During 2007 and 2008, we have established a monitoring program to assess the body condition and health of caribou of the George River and Leaf River herds. We compared the body condition and parasite loads of female-calf pairs in each herd during June (calving) and October-November (weaning). In both years and seasons, we collected the following measurements and samples on female-calf pairs: total body mass (kg), dressed body mass (kg), total length (cm), chest girth (cm), hind foot length (cm), peroneus muscle mass (g), back fat (cm), kidney fat (%), ear sample (for DNA), muscle and fat samples (for isotope analyses), rumen sample, ovaries, femur (marrow fat), mandible, tissues for Besnoitia analysis, blood strips (for blood parasites), visual evaluation of parasites (i.e. warble flies, lung cysts, liver flukes, tænia cysts in muscles) and protein samples (urine, feces, muscle and hair).

In 2007, calves from the George River herd had greater body mass and hind foot length at birth (6.2 ± 0.2kg and 33.2 ± 0.3cm) and at weaning (52.1 ± 1.3kg and 49.5 ± 0.4cm) than those from the Leaf River herd (birth: 5.2 ± 0.2kg and 31.9 ± 0.3cm and weaning: 41.3 ± 1.2kg and 46.2 ± 0.4cm). Adult females from the George River herd were heavier, both at calving (80.4 ± 1.8kg) and at weaning (98.5 ± 1.9kg), than those from Leaf River herd (calving: 73.0 ± 1.8kg and weaning: 88.7 ± 1.8kg), but they did not differ in skeletal size.

In 2008, calves from both herds were of similar body mass and hind foot length at birth (George: 6.1 ± 0.2kg and 32.7 ± 0.3cm and Leaf : 5.8 ± 0.2kg and 33.1 ± 0.3cm), but George River calves were much heavier and larger at weaning (George: 53.1 ± 1.6kg and 49.0 ± 0.5cm and Leaf : 44.2 ± 1.4kg and 47.9 ± 0.3cm). Adult females from the George River herd were slightly heavier, both at calving (83.1 ± 1.5kg) and at weaning (102.1 ± 2.4kg), than those from the Leaf River herd (calving: 73.0 ± 1.8kg and weaning: 97.0 ± 1.8kg), but they did not differ in skeletal size.

During the fall field season (October-November), we also determine an index of recruitment and the reproductive status of satellite-collared females. In falls of 2007 and 2008, the recruitment was low for both the George River herd (2007 : 29.3 calves per 100 females; 2008 : 24.8 calves per 100 females) and the Leaf River herd (2007 :16.7 calves per 100 females; 2008 : 33.4 calves per 100 females).

In fall 2009, the recruitment was estimated at 35 calves per 100 females for the Rivière George herd and 28 calves per 100 females for the Rivière aux Feuilles herd. Adult females from the Rivière George herd were heavier, both at calving (82.2 ± 1.8 kg) and at weaning (100.1 ± 2.5 kg), than those from the Rivière aux Feuilles herd (calving: 75.4 ± 1.6 kg and weaning: 91.3 ± 1.4 kg). Calves from both herds were of similar body mass (Rivière George: 5.8 ± 0.2 kg; Rivière aux Feuilles: 5.4 ± 0.2 kg), but Rivière George calves were much heavier at weaning (Rivière George: 48.2 ± 1.4 kg; Rivière aux Feuilles: 39.3 ± 1.8 kg). Our results suggest great differences in body condition between caribou of both herds.