Loon Monitoring

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A hunkering loon pressured by a boat on the other side of the sign

In a lake near Forest Metrix’s offices, a pair of loons started nesting for the first time in a number of years. They didn’t pick a particularly good location, it seems, putting their eggs a couple inches above a mud bar formed at the mouth of a creek.

Locals alerted the Vermont Center for Ecostudies, which employs Eric Hanson, who is pretty much the main guy in New Hampshire and Vermont for protecting loons. Eric came out and installed some sign buoys to help keep boaters from getting too close and disturbing the brooding parents. One thing led to another, and Eric asked us to turn our cameras to the loons, not so much to observe them, but to determine how the human lake population reacts to the signs. We went to the forest and took down the cameras from the trees, and then it got interesting.

 

They are visited every so often by curious boaters, and they react well (just lowering their necks to the water level, presumably to create a lower profile) when those boaters stay for short periods on the other side of the buoys that have been placed. Cruisers who linger for 25 minutes, or those that venture closer have “bumped” the bird sitting on the nest a few times since we started collecting data. In both instances I recorded today, the absence from the nest was about 30 minutes. One a couple days ago was just a few minutes. 

It seems loons can be identified from among each other with the fingerprint-like pattern on their neck band. Now, untitled_16-07-16_3146I don’t know which one is the male and which one is the female quite yet, but I can at least determine an individual. Eventually, we’ll get some good shots when they’re trading places on the nest, and size should clinch which one is female, and we can then backfill that data on the images taken to date. At left is an over-cropped example of the “neck print.” We’ve created a quick customization of our tree software so as to be able to collect and compare these images over time.

When visiting the cameras to refresh memory cards and batteries, I’ll often see a boater come in and have been able to hear their conversations, which gives a little insight into what they’re up to and how the signs cause them to react. The upshot is that most people are respectful, allowing the signs to overcome their curiosity. The people who appear to ignore the signs, or those that do things like cast lines toward the loons from the other side of the sign, have all been fishermen. They don’t appear to bear any curiosity, never mind malice, to the loons. They appear to be people who are unlikely to be impeded in their quest for fish. There are plenty of anglers who remained at a respectful distance, but the ones who did not, all were fishermen. untitled_16-07-16_3048

The picture at right is of two guys who were slowly trolling by, causing the reaction of the bird at top. You probably can’t see it in a JPEG sent on email, but the right-hand fellow’s line shows he’s cast well into the exclusion zone. They’re not even looking at the loon, and I’m not certain they ever noticed it. They’re just obeying the letter of the sentiment of the sign. 

This guy from CT (below) is my favorite. After they turned around, he got even closer, and casted toward the bird. untitled_16-07-16_5267From the two occupants’ conversation, I could tell there was no deliberate intention to disturb the bird, but they did notice it, and they just didn’t think much of it.

Interactions with other species are interesting. A family of geese and one of mallards comes by with some frequency, but doesn’t seem to elicit any reaction from the loons. A female wood duck, though, loitered an oddly long time, and generated the “hunkering” reaction eventually. Here she is giving the loon her odd risk assessment look. I don’t yet know what sort of interaction this is, but I can say that both duck and loon parents appeared leery and uncomfortable in the presence of the other.

untitled_16-07-18_0863The oddest one, though, was the great blue heron who decided upon it getting dark to stop his fishing for the day about 4 feet directly in front of the nesting loon. That heron roosted on the mudflat, staying stock still all night. Here is a photo at around 4 a.m., before it got light and the heron restarted its stilted walk along the delta. This is a picture I’m surprised we were able to get, given it was taken by moonlight from that evening’s half moon. It’s a 30-second exposure (thus those “hot pixels” showing up on the photo). The loon never appeared to be disturbed by this. It seemed sort of like the guy who sees you sitting on your towel on an otherwise unoccupied beach and decides to put his towel untitled_16-07-14_3006right next to yours.

 

One last disturbance to note: There were a couple times when a large wake was coming through. One in particular actually swamped the nest site a bit. The loon on the nest reacted by standing up and doing the poking and prodding behavior with the eggs that we see each time the male and female exchange guard. After ensuring that the eggs were there, it sat back down. I’m unsure whether or not they are turning the eggs when they do this. 

untitled_16-07-18_8029You can see from the white caps above that even this very small wake is enough to inundate the untitled_16-07-18_8833nest. At right, the loon is checking the eggs after the waves passed.

It appears no one knows when this nest started, so we’re a bit in the dark on when hatching would occur. I suppose this is a late first nest, and chicks would erupt momentarily, or it’s a second nesting due to a previous failure, and we could expect hatching 26-28 days after some unknown date a week or so ago. Or that they’re dud eggs because they weren’t incubated adequately. 

More coming soon.

 

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