# First record of a mixed species association between Hatinh langur (Trachypithecus hatinhensis) and red‐shanked douc (Pygathrix nemaeus)

## TL;DR

This paper reports the first observation of Hatinh langurs and red-shanked doucs associating in the wild, offering new ecological insights.

## Contribution

The first documented mixed species association between Hatinh langurs and red-shanked doucs in the wild.

## Key findings

- Camera-trapping records show a mixed association between Hatinh langurs and red-shanked doucs.
- This association may be linked to ecological or anthropogenic factors.
- The observation contributes to the limited ecological knowledge of these threatened primates.

## Abstract

In primates, mixed species associations are not common occurrences, and have been linked to both ecological and anthropogenic factors. We present camera‐trapping records of a mixed association between two primates, the Hatinh langur (Trachypithecus hatinhensis) and red‐shanked douc (Pygathrix nemaeus) and discuss possible hypotheses for this occurrence. To our knowledge, this is the first evidence of such an association in the wild of these two threatened primates, and thus contributes to our limited ecological knowledge of the species.

In primates, mixed species associations are not common occurrences, and have been linked to both ecological and anthropogenic factors. We present camera‐trapping records of a mixed association between two primates, the Hatinh langur (Trachypithecus hatinhensis) and red‐shanked douc (Pygathrix nemaeus) and discuss possible hypotheses for this occurrence.