October 19, 2009
The summer is ending at the Northern Jaguar Reserve. The vivid green tone of vegetation quickly turned yellow in just a few days; the landscape now looks like autumn. Tom Van Devender and other friends visited the Northern Jaguar Reserve with us this month. We spent several days together throughout the reserve – camping, walking, and registering the plants of one of the most remote areas of Sonora.
Tom and his team are botanical experts. They made an assessment of the reserve’s vegetation and collected a lot of plants that they will send to the University of Sonora herbarium and other foreign herbariums. It was a nice experience; we reviewed our botanical knowledge and learned more about the reserve’s plants thanks to their guidance. During this trip, we also found several surprises in regards to amphibian and reptile species, including some identified previously and others that are new records on the reserve. The new species are the ringneck snake (Diadophis punctatus), lowland burrowing treefrog (Smilisca fodiens), and the barking frog (Craugastor augusti) – the last two were found by Stephen Minter. We also found six amphibian and five reptile species seen previously on the reserve.
We continued the camera-trap work that we do each month. This time we obtained two new jaguar photographs on the Northern Jaguar Reserve. One of them was caught at Dubaral, near Los Pavos, but it was far away from the camera lens and showed its back. Unfortunately we could not determine which individual this was. The other photo was taken at Babisal; this animal seems like a female, but we only obtained one of her sides because that camera-trap station wasn’t paired. This jaguar seems like a different individual, but it also could be the jaguar that was seen here in May.
Carmina traveled to the University of Queretaro this month to work with Carlos López on a serious ecological study of the jaguar population at the Northern Jaguar Reserve and on surroundings properties. Using a mathematical analysis of all the data generated through monitoring this study area during the last 10 years, she was able to obtain mathematical models than explain jaguar detection and colonization probabilities in this region of the Sierra Madre.
To date, there are 99 jaguar photographs in our study area. These photos are from 30 different individuals, of which nine have been detected in 2009. With these analyses, we know that Los Pavos is the region with more jaguar detection probabilities and is the area with more jaguar records. The main factors that contribute to jaguar presence are low human presence, low livestock density, and high vegetation productivity.
These analyses have made it possible to also calculate jaguar density. At this time, the jaguar density at the Northern Jaguar Reserve is approximately one individual/100 square kilometers; the reserve is a total of 180 square kilometers. So we expect to find one or two jaguars dominating the reserve area (maybe Perrito and one other individual); the others we’ve identified may be transient from areas adjacent to the reserve and could also be young jaguars (new births). We intend to formally communicate these results to the scientific community soon at a carnivore meeting and through a scientific paper.
We’ll bring more news for you next month once we’re back from the reserve and checking up on the cameras!
– Carmina & Miguel
Our jaguar guardians, Carmina Gutiérrez and Miguel Gómez Ramírez, have worked at the Northern Jaguar Reserve since October 2008. As the reserve’s resident biologists, Carmina and Miguel patrol lands to keep out poachers, sustain ongoing management of the reserve, maintain a network of motion-triggered cameras, and inventory the ecological health of reserve lands and waters.