Mystery Bird: Tawny Eagle, Aquila rapax

hmmm, well certainly Accipitridae, so I'm going to take a look at African eagles (genus Aquila) first, where there are a number of brown eagles possible...

I think both the Steppe and Tawny can be eliminated because this bird has round nostrils, so we are left with both Spotteds, a juvenile Verreaux's, a Wahlberg's, and the Eastern Imperial...

the gape seems to extend to just past the middle of the eye which should eliminate the Lesser Spotted (the gape on which extends to the back of the eye), and the suggestion of a crest helps eliminate the Greater Spotted, so we seem to be left with three...

a juvenile Eastern Imperial would show light patterning on the wings and tail and an adult an obvious lighter crown and nape...

I wanted to say a juvenile Verreaux's Eagle, Aquila verreauxii, with the light and dark brown plumage I see, but I don't see a black face which several records indicate is characteristic of a juvenile of that species...

which leaves us with the Wahlberg's Eagle, Aquila wahlbergi, where the gape only just reaches the middle of the eye, a slight crest, uniformly brown (although there is a lot of variation within the several morphs) with slightly darker primaries and tail, and with juveniles and adults virtually identical, this could be the one...

I don't see any coconuts, so it must be an unladen African Swallow.

Definitely not a Verreaux's, which has very dark eyes and a lower bill profile. I'll go along with David's ID of a Wahlberg's, but will go further out on the limb to call it a juvenile, because of the pale mantle and facial feathers.

A nice piece of video footage of a Wahlberg's Eagle from Djuma Game Reserve in South Africa

Does anyone know why the Wahlberg got its name? I'm curious because I had a colleague in Helsinki called Wahlberg who's father was a Finnish diplomat, so had been all over the word. I'm wondering if it was named after a relative of his.

Not to make Grrl jealous or anything, but this colleague spent several years living in PNG.

According to Wikipedia:

[Wahlberg's Eagle] is named after the Swedish naturalist Johan August Wahlberg.

Hey Bob,

Johan August Wahlberg was a Swedish naturalist after whom several other species have been named: the Brown-backed Honeybird, Prodotiscus regulus, also known as the Wahlberg's Honeyguide; the Bank Cormorant Phalacrocorax neglectus, also known as Wahlberg's Cormorant; and the Wahlberg's Epauletted Fruit Bat, Epomophorus wahlbergi...

It appears that the Swedish zoologist Carl Jakob Sundevall was the recipient of many of Wahlberg's collected bird specimens (Wahlberg travelled in southern Africa between 1838 and 1856, sending thousands of natural history specimens back to Sweden) and described the eagle, honeybird, and bat- Wahlberg himself described the cormorant in 1855.

While he was exploring the headwaters of the Limpopo River, Wahlberg was killed by a wounded elephant.

I think you'll also find a species from the legume family Fabaceae, Entada wahlbergi, is also named after him, a shrub/tree which is related to the popular sea beans where the large seeds of many Entada species end up washed ashore on beaches- I happen to have a Central American one in front of me right now!

Also a midge species Dolichopus wahlbergi, decsribed by a fellow Swede Johan Wilhelm Zetterstedt in 1843 (in turn, Zetterstedt has his own species of Dolichopus too!), as well as a species of African Saturnid moth, Imbrasia wahlbergi, and the African Flower Mantis, Pseudocreobotra wahlbergi.

and Bob, a couple of other African species such as the southern African Tricolor Scorpion, Opistophthalmus wahlbergi, and a species of brittlestar that inhabits the reefs off the Cape, the Serpent-skinned Brittlestar Ophioderma wahlbergi, can be added to the list!

LOL, David! Wikipedia simply can't keep up with you! (Just goes to show how unreliable that site often is- a colleague of mine entered some great research on the native status of Phragmites and within a couple of days it was refuted because someone looked it up in a 20-year old field guide that no one ever buys!)

I'm going to have to go with an older immature Tawny Eagle on this one. The eye doesn't seem dark, which my (one) reference shows for all ages of Wahlberg's. The lack of barring on the tail and wing feathers are sufficient to rule out any Buteo, or most of the other groups of Afrinca raptors not found here in the US. The date and locale don't leave too many expected options, but Tawny does fit, shows the overall even plumage, yellow eyes in adults, and even the darker scapulars in paler morphs. It's not a true juvenile, because of the slightly paler eyes, very worn flight feathers (look at the tertials), and apparent molt limit in the secondary coverts on the left wing.

Paul,

It certainly looks like a Tawny, however I decided that the nostril shape was all wrong- the one above is round whereas the two Tawny profiles below show the elongated nostril characteristic of that species:

Tawny Eagle profile 1

Tawny Eagle profile 2

Well having perused a zillion South African safari blogs, I think I might have to concede this one!

This morning I was adamant that the nostril was the tell-all but apparently there is some confusion as to whether "round" is actually round and that the "elongated" nostril of a Tawny or Steppe is in fact "oval"!

In the end, virually everyone agreed that plumage could not be considered reliable enough as there are too many variations within either Tawny or Wahlberg's or between various stages of maturity, but what I did find consistent was the mention of the "robustness" of the beak on a Tawny versus a Wahlberg's, and in comparing ours with others, this one does seem more robust...

the second definitive mark was the roundness of the tail, with Wahlberg's tending to be square (more noticeable in flight), with that of a Tawny more rounded- again, reflected in our photo.

Based on those criteria, as well as more obvious shots of nostril shape, it seems very clear that many of the African brown eagles all over the internet, including bona fide raptor organizations, have been misidentified more than a few times!