Jaguar (Panthera onca) density and tenure in a critical biological corridor

Abstract

We estimated jaguar density and tenure, and investigated ranging behavior, using camera traps across the Maya Forest Corridor, a human-influenced landscape in central Belize that forms the only remaining connection for jaguar populations inhabiting two regional forest blocks: the Selva Maya and the Maya Mountain Massif. Jaguars were ubiquitous across the study area. Similar to the neighboring Selva Maya, mean density ranged from 1.5 to 3.1 jaguars per 100 km 2 , estimated by spatial capture-recapture models. Cameras detected almost twice as many males as females, probably reflecting detection bias, and males ranged more widely than females within the camera grid. Both sexes crossed two major rivers, while highway crossings were rare and male-biased, raising concern that the highway could prevent female movement if traffic increases. Jaguars were more transient where the landscape was fragmented with settlements and agriculture than in contiguous forest. Compared with jaguars in the protected forests of the Maya Mountains, jaguars in central Belize displayed a lower potential for investment in intraspecific communication, indicative of a lower quality landscape; however, we did detect mating behavior and juveniles. Tenure of individuals was shorter than in the protected forests, with a higher turnover rate for males than females. At least three-quarters of reported jaguar deaths caused by people were male jaguars, and the majority was retaliation for livestock predation. Jaguars seem relatively tolerant to the human-influenced landscape of central Belize. However, intensification of game hunting and lethal control of predators would threaten population persistence, while increased highway traffic and clear-cutting riparian forest would severely limit the corridor function. Our results show that the viability of the corridor, and thus the long-term survival of jaguar populations in this region, will depend on appropriate land-use planning, nonlethal control of livestock predators, enforcement of game hunting regulations, and wildlife-friendly features in future road developments.

Habitat destruction threatens jaguars in a mixed land use region of eastern Bolivia

“…The results from a radiotelemetry based study estimated a 22-24 month breeding interval for wild jaguars (Carrillo et al, 2009). Our data indicates no mating season in jaguars, which is consistent with previous studies (Cavalcanti & Gese, 2009;Beisiegel et al, 2012;Cavalcanti et al, 2012;Harmsen et al, 2020). The occurrence of females and cubs was concentrated in forested areas, suggesting that these patches provide better conditions to raise offspring than a more disturbed and fragmented environment.…”

“…These results provide further support that unprotected areas with intact natural habitats, especially cattle ranches, represent crucial habitats for jaguars (Arispe et al, 2003;Rumiz et al, 2003;Maffei et al, 2011;Jędrzejewski et al, 2018). Ecological research on jaguars to date has focused on protected areas and only one fifth (27/131) of the available density estimates are derived from unprotected areas (Foster et al, 2020). Density estimates with SECR in small study areas over short time frames require cautious interpretation.…”

“…However, extending survey periods from traditional values of e.g. 90 days to 180 days has been shown to improve precision and stability when estimating densities of longlived mammals across multiple iterations (Dupont et al, 2019;Harmsen et al, 2020). We selected seven overlapping periods of 180 consecutive days in monthly intervals throughout 2019, from the first day of January to July 2019 (Harmsen et al, 2020).…”

“…90 days to 180 days has been shown to improve precision and stability when estimating densities of longlived mammals across multiple iterations (Dupont et al, 2019;Harmsen et al, 2020). We selected seven overlapping periods of 180 consecutive days in monthly intervals throughout 2019, from the first day of January to July 2019 (Harmsen et al, 2020). Two consecutive sessions had a mean overlap of 83.2% which decreased by a mean of 17% for each session in-between.…”

Dietary similarity among jaguars (Panthera onca) in a high-density population

“…Given that the local population sex ratio is considered relatively even [ 37 ], we attribute this male-bias in scats to large-scale differences in ranging behaviour between the sexes and to differential trail use and marking behaviour. Female jaguars are philopatric, whereas males disperse widely and maintain larger ranges, overlapping with both sexes [ 54 , 56 , 73 , 81 , 82 ]. Under such a system, we expect to detect more males than females as males move in and out of the survey area, while the resident females remain [ 53 ].…”