Later he explained that the point of his story was to illustrate “how important these raptors can be to small scale organic agriculture.”<\/p>\n
Tom agrees that he was mistaken about the ID of his hawks (Rough-legged Hawks are strict arctic breeders) and I believe there’s a very good chance they were actually Red-tailed Hawks but his story sent me on a quest to see if I could come up with some actual numbers of individual rodents that some raptors eat in the wild (as opposed to in captivity where the numbers would presumably be smaller because of significantly reduced energy demands).<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2019\/02\/rough-legged-hawk-9202b-ron-dudley.jpg\" "\\"rough-legged-hawk-9202b-ron-dudley\\"")
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At first I focused on Roughies because they had been the subject of my conversation with Tom. In my experience Roughies primarily eat voles while they’re “down here” for the winter. This bird almost bit off more than he could chew with this feisty little vole that actually bit the hawk on the right foot. Those little rodent incisors are both nasty and sharp!<\/p>\n
So how many rodents do Roughies actually eat? The Cornell Lab of Ornithology has this to say on the subject:<\/p>\n
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- “Nonbreeding adults eat about a quarter-pound of food daily, or a tenth of their body mass – that\u2019s about 5 small mammals. Nestlings start feeding themselves (swallowing lemmings whole) at about 16 days old. It\u2019s estimated that a brood of 2 nestlings requires 26 pounds of food during the 40 days between hatching to fledging.”<\/em><\/li>\n<\/ul>\n
Various vole and mouse species average about 1 oz. in weight (lemmings in the arctic weigh a little more) so if you do the math every adult Roughie eats 4-5 small mammals every day (about 1460 annually) and two nestlings consume roughly 278 rodents in only their first 40 days. Clutch size is usually 3-5 eggs so the actual number of rodents consumed by nestlings is often much larger.<\/p>\n
That’s a lot of rodents to bite the dust originating from only a single breeding pair of Rough-legged Hawks! But Roughies aren’t here in the breeding season so what about other raptor species that are here in the summer or year around?<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2014\/09\/red-tailed-hawk-6764-ron-dudley.jpg\" "\\"red-tailed-hawk-6764-ron-dudley\\"")
<\/p>\nRed-tailed Hawks are voracious consumers of rodents and they’re here all year long, including breeding season. This one already had an enlarged crop from an earlier meal when I photographed it with yet another vole in its talons. I see red-tails eating voles and mice far more often than I see them eating anything else.<\/p>\n
The Red-tailed Hawk is our most common, widespread, and well-known hawk and it’s larger than the Rough-legged Hawk so it seems logical to assume that they eat at least as many small mammals as Roughies do.<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2015\/06\/red-tailed-hawk-9180-ron-dudley.jpg\" "\\"red-tailed-hawk-9180-ron-dudley\\"")
<\/p>\nHere the male adult of a breeding pair of Red-tailed Hawks in Montana has just delivered a vole to his hungry chicks as his slightly larger mate looks on. It would take a lot of rodents to keep the ravenous youngsters satisfied through and even past fledging.<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2016\/04\/swainsons-hawk-9299-ron-dudley.jpg\" "\\"swainsons-hawk-9299-ron-dudley\\"")
<\/p>\nMany other species of buteos consume rodents also, including Swainson’s Hawks in summer. This Swainson’s is trying to avoid being bitten.<\/p>\n
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In addition to the buteos (soaring hawks) many other species of raptors prey on large numbers of rodents including some falcons and many owls. A single Barn Owl can consume about 1,500 rodents per year and a family of Barn Owls can prey on up to 25 rodents each and every night. No barn cat can even come close to those numbers.<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2014\/02\/short-eared-owl-7293b-ron-dudley.jpg\" "\\"short-eared-owl-7293b-ron-dudley\\"")
<\/p>\nShort-eared Owls consume vast quantities of rodents.<\/p>\n
Red-tailed Hawks, Swainson’s Hawks and Ferruginous Hawks are found in large numbers on our Montana family farm, especially during migration and the breeding season. They help immensely in keeping our ubiquitous Richardson’s Ground Squirrels (gophers) under control. Gophers can literally wipe out many acres of wheat and barley in the spring and early summer. And the Great Horned Owls living in our many old granaries are prolific consumers of both gophers and mice living in those old, mostly abandoned buildings.<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2020\/01\/american-kestrel-4573-ron-dudley.jpg\" "\\"american-kestrel-4573-ron-dudley\\"")
<\/p>\nSome of the falcons are also efficient rodent killers. This male American Kestrel, our smallest falcon, is about to chow down on a vole.<\/p>\n
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![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2017\/07\/prairie-falcon-5873.jpg\" "\\"prairie-falcon-5873")
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