Returning spider monkeys to Belize's forests

As we move into November, we look back over the last year - and what a year it has been! The spider monkeys have been illusive over the last few months - a sighting here, and a glimpse there, but not enough to build a picture of how they have been doing. These fast moving monkeys have been a step ahead of us for most of the post-release, leading the tracking crew into the depths of the tropical forest that cloaks the North East Corridor.

In between tracking the spider monkeys, the team has also been keeping an eye on the howler monkeys, checking on the established troops and most recently, their new wild born babies. Wildtracks has one of the most successful primate reintroduction programmes in the world, with the reintroduction of endangered Yucatan black howler monkeys into Fireburn, an area they disappeared from more than eighty years ago. Sixty five adults have been released in groups over the last seven years - groups formed during the rehabilitation process...and more than fifty young have been born in the wild. This is testament to the fact that confiscated pet monkeys can go back into the wild and live full lives, contributing to successful conservation outcomes. Listening to their howls reverberating around the forest at night brings home the impact a programme such as this can have - re-wilding an area and bringing back the sounds of a species that had disappeared. Fireburn once more echoes with the calls of howler monkeys.

During a recent survey, while watching one of the wild troops, the tracking team noticed a female howler moving fast through the trees with a youngster holding tight to her back... being chased by another female. As they followed the two females deeper into the forest, they heard a shriek...and came across the youngster lying on the ground, with a serious injury to his upper arm. With a obviously broken bone, the team decided that the only option was to bring the tiny baby howler monkey back to the Rehabilitation Centre. 

Now named Mowgli, this youngster was rushed to the vet where he received amazing, almost microscopic surgery on his tiny upper arm. Despite needing a pin and external fixator, this small individual has kept his sense of adventure and exploration, and strolls through life with a great attitude. His injury hasn't held him back, and his recovery has been fast...his arm has healed and he has now joined the nursery troop. He is climbing as well as his troop mates, jumping from branch to branch, showing no signs of being held back by his injury, and is now on his own journey back to the wild.

There was always the question as to how the five spider monkeys would react when the door to freedom was opened - would they run out and disappear in separate directions into the surrounding tropical forest, or would they stay as a group near the enclosure and start exploring their surroundings? The release process in many countries is to carry the spider monkeys in kennels to the release site, then open the kennel doors, often with the monkeys shooting off in different directions, becoming lost and fragmenting the group. Our pre-release process was designed to address this issue, with three months in the release enclosure at the release site, to ensure the Wildtracks monkeys were accustomed to the sites and sounds of the forest they were being released into, to give them a better chance of success.

As we watched, they cautiously emerged from the open trap door, and started exploring the nearest trees, returning to the enclosure for fruit and water, and generally staying together. Charlie, Penny and Mattie enjoyed the fruit of the nearby negrito trees, while Duma and Mel stayed closer to the enclosure, with Duma reluctant to leave the safety of the enclosure roof. Mel started to explore further, returning to the enclosure and Duma at times. The others increased the range of their exploration - on the third day, Penny was tracked down to the middle of a swamp area more than 600m away, high up in an emergent tree, eating flowers buds, before returning to the release site and the rest of the group later that day. 

Not all spider monkeys are ready for the wild. After six days, it was obvious that Duma was not adapting well...she was tracked to a kilometer from the release enclosure, and found on her own...and on the ground. She was encouraged to follow the trackers back to the enclosure, was kenneled, and brought back to Wildtracks. The others, however, pay less and less attention to the trackers, more intent on exploring their environment.

The tracking team are now focused on the remaining four monkeys - on checking how Charlie, Penny, Mattie and Mel are doing, and where they have been roaming since their release. With many thousands of acres of forest, keeping up with them is proving challenging, but post release tracking still continues. The team range through the forest using the receiver to pick up pings from the transmitters, indicating their location. At times there are no signs, then a signal will be picked up, showing the trackers that they are on the right trail. However, the spider monkeys are not making it easy, as they are can travel silently through the canopy and are now moving away from people - excellent behaviour, but also making it harder to pick up their signals.

We are now four months into the post release monitoring. We have passed the $8,000 mark in our appeal, and would like to express our gratitude to all those amazing supporters who have been with us on this project - particularly our recurring donors. You have been instrumental in ensuring that we have the support, backup and operational funding for maintaining our tracking team in the field. Since the release, the team has encountered not only the spider monkeys, but also come face to face with a jaguar, avoided a large herd of white-lipped peccary (the Belize equivalent of wild pigs), watched an ornate hawk eagle soar over the canopy and listened to the howls of well established groups of reintroduced Yucatan howler monkeys, announcing their locations to stake their territories.

As we continue the post-release monitoring, we are entering a somewhat delayed wet season, which will bring changes to the forest and potentially to the areas the spider monkeys use. Thank you for joining us on this adventure!