Frigatebirds

 

Much of what the land iguana eat is prickly pear cactus. They grow to great size on these islands and provide shade as well as food for those stuck on the ground.

But if you can fly and need to make a nest, then the scrubby bushes here are a much better choice.

The fellow below is not in a puffed-up "I'm in charge here" kind of mood. His gular sac is just a bit inflated. Maybe he's tired.

Here is a good view of a female frigatebird. She is a little larger than the male but definitely much plainer.