On one exciting day this week two stoats and a weasel all visited in the same morning, the stoats only 10 minutes apart. The second one was paler with partial ermine colouring and was noticeably smaller so I think the first was a male and the second female. I now know it was the female whose partially white tail showed briefly on a camera last month. This is the male.
And this is the female.
The video shows them first in real time and then with two zoomed-in slow motion replays. Unfortunately neither stoat went into the box so the inner camera wasn't triggered by either of them. I suspect the male left a scent mark as he turned round in the pipe because the female seemed very interested in the scent.
I read a report from Ireland that showed that stoats were only detected by the Mostela camera 50% of the time compared with an external camera (Croose E et al. 2021). And research from the Netherlands which found that a 10cm entrance pipe was significantly better than an 8cm pipe (Mos J & Hofmeester TR. 2020). The pipe these two stoats went into is 16cm but narrows to 10cm inside so perhaps that put them off.
And here's the weasel visit. I like weasels because they often run in and out more than once which gives the cameras a better chance. This time the inner camera missed the first pass but did catch the weasel the second time. There is a puzzling distinctive straight-edged mark on the flank and judging by the under-chin markings (gular spots) this is a weasel I haven't seen before.
A couple of days ago the cameras made two recordings of weasels within two hours. I suspect these are two different animals although it is difficult to be sure. I think the first one is smaller so they are likely to be female and male. The first one didn't go right inside and wasn't detected by the inside camera. The second one went through so quickly that it wasn't seen either.
The recordings also give us the opportunity to compare the size of a (male) stoat and a (presumably female) weasel. I posted this picture on the Mammal Society Facebook page where it attracted a lot of interest. As above, the pipe's internal diameter is 160mm.
I read a report from Ireland that showed that stoats were only detected by the Mostela camera 50% of the time compared with an external camera (Croose E et al. 2021). And research from the Netherlands which found that a 10cm entrance pipe was significantly better than an 8cm pipe (Mos J & Hofmeester TR. 2020). The pipe these two stoats went into is 16cm but narrows to 10cm inside so perhaps that put them off.
On a previous occasion a stoat (I think the larger male) went into the box so quickly that he was already behind the camera by the time it was recording. (I wonder if this is a tactic to try to ambush any prey that might be inside.) The video shows him running out. The outside camera also missed him going in but did see him exploring the outside.
And here's the weasel visit. I like weasels because they often run in and out more than once which gives the cameras a better chance. This time the inner camera missed the first pass but did catch the weasel the second time. There is a puzzling distinctive straight-edged mark on the flank and judging by the under-chin markings (gular spots) this is a weasel I haven't seen before.
A couple of days ago the cameras made two recordings of weasels within two hours. I suspect these are two different animals although it is difficult to be sure. I think the first one is smaller so they are likely to be female and male. The first one didn't go right inside and wasn't detected by the inside camera. The second one went through so quickly that it wasn't seen either.
The recordings also give us the opportunity to compare the size of a (male) stoat and a (presumably female) weasel. I posted this picture on the Mammal Society Facebook page where it attracted a lot of interest. As above, the pipe's internal diameter is 160mm.
Here is another version - male stoat, male weasel and female weasel. Unfortunately the female stoat didn't stand up in the same way as she came out so I can't add her in. I hope she'll be back to pose properly.
* All trail cameras have a "trigger time" - the delay between detection and the start of recording. Trigger times are shorter for photos (typically ～100ms) than for videos (～400ms). The target also has to move in one of the detection zones - the trigger sensor doesn't "see" the same area as the camera lens. In a Browning, which I use and which has about the fastest video trigger time, the three detection zones are in the centre and at either side. I suspect that my camera position in this new box means that an animal in the pipe is in between the centre and side trigger zones, thus delaying a response. I'll have to try adjusting the position a bit to see if I can improve things without spoiling the view.
1. Croose E et al. (2021) Mammal Research https://doi.org/10.1007/s13364-021-00598-z
2. Mos J & Hofmeester TR. (2020) Mammal Research https://doi.org/10.1007/s13364-020-00513-y
Stoatally captivating Chris! Sorry. David
ReplyDeleteEither a weasel or a stoat is turning up on the cameras several times a week David. I have seen the male stoat near the gate twice this month and a male weasel in the kitchen garden. I hope there will be more pictures soon.
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