ARCTIC Parental Care and Adult Aggression toward Juvenile Snowshoe Hares

ABSTRACT. The early life o the snowshoe hare was studied through observations and experiments involving penned and wild hares. Parental care was limited to the adult female. Her care extended only to lactation nd possibly to some guarding of her offspring. The leverets gathered at the birth/nursing site 1-2 hours after sunset and suckled immediately upon the arrival of the female for 2-5 minutes. The leverets born in the pens gained 17.1 g per day for the Fist 60 days of life. Weaned juveniles caught in the wild were introduced into a pen containing resident adults and juveniles. All 30 introduced juveniles were involved in interactions with residents, both adults and juveniles. The introduced juveniles were involved in and were the losers in more agonistic interactions than were resident juveniles. Similar adult/juvenile and juvenile/juvenile interactions were observed in an unmanipulated wild population of h res, although the residential status of many of the participants was unknown. We concluded that aggression from resident adults and juveniles could lead to spacing behaviour and might therefore affect juvenile recruitment. Key words: Lepus americanus, snowshoe hare, spacing behaviour, dispersal, aggression, lactation &SUMÉ. On a étudié les premiers mois de la vie du libvre d’Amdrique en faisant des observations et des expkiences sur des l i k e s parquCs dans des enclos et sur d’autres vivant B I’ttat sauvage. La femelle adulte dtait seule B s’occuper des petits, et les soins qu’elle leur donnait se limitaient la tétée et peut-être B une certaine surveillance. Les levrauts commençaient B se rassembler au lieu de leur naissance et des t&&s de une B deux heures ap&s le coucher du soleil, et ils tdtaient de 2 B 5 m n, dbs I’arrivbe de la femelle. L s levrauts nds dans les enclos gagnaient 17,l g quotidiennement pendant leurs 60 premiers jours