# Jaguar Density at the Northeastern Limit of Its Distribution in Mexico

## TL;DR

This study estimates jaguar density in northeastern Mexico using camera traps and a new model, providing a baseline for conservation in data-limited areas.

## Contribution

The first application of a random thinning spatial capture–recapture model to jaguar data in Mexico.

## Key findings

- Jaguar density was estimated at 1.29 individuals per 100 km² in the El Cielo–Sierra de Tamalave corridor.
- The random thinning spatial capture–recapture model provided robust density estimates despite low detection rates.

## Abstract

Reliable estimates of population density are essential for the conservation of apex predators such as the jaguar (
Panthera onca
), particularly in peripheral regions of their distribution where existing data are insufficient to guide effective management. In Mexico, northeastern landscapes remain underrepresented in jaguar research, limiting the development of context‐specific conservation strategies. To address this gap, we conducted a camera trap survey in the El Cielo–Sierra de Tamalave biological corridor, a transitional zone located at the northeasternmost limit of the species' range. Over a 91‐day sampling period, we deployed 104 cameras across 52 paired stations and applied a random thinning spatial capture–recapture model (rt‐SCR), which integrates both identified and unidentified photographic detections. This represents the first application of rt‐SCR to jaguar data in Mexico. The model yielded a density estimate of 1.29 (0.93–1.70) individuals per 100 km2, with adequate goodness‐of‐fit across multiple detection metrics. Despite low detection rates, the rt‐SCR framework allowed for robust inference by maximizing data use and mitigates the loss of precision associated with excluding unidentified detections. Our findings provide a baseline for future monitoring in northeastern Mexico and demonstrate the utility of rt‐SCR models in data‐limited contexts. These results support the implementation of localized conservation actions and long‐term monitoring programs in peripheral jaguar habitats, where population viability may depend on maintaining ecological continuity and minimizing anthropogenic pressures.

This study presents the first estimate of jaguar density in northeastern Mexico using a spatial capture–recapture model with random thinning, which incorporates both identified and unidentified camera trap detections. Conducted over 91 days with 104 cameras, the model yielded a density of 1.29 individuals per 100 km2 in the El Cielo–Sierra de Tamalave corridor. The results provide a baseline for monitoring and support conservation efforts in peripheral habitats with limited data availability.