Moving On

On Tuesday, we packed up camp and left our refuge in the willows for new adventures. The season with C. sociabilis went fast, and tomorrow, we head for the north part of Argentina to investigate another social tuco-tuco. The past few days were spent outside a small town, El Maiten, south of Bariloche. Years ago, some professional animal collectors found a bunch of tucos living in a valley. Their report was that these tucos were up everywhere and "chirped like birds". That's classic sociabilis. Since then, some local mammalogists checked out the area and found burrows but did not see the animals. We went to see for ourselves just what tuco was living there. As it turned out, it was C. haigi, a solitary tuco known around Bariloche. Even though this species is found close to where we find soci, I had not yet met haigi up close and personal. We caught a mom and her pups and two males. They communicated more with grunts, rather than chirps, and were quite docile.

Today's picture shows John and Eileen on one of our last nights in camp. Like I said, the weather finally turned warm and we were often eating dinner outside. John has taken up guitar playing and brought his travel guitar with him, practicing all the time. Eileen, of course, continues to work even "after hours". By 9 pm or so, we hunker down in the truck for our nightly video of House. We're now on Season 3, and watching it has become our favorite tuco team past-time. I am hoping to post some more from Jujuy and parts north, but until then, I send my wishes to you all for a wonderful Christmas. Cross your fingers for me on Tuesday... we head to 14,000+ feet altitude and I am hoping that I don't get sick! From Bariloche, Felices Fiestas!!

Spring, Glorious Spring

Finally, spring has arrived in the Limay River Valley! It has turned wonderfully warm, so warm that the wind is a welcome friend. We’ve had a few sprinkles of rain but the temps are good enough to take a bath in the stream. We are now upon our last week of field work for C. sociabilis. It has been an interesting field season, surprising with who we’ve found has survived. Overall, older females seemed to do better than yearlings and even more of a surprise, there has been an adult male in nearly every colony! Those of you who know the tuco-tuco story know that male survival is quite low in this species, and in fact, we rarely encounter an adult male. It’s a good year when about 40% of the colonies have a male. So why such a difference this year? While they had rain in May (their Fall), they had little rain through the winter when tucos are mating. Perhaps, mortality was very high for last year’s litters, but I’m not sure if lowered competition for the males gave those remaining a better chance at survival. Who knows? But we also have seen a strong male sex ratio bias in the pups. And finally, I have only come across one lone female. The rest are living in groups this year. I have seen this downward trend toward fewer and fewer females living alone over the past 6 years. I am anxious to go back over the data to see if there may be a pattern that emerges with weather, yearling survival, sex ratio and number of lone to group colonies.

Today’s photo show a little pup and his generous donation to my dissertation cause. I do need more than one poop to get a sufficient sample of CORT hormones but he came through with more! I’ve collected a fair amount of samples and will add it to what I’ve already analyzed in the lab. In general, I have found that group living females have lower baseline CORT (or stress) hormones than females living alone. I have also found that CORT in pups is also high or low depending on living with a lone mom or group living moms. How much of that is inherited or passed through mom’s milk is yet to be known, but it is interesting to me. With the help of the best undergrad “wranglers” ever, I continue to run behavior tests with the pups in the lab at Berkeley, looking to see if behavior and hormones are correlated. Specifically, I am testing exploratory or bold behavior in an open arena in which they have the option of running around or hiding in a refuge. We have found in the adult lab females that there’s a strong correlation with CORT and boldness. That is, lower CORT, higher exploratory behavior. We’ll see how this holds with the pups.

We leave in about 5 days for a place called Chubut to check out a possible population of C. sociabilis. It’s been rumored that there use to be some living in this region south of Bariloche. We’ll be breaking camp on the 15th, head down to Chubut for a few days and then back to Bariloche, where we catch the bus to Salta. There we will rent a truck and head into the mountains near Jujuy and I will get to meet another social tuco-tuco!

Wind-worn

We made a last minute decision to come into town today, only because we´ve gone two days now with such high winds and intermittent rain, that we´ve been unable to trap tucos. The good news is that the weather is suppose to turn warm. Cross your fingers! We have about 5 more colonies to go.

Meanwhile, I do a lot of bird watching when I´m not watching the tucos or the holes from which they pop up. This little girl in the pic, Fio Fio, in Spanish... and I think from the genus, Elainea, or something like that, has been the most noticeable visitor around camp and the field. They´re cute little buggers, which hang on to sticks and watch for bugs, quickly popping down to the ground to snag a bit and then back to their perch. They remind me of kinglets but Claire, you might have to hunt this one down for me. Anyway, they´re quite the chirpers and fun to follow. We also came upon a Loica´s nest. They are like the southern hemisphere´s version of a meadowlark but with a brilliant red chest. They nest on the ground and this nest had a cowbird chick in it and what looked like another cowbird egg along with its own two eggs. Unfortunately, the parents abandoned the nest. I continue to watch our kestrel pair feeding in the lower hollow of a tree and hope to post a short clip soon. They are quite the beautiful birds and their hatchlings are getting quite the gourmet meals, usually consisting of large juicy lizards. Finally, we´ve had our "regular" little gray bird (Doica) show up to fight himself in the truck side mirrors. It´s funny to watch as he flies at the mirror over and over again. From the condors to the swallows, this place is full of amazing birdlife.

We bought our bus tickets for Salta today. It´s a two day bus ride to where we pick up our rental truck and head into the mountains near Jujuy. Should be fun. Also, we will be checking out a site about 150 km from here on reports that another population of C. sociabilis may be there. We´re all doubting this but gonna check just in case. That´s all for now. I´m probably going to be out of touch until Dec. 11 or so as we hope to take advantage of the promised good weather. Hope you´re all staying warm during the winter. I´m betting my spring is colder than your (i.e. California) winter... at least right now. Missing you all ... Julie