Hawks in an Eagle Nest

It was a beautiful sunny afternoon on July 9, 2017, and there, perched high in a tree, resplendent in its first coat of feathers, was a male red-tailed hawk. Only four or five feet away was the huge stick nest it had recently fledged from, inhabited by its three nestmates. But this was no ordinary red-tail and these were no ordinary nestmates.

Roll the camera back to early June. A strange thing took place at a bald eagle’s nest right in the suburbs of the small charming town of Sidney, British Columbia, only a five-minute drive down the Patricia Bay highway from my house. I had learned about this nest from David Hancock, a former wildlife cinematographer, founder of the Hancock Wildlife Foundation (HWF), and arguably the top expert in the world on bald eagles. Hancock lives and breathes these birds.

Hancock’s records, which go back several decades, indicated that this particular nest, located about eighty to ninety feet up in a huge Douglas fir right on the shoreline of Roberts Bay, has been active for no less than twenty-five years and is usually successful, often rearing three young, occasionally two, and also failing the odd time.

But this year, there was a new twist. It all began when one of the local folks living within a few yards of the nest tree noticed something odd in the nest. Yes, there were indeed three good-sized, chocolate-brown eaglets, but occasionally popping up its head was a much smaller raptor, about a quarter to a fifth of the size of the eaglets.

The curious observer contacted another neighbor, Kerry Finlay, whose shoreline lot actually bordered the land on which the tree grew. Kerry was an appropriate go-to guy because he is well known as a bird watcher and waterfowl expert in the Sidney area. Aiming his telescope on the nest, he quickly identified the little gaffer as a red-tailed hawk.

It did not take long for David Hancock to hear about it, and within a day or two, he showed up at the nest accompanied by Christian Sasse, a videographer whose star is rising rapidly in the world of natural history and astronomy. Because I have been on the board of directors since HWF’s inception, have studied birds of prey all of my professional life, and live so close to the nest, the two kindly brought me into the picture. It did not take long for this to become international news!

So, let’s get this straight. A baby red-tailed hawk was being raised in the same nest as three young bald eagles. According to Hancock, on June 6, 2017, the eaglets were roughly nine weeks old and the smaller interloper was likely around three weeks.

Then the debates began. How could such a thing have happened? How did it get there in the first place? Can it survive on a diet for bald eagles? What were the chances that the hawk could not only escape being eaten by its larger nest mates but also successfully fledge from the nest? And by “fledge,” I mean making it to a stage of total independence from the parents, not just departing from the nest.

How Could This Have Happened?

Let’s tackle the first question. Red-tailed hawks are not strangers to the Saanich Peninsula. I see them flying over my house up by the Swartz Bay ferry terminal quite commonly, and I am fairly sure that those birds are a nesting pair. Besides those particular birds, I can be certain to see at least one red-tail foraging from a perch on a light standard or a fencepost right along the Pat Bay highway while driving south into Victoria.

Hancock has also observed this species nesting within sight of active bald eagle nests, too. The smaller, more agile red-tails frequently harass the larger, less maneuverable eagles. And if you peruse a list of dietary items on the menu of bald eagles, you will find red-tailed hawk among them. In short, the two species do not like each other.

Not everyone agrees on how the red-tailed nestling got into the bald eagle nest. My first thought was that the hawks had laid eggs in the nest but were chased off by the bald eagles that subsequently incubated the eggs along with their own.

However, bald eagles in our area begin nesting long before red-tailed hawks do and would have taken possession of this nest much earlier. And red-tailed hawks attempting to displace bald eagles from their nest is highly unlikely.

Some believe that one of the eagles captured a female red-tail with an egg in its oviduct and brought it to the nest and that just before it expired, the egg was laid and incubated along with the eagle’s eggs that were at the point of hatching. It is true that many incidences of birds successfully incubating eggs of another species abound in the literature. Just think of cowbirds.

Anyway, this hypothesis is a nonstarter, if only because at one point there had actually been two red-tail nestlings in the nest! Amateur photographers had taken pictures of two fuzzy hawk heads bobbing above the nest edge at the beginning of June. There is no way any raptor would be carrying two eggs in its oviduct at any one time. And red-tailed hawks are not known to be brood parasites, aka egg dumpers.

As for someone physically placing the hawk nestlings in the eagle nest for whatever reason, that scenario is highly implausible, too. The nesting tree, at least 80 feet high, would take a long time to ascend for even an experienced climber, and it is located in a busy neighborhood with many eyes watching. Finally, based on the age of the two downy nestlings, it is inconceivable that they somehow flew to the eagle nest.

So, here’s how this incredible event likely evolved. Being highly opportunistic predators, one or both of the adult bald eagles raided a local red-tail’s nest, possibly even the one in my neighborhood. They grabbed at least two nestlings in their talons and transported them to their nest to feed to their own young. But something amazing transpired!

The two hawklets, not even realizing the danger they were in, began begging for food with open gapes and constant cheeping. The three eaglets in the nest were probably well fed and not really aware of what to do with live food in their nest in any case, and, so, they obviously ignored the begging hawks. The adult eagles were immediately conflicted: Do they kill the tiny hawks to feed them to their own young, or do they start placing morsels of food into their beaks? And here we must avoid the tendency to anthropomorphize this situation.

