I found three mud balls on some porch furniture in Allegheny County on 23 July. A week later, this Potter Wasp ( Eumenes sp) emerged from one of the mud balls. Presumably the mud ball was full of paralyzed caterpillars, and this wasp spent its larval period eating those caterpillars.
One of my favorite times of year is that brief two-to-three week transition in late March and early April when winter turns to spring. During the last few years I have spent that winter-to-spring transition studying wood frogs (Rana sylvatica). Wood frogs are an incredibly exciting amphibian to study. During the brief breeding season, male wood frogs gather together in large leks to mate. In these leks, the males wrestle and “cluck”; at one another as they attempt to mate with incoming female wood frogs. When female wood frogs enter the lek, multiple males will grab the females, clinging to her until one male wins out. Below is a video showing a group of male wood frogs clinging to a single female wood frog. This video was taken near the end of the breeding season, when most of wood frog females in this pond had already laid their eggs.
Sometimes the male wood frogs are in such a mating frenzy that they will grab other amphibians like they would a female wood frog. In the video here, a male tiger salamander has come too close to the wood frog lek, and has been grabbed by several males. I freed this male salamander and let him swim away. I don’t know what his fate would have been if I hadn’t released him; the wood frogs might have drowned him.
Spring at my field site in southeast Michigan brings out a variety of other exciting amphibians and reptiles. At the same time wood frogs are breeding, Spring Peepers (Pseudacris crucifer) and Western Chorus Frogs (Pseudacris triseriata) are actively calling and mating.
Spring Peeper Video:
Chorus Frog Video:
Two male Chorus Frogs looking at each other:
This is also a great time of year to see some beautiful Spotted Salamanders (Ambystoma maculatum):
Leopard Frogs (Rana pipiens) usually breed shortly after the wood frogs breed. They are not common at my field site, but I usually see a few each year. Here is one hiding underwater:
Reptiles are also active this time of year. Garter and ribbon snakes can be seen moving around ponds and marshes, hunting amphibians. Here is a Northern Water Snake (Nerodia sipedon) found cruising around a pond, possibly hunting frogs :
In the middle of February I headed back to California to do some research at the University of California's Quail Ridge Reserve. By the day I arrived, Napa County had received lots of rain, the ponds were full, and the California Newts and Pacific Chorus Frogs were in full reproductive action.
One of the male California Newts that we saw had an interesting set of deformities. His right hind foot was split, and he had an unusual pair of protuberances coming out of his tail. The hind foot deformity was no real shocker; while this is the first time I've seen a limb deformity out of thousands of Taricha torosa I've looked at, limb deformities have been described in many amphibians. I've also seen occasional limb deformities in frogs and salamanders. What really caught our attention were the strange protuberances on the salamander's tail. I had never seen deformities like this before, and they are not commonly reported in many of the scientific publications on the topic. It left us wondering what caused them ... parasite infection? . . . tumor? If you've got an idea, let me know.
After a couple quick photos, we released the newt; despite his deformities he appeared healthy and ready to continue on with his quest for mates. He wasn't the only amphibian who felt that romance was in the air. We visited a few more ponds, and found newts and chorus frogs in full mating mode.
Here is a male newt on the edge of a pond; he almost appears to be waiting for a female to approach:
Here is a different male newt, floating underwater. He was slowly working his way around the edge of the pond, presumably sniffing for a mate.
Here is a female California Newt trying to lay eggs. Despite her focus on egg-laying, a male clung to her back in amplexus, perhaps in the hope that she would still mate with him.
In case the still photos don't capture the mood of the newts enough, here is a video of California Newt breeding activity. In the first part of the video, you can see some of the courtship behavior of the newts. A male newt clings to the back of a female, and uses his hindlimbs to repeatedly stroke her body and hindlimbs. This behavior can go on for well over an hour; if the male does things right, the female may accept him as a mate.
Clearly plenty of newt breeding activity had already happened by the time we visited this pond. Here is a clump of California Newt egg masses.
This post wouldn't be complete without acknowledgment of the true king of North American herps: The Pacific Chorus Frog (Pseudacris regilla). Here is a photo of a male calling his heart out, as well as a video of the little dude.
Video of Pacific Chorus Frog singing:
Finally, for anyone not fortunate enough to have herped California's Coast Range, here are a few habitat photos.
I had the good fortune to spend the first day of 2010 herping with a friend along the coast in Monterey County, California. We selected this spot in part because in previous years we had found legless lizards there. While we had no luck with the legless lizards, we did see some interesting things.
