A short while ago, I mentioned my once-a-spring visit to a certain roadside ditch to witness the Chorus Frog “show.” As usual, it turned out to be quite a demonstration of amphibious lust and loquaciousness and I was not disappointed. In fact, the addition of Wood Frog activity to the fray made it all that much more interesting. I felt like I was missing a part of the picture, however. All that “Creeking” and “Clucking” was geared to reproduction and I had yet to see any of the fruits of that singing – aka egg masses. This was primarily because of my timing. So, I decided to make my once-a-spring endeavor into a twice-a-spring thing and return to the dance floor at mid-dance.
Frog eggs vary in appearance depending on species. The individual eggs are always enclosed in clear gelatin packages but they can be arranged into big globs, small clusters, or even clusters of globs. Toads lay their eggs in long strings which look like old fashioned dime store dot candies. Some of these frog egg clusters are adhered to sticks and submerged grass stems while others are allowed to float at the surface. Putting the right egg to the right frog is a matter of knowing the right checklist, although it can be difficult. When salamanders are in the neighborhood, things can be very mixed up indeed. In the case of my ditch, the challenge wasn’t too great because only Chorus and Wood Frogs hang out there and their egg masses are quite different from one another.
Locating the Wood Frog eggs proved to be a simple task. These creatures tend to lay their egg masses into communal nurseries. Generally when you find one cluster you’ll find many. There were two such nursery clusters in the deepest part of the ditch. The larger aggregation, consisting of about 18-20 clusters, was “guarded” by a female wood frog who hovered over the spot like a mother hen (see beginning photo and above). In truth, there is no egg defense or brooding going on, but it was almost as if she were admiring her creation. If you look closely you’ll see that she is proudly pointing to the third bunch from the left (don’t look too closely, now). You don’t have to look that hard to notice that a few of the clusters are actually floating at the surface. Eventually all of them will do so.
According to the literature, there is an average of 1,000 eggs in per Wood Frog egg cluster but these clusters appeared to be a bit shy of the average. The individual eggs are about ½ inch in diameter- including a clear envelope and a tiny black and white embryo. They adhere to each other without the benefit of an additional gelatin coating holding them together. When first laid, the round egg mass is about the size of a ping pong ball but it soon expands to soft ball size as water is absorbed. I gently cradled one of the masses in my palm to get a better view (see below). As you can see this particular clutch was about ready to hatch. It only takes about 10 days to emerge when the weather is warm and I’ll bet this bunch was on its ninth and 3/4 day. Some of the tiny tadpoles were already free of their egg capsule.
Finding one of the Chorus Frog egg clusters proved to be much more of a challenge. Though they perform in communal singing groups, Chorus Frogs prefer to lay their eggs in small solitary clusters stuck onto submerged grass stems. A female (see here) will lay dozens of separate clusters in dozens of separate places. It took a few minutes of re-focusing before I spotted my first cluster (see below).
These delicate masses only contained around 75-100 seed-like eggs apiece and were cylindrical in shape. They probably measured about 1 by 3 inches but, admittedly, measuring a glob of jelly is a difficult task. When placed in the palm, the masses become shapeless although the embryos became clearly outlined within (see here). Judging by the advanced state of the tadpoles in the one cluster I was able to pull within reach, they too were about 7 or 8 days along.
I elected to take one of the clusters home in a take-out bag (see below) and watch their further development. A few of the tadpoles started hatching out later that day and the whole brood was out by the following afternoon. I was now the proud father and choir director for a clutch of very tiny Chorus Frog tadpoles. I’ll send baby pictures as soon as they are big enough to smile.