What's for Dinner? The Diet of the Snowy Owl and Canada Lynx
A look into the similar rodent-based diets of the Snowy Owl (Bubo scandiacus) and the Canada Lynx (Lynx canadensis)
Energy Requirements
Information was gathered from Aldama et. al, 1991. (1)
BMR= 486.18 kcal/day
DEE males: 914 kcal/day.
DEE females: 673 kcal/day.
Average energy of Expenditures for...
locomotion: 585 kcal/day male 433 kcal/day female
eating: 69 kcal male 49 kcal female
hunting: 29 kcal male 19 kcal female
Males increase energy in winter months and females don't
Energy needed for gestation is 1.5-1.7x BMR.
Energy needed for lactation is 1.7x BMR
Reproduction energy: 2.6x BMR
Kits are fed by their parents and consume milk for the first 5 months of life. Lynx milk is high in the essential amino acid Taurine.
In housecats, milk is 23% DM, 9% CP, 117 kcal/100 g. DM GE, and 6.4% EE. Kittens consume 8cc's of milk for every ounce they weigh. Newborn Lynx are 6.2-8.3 ounces, so they will consume 56 cc's of milk, which is roughly 60-70 kcal. Feedings are periodically throughout the day, so energy of growth is estimated at roughly 400 kcal/day (18).
What Do I Eat?
The Snowshoe Hare (Lepus Americanus) makes up the majority of the Canada Lynx diet. It was discovered that they are the primary food source in varying amounts ranging from 1/3rd to 100% of the diet (17). In the summer months when snowshoe hare populations are lower, the Canada Lynx is also known to depend on the red ground squirrel (Spermophilus erythrogenys) for food (22).
Energy Values of Common Foods
Canada Lynx, Tom and Pat Leeson, www.Arkive.org (7).
After catching it's prey, it takes 30-50 minutes for the lynx to eat it's hare.
Showshoe hare nutritional values:
DM= 29.7%, 4.7 kcal/gram DM. DE= 83.5% ME=72.7% CP= 70.1%
Per average sized hare, 1218 kcal are eaten , 885 kcal are used metabolically, and 333 kcal are excreted.
In order to keep up with energy expenditure, male lynx need to eat 1.4 hares a day, and females need 0.76 hares per day. The average adult male lynx uses 747 kcal/day when resting 10 hours, travelling 7 km, eating 308 rabbits/year. (18).
Red squirrels are the preferred alternate source of food for the Canada Lynx during the summer months. Nutritional values: provides on average about 1.4 kcal/g. body weight. So, for an average adult weighing 250 g., this provides 350 kcal.
DM= 35.4%, CP= 33%, EE= 24.9%.
An adult male lynx will consume about 3 squirrels each day, which provides 1050 kcal of energy, satisfying the average daily energy expenditure of 914 kcal/day (18).
Canada Lynx Kit, T. Kitchin, and Snowshoe Hare, M. Watson, www.Arkive.org (7)
