Last May, John and Eileen and Rachel, my labmate, went to the Los Pozuelos field site for the first time. They had been told by Pablo Cuello, a grad student in the university at Mendoza, Argentina, who had assisted us the year before and knew what a social tuco was, that the tucos he was seeing at this high altitude location looked suspiciously social. Not only were there lots of them in one area, one or more adults could be seen coming out of the same hole. It didn't take John and Eileen long, once they got there, to see that the tucos were social, and one of the primary reasons for this second trip was to confirm by radio telemetry that the areas individuals were using really did overlap.
Tissue sample was collected last May and we are still waiting for the genetic results from the lab in Mendoza but originally, this species was identified as Ctenomys opimus, which, from observations in other places, was characterized as a solitary animal. We are anxious to find out where this animal places in the known species of Ctenomys and if it truly is opimus or some subspecies or perhaps, something altogether different. Any of those possibilities are exciting... however, one thing is certain, the tucos that live in this area are social but do not exhibit the same social patterns we see in C. sociabilis in Patagonian Argentina.
In C. sociaibilis, we find females living in distinct colonies along with one adult male. Here, after MANY hours of radio telemetry (just ask Anna, the grad student who came out to join us!), we found that multiple males and multiple females overlap in the areas they use but not completely. The data are still being picked apart and analyzed but it looks like there are distinct groups but the groups don't necessarily inhabit the same space all the time. In addition, we did 3 nights of radio telemetry. There were 22 animals with radio collars and every hour on the hour all through the night and day, fixes were being made so we knew exactly where each individual was for that moment. This was no small feat... and I had to ask myself more than once, what the heck an almost 50 year old woman was doing out in the middle of nowhere in the middle of the night stumbling around in the dark with an antenna in her hand looking for a rodent!
However, we did collect a lot of information and are trying to better understand the unique society this mystery tuco participates in. The other big question we are asking is what the mating and breeding cycle is. Last May, they found fairly large pups. In January, we saw a number of pregnant females but also some decent sized pups. The picture in this post is one of them. Do these tucos breed multiple times through the year? Or are females on different reproductive cycles? With multiple males living in the same group, is there competition for mating or is there one male dominating? Who disperses? Who stays? Although I found this place to be a rather intense field site, I have to admit that these tucos intrigue me. There are so many things to discover, and discovering the stories of animals is what excites me most in biology. More to tell in the next post!
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