Hello again faithful readers,
Last week I returned to the BIObus for more aquatic sampling. This time we visited sites within the Backus Heritage Conservation Area, Long Point Provincial Park, and the Nature Conservancy of Canada (N.C.C.). Today I’ll be talking about the river damselflies that were almost ubiquitous across our sampling areas and some details about our time in Long Point and the N.C.C.
Most of the areas we sampled during our trip were rivers or streams which are home to the larvae of damselflies, the suborder Zygoptera, and dragonflies, the suborder Anisoptera. Together, these two groups comprise the order Odonata. Distinguishing the two suborders is pretty easy with a little practice; dragonflies have larger more robust bodies and usually rest with their wings spread wide, while damselflies have thinner more fragile bodies and rest with their wings together above the body. Additionally, dragonflies ted to catch prey on the wing like fighter jets with legs, while damselflies usually scoop up their quarry from leaves.
The glittering jewelwings in the family Calopterygidae (which means beautiful wings) were by far the most populous odonate we saw on the trip, with so many at one site that you couldn’t help but have ten in your field of vision at a time. There we got to see a wonderful display of their mating and male-male competition. The males compete for the most desirable locations to display to females. I saw many sizing each other up in the air, and even a couple pugilists dragging their opponents right off of the sought after leaves. After a female has chosen the male who has the prettiest display location and aerial dance, she allows him to “mount” her and things start to drift from what we expect. The male will clasp the tip of his long abdomen onto the back of the female’s head, after which she obligingly connects her abdominal tip to the bottom of his body. Now you might ask “but how are little damselflies made from that?” Well, in preparation for this event, the males will place their sperm onto a special secondary structure located under the thorax. It’s this secondary structure that the female connects with to fertilize her eggs. Afterwards, the male will follow her around or stay attached until she lays her eggs and he can assure his paternity. Nature is weird, but fascinating.
Our trip to Long Point was interesting as well. Usually we use a boat to collect plankton samples once per week out in a large body of water. This week, however, we didn’t have access to the boat and had to collect from the dock of the boat launch using a jury-rigged collector made of two D-nets taped together. Despite the absurd appearance of our sampling method, we managed to trawl quite a lot of plankton out from the water.
In contrast to the readily available water at Long Point, our sites at the N.C.C. were more difficult to find. We searched grid like through the conservation blocks, which appear to be properties reclaimed for nature, and eventually came across a nice stream and small wetland area to collect in. We collected a lot of small crustaceans in that area, which might relate to the proximity of these sites to farm land and the high sulphur content in the soil. There’s always something to learn from the bugs you find if you keep your eyes and mind open. That’s all for this week’s blog, see you in a few weeks!