Bird Migration Routes

Illustration by Alden Freed

1.  MOUNTAIN PLOVER: (Charadrius montanus) A short-distance migrant, Mountain Plover is one of only 12 bird species endemic to the Great Plains. They are typically seen in short-grass prairies and are usually associated with prairie dog and pronghorn habitat. In recent years, Mountain Plover have taken to breeding on disturbed soils on agricultural lands. At the Chico Basin Ranch, they breed in very small numbers on the short-grass prairie areas associated with black-tailed prairie dogs. Mountain Plovers winter on agricultural lands in the dry grasslands of California, southern Arizona, and the deserts of northern Mexico. In March and April, they return to breeding grounds before native grasses begin to green.

2.  LARK BUNTING: (Calamospiza melanocorys) Colorado’s State Bird, the sparrow named Lark Bunting, migrates in spring and fall in large flocks often numbering over 100 birds. Occurring nowhere else in the world, Lark Buntings are one of only six passerines endemic to the prairies and shrubsteppe of North America. In the fall, beautiful breeding males molt to cryptic dull browns. They join females and juveniles forming groups wintering south into Texas, Arizona, and the high plateau of northern Mexico where flocks of over 1000 birds wander in search of food. In spring these flocks disperse, moving slowly northward back to the Great Plains to breed.


3.  BURROWING OWL: (Athene cunicularia) Burrowing Owl migration is not straightforward since they depart at different times in the fall based on age and gender. In states that remain warm during winter, Burrowing Owls may not migrate at all since an abundance of insects and rodents are available year-round. On Chico Basin Ranch, Burrowing Owls are exclusively associated with black-tailed prairie dog towns since these ground-nesting owls can’t dig their own burrows. On the Chico, Burrowing Owls arrive from their wintering grounds in New Mexico, Texas, and Mexico in late March into early April and most have begun their fall migration by late September.


4.  BLUE-WINGED TEAL: (Spatula discors) A long-distance and early migrant, Blue-winged Teal leave their breeding grounds long before other waterfowl, some wintering as far south as South America. Typical of dabbling ducks, Blue-winged Teal mate in winter; females frequently returning each year to their natal area. Males are not involved in incubation. They begin wing molt and fall migration well before females, appearing in southern state marshes in August. Because pure juvenile flocks travel together in fall, it is thought that migration routes are instinctive, not learned. In spring, Blue-winged Teal begin to arrive in Colorado fairly late for a duck, in early April.


5.  SANDHILL CRANE: (Antigone canadensis) Sandhill Cranes are the most numerous of the 15 crane species. The two subspecies of migratory Sandhill Cranes, Greater (mostly) and Lesser, pass through the San Luis Valley and therefore in close proximity to the Medano/Zapata Ranch in both the spring (peaking in mid-March) and fall (peaking in mid-October). This large gathering inspired an annual spring crane festival in the San Luis Valley. Some of the Greater Sandhill Cranes migrate north across the Bering Sea to Siberia to breed. It is the spring, staging Sandhill Crane’s loud, vocal, spectacular, and beautiful courtship displays that attract visitors to the increasingly popular crane festivals across the U.S.


6.  BLACKPOLL WARBLER: (Setophaga striata) One of two warbler species to winter in South America’s Amazon Basin, Blackpoll Warblers have interesting migration routes. During spring migration, Blackpoll Warblers become trans-Gulf migrants, flying north from the Yucatan Peninsula over the Gulf of Mexico. A few individuals stop at the Chico Basin Ranch as they continue northbound to breed in stunted coniferous forests. An example of elliptical migration, Blackpoll Warblers’ fall migration route first takes them to the East Coast to refuel, followed by a 2,000 mile, 80-hour non-stop flight over the Atlantic Ocean to South America to winter.

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