Wednesday, December 3, 2014


Hyenas are known to eat anything. However, their food preferences change with the seasonal migrations. For example, during the great wildebeest/zebra migration (about 3 months from July-September) hyenas feast on the traveling creatures with zealous (Cooper et al. 1999).

Roswell looks fat (and dapper!) after gorging on a wildebeest kill.
But, when the wildebeest and zebra start to dwindle, hyenas are back to boring old Tommies (thomson’s gazelle), Topis, and desiccated leftovers (aka that old wildebeest from a month ago.) In the Talek area, the hyenas seem to appreciate beef as a protein source as cow populations increase. Additionally, hyenas occasionally enjoy termites. Apparently they take the advice of your nagging nutritionist: they have a varied diet. One that includes ostrich eggs!

It was a morning obs in October (after the migration), when we plodded along Fig Tree territory searching for a clan that likes to go missing. Suddenly, we noticed a strange sight: hyenas! Also, hyenas chewing on what looked like oval shaped white bones. But, these were not bones...these were eggs laid by the largest bird on earth, the ostrich. (Fun fact: an ostrich egg can weigh up to 1.4 kg! That's 3.08 lbs for all my fellow Americans out there. For comparison a chicken egg weighs 1.5-2.5 oz. Imagine an omelette made from an ostrich egg...but I digress.) Whilst a group of female ostriches watched cautiously nearby, the hyenas attempted to devour the eggs, with little reward shown clearly by the pictures below.

The hyenas were wary of the eggs at first and approached with apprehension.

Mansalow attempts to crack open the egg...

And is quite disappointed with the outer shell's taste.
He tries gentle and cautious chewing, apparently a poor technique to ostrich egg cracking.

He decides to paw it around for a bit, maybe break it open that way.

Embarrassed, Mansalow is caught in his failure.
The hyenas would gently place their mouth around an egg and then attempt to chew softly. It was similar to how I must have looked when I tried to put a whole orange in my mouth (a likewise unsuccessful situation.) Unfortunately, we did not see any of the hyenas break open an egg and taste the yolky goodness of the treasured prize.

It appeared that the hyenas could not get their mouths around the eggs with enough leverage to crack them. Because Crocuta crocuta have an extremely powerful bite force, it seems unlikely that they can’t open an egg due to its durability. Rather the shape may be the tricky part.

It just goes to show that Mara hyenas tend to get a little ansty after the wildebeest leave and may even try vegetarianism.

The lady ostriches were not too happy with the hyenas behavior.

Cooper, S.M., Holekamp, K.E., and Smale, L. (1999). A seasonal feast: long-term analysis of feeding behaviour in the spotted hyaena (Crocuta crocuta.) East African Wild Life Society, Afr. J. Ecol: 37, 149-160.


Anonymous said...

Those pictures of Masalow trying to crack the eggs are now some of my favourites.

Anonymous said...

How come brown hyenas can open the eggs when spotted hyenas can't? According to research from Gus Mills.

Michigan State University | College of Natural Science