# Monk parakeets ‘test the waters’ when forming new relationships

**Authors:** Claire L. O'Connell, Gerald G. Carter, Annemarie van der Marel, Elizabeth A. Hobson

PMC · DOI: 10.1098/rsbl.2025.0399 · Biology Letters · 2025-11-12

## TL;DR

Monk parakeets gradually build trust with strangers by starting with low-risk interactions before making contact.

## Contribution

This study provides empirical evidence for 'Testing the Waters' in new relationship formation in monk parakeets.

## Key findings

- Stranger dyads were more likely to approach without contact before making contact.
- Strangers who progressed to contact had higher rates of associations than those who never made contact.
- Stranger dyads followed predicted sequences of affiliative behaviors more than familiar dyads.

## Abstract

Initiating and developing social relationships with strangers can provide fitness benefits, but it is an inherently risky process. To mitigate potential risks and develop trust, strangers may ‘test the waters’ by gradually escalating the type of social investment from low-cost to high-cost. Opportunities to capture the moment animals first encounter one another in the wild are rare, and detailed quantitative assessments of when and how animals initiate relationships are limited. We introduced four unfamiliar groups of feral monk parakeets together into a single 22-bird group and observed the sequence of social behaviours that occurred as relationships developed over 22 days. We tested the effect of relationship status (stranger versus familiar) on the probability of dyads following predicted sequences and whether strangers who progressed their relationships maintained higher rates of no-contact proximity compared with dyads that did not. We found that stranger dyads, but not familiar dyads, were more likely to (i) approach each other without contact before making contact and (ii) follow predicted sequences of affiliative behaviours. Strangers that progressed to contact also had higher rates of associations than did birds that never made contact. These findings provide support for ‘Testing the Waters’ during new relationship formation in a socially and cognitively complex species.

## Full-text entities

- **Diseases:** aggression (MESH:D010554)
- **Species:** Psittacidae (parrot, family) [taxon 9224], Homo sapiens (human, species) [taxon 9606], Desmodus rotundus (common vampire bat, species) [taxon 9430], Myiopsitta monachus (monk parakeet, species) [taxon 176066]

## Full text

_Full body text omitted from this summary view._ Fetch the complete paper as Markdown: https://tomesphere.com/paper/PMC12606181/full.md

## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12606181/full.md

## References

54 references — full list in the complete paper: https://tomesphere.com/paper/PMC12606181/full.md

---
Source: https://tomesphere.com/paper/PMC12606181