The summer solstice, commonly known as the longest day of the year, occurs when the tilt of the Earth’s axis is most inclined toward the sun. Animals living in temperate climate zones, like the north Atlantic, are greatly affected by the gradual increase in day length as the weather warms up.
Throughout the Aquarium’s exhibits, experts work to replicate these changes–most notably in the Sea Cliffs exhibit for the Atlantic puffins and other members of the family Alcidae.
Over the past few months, programmable light timers have incrementally adjusted day length in the Sea Cliffs exhibit to mimic the light cycle in the north Atlantic. The use of halogen light bulbs that operate independently from fluorescent light bulbs allow for more intense periods of light when needed.
So just how does this actually trigger reproduction in Atlantic puffins? Light is influential in hormone development, which causes birds to molt into breeding plumage—a contributing factor to reproduction.
The National Aquarium also makes additional environmental changes, including the opening of burrows within an exhibit wall for nesting, to cue the birds to reproduce.
In Sea Cliffs, staff temporarily attaches artificial grasses near burrow openings to simulate live foliage growing among rocks—something birds in wild populations would normally see at breeding time. Birds are also offered nesting material, such as dried corn husks, pine needles, feathers and artificial plants. Recorded sounds from alcid bird colonies are also played to simulate the birds returning to their breeding grounds.
Learn about the Aquarium's puffin hatchlings!