EPOW - Ecology Picture of the Week

Shrike With a Helmet

Gray-crested Helmet-shrike (Prionops poliolophus), Family Prionopidae
Lake Nakuru, Kenya

Explanation:  This one is going to take some untangling.

First, where are we?  We are on the shores of Lake Nakuru in the Rift Valley of east Africa, in south central Kenya.  Put a pin in this; the location is a clue.

Second, this is clearly a helmet-shrike, a member of the avian family Prionopidae.  These are noisy birds that often move in social groups.  Well and good.

OK, so which helmet-shrike species is this?  

That's the rub.  

Kenya has five, but only two with crests like this:  the Gray-crested and the White-crested Helmet-shrikes.  And this bird seems to have characteristics of both!  And it's important to know which is which, as we'll see.

So who is this?

The most obvious feature is the crazy head crest.  This bird is sporting a tall gray crest on the back of its head, and a shorter white crest in front.  These are characteristics of the Gray-crested.  But it also has yellow eye "wattles" (extra folding skin), characteristic of the White-crested, whereas the Gray-crested has yellow eyes but no eye wattles.  But the White-crested lacks the broad white wing stripe shown on this bird, that occurs in the Gray-crested, except for a subspecies of White-crested that does have a white wing stripe but that bird has only a small, short white, not a gray, head crest.  

Back to its location:  Lake Nakuru, which is the northern edge of the distribution of the Gray-crested, where it is scarce.  The White-crested generally does not range to Lake Nakuru.  

Finally, this is important for conservation purposes to know which is which, because while the White-crested is a species of "Least Concern", the Gray-crested is listed as "Near Threatened."

So ... tentatively, I'm calling this a Gray-crested Helmet-shrike, but leaving the door open to its being an aberrant individual (mutation), or maybe a hybrid Gray/White-crested, or some other undescribed form.  In fact, hybrids have been observed in the Lake Nakuru area, and along with other threats, hybridization there could be another factor putting the Gray-crested at risk.  

Thanks for taking this journey with me!