Burning Silo

This will probably come as no great surprise to most of you, but I’m very much interested in animal behaviour. Each year, after the last snows have melted away, I begin to spend what, to many, must seem like an inordinate amount of time watching and photographing insects, spiders, and other creatures. An average day consists of at least two or three slow ambles through the gardens, fields and woods, stopping to observe and photograph flora and fauna along the way — but with a definite emphasis on arthropods. While I’m not exactly methodical in my observations, I do try to record what I see in photographs, making sure to revisit as many ’sites’ as I can each day. A site is nothing more than any place where I’ve found an insect or spider ‘hanging out’ for a day or two.

Now, I must confess that when I first became interested in arthropod-watching, I didn’t give much thought to such things as territorial behaviour. But, after the first few weeks of casual observation, I soon found that a certain spider could be found hidden on the underside of a particular leaf for many days, or that a very possessive bumblebee would fly out and buzz me if I walked too close to its favourite bush. Gradually, I came to see the world through insect eyes - a landscape filled with plants and trees that function much like restaurants and highrise apartment buildings. Insects often make their homes on a favourite plant — perhaps one that provides good nectar or tasty leaves, or that attracts certain prey. So long as the food supply continues to be adequate, the insect or spider will hang around, taking advantage of the bounty. But when conditions change and the preferred food becomes scarce, it’s time to pack up and move on to greener pastures.

Plant hang-outs are a good place to study insect behaviour. Often, the territorial behaviour of an insect or spider will cause it to be bolder than we might otherwise expect. A few weeks ago, I wrote about watchful spiders, female spiders who bravely guard their egg cases to protect them from harm. Today’s example is of a female Bush Katydid — maybe Scudderia furcata — which I found in a small tree alongside the K & P Trail near Snow Road Station. Perhaps it would be more accurate to say that the katydid found me while I was busy photographing another insect. Out of the corner of my eye, I saw the katydid glaring at me from a nearby leaf (see above photo — click on any of these photos for a larger view). I turned the camera towards it to take a few shots. Apparently angered, the katydid began marching down the branch towards me, antenna raised so that the insect looked alert and confrontational (see below).

Curious to see what it might do, I put my index finger in front of the katydid. It reacted with hostility, at first bunting at my finger with its head, the way a goat will bunt when it’s feeling pushy and combative. When I didn’t remove my finger from its path, it began waving its antennae and raised its body up so that its front pair of legs were free to pummel at my finger in much the same way as a boxing kangaroo. When those actions failed to get the desired effect, the katydid gripped the tip of my finger with its spiny forelegs and struggled in vain to shove me out of its way (see below). As a last resort, it climbed onto my finger, gripping the tip with all six legs while wrestling and kicking — enough so, that it actually managed to produce some discomfort. At last, admitting defeat, I pushed the katydid off onto a leaf and retreated to leave it to its bush. I’ve no real idea why it acted so aggressively — but perhaps, like the watchful spiders, it was protecting an area where it had or intended to lay eggs. In the past, I’ve noticed that some grasshoppers can be quite determined to lay eggs in a particular place and will not be deterred even when removed from that spot several times, so that may also be the case with these katydids. I’ll post some notes and photos concerning grasshopper behaviour another day.

Tags: Bush Katydid, Scudderia furcata, insect behaviour