Tens of thousands of flamingos live in the Yucatan peninsula year-round, but they change their breeding and nesting locations. The Celestun Biosphere Reserve is their favorite breeding ground, and Ria Lagartos is great for nestling.
The best time to observe large populations of flamingo in Celestun is from December to April. The season in Rio Lagartos runs from March through June when they lay eggs and take care of chicks.
The bird colonies tend to stick together, and the views are really splendid. However, take into account flamingos are extremely shy, so it's better to stay at distance from the pink mass in order not to scare them off. Binoculars and cameras with good zoom will be really useful.
Flamingos remain on their nesting ground till autumn, and then fly back to Celestun.
Rio Lagartos is located in about 65 miles (105km) north of Valladolid. Rio Lagartos means “alligator river”. It's best to hire a boat to explore the lagoon and see flamingoes here. Celestun Bioreserve could be reached by bus from Merida in one hour. Boat tours and private boats for hire are available in Celestun.