What's a hawk chick doing alive in an eagle nursery?

What's a hawk chick doing alive in an eagle nursery?
By Ethan Shaw June 13 2017

Update (June 27, 2017): The red-tailed hawk – who's since been nicknamed "Spunky" – is still quite at home with its adopted eagle family, and according to reports from locals observing the nest, the young bird has now fledged! The hawklet took its first short flight late last week, and was able to make it back to the nest where it was fed by its bald eagle "parents". Read the full story behind this amazing avian "adoption" below – and check back in for updates! Here's a recent video of feeding time at the nest, taken just before Spunky fledged: 

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Exposure to the elements, sudden raids by predators, incompetent (or outright callous) parents, the omnipresent spectre of starvation: any baby bird faces some steep odds in its journey to full-feathered, high-flying adulthood. But one weeks-old red-tailed hawk in British Columbia has managed to beat odds that are both steeper and stranger than usual. How long it can keep doing so, though, remains a very open question.

This spring, bird watchers monitoring a long-used bald eagle nest along the seacoast of Vancouver Island's Saanich Peninsula noticed a strange-looking tenant amid three eaglets: a much smaller nestling identified as a newborn red-tailed hawk. The eagle parents have been feeding the hawklet alongside their own chicks, treating the imposter as a member of the family.

It's an unusual and fraught situation. Eagles and hawks aren't naturally chummy: brooding redtails (and other hawks) defensively harass much larger but less agile bald eagles, which in turn will readily prey on hawk nestlings.

So what's a hawk chick doing alive and (apparently) well in an eagle nursery? We can't say for sure, but local raptor experts suspect the likeliest scenario involves the eagles plundering a redtail nest and hauling some chicks back to their aerie as prey. Perhaps the hawklet in question, still kicking, started gaping for food and triggered the eagles' parental instincts.

Supporting this hunch is the fact that a local nature photographer actually took a picture on May 29 of two hawklets in the eagle nest. That second redtail chick didn't make it – eaten, perhaps, or simply a victim of the harsh, sometimes fratricidal competition common within eagle broods.

The surviving hawklet, though, has proved its mettle so far, successfully vying with its much heftier nest-mates for scraps. "It's quite something to see the way it is treated," Kerry Finley, a caretaker at the Shoal Harbour Migratory Bird Sanctuary where the eagle nest is situated, told the Vancouver Sun. "The parents are quite attentive."

Dr David Bird, retired professor of wildlife biology at McGill University and director of the Hancock Wildlife Foundation that's long kept tabs on this particular aerie, notes that the redtail likely assumes it's an eagle. "That's probably why it's so cocky and has a lot of swagger," he explains. "Because of its spunkiness and aggressiveness, it's been able to survive among those big eaglets."

The hawklet is obviously ascribing to an eagle's diet. "Let me put it this way: it's eating a lot of fish," Bird says. The eagle aerie – occupied for more than a quarter-century – lies in a Douglas-fir tree on Roberts Bay, with easy access to rich fishing and foraging waters in and along Haro Strait. The chick's mostly piscivorous menu isn't exactly typical for its kind, but Bird doesn't expect any long-term issues: red-tailed hawks, after all, are generalist predators up for eating just about anything they can catch and overpower.

Then again, "long term" isn't necessarily in the cards for a hawk in a bald-eagle foster family.

The eaglets hatched at the start of April, and observers estimate the hawklet to be roughly half their age – maybe five weeks old. It would, of course, be outsized regardless of any age disparity. A mature bald eagle may tip the scales at ten pounds or more and sports a wingspan of six or seven feet; an average red-tailed hawk weighs four or five times less. You can see just how much smaller the hawklet is than its nestmates in this recent video of feeding time in the mixed brood:

Impressive as the youngster's ongoing survival literally in the heart of an eagle's nest has been, a perilous period lies ahead. Within the next couple of weeks, the hawklet and its adopted siblings will fledge. They'll leave the nest for longer and longer periods, practicing flight and eventually hunting. Mom and dad will still feed them for perhaps seven to ten days further, Bird explains, but it's something of a free-for-all: the adult eagles may just drop food in the nest, and the fledglings will have to scramble for it. At this stage, eaglets will even aggressively commandeer morsels from incoming parents.

It'll be a real test for the young hawk to muscle its way into this fray – and, as it does so, to avoid looking like dinner to the increasingly big, mobile and mature eaglets. Bird notes that it's also possible the eagle pair will wind down their parental duties before the redtail's adept enough to catch prey on its own.

Should the hawklet survive the trial-by-fire of its upbringing and successfully reach adulthood, Bird is especially intrigued by what sort of path it might take. "The redtail may or may not leave the nest safely," he says, "but if it does, will it try to court a bald eagle or court its own kind?" In other words, will it keep on assuming it's an eagle? (Just keep it away from a mirror.)

Decades ago, Bird and his colleagues conducted experiments into "cross-fostering" among raptors, specifically the little falcons called kestrels. The researchers swapped eggs and babies between American and common (aka European) kestrels, and then tracked their mating preferences as adults: would they shun their own species and romance potential partners belonging to their adopted one? "About 50 percent of them made the wrong choice," Bird notes.

Of course, should this foster-raised redtail try getting fresh with a bald eagle, it's unlikely to get very far. "It will probably be immediately rebuffed, if not killed," Bird says.

Even without self-identity issues and potentially murderous family members, a young raptor has its work cut out for it: about half die within the first year. Those are the cold hard facts, but we probably shouldn't be writing off this spunky red-tailed hawk just yet: it's got the outlook of an eagle, after all.

For the latest updates on the mixed-brood aerie, visit the Hancock Wildlife Foundation website, which maintains a wide variety of live-streaming nest cams (though not for this one).

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Top header image: motox810/Flickr

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