# The loud scratch: a newly identified gesture of Sumatran orangutan mothers in the wild

> Research article (Biology Letters, 2019) · cited 15× · AI/ML

**Wikidata**: [openalex:W2957600714](https://www.wikidata.org/wiki/openalex:W2957600714)  
**Source**: https://4ort.xyz/entity/the-loud-scratch-a-newly-identified-gesture-of-sumatran-orangutan-mothers-in-the-wild