Wednesday, March 9, 2011

Meet Our Monkeys: GS

This group of titi monkeys inhabits one part of Jardin Botanico. The second, somewhat bigger and less disturbed, study area of the project. 5 primate species range at this site: a group of capuchin monkeys, a group of howler monkeys (Alouatta caraya), night monkeys, marmosets and at least 8 (or more Kim??) titi monkey groups. GS is one of them. GS is special. I guess every observer would say that about his/her study subjects but it´s true for GS. Well, I will come back to that a little later. For now I would like to introduce them to you. When I started following them in September 2009 the group consisted of the breeding pair Hobs (the male) and Margo (the female) and their subadult son Evil Knievel. They didn´t behave like the other groups. I was told they usually hang out together but these guys did not really. I could either find the shy Margo alone or Hobs wandering around with Evil Knievel. One very special feature of Margo brought the name to the group GS, where S stands not for special but rather for short tail. This refers to Margo´s stump tail. Honestly we don´t have a clue how she lost it (supposedly capuchins!!??) but it´s gone. This should have several severe consequences for her daily life but she handles it quite well. She can jump as far and high as her male and does not show any shortcoming- well, maybe one. Unfortunately she is not able to enforce her pair-bond with Hobs using tailtwinning like it is costume in this species. But it makes group identification sooo much easier for us.
Margo- or short tail how she might be known to many


Evil Knievel looking evil

Ok, but enough to that. In October everything changed. All groups in both study sites already had had their babies and I was sure my group would not have one this breeding season. But one day I saw something weird in the lap of Margo and it was a tiny naked tail. Charlie was born and from that day on mom and dad spent all their time together- more like the other groups. The first day Margo carried him around but already on the second day Hobs took over and turned out to be a great dad. He carried the tiny Charlie around his neck and gave him away only for nursing and cleaning purposes. Evil Knievel was also heavily interested in the new group member and like a typical big brother might do he started pulling Charlie´s tail on the day he was born.

Evil Knviel pulling Charlie's tail

Hobs carrying Charlie and Evil Knievel

There is one more event that made the group special for me. I was following them in the morning and everything seemed quite normal- just another day. I was with Hobs, Charlie and Evil Knievel when I saw Margo in about 10m. But oh...Margo was not alone, she had another male on top of her and they were mating!! And that in front of Hobs carrying their baby. Well, let´s talk about the definition of monogamy again. When Hobs started moving towards them Margo decided to better get rid of the “other” guy. They chased him and his group (there was another female and a subadult) through almost their whole territory and both groups vocalized like crazy for over 2 hours. After this exciting incident I saw this group several times in GS territory and was told from my successor Jack that their territory seemed to shrink over time due to the pressure of the neighboring groups.


  1. Thanks to Nicole for some of the pictures ;)

  2. No problem, great post Rebecca! I especially enjoyed the retelling of that last bit ;)

  3. Margo really was not a fan of me, always leading the group off when I was around. Charlie fell out of the trees a few times, sometimes as high as about 15 metres! I also saw a massive fight between Hobs and a strange male (maybe who mated with Margo?!), they were tackling each other out of the trees to the ground then grappling and biting each other on the floor, it was scary! Is anyone following them this season?

  4. Sadly no one is following GS this season. It is difficult to find the right people to work with them so I've decided to put all energy into YG and developing, hopefully, a new site.