Birds
Distribution of Birds and Plants at the Western and Southern Edges of the Madrean Sky Islands in Sonora, Mexico
The western and southern edges of the Madrean Sky Island region are poorly defined and have received little study. After exploring mountains in these areas, we documented range extensions and additional records for several species of interest. Although many of these disjunct mountains have not been considered Sky Islands, their flora and fauna are similar to other areas within the region. Therefore, we suggest their biota indicate they require inclusion as part of the Madrean Sky Island region.
rufous-capped warbler
This bold warbler prefers lush thorn-scrub canyons, sometimes in moist canyons dominated by oak. It commonly forages in the understory or even at ground level.
Glaucidium brasilianum cactorum, cactus ferruginous pygmy-owl
The cactus ferruginous pygmy-owl (CFPO) or Glaucidium brasilianum cactorum is a small owl (6.5 inches) that reaches the northern end of its range in southern Arizona. It is locally common in parts of Sonora (especially in the south), but is often very localized to specific habitat requirements.
Northern crested caracara
The northern crested caracara is widespread in Sonora's lower country, including much of the Sonoran Desert, semi-desert grasslands, and thorn-scrub. It is uncommon in Arizona except on the Tohono O'odham Nation and some surrounding country. It nests often in saguaros and occasionally in tall trees. The nest is easily distinguished from other raptor nests because it is made entirely from very fine materials such as grass, never out of sticks or heavier material.
Nesting bald eagles in the southern end of their distribution
This bald eagle nest has been occupied at this spot on the Rio Yaqui for many years. They continue to nest here after the building of the Sahuaripa bridge nearby.
