What's for Dinner? The Diet of the Snowy Owl and Canada Lynx

The Canada Lynx has evolved into a hare-hunting expert. All of it's techniques are uniquely specialized to hunt for snowshoe hares. The most common hunting strategy used is stalking and rushing at their prey. Another strategy is to make an "ambush bed" near commonly used hare trails, and pounce when a hare passes by. Lynx eat fresh-killed prey rather than caching it for later. Hunting is most often done in solitary, but also can be done in mother-kit groups, where one will flush out the prey, and another will kill it. However, this strategy does not always prove to be effective (19). 

The digestive anatomy of the Canada Lynx is typical for felines, and can be modeled by the digestive tract for the domestic cat Felis catus. 46 cm., taken from Stevens& Hume, 1995 (3).

After catching it's prey, the Lynx wil use it's teeth to rip off pieces of meat. It will produce saliva in it's mouth to begin digestion, and then food will enter the esophagus to pass down into the stomach. Chemical digestion occurs in the stomach with it's low pH and many enzymes to digest protein material. Stomach acid of the Lynx is more acidic than that of humans, and can even soften bone. After passing through the stomach, ingested material then moves into the duodenum, where most of the digestion occus when food interacts with bile secreted from the pancreas and liver. The pH is raised and digesiton continues. Amino acids and fats are absorbed in the small intestine, and the rest of the material moves into the large intestine where water reabsorption takes place. After this, the wastes are excreted throgh the rectum and anus. This whole process takes 20 hours (22).

In order to catch prey, the Snowy Owl will hunt late at night or ery early in the morning. They remain motionless perched for several hours during the day, even when accompanied by their young. If food is spotted, it will ambush it by either dropping directly from above, or by gliding down to it and seizing it with one or both feet (24).

The Snowy Owl digestive system has the traditional avian digestive tract. Here is the digestive tract of the Red- Tailed Hawk, 45-65 cm. Buteo Jamaicensis, taken from Stevens& Hume 1995 (2). 

The organs of apprehension in the Snowy Owl are the beak and feet. Food is typically swallowed whole, or chunks are ripped off of the carcass by the beak and feet to ease swallowing. Food then passes down the esophagus, and enters the proventriculus. Unlike most other birds, owls do not have a crop, so food begins chemical digestion right away. Acid digestion of protein material occurs here by enzymes and mucus, and then the food continues onto the ventriculus. The ventriculus is where mechanical digestion occurs. The soft parts of the food are digested by muscular contractions here before passing onto the small intestine, where the liver and pancreas secrete enzymes to further digest the animal material for absorption. Waste products are stored in the cloaca, where the digestive and urinary systems meet, and are excreted through the vent (9). 

After eating, the indigestible material (bones, feathers, fur) still trapped in the gizard are compacted into a pellet, which travels back up to the proventriculus, and ejected 10 hours later. The owl cannot have another meal until the pellet is ejected, since it blocks the digestive tract (9).