According to the research I've done so far, Brown Pelicans periodically stretch their gular pouch by putting their heads back and stretching it over their breast. In some cases, they turn their pouch inside out, which is what can be seen in these pictures here. You can see the pink, fleshy inside of the pelican's pouch as he completely inverts it. I thought I'd leave you with at least one presentable picture of the Brown Pelican, looking dapper and smiling. It's the least I can do after intruding on his pouch stretching ritutal! These pelicans we saw relaxing on the abandoned pier at our resort in Cancun, Mexico. The birds enjoyed relaxing and sunning themselves on it. And it made for some easy birdwatching for me!