Species at Greatest Risk

Due to decades of trapping for the cage-bird trade, many of North America’s parrots, such as this Yellow-headed Parrot, have disappeared from large parts of their ranges. Although Mexican laws now prohibit the capture of wild parrots, continued illegal capture is still a serious concern for remaining populations.

Photo by Eduardo E. Iñigo-Elias

Species at Greatest Risk of Extinction 

• 44 species at greatest risk

• 5 species already possibly extinct in the wild

• 91% listed under endangered species laws in at least one country

• 73% listed by the IUCN as globally “critically endangered,” “endangered,” or “vulnerable”

This group includes North American species at greatest risk because of severe threats, distributions of less than 80,000 km2, and small, declining global populations. These species occur from the northern United States to southern Mexico, with the greatest number in the highland and Pacific coast regions of Mexico (for details, see Appendix B).

Overlay of year-round distributions for 44 landbird species at greatest risk of extinction.

Most of these species face heightened risk because of their specialization on threatened tropical forest habitats: 25% require tropical deciduous forests; 23% are found in tropical highland forests; and 23% are in tropical evergreen or pineoak forests of Mexico. The remaining species are dependent on specialized conditions in temperate forests (e.g., Kirtland’s Warbler), grasslands (e.g., Sierra Madre Sparrow), aridlands (e.g., Gunnison Sage-Grouse), alpine tundra (Brown-capped Rosy-Finch), coastal saltmarsh (Saltmarsh Sparrow), and freshwater marshes (several endemic yellowthroats).

The primary threat to most of these species is loss of tropical forests in Mexico from unsustainable logging, wood harvesting, clearing for agriculture, and livestock grazing. These threats are particularly severe within high-elevation cloud forests, which support nine of Mexico’s most endangered birds. The primary threat to birds in Mexican pine-oak forests, including Thick-billed and Maroon-fronted parrots, is continued logging of large-diameter trees and catastrophic wildfire. We cannot resolve these threats to habitat unless we address the socio-economic needs in human communities with limited resources.

Urbanization is a threat to at-risk species in a wide range of habitats, from coastal saltmarsh and Texas Hill-country woodlands to high-elevation cloud forests and grasslands in Mexico. Large-scale development of vacation properties threatens to destroy and fragment remaining tropical deciduous forests along Mexico’s Pacific Coast and Yucatan Peninsula. In addition, natural systems modifications, including disruption of natural fire regimes and draining of wetlands, directly threaten nearly one-third of the species most at risk of extinction (see Appendix B for listing of primary threats by species).

	Climate Change Predictions More than 40% of the most at-risk species are vulnerable to habitat changes predicted to occur due to climate change. This is especially true for birds of alpine tundra on mountaintops, such as the Brown-capped Rosy-Finch, and birds restricted to high-elevation cloud forests, such as the Horned Guan. Effects on other species are poorly understood and require further study.
	Images L-R: Dave Krueper, Fulvio Eccardi