I photographed a Great Blue Heron sunning itself on a cool morning last week at the Sequoyah National Wildlife Refuge in Oklahoma. It is neat how they droop their wings like this.
I have observed several different types of birds sunning. Mainly the Turkey and Black Vultures. I will see them basking in the morning before they leave the roost. Double-crested Cormorants are another bird I see sunning a lot.
Great Blue Herons sun different than these birds (besides the drooping of the wings). They face the sun.
I posted a video last year of a Great Blue Heron while it was Gular Fluttering on a hot summer day. It's not hot enough for this behavior yet but I thought I would still share this behavior on this post: Great Blue Heron Gular Fluttering
Great Blue Heron Sunning - Sequoyah National Wildlife Refuge - Oklahoma