“Though Ospreys mainly eat live fish of a wide variety of species, the types of prey they might catch are quite diverse. Snakes, birds, frogs, reptiles, mammals, crustaceans, and other invertebrates can all fall prey to the deft, sharp talons of an Osprey.”

Dear RL:

I agree with Dave (although with much less experience!). It’s always interesting and valuable to report observations such as this.

This passage from the osprey account in Birds of the World (Cornell Lab of Ornithology) is relevant:

”
Anecdotal observations of Ospreys with non-fish prey include birds, snakes, voles, squirrels, muskrats (Ondatra zibethica), salamanders, molluscs, and even a small alligator (Alligator mississippiensis; Wiley and Lohrer 1973, Proctor 1977, Thorpe and Boddham 1977, Castrale and McCall 1983, Taylor 1986d, King 1988, Poole 1989a, Pawloski 1996, Watermolen 1996, Douglass 1997, Jennings 2010). An Osprey was observed foraging by walking along the ground and sallying out 2 m to capture ground squirrels (Citrellus sp.; Werren and Peterson 1988). Known to drop conch shells on to hard surface to extract mollusc inside (Jennings 2010).
Some of these reports include non-fish taken in water, probably using
typical foraging techniques (e.g., alligator, muskrat) and emphasizing
the generalist nature of Osprey predation while hunting over water.
Other reports may result from Ospreys trimming their nests with skeletal
remains and thus not represent prey taken (e.g., remains of birds found
in nests in Arabia were up to size of Socotra Cormorant (Phalacrocorax nigrogularis) and Slender-billed Gull (Larus genei), but unclear how or if these were definitely caught by Osprey (Jennings 2010).
Bad weather (high winds, choppy or turbid water) or early arrival on
breeding grounds (when lakes are frozen) may promote such behavior;
e.g., feeding on dead and dying fish tossed on the ice by fishermen in
Georgian Bay of Lake Huron (Ewins and Cousineau 1994).”

Cheers,

Erik

Caldwell, Idaho

The longer I live, the more convinced am I that this planet is used by other planets as a lunatic asylum.  -George Bernard Shaw

Kathy Lopez

Nampa, ID

Cool observation!

I don’t know if there is anything similar in the literature for Ospreys, but having spent much of my career studying raptor foraging ecology, I have noted such surprises reasonably often. 

In a long-term raptor study in Guatemala, for example, long-ago BSU grad student Megan Parker found one pair of Laughing Falcons, which are nearly absolute snake specialists, to take a few fish (they were nesting along a lake shore). I’ve always suspected that “fishy locomotion” appears somewhat similar to serpentine locomotion. This pair also took a huge beetle grub, arguably also somewhat snaky-looking.

In a more surprising case, a Black Hawk-eagle was witnessed eating raccoon feces. This species generally took mostly mammals including nearly half bats, which they brought to nests throughout the day-light hours. Both the diurnal bat-catching (clearly from their roosting sites) and feeding on stationary raccoon feces suggested to us they may have used olfactory cues in foraging. 

Bottom line, even species that are generally dietary specialists tend to behave more opportunistically at times.

You might consider publishing this as a note in one of the bird journals, as it does seem likely this may be fairly uncommon. I wonder if the Osprey account in  Bent’s life histories has anything similar? 

Dave Whitacre

Hey all, RL here.

Got a “poser” for you all.

Setting the scene:

This past Saturday was Global Big Day. Here in Ada Co,. Gary Worthington and I were “birding buds” for the day. Our first stop, 0745, was at the Joplin Rd./Phyllis Slough ebird Hotspot to get the BBPL. It was raining pretty good at the time so we had to remain in Ag, my vehicle (see Periodic Table of Elements).

The pasture was being flood irrigated so there were likely fish in some of the pools, watched a GREG pull out a good-sized one couple days before and choke it down.

Anyway, while we were counting birds/numbers we saw an OSPR swing down and come in low from the back of the field and toward our vehicle. We weren’t sure what was going on, it did not dive for a fish, but, instead snagged a small bird from the ground, continued toward us before veering up, off and away from our stationary vehicle. Three BNST’s came up immediately and went hard after the OSPR but only for a few seconds before turning back. Our suspicion is the OSPR had grabbed a stilt chick as we could see two small bird legs dangling down limply under the OSPR.