose to raise cubs, eventually, upstream or downstream.
I am hoping for upstream because the downstream area is very restricted in access.
The female’s localizing downstream might suggest she arrived from there (which makes sense because the river flows through the town upstream and through the countryside downstream), and maybe she is only discovering the opportunities of her upstream range.
Notes by Ieva 