A Caribbean frog showed up in Cleveland, Ohio, last week. A colleague stopped by my lab in the CWRU Biology Department with the news that an unusual treefrog had showed up in a Cleveland flower shop after hitching a ride from Florida. Of course we wanted to see this frog!
I didn’t see the full swarming of the Brood V periodical cicadas until a little later in June when I visited the Cleveland Metropark’s South Chagrin Reservation. Here is a video with the sound of their calls:
Some of the cicadas at South Chagrin were starting to die, and their orange-and-black bodies were easy to see on the ground and in the stream:
A couple days later I visited the Cleveland Metropark’s Bedford Reservation. Brood V Cicada calls could be heard scattered around the reservation, intense in some areas, subdued elsewhere. The cicada exuviae (shed exoskeletons from the larval life stage) were still attached to trees and other plants. I was struck by this shed cicada skin clinging to a vandalized tree:
In other areas, there were huge piles of dead cicadas mixed with cicada exuviae. Not only can the huge numbers of cicadas provide a boost of food for forest animals, but the dead cicadas also fertilize forest plants.
Beyond the enormous piles of cicada bodies, I was most struck by how many cicadas were continuing the crawl and fly while missing big parts of their bodies (like their abdomen!). The two videos below show some of this “zombie cicada” behavior. I shared this with a colleague who is an entomologist & neurobiologist. He remarked that the “zombie” behavior emphasizes just how neurologically different insects are from people and other mammals.
A Brood V cicada with an empty abdomen:
A still-living Brood V cicada crawling on the ground as a yellowjacket wasp eats it.
Earlier this summer, I was able to observe a yellow garden spider (Argiope aurantia) that built its web next to my parents’ front door. I noticed that it displayed a peculiar behavior in each of several heavy rainstorms. Instead of fleeing its web when the big raindrops started to pour down, the spider stayed near the center of its web. It let go of the web with its front legs, but continue to hold with its hind legs. This peculiar behavior resulted in the spider hanging perpendicular to the ground. I watched the spider do this through several heavy rainstorms, so it wasn’t just a one-time fluke. Such a distinct behavior may be an adaptation to deal with the rain. For example, perhaps this behavior reduces the amount of the spider’s body vulnerable to hits from raindrops. If it reduces hits from raindrops, the spider may be less likely to be injured or knocked from its web.
Here is a photo of the spider in its normal posture, when there is no rain:
And here is a photo of the spider in a heavy rain, with its body oriented perpendicular to the ground.
Here is a video of the behavior:
I also wondered if this behavior had been observed in other spiders. After searching a bit, I found that two spider biologists, Robinson and Robinson, had described this behavior in a 1974 paper on Giant Wood Spiders in New Guinea:
From our observations on Argiope argentata in Panama, we know that some spiders may adopt special rainfall postures if they remain in their webs and do not seek shelter under nearby vegetation. Thus Argiope argentata hangs away from its sloping web so that the body is almost perpendicular and legs I and II, which are always directed anteriorly, are off the web. In the rainfall posture these two pairs of legs are held outstretched in line with the midlateral plane of the body and at a fairly acute angel to the long axis, i.e., they are held more anteriorly than in the normal resting attitude. This position could be interpreted as minimizing the cross-sectional area exposed to the rain – assuming that tropical rains fall more-or-less vertically – or that the spider in this position maximizes the flow of water off its body surface with the anterior appendages forming a sort of drip-tip. We have since seen this behavior in Nephilia clavipes, and Leucauge species.
To wrap this post up, here is a final photo of the spider eating (note that the spider only has seven legs):
I was recently given some shed snake skins that were found at the CWRU Farm in northeast Ohio. These sheds will provide a fun way to teach CWRU herpetology students snake identification skills. Shed snake skins have a number of characters that can be used to identify the species of snake.
I looked closely at the scales to determine whether they were keeled or smooth. Keeled scales have a small ridge running down the middle, whereas smooth scales lack the ridge. By examining this close-up view of the scales in the photo of this shed, you can see that they are smooth. Since this shed has smooth scales, we can rule out several additional species, including the Northern Water Snake and the Garter Snake. We can also rule out the Black Rat Snake, as it has weakly keeled scales.
This leaves a couple snake species that could be the source of the shed: Eastern Milk Snakes and the Black and Blue Racers (which are geographic variants of the same species). To separate the remaining snakes, we need to look at the anal plate. The anal plate is the last of the large belly scales on the snake’s body, and it is located directly over the snake’s cloaca (excretory and reproductive orifice). The photo below shows the anal plate (circled). In this photo, the snake’s head would be to the right, and the tail would be to the left.
As you can see from the photo, the anal plate on the shed is single, not divided. Racer snakes have divided anal plates, but Eastern Milk Snakes have single anal plates. So this snake ends up as an Eastern Milk Snake (Lampropeltis triangulum):
Here is one of two Brood V Cicadas that I spotted in a parking lot in Warrensville Heights, Ohio, on 19 June 2016. I’ve also recorded this observation in inaturalist. This is the first time I’ve seen these cicadas in my life, so it was pretty exciting!
mister-toad.com is the personal website and blog of Mike Benard, a biologist who studies the ecology, evolution and conservation of amphibians and other organisms.
Mike can be contacted at: mfbenard -at- gmail . com.