Martita crossed a busy road with her baby clinging to her belly. Her tracking data helped turn that dangerous journey into a new canopy bridge for local wildlife.
Conservation sometimes begins with a dramatic rescue. In Martita's case, it began with a strange radio signal and a few dots appearing on the wrong side of a road.
Martita is a wild brown-throated three-fingered sloth, Bradypus variegatus, monitored by the Sloth Conservation Foundation's Urban Sloth Project in Costa Rica. Researchers fitted her with a VHF collar so they could follow how she navigated a landscape divided by houses, roads, fences and power lines.
What they learned did more than add another route to a map. It identified a dangerous crossing, helped conservationists make the case for a new canopy bridge and eventually showed Martita beginning to use the safer path built from her own data.
The signal that crossed a live road
Researchers first encountered Martita while tracking another sloth. Soon after fitting her collar, they discovered that she was carrying a tiny baby on her belly. The youngster was named Pati.
Months into the monitoring work, Martita's collar began producing signals that seemed unusual. Radio tracking in a built-up landscape is not always simple. Signals can bounce from trees and infrastructure, so the team had to triangulate carefully. Once they resolved the pattern, it led them across a live road.
Martita had crossed at ground level with Pati pressed against her chest. For an animal specialised for life beneath branches, that journey exposed both mother and baby to vehicles, dogs and direct human contact. The crossing was alarming, but it also created something conservation planners need: location-specific evidence of where a safe connection was missing.
Why individual tracking data matters
A general map can show that a road cuts through habitat. Tracking an individual animal shows how that barrier is actually experienced. Martita's movements connected a particular sloth, a particular point on the road and a particular risk.
The Sloth Conservation Foundation had wanted a bridge at the location, but installing one above roadside infrastructure required coordination with the Instituto Costarricense de Electricidad, Costa Rica's national electricity provider. Martita's data made the request concrete. It was no longer simply a claim that wildlife might cross there. A monitored mother sloth had already made the dangerous journey with her baby.
In June 2026, the partners installed canopy bridge SC-398. The structure connected trees above the road, allowing arboreal animals to move without descending into traffic.
The first users arrived within a day
The bridge produced a quick surprise. Within 24 hours, an entire troop of howler monkeys had crossed it. The monkeys continued using the route regularly.
Sloths can take longer to explore a new structure. That is not failure. A cautious animal moving through a familiar home range may need time before a new rope route becomes part of its normal landscape. The team later received a report that a sloth had used SC-398, although they could not confirm that first user was Martita.
Then came the observation everyone had hoped for. Researchers saw Martita using part of the bridge that connected two trees she already visited. She did not cross the whole road on that occasion, but the behaviour still mattered. The foundation's August field update confirmed that the animal whose movements justified the bridge was becoming comfortable with it.
A bridge can help more than one sloth
Martita's story is personal, but SC-398 is not hers alone. Howler monkeys adopted it immediately, another sloth was reported on it, and other female sloths live nearby. Pati is now independent and wears a small research collar of his own, so future monitoring may reveal whether he also uses the crossing.
This is why a wildlife bridge should not be judged only by whether one named animal completes one full crossing. It becomes shared infrastructure in a living landscape. Different species and individuals may approach it at different speeds and use different sections.
Monitoring is essential. Camera traps can reveal which animals use a bridge, when they cross and whether the design is serving the intended route. In an earlier project, the foundation collected more than 6,000 camera-trap images from one sloth crossing, showing how repeated observations can turn a simple rope structure into usable evidence.
What Martita's route teaches us
Urban wildlife conservation is not about pretending roads and buildings will disappear. It is about learning where animals move, identifying the most dangerous gaps and reconnecting habitat in ways that match real behaviour.
Martita helped locate one of those gaps. Her collar documented the risk. Researchers translated that evidence into a practical proposal. A utility provider helped install the bridge. Monkeys tested it almost immediately, and Martita later began to make it part of her own route.
The result is modest compared with restoring an entire forest, but it is specific, measurable and useful. One set of tracking points became a safer connection for a whole neighbourhood of canopy wildlife. That is conservation working at the scale of an individual animal while improving the landscape around her.
Sources and image credit
- The Sloth Conservation Foundation: How One Sloth's Tracking Data Got a Canopy Bridge Built
- The Sloth Conservation Foundation: Tales from the Jungle, August 2026
- The Sloth Conservation Foundation: More than 6,000 camera-trap images from a sloth crossing
Featured image: The Sloth Conservation Foundation, from its report on Martita and canopy bridge SC-398.