This bird has just discovered that golf balls bounce on concrete and he's absolutely loving it:

[cab67]

15. They're one of three bird groups that look like that.

The other two are roadrunners and African secretary birds.

Fun and useless fact - these three groups helped a student and I debunk one of the lines of reasoning behind claiming that larger and more "robust" tyrannosaurs were female. This was claimed, in part, because females are usually larger than males in birds of prey. But we showed that the degree of difference depends on feeding mode - females are substantially larger in birds that fly after other birds (e.g. goshawks, sharp-shinned hawks, some falcons), larger but not to a substantial degree in birds that subdue prey on the ground but feed in trees (e.g. most other hawks and eagles, owls), the same size as males in birds that feed on the ground (e.g. Old and New World vultures), and smaller than males in birds that hunt on the ground (e.g. secretary birds, seriemas, roadrunners).

This isn't to say larger tyrannosaurs were necessarily male, but the analogy doesn't work - tyrannosaurs weren't flying after their prey.