News and stories from our outreach events as well as journal entries from Katie's fieldwork seasons.

Follow the #E2HD Twitter handle for more updates on Evolutionary and Ecological Approaches to Health and Development, Northwestern's Biological Anthropology research group. 

Sunday
May292011

Updates - Round 3 Week 6

The heat continues! Melanie's interest in Isa's baby also continues. Melanie constantly follows Isa around and handles her baby whenever she gets the chance. There have been a couple more instances of aggression between the females, too. Although social behavior is not my focus, it's very interesting to watch all of these interactions. They remind me how important inter-individual relationships are among primates.

As I've mentioned several times, the heat is affecting the monkeys' behavior. We've had a few days where the monkeys rested for eight hours! This makes collecting behavioral data easy since they are not moving very much, but it makes collecting fecal material difficult. Instead of defecating several times each day, the monkeys defecate only once around 4pm. Howler monkeys in a single group tend to defecate all at one time. Now though, because they are all resting in a pile, they also all defecate in the same place. This makes matching samples to monkeys tricky. We get all of the samples coming at us at one time in one place, and we only have one chance at them per day. Sample collection is hectic to say the least. Still, we're getting it done. We have not missed a single sample, and we were able to collect from the 5-month-old infant again this week!

This week we also ran into a large fer-de-lance (or nauyaca). It was at least 2m long and curled up in a ruin. It was beautiful. Its coloring was quite different from the small one we found a few weeks ago though. I believe this week's was a true fer-de-lance. The small one is likely a different species, but I'll have to check with a herpetologist.

The hummingbird nest we found (unharmed) near the nauyaca this week was also beautiful. It's amazing how small they are! Slightly bigger than a golf ball...with mint-sized eggs. It was in a tree about 1.5m tall. I'm always amazed at how fragile they seem and at how precariously placed they are. I wonder how often they are damaged or destroyed.

A nauyaca resting in some ruins under a tree where the monkeys were resting.

 A hummingbird nest on top of the ruins where the nauyaca was curled up.

Sunday
May222011

Updates - Round 3 Week 5

There's another new infant! This time it's in our other focal group, Balam. On our last day with Balam, two weeks ago, we couldn't find Luz, and when we found her this week, she had a baby! Just like in the Motiepa group, the other female in the Balam group kept taking the infant from Luz. It's a little different in this case though because Teresa does not have her own young one, and we haven't witnessed any aggression over it yet.

The other exciting news is that we were able to collect from two more of our outside groups this week. That means that only one remains, and we still have five weeks. Although we're not completely finished with the extra groups, being so far along this early on takes a lot of the stress away.

Aside from these two developments, the rest of the week was pretty routine. We did spot a new kind of snake (for us) on Tuesday though. It was only a couple of centimeters in diameter and maybe a meter long, but it was a beautiful green/blue/turquoise color with a red/brown head. I've never seen it before, and I haven't been able to identify it yet, but it was quite striking. Unfortunately, the encounter was too quick for a photo so I'll have to rely on my memory as I continue to search for it in books.

Teresa inspects Luz's new infant.

 

 

Sunday
May152011

Updates - Round 3 Week 4

Week 4 was full of little surprises. The most exciting was that we were able to collect a fecal sample from Melanie’s “infant,” who is now about 5 months old. Samples from monkeys that young are tiny and tend to fall without warning so they are very hard to get. Furthermore, the unique developmental stage and diet (milk and solid food) of this juvenile suggest there may be interesting microbial differences when I compare this sample to the others. The fact that we were able to get it made me happy for most of the week.

Most of the other surprises this week involved Isa’s infant, who is only about three weeks old. The first series of situations came about because Melanie kept taking the baby from Isa. Most times Isa didn’t seem to mind, but one time she clearly wanted him back. The only problem was that Melanie didn’t want to give him back. She grimaced and swatted at Isa, who acted submissive and had to wait patiently until Melanie finally allowed Isa to take him. Intra-group aggression is fairly rare in howlers, so to see Melanie lash out was unexpected, especially when she is not the mother. Brianna and I were on opposite sides of the tree watching different monkeys when it happened, but we both saw it and gasped at the same time. Obviously, Melanie has a strong interest in this infant, but we’re still not sure why.