The decision made by the eagles was strictly hormonally based. There was no emotion involved. We now know that in this particular instance, the hormonal urge to feed begging young simply overrode any desire by the parent eagle to tear the hawklets apart and feed them to their own young. At least that’s the way I see it.

In support of the nest-raiding hypothesis is the fact that this has happened before in other bald eagle nests. Hancock had heard of two other undocumented cases in British Columbia, but, more important, Jim Watson and his colleagues in the Washington Department of Wildlife had actually published an anecdotal note citing at least four similar cases in the June 1993 issue of the Journal of Raptor Research, including an earlier case in a Michigan bald eagle nest published in the journal the year before.

All of the published reports concluded that these cases resulted from non-lethal predation leading to subsequent adoption by the parent eagles. Once the parent eagles attending the Sidney nest had begun feeding the hawk nestlings, they basically formed a parent-nestling bond, which is exceptionally strong in birds of prey.

Many raptor biologists, including myself, have successfully cross-fostered raptor young of one species into the nest of another species in efforts to reintroduce captive-bred raptors into the wild. Raptor rehabilitation centers also often rear different species of hawks under different species of captive mature raptors that show maternal behavior.

How Could the Hawks Survive?

But that’s not the only amazing aspect of this story. It is one thing to be accepted and fed by foster parents but quite another to survive in such a situation. One of the two hawks did indeed perish, its fate unknown. But the remaining bird appeared to thrive. Here we had this pint-sized red-tailed hawk, probably weighing no more than a pound or two, living in a restricted nesting space with not one but three eaglets, each four or five times larger than itself! What would stop any of the three eaglets from suddenly killing and eating the much smaller, weaker hawk in a spate of hunger?

It is also well known that siblicide in eagle nests is quite common, sometimes for food and occasionally out of boredom or bullying. To my mind, two things were at play. First, there was plenty of food being brought in by the parents. Thus, physical aggression among the nestlings was minimal. Second, and I deem this to be equally important, this little hawk certainly had attitude.

It was obvious to me from the start that it was a bold, cocky bird. It essentially thought it was an eagle and it acted like one: a classic case of “little big man complex” in the bird world. Without that aggressive behavior, the hawk would surely not have survived.

I’d seen a similar situation before, back in 1973 in a gyrfalcon’s nest located on the Fosheim Peninsula of Ellesmere Island, about 800 miles south of the North Pole. All four young had hatched, but the last one out was quite late—a runt. I bet against it surviving, if only because every time a parent came to the nest with food, the runt was outmuscled by the three larger nestlings.

If it sat in the back, it was ignored, and if it pushed itself to the front, its taller siblings simply reached over it and grabbed the offered morsels. One day I settled into the blind to find only the three larger young remaining. Whether the weakened runt died from wounds inflicted by the others and was possibly consumed by them, we will never know.

But, I watched this “adopted” hawk at feeding times. When the parents brought in a food item, the larger eaglets immediately commandeered it, moved to the edge of the nest, and mantled it with their wings while swallowing large chunks. The little hawk, to its credit, would run from eaglet to eaglet begging to no avail, and then finally rely on the parents bringing in yet more food to the already satiated eaglets. I also watched it aggressively taking morsels from the female’s beak.

Later on, though, other folks watching the nest observed incidences of the hawk being fed by one of the eaglets, but also witnessed it in turn feeding one of the eaglets! The eaglets actually accepted this strange-looking bird as one of their own. I believe that they benefited from its presence, too, mainly because the hawk, constantly hungry, seemed to do enough begging for all four of them.

So, the big question on everyone’s minds was, would the little hawk survive all odds and safely fledge from the nest? The short answer was yes. At last report, it was out of the nest for about a week, perching nearby and frequently flying into the nest to feed upon items dropped into the nest by the parents.

And what about its diet? Bald eagles are known for surviving on a steady menu of fish. Would this work for a red-tailed hawk? Apparently so. When I last viewed the hawk on July 9, it was not only in extremely good health but also sported beautiful plumage. I was not really surprised.

According to the scientific literature, red-tailed hawks, like bald eagles, are highly opportunistic raptors, eating carrion, snakes, birds, mammals, and even fish. According to Hancock, this particular red-tail was later seen walking on the sand flats by the shoreline, poking in the seaweed for tidbits to eat. It was also observed hanging about local bird feeders.

As with most fledged raptors, it has about a 50 to 60 percent chance of seeing its first birthday. Adult bald eagles tend to just dump food into the nest and otherwise pay little attention to their fledged young: Will this work for a fledged red-tailed hawk? Will it become a successful hunter all on its own? That remains to be seen.

And another question comes to mind, based on my own research into cross-fostering with two captive falcon species in the 1980s. I am one hundred percent certain that this red-tailed hawk thinks that it is indeed a bald eagle. Should it survive to breeding age, I wonder what species it will attempt to court.