April 20th, 2007
Variations, and the return of the Wood Frogs
One of the problems that we encounter when trying to identify species is that there can be quite a lot of variation in appearance. The above example is a case in point. I found this very tiny lady beetle while I was walking about in the woods yesterday. Although it has 4 black spots on its elytra, I am certain that it’s actually the native Two-spotted Lady Beetle (Adalia bipunctata), which is known to have variable markings. The two-spotted specimens look like this, while the four-spotted specimens look like this — pretty much the same as the beetle I found yesterday. It’s helpful to know about such variations when you’re out looking around for insects or other creatures. Unfortunately, most guide books just show the most common field marks and don’t tend to show variations.
Well, they’re finally back! The Wood Frogs (Rana sylvatica) have returned to the drainage creek out behind the barn. Two days ago, I heard some in the ditch that runs along the highway in front of our place. Yesterday morning, I heard and saw them in the drainage creek. I made this little .mp4 movie clip in the afternoon — you won’t actually see any frogs, but I wanted to show the habitat — willow brush and cattails in about 30 to 40cm (12 to 16 inches) of water — and give you a chance to hear these frogs. When we first moved to the farm about 30 years ago, I used to hear this quacking and thought there were ducks out behind the barn. At times, there were a couple of ducks, but most of the quacking was actually coming from the many Wood Frogs that gathered in the drainage creek each year.
The Wood Frogs are a little late in making their appearance this year. Last year they turned up on April 12th, so we’re lagging by about eight days. By this time last year, the eggs were already starting to look like tadpoles. There are a few other posts about the Wood Frogs between those two posts from last year if you’re interested in learning more about them. The photo below is of one of the Wood Frogs seen yesterday. At this time of the year, their coloration usually looks somewhat different than it will later in the year. This page from the Rhode Island Vernal Pools website has a nice photo of a pair of frogs during breeding season, as well as a typical photo of an adult with its characteristic mask. You can also see my own photo of a frog as it looks outside of breeding season here.
Well, tomorrow is the beginning of the Blogger Bioblitz. For the next week, I’ll be busy here at the farm, and perhaps at a couple of other locations as well, making a list of the flora and fauna that I see. As of yesterday, they were 44 bloggers signed up to blitz a site in their area. You can check out the list here. I plan to post almost-daily progress reports with highlights from my counts. I’ll be setting up a photo gallery for images, and a spreadsheet which I hope to be able to share with you. I’ll also try to draw up a little map and post that somewhere so that you’ll have a better feel for the areas that I’ll be surveying. I’m quite looking forward to seeing what other bloggers find in their regions. Once the bioblitz week is over, everyone’s data will be collected and a few volunteers are going to put it all together into a format where we can share the results. I’m really quite impressed with the way this is coming together so far. If you’re a blogger and wish to participate, I don’t think it’s too late. Just visit Jeremy Bruno’s Voltage Gate blog to sign up. To all of the other participants, good luck. I hope all of you find plenty of interest at your sites!
Tags: Adalia bipunctata, Two-spotted Lady Beetle, Wood Frog, Rana sylvatica