Under a number of logs there were a load of termites, some of them nearly a centimeter long. Alex Wild was kind enough to identify them from the photos as dampwood termites Zootermopsis sp. These plump termites looked like they would be a perfect little prey item for legless lizards.
However, the highlight of the trip came when we were at a site about 100 meters from the ocean. There we checked under a clustering of old driftwood, and found a slender salamander (Batrachoseps gavilanensis). This was the first time either of us had seen a slender salamander so close to the ocean. We wondered how the proximity to the ocean affected these salamanders. Would the slender salamanders living within a few hundred meters of the ocean tolerate salt water better than slender salamanders from further inland? Not surprisingly, this very question had already been investigated. In a 1975 paper, Paul Licht and colleagues showed that slender salamanders from near the ocean survived exposure to salt water much better than salamanders from much further inland (Licht et al. 1975 Salinity tolerance and osmoregulation in the salamander Batrachoseps J. Comp. Physiol. 102:123-134). While they could not tell if this was due to individual acclimatization or genetic differences among the populations, it would not surprise me if this was a case of local adaptation.
Here are a couple photos of the slender salamander we found:
Here is the habitat where the slender salamander was found:
Not a bad way to spend the first day of the new year!
Earlier this week I was contacted by Tammy Davis, Project Leader of the Alaska Department of Fish and Game Invasive Species Program. She sent me a few photos of a mysterious frog that turned up in a Christmas Tree in Alaska. The person who had bought the tree was curious about the frog, and sent in the photos to Tammy. The photos were clearly a Pacific Chorus Frog (Pseudacris regilla, also known as the Pacific Treefrog). According to Tammy, the trees originated in Oregon. This is not the first time that Pacific Chorus Frogs and other amphibians have been found to be transported in Christmas Trees and other horticultural products; for instance, Christy et al (2007 Diversity and Distributions) report on Pacific Chorus frogs being brought to Guam in Christmas Trees.
I've been studying the Pacific Chorus Frog since 1999. Most of the time, when I am thinking about conservation biology and pacific chorus frogs, it is from the perspective of potential threats that could damage their populations. However, the observation of Pacific Chorus Frogs hitchhiking from Oregon to Alaska raises the question of whether there is real potential for them to become established in Alaska. There are already several cases of these frogs being established out of their native range. For instance, a population of Pacific Chorus Frogs that was established in the Alexander Archipelago of Alaska in the 1960s was extant at least until 2002. However, it did not appear to have spread beyond a single lake, according to S.O. MacDonald's "Amphibians and Reptiles of Alaska". This suggests that perhaps Pacific Chorus Frogs would not spread far if introduced in Alaska.
In contrast, Reimchen (1991, Canadian Field Naturalist) reported on his studies of Pacific Chorus Frogs introduced to the Queen Charlotte Islands, British Columbia. The Pacific Chorus Frogs on the Queen Charlotte Islands spread at a rate of approximately 2 km per year. While the Queen Charlotte Islands are considerably south of Juneau, the islands are also north of the natural geographic range of these frogs. This suggests that Pacific Chorus Frog populations introduced to Alaska may be capable of increasing in size and spreading.
The observation of these frogs being moved so far in Christmas Trees has also made me think about the consequences of frogs being moved around within their natural geographic range. It is well-known that amphibians are transported with horticultural and agricultural products. However, it is not known whether these movements have much of an effect on local populations. Do these movements alter the population-genetic structure of any of these species? Are these movements associated with the introduction or spread of pathogens like Chytrid Fungus or Ranavirus? These are all questions worth answering.
Pacific Chorus Frogs in Christmas Trees in Alaska turned into a news story, and I have had a few people point it out to me. The comments section of these stories are predictable. They range from people upset about the recommendation to kill the frogs, to other people complaining about endangered species, but in skimming the comments, I don't see anyone else reporting finding a frog. With this increased publicity, it will be interesting to see if there are more reports of pacific chorus frogs turning up in imported Christmas Trees in Alaska.
I have also seen a rise in hits on my Pacific Chorus Frog webpage, that corresponds to the release of this story. I wonder if all this extra web traffic is from people concerned about the invasive potential of pacific chorus frogs? If you've found a Pacific Chorus frog or other amphibian in your Christmas tree, I'd be interested in hearing about it. Please send me an email at 'mfbenard@gmail.com'.
