April 2010 – Seabrooke Leckie

Out to lunch

There are, of course, lots of birds around at Innis Point. That’s the whole reason we’re there, after all: to monitor the birds. What I wasn’t expecting there to be lots of was porcupines. Spring is their season, the time of year when they’re most likely to be encountered, although I’m not exactly sure why this is the case, since they’re active year round. Even still, prior to this year I’d only ever seen the odd one here or there, and most of them tended to be in the form of roadkill, sadly. I spotted one in our own woods while out with Raven last week (fortunately, she hadn’t seen it yet and I steered her the other way before she had a chance to; Dan came across one with her a couple days later and wasn’t so lucky with the timing, though he was still able to call her away before she actually made contact with it), but have just seen the one. Out at Innis we’ve seen them every day. One day there were as many as four of them spotted around the site. One of them was especially laid-back, allowing me to approach within a couple dozen feet while it calmly continued foraging. I guess it has a lot of confidence in its protection.

They’ve mostly been up in the big, gnarly oak trees. They clamber along the thick, sturdy limbs, reaching out to the little twigs to snip the tender green buds off. Their hands seem to be remarkably dexterous, reminding me a lot of the fingered feet of raccoons.

They reach out with their broad paws to snag the twigs and bend them back to where they can easily reach the buds. Check out the long, thick claws. They and the rough pads would be useful in gripping the tree as the animal clambers about. Also for hauling that huge bulk straight up the trunk. On my way back from the washroom one morning I heard a rustling in the underbrush and spotted a porc approaching in my direction. It hadn’t seen me, so I stopped and watched it for a few minutes. It wandered to a small line of young trees, approaching the base of each and giving each a good sniff as it decided whether it was worth climbing. It passed by two trees in favour of the third, which was of a different species. I found it fascinating that it could apparently tell the difference just by smelling the trunk.

Porcupines are rodents, and one of the obvious features that they share with members of the group is the evergrowing, sharp orange teeth; they’re not dissimilar from beaver teeth. Since part of their diet, especially in winter, consists of the inner bark of tree trunks (which requires chewing through the outer bark to get at), these teeth come in especially handy.

When the twigs were too long for simply bending the branch to bring the buds within reach, the porcupine put its teeth to good use. It would bend the twig down…

…and then chew through the twig to remove it from the tree. Then it would manipulate it with its hands and snip off the buds before finally dropping the denuded twig.

I’ve written a bit about porcupines before, discussing their ecology a bit more in-depth. You can find previous posts here, here and here.

Painted Turtle

As I was returning home yesterday, on a beautiful, warm, sunny afternoon, I turned onto our road to spot a turtle shuffling off the edge into the grasses. Though it wasn’t necessary for me to hop out to move him, I hopped out anyway, with my camera. The warm sun had kicked his metabolism into high gear, and he had no intentions of just pulling into his shell and waiting for me to finish playing with him. He dug his claws in and motored away from me. Even when I picked him up and moved him back to the open road to try for a photo, he was too quick to get anything but his backside as he turned away from me and ran off again. When I picked him up to hold him for the camera, he looked boldly right at me. I’m calling it a him, but I admit that none of the photos I took clearly show the characteristics that would separate a him from a her: presence or absence of a notch in the back of the shell, and the position of the cloaca underneath the tail. A notched shell and the cloaca partway down the tail would make this a him. It’s still a tad early for females to be out looking for nest sites, but if this was a male then he might be on the hunt for females to mate with; I’m not sure what the “gestation” time is for a turtle. Raven found a Painted Turtle at the lake house last year, and I wrote more about it, including other notes on behaviour and physical characteristics, in this post.

On banding birds

Yesterday I started a new job, running the spring migration monitoring program for Innis Point Bird Observatory on the Ottawa River. It’s a short-term contract, running until June (the length of the spring migration, unsurprisingly), but during that period I’ll be out there six days a week. Even after just two days, I’m quickly realizing that my available time is going to be considerably more limited than it was before, and I’m going to have trouble keeping up with everything, at least as I do it now. So, at least for the time being, I’ll be scaling back my blog posts a bit; instead of doing the occasional “Tay Meadows Tidbit”, they’ll all be tidbits, and I’ll do away with the title (which would just get repetitive). Now let’s just hope I can keep my rambly fingers in check!

The focus of the migration monitoring program is to monitor birds, of course. It’s a bird banding program, where birds are captured using standardized methodology that allows for comparison of results over many years. Data is collected for each bird caught, including age and sex, weight and fat levels. The former two measurements tell us something about the demographics of the population, which can be useful in detecting and assessing population trends. For instance, if a particular species starts showing a lower-than-normal proportion of young birds in the captured sample, it’s a suggestion that they’re having trouble reproducing successfully, perhaps due to poor breeding seasons because of weather conditions, or because of environmental problems that are causing increased chick mortality. The latter two measurements (weight and fat) are used in assessing the health of the birds arriving at the station. Low weights and fat levels are generally an indication of a bird that’s just arrived from a long flight, but if it doesn’t bulk up quickly in preparation of its next leg (which is detectable through recaptures of the birds again before they leave the site to carry on) then it could be the bird is in poor health, or it’s having trouble finding food. Over and above all that, though, is simply a documentation of the numbers of each species banded. If you start to notice long term trends – for instance, you band fewer of a species now than you did ten years ago – it’s probably cause for concern. The migration monitoring is especially useful for bird species that nest in the boreal, north of what’s sampled by the Breeding Bird Survey, since it’s often the only reliable means of monitoring their populations.

Of course, each bird also gets fitted with a band that will identify where and when it was banded if it should ever be encountered again. Historically banding was used as a way to track migration routes and patterns, but fewer than one of every 1000 birds banded is ever seen again away from the site where it was banded. That’s pretty slim returns; you have to band a heck of a lot of birds to get even a small sample size. Still, hundreds of banders banding over several decades have built up a pretty good database of re-encounters, and these days we’ve got a decent idea of where birds go. The focus of banding has shifted to population monitoring, as explained above. The bands are still useful for this, though. A substantially higher percentage of birds are recaptured again between their first banding and when they leave the site to finish their migration. By recording their weight and fat levels again next time they’re encountered (for which you need a band in order to be able to identify individuals again) it’s possible to track how the birds are faring and how well the site fulfills its role as a stopover location.

Sunday Snapshots – Promises kept

Tay Meadows Tidbit – Blister beetle

A week or two ago, Dan discovered a large, shiny blue beetle crawling through the grass on our lawn and called me out to see it. Even before investigating I had a fair idea of what it was: a blister beetle, of the genus Meloe. This isn’t the first one I’ve seen, and it isn’t even the first one Dan’s found for me – last fall he brought me a male one. The one above is a female; you can tell the difference by the antennae, since the males have a U-shaped kink in theirs, which they use for grasping the female during mating, and those of the female are straight. Females also have larger abdomens. Blister beetles are so named for the liquid they exude from their joints when startled or threatened, which contains a chemical called cantharidin. There are some third-party beetle species which will collect the cantharidin from blister beetles and use it as a sperm additive (putting it into the sperm packet they transfer to the female); when she lays her eggs, the eggs are coated in this protective chemical. Humans use the chemical too, but for less honest purposes – it’s used in making the aphrodisiac/date-rape drug “Spanish Fly”. I wrote more about blister beetles when I found my first one; you can read a bit more here.