Herons, Egrets and Bitterns oh my!

[Tcg]

.

This isn't based on any serious study, but rather casual observation. I've noticed that herons, egrets and bitterns are widely distributed throughout the world. These types of birds are very similar looking. Here are two specific examples of what I am describing:

Pacific Reef Heron from Figi



Little Blue Heron from North America



How can we explain the wide dispersion of these very similar birds?


Tcg

[The Barbarian]

Well, the easy answer is "allometry." That is relatively faster or slower growth of body parts with change in absolute size.

Small heron....
Dark-crowned night heron


Big heron...
Great blue heron


Absolutely bigger is relatively longer. But it turns out, that has some selective advantage for a waterfowl.

[Purple Knight]

Convergent evolution's fascinating. It's amazing. Crabs. Six times. In the future we'll all be crabs.

That, and intelligence twice. This octopus can think about the shell, that the shell is something it would like to have later on, and it carries it as it goes, taking pains now so that later will be better. Its arms act like their own brains.



Wish I could have resized that.

Now, as for the herons, to be fair, birds may not deliberately fly that far, but they are sometimes caught up in storms and blown that far. It's sometimes how they get to uninhabited islands.