Saturday, March 14, 2015

Frogs, Frogs, Everywhere there's Frogs

Our group. Photo by S. Burton
It's Friday night, cool and rainy. So what to do? Go searching for salamanders, of course. And maybe a frog or two. Twelve of us from the Peninsula Master Naturalists gathered to search for salamanders, frogs, and whatever else the night rains might bring out. We drove to a different part of Grafton Ponds than our last outing where we knew there would be some active ponds much closer to parking. It was twilight as we walked down the abandoned road; a quartet of Wood Ducks flew high overhead calling as they went. We passed one vernal pool where we could hear a lot of spring peepers calling. But they are hard to see and our goal was salamanders so we plunged deeper into the park while keeping in mind that we would pass by here on the way out. We finally reached our target pool and dove into the woods. Daylight was failing and the tree cover was thick so on came our lights. As soon as we arrived at the pool, we found our first southern leopard frog. The first of many, many, many. We placed the frog in a small baggie so we could all get a look at it and it could stay moist. But the frog was a bit peeved and started extruding a toxic substance so we released it back. While humans are not particularly susceptible to this toxin, any other frog placed in that baggie would quickly succumb.
First Southern Leopard Frog of the Night

The group was large enough that we often ended up breaking into two or three smaller groups to explore along the pool's edge. One group had moved ahead and found a bunch more frogs calling. As the rest of us moved to catch up, someone spotted this small mass of eggs on a rotting log.

None of us were sure what they were. Most salamanders and frogs would lay their eggs in the near-by pool so they would stay moist. So who would leave them out on a rotting log? Later we discovered the likely source of these eggs. They would be frogs eggs that never made it to the water. (possibly disturbing image next, you are warned)
This frog had succumbed to a predator and showed the same type of eggs as we had seen earlier. A bit of a gruesome find but also fascinating to see the eggs still with the frog. The carcass was drying out so it had been there for a while. We aren't sure what the predator was or why it would leave such a meal behind. Surely the eggs must be a good source of fat and protein. And all of that meat. That will remain a mystery.
Now back to the less gruesome. The lead group had found a small cove [do vernal pools have coves?] that had several dozen calling southern leopard frogs and masses of frogs eggs.With all of the human commotion the frogs had moved away from the edge out of camera range. But as Sharon scanned the water's surface out to 30-50 ft, the surface was dotted with tens of pairs of eyes. And those were only the ones looking in our general direction. It was fascinating to see the eye-shine from the frogs on the dark water.
Southern Leopard From Egg Mass

Same Type of Eggs but Under Different Lighting
Photo aside:  These night-time hikes have been my first real experience with animal photography in the dark and I'm still feeling my way around. Between using other people's headlamps, the on-camera flash, and, tonight for the first time, my wife's LED macro light, the lighting and color is quite variable. I would like to find a time to go out on my own and just experiment to see what works. I've seldom used a flash in the past, preferring natural light. But in the dark, everything looks the same in natural light: black. Many of my photos last time were blurred because I had exposed for the light from headlamps and used flash. So long exposures allowed for camera shake and ghostly second images to appear. Tonight I tried to either use the steady light or flash and not both. It didn't always work out but that is why I took so many photos.

We were successful in finding a handful of salamanders. Most of what we found, and all I saw, were Mabee's again. Mabee's is a state threatened species only occurring in the tidewater region but not too close to the coast. Grafton Ponds is one of its strongholds. An interesting find was the variability in size. This first one was about half the size of the later ones. We would find most, or maybe all, of them under the edge of a rotting log (I wasn't actually there for any of the salamander finds). So like the curious herpetologist we are, we rolled over every good looking log we could find. And then returned the log to their original place if we found nothing. If we did find a salamander, we would get a good look and then return the log and make sure the salamander was right next to it (you don't want to put the log back on top of the salamander and squish it).

Mabee's Salamander

By the time we reached the far side of the pool we were once again separated into two group. Here's the other half on the other side of a finger of the pool. I think that must be Fred with his double-barreled light source at the far right side. He is the only one you could pick out by his headlamp.

Along the way I found this cool-looking feather floating in the water and a wonderfully posed frog. The frog showed much more green and distinctive markings than any of the previous ones. It was just sitting on the side of a fallen tree. You can see the rounded, irregular spots on the back, the strong lines along the sides, and a hump in the middle of the back. I'm not sure what that hump is; perhaps it is where the leg muscles attach?

In this wonderful night, we had a great climatic find. A group of calling frogs even larger than the first (or at least what I saw of that group). And eggs everywhere. Play the movie to hear the frogs calling. It was too dark to see anything except the flash from someone's camera.

There were several pairs caught in amplexus. The male will grab onto the female's back and stick with her. This helps stimulate her to release her eggs which he then fertilizes. The southern leopard frog leaves a gelatinous egg mass that is in the shape of a rough ball. We touched a few, gently, and they are firmer than they look.

On our way out we again heard the calling spring peepers. They had been joined by upland chorus frogs. Both frogs are much smaller than the southern leopard frog and tend to call from vegetation making them much harder to find. But Kory did find this pair in a small ditch along-side the road. A great find that was a perfect way to finish off the night.

Thanks to Elisabeth, for organizing, and everyone else for making a great adventure. Hopefully in a few weeks we will be out again and find new salamanders and frogs.

Thursday, March 5, 2015

Salamander Hunt

Last night there was an impromptu walk to visit the Grafton Ponds vernal pools in search of salamanders. With warm temperatures and rain in the forecast on the night with a nearly full moon, it was the perfect time for the salamanders to be on the move. Unfortunately, they weren't checking their emails. So five of us wandered around the area in the dark with our flashlights looking for the creatures that were probably tucked up at home with a nice book in front of the fireplace.
But while it wasn't the salamander-paloosa that we hoped for, we did have a few great sightings. The best, by far, was this Mabee's Salamander. In fact, it was the only salamander seen.

We saw a lot of aquatic insects. That surprised us. I, at least, was expecting that most of the insects would be hibernating or otherwise inactive. Especially since most of the pools were still ice-covered. We also saw a handful of frogs. Like this Southern Leopard Frog.

For our next trip I think several of us will be getting much brighter lights.