Another time, Maia, the infant’s one-year-old sister somehow ended up with him on her back. It was amazing to see how big such a tiny monkey looked on an only slightly-bigger monkey. The whole situation was funny in a sweet kind of way until Maia decided she wanted to play. All of sudden, she was hanging from her tail with her brother clinging onto her for dear life while she tried to undo his grasp one limb at a time. We all held our breaths until Isa came to the rescue and took him back. To be honest, I was impressed that Maia could hold both of them up for so long using only her tail. He looked heavy!

Maia with her 3-week-old brother hanging on for dear life.

Isa comes to the rescue!

 

Everything else was fairly routine this week. The heat index was at 43C (109 F). The monkeys slept for four hours each day. We found some more ticks. There were several intergroup interactions in opposing Poulsenia trees. And, of course, we had to walk part-way home yesterday because no ‘colectivos’ showed up outside the ruins and the forest when we were done for the day. Also, on a slightly unrelated note, I went on a run this morning, and there are trees with beautiful pink flowers in bloom everywhere along the highway. It made me smile.

Monday
May092011

Updates - Round 3 Week 3

Things got a little crazy with the beginning of May. Our focal group this week decided to stay out of view during many of the hours we were following them. We got data, but we had to work hard for it. At the same time, a neighboring group that we want fecal samples from for this season appeared and foiled us on two separate occasions. We decided to try to get samples as long as we knew where the group was, but the first time they appeared, they did not defecate. The second day, they all switched spots right before they defecated and did it from high up in a tree so that not a single sample fell to the ground in one piece.

To make up for our lost opportunity with the extra groups, Brianna and I split up to collect from two other extra groups on Saturday with the help of colleagues. Both of these forays were successful , and we now have half of our extra groups sampled in addition to the focal data we have been collecting.

The dry season means ticks, and this week I had my fair share of ticks. I found ten on me in the field in one day, which is more than the total number I have found on me in past years. Luckily, most of them were still crawling around looking for a place to dig in when I saw them. I only found one or two that had actually bitten me already.

5 de mayo was this week, and although it was quiet in Palenque, just the thought of a holiday put me in a good mood. This was a good thing though because it kept me alert, and I was able to spot what I consider my “5 de mayo present from the forest” quickly.  As we were marching out of the forest for the day, I spotted a ‘nauyaca,’ or fer-de-lance, in the center of the path. It was very small (maybe 0.5 meters), and it was coiled up and seemed to almost not notice us. These snakes are very venomous, and supposedly common in this forest, but I’ve seen very few during my time here. I prefer that for our safety, but snakes fascinate me. We stood and took pictures of this one from a safe distance until I was able to tear myself away. Unfortunately, this made us a little late in getting out of the forest, and there were no ‘colectivos’ (public transportation vans) to give us a ride when we emerged from the forest. We had a long walk home, but to me it was worth seeing the nauyaca.

Nauyaca or fer-de-lance!

 

 Colorful fecal samples from one of our extra groups in a forest fragment.

Monday
May022011

Updates - Round 3 Week 2

This week went by quickly despite the hot weather. It was still hot, though. After a certain point, you expect to not be able to tell the difference between a few degrees, but you definitely can tell.

The most exciting discovery of the week was that there is another baby in the Motiepa group. I wrote about Melanie having an infant a few months ago, and she is still around. Isa has an infant now too though. We think it is about two weeks old, and we think it is a male. I tried to take a picture again, but when they’re so small, it’s hard to see them in the photos.

Another interesting thing is that one of the males copulated with Isa this week. The interbirth interval in these monkeys is supposed to be a little more than a year, but Isa’s last daughter just recently turned one, and she has already given birth, AND she is apparently copulating now even though she has a tiny infant. My guess is that nothing will come of the copulation, but it did happen!

Everything else has been pretty routine. The monkeys are starting to eat more fruits. One, Poulsenia armata, is very sweet, and I’ve seen tourists pick one up for a snack occasionally. They’re about the size of a strawberry though and have lots of seeds inside (approximately the size of orange seeds), so it’s not much of a snack. The monkeys also started eating a fruit that I hadn’t seen them eat since my seed dispersal work in 2008.

Isa is on the right, and you can barely see the baby on the center of her body.

 

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