Methodology

Scat-detector dog

The use of scat-detector dogs to find jaguar scat is an efficient and non-invasive method to study this cryptic species. As jaguar scats are very hard to find in random searches, it is difficult to collect a significant sample size and conduct a scientific study using scat without the aid of detector dogs. With each scat sample collected it is possible to obtain DNA and thus identify, count and determine the sex of the jaguars from the area surveyed. Additional information can be obtained concerning prey consumed (diet), genetics, reproductive status, stress hormones and sanitary condition (health status). The detector dogs from Jaguaretê Kennel are trained to recognize jaguar scat only. In routine fieldwork the dogs walk about 20 kilometers in search of scat samples. Therefore, with this non-invasive method it is possible to sample large areas in short periods of time.

Live jaguar capture

Depending on the goal of the research it sometimes becomes necessary to capture a free-living jaguar. Three methodologies can be used to capture a live animal. Trained jaguar hounds can track and tree the animal. Also jaguars can be caught in live-cage traps lured with live bait, or caught with a leg snare. Jaguar hounds can be very efficient in areas where jaguars are too shy to enter a trap. Live traps are useful when jaguars are seen near roads or trails which provide access to setting and daily checking of traps. Leg hold snares are more efficiently used near recent jaguar kills. Jaguars are darted with an anesthetic after their physical capture in each of these three methods and biological samples such as blood and urine are collected and a radio-collar is placed on the animal for tracking purposes.

Radio telemetry

Radio Telemetry is a commonly used method to study animal movement, home range and activity patterns. The method uses a VHF radio transmitter and/or a GPS unit affixed to a collar which is placed around an animal’s neck after the animal has been captured alive and anesthetized. The collar battery usually lasts between one and three years. During this time the collar can be located using a radio receiver, providing data on the geographical locations of the animal. Collars that bear a GPS unit use satellites to determine the animal’s geographic location in pre-determined time intervals. These data are stored inside the collar and, depending on the model, can be downloaded remotely. This information is crucial to understand how the jaguar uses the landscape and which areas it prefers or avoids and thus, serves an important role in guiding conservation plans for the species.

Camera trapping

Camera trapping uses a camera connected to a motion and heat sensor that triggers the camera when an animal passes in front of it. Thus, when set along an animal trail this device will take pictures of all animals using this trail. With this technique it is possible to spread several cameras in a determined area and count individual jaguars as each animal has a unique coat pattern. Camera trapping also makes it possible to determine the kind and abundance of other species beside jaguars in the area sampled. It is especially important to investigate and quantify the jaguar’s prey species occurring in the area.