23rd Annual Smithsonian Magazine Photo Contest Wildlife
River Guard
A caiman lays on a sandy riverbank with its mouth wide open to thermoregulate. Temperatures in Brazil's Pantanal can be intensely hot, so the only way cold-blooded reptiles cool down is to enter the water or let heat escape through their open mouths.
Photo Detail
| Date Taken: | 08.2024 |
| Date Uploaded: | 12.2025 |
| Photo Location: | Mato Grosso, Brazil |
| Copyright: | © Rylee Jensen |