Effect of insect harassment on the behaviour of the Rivière George caribou. Arctic 49:375

• Main Authors: Brigitte Toupin, Jean Huot, Micheline Manseau
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1996
• Subjects: Arctic; Rivière George; Rangifer tarandus
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.9080; http://pubs.aina.ucalgary.ca/arctic/Arctic49-4-375.pdf

ABSTRACT. Recent studies on the body condition of females of the Rivière George caribou herd (RGH) in northern Québec have shown that fat reserves declined markedly during the first month of lactation. For many populations of reindeer and caribou, it is widely accepted that insect harassment can affect food intake, energy expenditure, and consequently the accumulation of body reserves. To assess the role of biting and parasitic insects on caribou body condition, we monitored the behaviour and habitat use of RGH females from late June to early August in summers 1992 and 1993. In 1992, biting insect activity started on 27 July, while in 1993, insects were active from 14 July. Oestrids were present on the post-calving range in 1993 only. In both summers, we observed caribou harassed by flies on only four days. When insects were present, harassment reduced the time spent feeding from 53 % to 30%, increased the time spent standing from 1 % to 39%, and modified habitat use towards snow patches. Insect harassment had a significant impact on caribou behaviour, but its contribution to the negative energy balance during the first month of lactation seems negligible. Key words: caribou, Rangifer tarandus, George River, Québec, behaviour, insect harassment, mosquito, oestrid, summer range, habitat selection RÉSUMÉ. Des études récentes sur la condition physique des caribous femelles du troupeau de la Rivière George (TRG) au Québec nordique ont mis en évidence que, durant le premier mois de la lactation, les réserves de lipides diminuent de façon marquée. Il a été démontré, pour plusieurs populations de rennes et de caribous, que le harcèlement par les insectes peut affecter la prise de