June 18, 2015

Nesting Season

It's nesting season here in the northern hemisphere, a perfect excuse to experiment with the Therm-App infrared camera (and a new 35mm lens with higher magnification).

First, a red-eyed vireo scrutinizes my shenanigans from its low cup nest.

Here's a warbling vireo nest found by Kevin McGowan:

Unlike the previous nest, this was on a sunny morning, and I wasn't sure how well the nest would register. Turned out to be fairly noticeable, since the leaves of the elm tree were not as warm as, say, the trunk of the tree which appears as warm as the nest. But I suspect I would not have been able to find the nest in this sunny weather if I hadn't known it was there.

Here a baltimore oriole's hanging nest glows with warmth on a foggy morning:

I was told that one of these holes was occupied by a pileated woodpecker. Can you tell which?

I observed a sapsucker actively feeding young in one of these cavities: can you tell which?

The trunk of this tree had already been warmed by the sun this morning, so the heat signal would seem to be lost: it is the middle hole (second from bottom). However, on closer scrutiny, it seems like the region of the trunk just below that hole is a little warmer. Warmth from the nestlings, or just coincidence or noise?

For what it's worth, here's a composite I took of the male sapsucker leaving the cavity:

Finally, while there's really no reason to take a thermal image of these red-tailed hawk fledglings on a cliffside nest, sometimes you don't really need a reason:

June 13, 2015

A Walk in the Woods

Here are some thermal observations from a walk in the Mulholland Wildflower Preserve in early June. First, some ducklings, cute even in infrared.

Mama mallard with a train of ducklings.

Continuing with waterfowl: a pair of common mergansers preening on rocks in the creek.

But take a closer look. In the thermal image (less magnified than the photograph), notice how the mergansers' breasts are cold, colder than the surroundings even! Presumably they have not been out of the water for too long. It's worth noting that because water reflects infrared, it's hard to gauge the temperature of the water from the thermal image.

Further down the trail, an eastern wood-pewee was singing its beautiful plaintive song, quite loudly, in fact, from somewhere above. This is a common scenario for woodland birding: you have this small brown bird sitting still somewhere high in the trees, and you just can't seem to find it. But with a thermal imager...

the warm body pops out from its cooler surroundings. Unfortunately, this only works on overcast days, for as soon as there is any amount of sunlight, the reflected IR from the sun makes many things (tree trunks and branches in particular) appear hot, and warm-blooded animals no longer stand out.

Nearby was this set of cavities in a sycamore tree:

I would like to conclude that the top cavity is occupied while the lower two are probably not, but I have no means to confirm this. I should write a blog post focused on cavities in the near future.

Finally, while walking down this dry creek bed, the high-magnification 35mm lens on my Therm-App showed this clear profile of a resting deer.

The deer was remarkably well camouflaged, such that I could never visually see it in its sitting position as shown in the thermal image, even with my binoculars. The deer did eventually walk away (they have little fear of humans in this area, and are actually quite the nuisance for plant life), and I still can't tell whether the deer is present or not in the visual photograph above.

June 11, 2015

Birds and Bees (and Toads, Oh My)

On Saturday, May 30, 2015, I brought my Therm-App to the Finger Lakes Land Trust's Spring Bird Quest at the Ellis Hollow Nature Preserve. It was a cool overcast day, which I thought would be good for thermographic wildlife detection.

After showing off the novelty of seeing squirrels and chipmunks in the woods, I found a warm spot I could not locate with binoculars, until I realized it was not a large object far away, but a tiny object much closer: it was a bee!

Like everyone else there, I'd assumed that insects were cold blooded and would not be detectable. But walk leader Mark Chao later did some web research and reported that "Various insect species, especially bees, thermoregulate. They do not maintain a high temperature all the time, but can warm themselves up quickly when they need to. A bumblebee can warm up its body from an ambient air temperature of 55 degrees Fahrenheit up to 98.6 degrees Fahrenheit in just six minutes!" Thanks, Mark, for the information.

Further along the trail, we found a large warm area high in a tree: a short protruding limb was registering significantly warmer than the rest of the tree, and I conjectured that it might be hosting a roosting warm-blooded critter. Before long, a yellow-bellied sapsucker flew by and into an unseen cavity in that same limb! I regret not having taking better photos of this encounter, but here's one showing the warm limb in the lower-left corner, and the sapsucker perched in the next tree over:

In the visual photograph, the sapsucker is situated lower than in the thermal image, about midway in the second tree from the right. In the thermal image, the warm limb in the lower left does not look as pronounced, because the presence of the warmer sapsucker in the frame of view has shifted the upper bound of the Therm-App rendering. When the sapsucker was absent, the limb was a more prominent yellow against the darker background.

Shortly after, we found a small frog (or toad) leaping through the leaf litter, and I was curious to see its thermal signature:

Cold-blooded: that's more like it. Actually, I was a little surprised that it appeared that much colder than the surrounding leaf litter, rather than matching the ambient temperature. For what it's worth, here's a photograph of the same frog/toad (different pose).

And here are photos of a larger toad that I encountered later.

Finally, here are the bird quest participants hiking through the woods.

Many thanks to Mark Chao for leading the bird quest, and to the Finger Lakes Land Trust for all their work in conserving the natural areas for all to enjoy. Please check out Mark's blog about the month-long bird quest, of which this walk was only a small part: http://www.fllt.org/spring-bird-quest-blog-by-mark-chao/