Hawk Conundrum

One of the most curious sights I’ve had this year took place during our collective October Big Day. While birding some agricultural pastures in the mid-morning, we came upon a beefy-looking raptor standing among the bare beds of a field that was being prepared for planting. The bird stood motionless about two hundred metres away from where I was, but only twenty metres away from the farmers who were toiling under the rapidly climbing sun. To this day, I am still not entirely certain what that bird was.

When I first caught a view of it, my first instinct was to call it as a White-tailed Hawk, which I did, initially, with a moderate degree of confidence. An exciting find, as it is a rarity on Trinidad. However, I began to question that initial identification as I observed the bird more. I don’t have a lot of experience with White-tailed Hawks, having seen them a few times in Guyana and only once before on Trinidad. The other, similarly sized raptor that often shares the same habitat is the much more widespread Savanna Hawk. Both species are civil toward each other, sometimes to a degree that far exceeds one merely tolerating the other.

Every White-tailed Hawk we saw while in Guyana sat on a fencepost. I shunned them all, except this one that sat in delicious light.

Savanna Hawk

Some Savanna Hawks are more rufous than others.

Immature Savanna Hawks are fairly distinctive.

Let me explain: a few years ago a White-tailed Hawk was seen in central Trinidad, this one, however, had underparts that looked as if the bird had a dust bath with powdered red brick. Viewed from above, its dark head and upperparts contrasted sharply with a mostly white tail. From below, one would be swiftly forgiven for calling it as a Savanna Hawk. It follows that it was soon confirmed that this bird was the hybrid offspring between a White-tailed Hawk and a Savanna Hawk.

While I didn’t see that particular individual, earlier this year we ran into another mysterious raptor on Trinidad’s wild Atlantic coast. First seeing it from behind as it stood in a field, its dark head and bulky stature gave me the confidence to suggest White-tailed Hawk. As it flew into a tree nearby, the familiar spectre of doubt grew much more prominent. The more I looked at this bird, the more I leaned towards Savanna Hawk. I began to consider another occurrence of a White-tailed x Savanna Hawk hybrid.

I first saw the long legs of this bird when it alighted on this branch. Interestingly, it chose to fly towards us (below)

Turns out that I was wrong again, as the verdict came back as a back-cross, i.e. the offspring of a White-tailed x Savanna Hawk and a pure Savanna Hawk. Thankfully, that bird gave us excellent views!

This brings me back to the bird I began this piece with. I quickly began considering the possibility of it being another hybrid; I wandered to White-tailed x Savanna Hawk again. The bird was distant, but eventually flew into a tree that I was able to approach close enough to get some decent photos. I returned to the vehicle more confused. The bird was overall fairly dark, with rufous shoulders and a mostly white tail that was neatly tipped black.

I began to question the universe at this point.

I noted the lack of a strong, creamy eyebrow, and pale, thinly barred underparts. The closer I got, the more fervent my self-interrogation became.

Later that morning, we crossed paths with that bird again – this time as it rose on the loose arc of a thermal. It careened over the road directly in front of us; I cursed the wind as I stopped the car in an attempt to get my bins on the bird, and again as I realised I was tangled in the seatbelt. Maddeningly, the bird disappeared by the time I got out. Within a minute, however, we spotted it again. Much more distant this time, but nevertheless we managed to get good looks at it in flight.

I still believe that it may be a White-tailed x Savanna Hawk but I’m incredibly wary of falling into the trap of force-fitting an ID. I simply don’t know enough to say with certainty what this bird was. All this has made me view my only prior sighting of White-tailed Hawk on Trinidad with a healthy degree of suspicion. That was a very distant sighting that never ventured closer to me, and all I could discern was a dark bird, rufous leading edge to the wing, and a white tail. Subtle details to suggest a different ID would be imperceptible at such a distance.

Sadly, this supposed White-tailed Hawk on Trinidad never ventured closer. The doubt began years after this sighting.

Other suggestions included Savanna Hawk and Bay-winged Hawk (some consider it a subspecies of Harris’s Hawk, neither of which I have personally ever seen). What do you think?