Jaguar Density Research Articles

Density of the Near Threatened jaguar Panthera onca in the caatinga of north-eastern Brazil

We report the first estimate of jaguar density in the semi-arid caatinga biome of north-eastern Brazil. During August–October 2007, in the Serra da Capivara National Park, we used camera traps to identify and count jaguars. Jaguar abundance and density were calculated using mark-recapture models. In a sampling effort of 1,249 camera-trap-nights we identified 12 adult jaguars and estimated an abundance of 14 ± SE 3.6 jaguars in an area of 524 km2, i.e. a density of 2.67 ± SE 1.00 jaguars per 100 km2. This estimate is higher than in most other Brazilian biomes and indicates Serra da Capivara National Park as an important reserve for protecting jaguars in north-eastern Brazil.

Critical condition of the jaguar Panthera onca population in Corcovado National Park, Costa Rica

The jaguar Panthera onca is threatened throughout its range and categorized as Near Threatened on the IUCN Red List. To inform conservation of the jaguar population in Corcovado National Park, Costa Rica, population size was estimated using data from a 3-month camera trap study. Individuals were identified from their coat patterns. The resulting density estimate of 6.98 ± SD 2.36 individuals per 100 km2 was lower than expected. The sex ratio was 1.33 males per female, and the minimum home ranges of two males were 25.64 and 6.57 km2. Hunting pressure on jaguar and white-lipped peccaries Tayassu pecari, the jaguar's main prey in the Park, may be responsible for the low jaguar density as space does not seem to be a limiting factor. The numbers of females may have been underestimated because of sampling bias and therefore the sex ratio obtained in this and similar studies must be interpreted cautiously. Better protection of the corridor that connects the Park with other protected areas is essential to guarantee long-term survival of the jaguar in Costa Rica.

The decline of jaguars Panthera onca in the Argentine Chaco

We assessed the distribution and status of jaguar Panthera onca in the Argentine Chaco, one of the least known areas within its range. Current jaguar distribution in the Chaco encompasses parts of central and western Formosa, western Chaco, eastern Salta and north-eastern Santiago del Estero Provinces. Jaguar range was reduced following colonization of the semiarid Chaco even though there has been little deforestation. Jaguars have not been observed over the last 15 years in areas where colonization occurred more than 35 years ago, probably reflecting hunting pressure. Livestock predation is lower now than when the area was first settled in the 1920s. This may indicate low jaguar densities as the livestock management system has not changed. Local people, however, continue to hunt jaguars with the intention of exterminating them. Education, enforcing jaguar hunting laws, increasing control of poaching in protected areas, and creating more protected areas may be the most efficient strategies to preserve the jaguar population of the Argentine Chaco.

Densidad y estructura de una población del Jaguar (Panthera onca) en la Reserva de la Biosfera Calakmul, Campeche, México)

Jaguar density and population structure were estimated in the Calakmul Biosphere Reserve, through the collection and analysis of their tracks. Fieid work was conducted in a 380 km² area in the Southern part of the reserve, where 18 individuáis were estimated present: 6 adult males, 8 adult females, and 4 juveniles. Population density was one jaguar per 24 to 27 km². Also jaguar home range was estimated in 63 to 79 km² for adult mates and 20 to 26 km² for females.