High Stakes Dispersal
It’s not easy making it on your own as a young man or woman in this world. As it turns out, it’s not all that easy for a young fortune seeking pichico either. To be fair, we humans ask for a lot more when we strike out on our own, while pichicos shoot for the basic amenities such as companionship, food, and sometimes a mate. Nevertheless, the stakes are comparatively low for us because 95% of what we want is dispensable, and generally, there is the option to return home. Pichicos, on the other hand, enjoy no such luxury and that is why the next few months, fondly known as the season of high stakes dispersal, is going to change the landscape of pichico groups around here forever.
Put yourself in the shoes of OPY for a moment; a young 420-gram adult female from the Westside. Your whole life you have been surrounded by your twin sister, your father, your mother, your grandfather, and your grandmother. All day you run around with them foraging for food, occasionally stopping to pick flies and lick sap off your grandparents’ backs, and, even though you are a perfectly capable adult, your mother and father still insist on giving you a proper cleaning every night.
Lately though, you’ve been getting lots of attention from adults in the neighbouring groups. Other young adult females want to gossip with you and males have sometimes shown interest in your newly perfected scent marks. Pretty soon the grass starts looking a lot greener on the other side, where other tamarins will treat you like a grown-up and you can have a say in things. Plus, there is a dashing young male tamarin in the group just south of you, and even though you know he is already surrounded by females that doesn’t mean he wouldn’t take interest in you; if, perhaps, you were around more often…?
And just like that you decide to take off one day. At first you thought that your own group might protest, but quite to the contrary they rejoiced at your departure because that meant one less mouth to feed. This throws you off a little, but not enough to stop you, and you race down south to check in with that dashing male that they call GBR. You start to sing real loud as you approach the new group so that they are alerted to your arrival and you scent mark a few times because the males seem to like that. You can hear the group responding to your calls and it sounds oh-so-inviting and exciting. Eventually you see them, and they see you, and you’re smiling, but they are scowling back. While GBR hangs back a pace, the other two adults in Group FC, both females, blitz right toward you at a frightening pace, and it doesn’t appear friendly. In minutes they are chasing you up and down the trees, without real aggression but definitely some animosity. They are intent on letting you know that you are not welcome, but they won’t harm you if you just leave them be. You have no choice but to shriek and run away.
Scratch one prospective group off your list, but hey, there are plenty more dashing males in the forest.
Emboldened by the possibilities of moving up in the world you take off into previously unchartered territories.
You cross the great ravine that your family told you never to cross. You’re looking for groups and getting further and further away from your homeland. Unfortunately, there are two immense obstacles you didn’t consider until now. One, it is the driest time of year and food is scarce. Two, this happens to be the exact time when other tamarins are leaving home, which means that competition is steep.
Now you are in a strange part of the jungle and you’re singing like crazy to attract prospective groups. You’re getting a bit lonely and hunger is always an issue, but suddenly you stumble upon a jackpot – a resource no tamarin can ignore. This unique place not only has an enormous blooming Symphonia tree that is attracting primates and birds from miles around with it’s little red flowers and fruit, but in it’s lower reaches it also has delicious oblong fruit, yellow on the outside, a creamy inside, and sheer heaven to taste. It occurs to you that a great food source like this must be popular among the local tamarins and if you hang around long enough you can eat to your hearts content while awaiting your new posse. Moreover, the fruit is continually produced, as if by magic, and if this troubles you slightly you push the thought away with the sweet delight of consuming it.
In one of your daily forays to the yellow fruit, you find that a new group has arrived. Having learned your lesson from the last attempt to ingratiate yourself with strangers, you slow down, compose yourself, and casually approach the group. Unfortunately and without warning, a female tamarin that was waiting in hiding comes screeching toward you.
At her alert the others follow suit and soon your being dive-bombed by tamarins from all sides. Your only choice is to flee the scene, but the group is rearing for a chase--even the group’s little infants are getting involved. Thankfully, like all tamarins, you’re fast and small and can easily escape their wrath, but now you must scratch another prospective group off your list, at least for the moment.
Instead of taking off into even farther flung territories you decided to stick it out at this place a bit longer. There must be more groups in the area that aren’t overrun with psychotic females. On one particular day you see to your surprise, not a group of tamarins, but a single pair of females that are foraging discretely on the bananas. Surely they must have been two loners that found solace in each other and they won’t mind a third? WRONG! No sooner did you pop out of the brambles to say hello, than they hollered and screeched at you like everyone else. You stood your ground for sometime thinking perhaps they just don’t understand you, but this only made them angrier and at last they chased you away.
So things are looking grim at the moment, and now you have some tough decisions to make. Do you go home, and risk that your family won’t take you back? Do you pack your bags and move on to another place with friendly tamarins, but run the risk of not finding another food source? Or, do you stick it out at the good food source but keep a low profile?
Every population of tamarins differs in their capacity to disperse. In some areas, dispersal is not very successful at all, and groups will carry on until their oldest members age significantly, which could take almost 15 -20 years. Groups sometimes will be inclined to grow, while in other places, they splinter off when they get to more than a set number of individuals. Sometimes a single tamarin can find its way, but unlike those in a group, this individual must seek out all its food on its own, and must keep an eye out for predators. Gone are the comforting alarm calls, coded with instructions on whether to let go and drop to the ground or to run high up in the trees. Gone is the ability to know if a particular new berry is edible or not – there’s no collective group memory, with one old and wise tamarin with all the answers.
Making it on your own is tough out there. And yet, staying with one’s family means a complete loss of reproductive success. Do all young tamarins disperse? How far do they go? Do they join current groups? If so, which kinds of groups? Or do they have to create their own groups and carve out their own territories within the home ranges of other groups? How many are ever successful? After all, if you are having twins every year, then you’re replacing the young adults who were lost pretty quickly.
Stay tuned to find out some of these answers, as our work with the pichicos continues.