Table 1. Juvenile play ethogram.
The frequency of juvenile play and social exploration/affiliation with a novel conspecific was coded using the above working definitions of behaviors. Behaviors initiated by the subject animal over a 10min period for 3d were coded by a blind observer.
| Category | Behavior | Definition |
|---|---|---|
| Play | Aggressive grooming (AG) | one animal violently grabs at the fur of another and grooms, usually in the back region |
| Boxing (B) | both animals stand on the hind legs and use only their forepaws to attack repeatedly | |
| Chasing (C) | active following | |
| Pinning (Pi) | the action of one animal holding another down overhead and the other is typically on its back or supine | |
| Pouncing (Po) | jumping on another animal making contact with forepaws and a common play initiation behavior | |
| Pulling/biting (PB) | mouth to body contact | |
| Supine (Su) | subject on its back, commonly a result of physical attack or pinning or can be independently induced | |
| Wrestling/tackling (WT) | ventrum-to-ventrum embracing with biting without inflicting wounds | |
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| ||
| Social Affiliation/Exploration | Allogrooming (Allo) | received or directed grooming to another subject |
| Genital investigation (GI) | Sniffing or grooming directed towards other animal’s genital region | |
| Huddling (H) | immobilized and in close contact | |
| Sniffing (Sn) | general sniffing the stimulus animal | |
| Social Contact (SC) | passive bodily contact | |