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Songbirds Arrive on the Yucatan Peninsula December 5, 1997 "Ya llegaron! Acabo de regresar del manglar donde he ido cada manana y he visto una gran cantidad de nuevas aves que han llegado recientemente. Estan muy cansadas y tienen mucho hambre por su viaje tan largo." dice Maro Berlanga. "They're here! I just got back from the mangrove swamp where I've gone each morning and spotted a host of new species that has recently arrived. They're worn out and hungry after their long trip," reported, Mauro Berlanga research biologist with ProNatura Yucatan in Mexico. Huge numbers of birds have just moved into Mexico, Central and South America, and the Caribbean. Scientists estimate that a grand total of 2 to 5 million individual birds take part in this biannual migration. Species which breed west of the Rocky Mountains spend the winter in northern and western Mexico. Some eastern species travel to the islands of the West Indies and the Caribbean. A few migratory birds fly straight to South America without stopping. The rest, or approximately one-third of the total, migrate to the Yucatan Peninsula, the southern Mexican state of Chiapus and the Peten region of Guatemala. Why do you think such a large percentage of the total number of migratory birds go to the Yucatan? A quick look at a map of the Western Hemisphere should reveal a clue to this question. Migration is hard work. Itís no wonder that birds which fly over the Gulf of Mexico seek out the closest possible destination to land. While it is not an airport, the north coast of the Yucatan Peninsula does serve as one large arrival terminal for huge numbers of birds moving over the Gulf each autumn. Energy to Burn Birds migrating over land from eastern and central regions of Canada and the U.S. to southern Mexico will eventually hit a big hurdle, the Gulf of Mexico. The Gulf covers over 1,000 square km. and has only a few scattered, tiny islands. Upon reaching the Gulf, birds must decide whether to fly around the Gulf, stopping at wood lots along the way, or fly straight over it. For years, ornithologists wondered if those birds which flew over the Gulf made the trip in a non-stop flight. Recently, scientists have used radar systems to detect waves of thousands of birds flying over the Gulf of Mexico. Radar images now confirm that bird migration over the Gulf is indeed a non-stop flight and that the flight takes a total of approximately 20-40 hours depending on the weather. Can you imagine staying in the air for nearly two full days? How do the tiny birds, some weighing less than one ounce, stay airborne for this long to make this extraordinary trip? Energy to fuel migration is stored in little lumps of yellow fat which are found underneath the skin of the bird, on its back, throat, and sides. Fat supplies a lot of energy and it is also very dense. A few grams of fat can be enough to fuel a hummingbird or a warbler for a thousand miles over the Gulf and beyond. Winter Homes The list of migratory bird species which arrive at the Yucatan Peninsula each year includes a staggering 189 species. This does not include resident species, birds which live on the Yucatan all year around. All told, close to 500 migratory and resident species make their home on the Peninsula. The northern coastal region of the Yucatan Peninsula includes many wetland areas which provide rich food supplies for hungry migrants. As birds move southward and inland on the Peninsula, they find scattered forests and open areas providing diverse habitat in which to spread out and establish wintering territories. Some species spend the entire winter on the Yucatan Peninsula while others move southward toward the states of Chiapus and Wahaka in southern Mexico and the Peten region of northern Guatemala. Southern Mexico is extremely important to birds and supports even greater numbers of migratory and resident birds than the Yucatan Peninsula--upwards of 800 species. Just like areas of the U.S. and Canada that attract many different nationalities of peoples, Southern Mexico is at a confluence of migratory pathways. The region is a melting pot for migrants coming to Mexico from western regions of North America, those flying over the Gulf through the Yucatan Peninsula, as well as those traveling from the east following the Texas coast into Mexico. How You Can Help Track Fall's Journey South How You Can Help Track Spring's Journey North