Grassland birds from South America expanding through Central America
eBirders have been witnessing the expansion of several South American grassland species into and through Central America. These include Pearl Kite (Gampsonyx swainsonii), Savanna Hawk (Buteogallus meridionalis), Long-winged Harrier (Circus buffoni), Yellow-headed Caracara (Milvago chimachima), and Red-breasted Blackbird (Sturnella militaris). Widespread deforestation and cattle ranching, one of the major problems for forest bird species, has nonetheless created possibilities for some opportunist grassland species to disperse and establish new populations.
The Southern Lapwing (Vanellus chilensis), a type of plover in the Charadriidae family, is another good example. This charismatic species has spread north and west from Colombia, colonizing in order Panama (first eBird record 1978), Costa Rica (2000), and Nicaragua (2010). A few birds have made it into Belize (2004), El Salvador (2012), and Honduras (2014) but the species is not yet established in these northern countries.
The Southern Lapwing is not a shy species, and can be detected by its loud alarm calls. It is often found near people. It frequents sports fields, golf courses, cattle pastures, oxidation ponds, and sewage treatment facilities. The lapwing in Central America is not migratory, and colonizing individuals may take up residence for weeks or even years, while they attempt to establish their spreading population. For example, an individual in Belize was observed at Crooked Tree Wildlife Sanctuary from December 2004 until March 2007. Another in Honduras was observed at dairy cattle pens, daily from 23 January until 16 February 2014. eBird is tracking the lapwing’s spread towards Mexico (see the interactive map). We predict it will soon be reported for the first time in Guatemala.
Watch for these species, or other unfamiliar species, that could represent the beginning of a new expansion trend. We encourage birders to share observations of all unusual species by publishing the observations, documented with photos or descriptions in the comments field of your checklists, in eBird.