Tracking paper wasp posture at the nest
For Andrew Legan's field study of nest-guarding paper wasps, published in Ecology and Evolution, I tracked the posture of wild foundresses on their nests with SLEAP pose estimation.
Andrew Legan’s study asked how a lone northern paper wasp foundress (Polistes fuscatus) behaves after defending her nest from an intruder. At Cornell’s Liddell Field Station in July 2020, each foundress was filmed on her nest for 320 s before, during and after the presentation of a simulated intruder (a pinned wasp) or of a plain wooden dowel. My part was tracking the wasps’ posture in those videos.
What I did
- Pose tracking with SLEAP. I trained a SLEAP model on seven points on each wasp: both antenna tips, the head, the thorax–abdomen bridge, the abdomen tip and both wingtips. The videos were converted to grayscale, and 20 frames of each 320-s interval were labelled by hand.
- SLEAP vs DeepLabCut. In a preliminary analysis the wasps were also tracked with DeepLabCut (ten points). SLEAP did better on these videos, and all of the paper’s measurements come from the SLEAP tracking. The clip at the top shows the same foundress tracked by each.
- Measures from the tracked points: the distance each wasp travelled (head and thorax), the angle between her wingtips (wing extension) and the angle between her antenna tips (antennal separation).
The paper
Legan, A.W.*, Vogt, C.C.*, & Sheehan, M.J. (2023). Postural analysis
reveals persistent changes in paper wasp foundress behavioral state after
conspecific challenge. Ecology and Evolution, 13(9), e10436.
doi:10.1002/ece3.10436
*These authors contributed equally.
Read the paper for what the wasps did and what it means for how they guard their nests.
Thank you to Andrew Legan, who led this study, and to Michael Sheehan.