Birds
Curve-Billed Thrasher
Toxostoma curvirostre · also called curve-billed thrashers
A curve-billed thrasher navigates its way carefully into the dense spines of a cholla cactus, heading toward a nest tucked deep inside, a location so thoroughly defended by the plant itself that almost nothing else is willing to follow it in.
Overview
The curve-billed thrasher, Toxostoma curvirostre, is a bold, vocal songbird native to desert scrub and cactus habitat across the southwestern United States and much of Mexico. Its long, downcurved bill, unusual habit of nesting inside spiny cholla cactus, and notably aggressive territorial defence make it one of the more distinctive and behaviourally assertive birds of the desert Southwest.
A nursery guarded by spines
By choosing one of the most heavily defended plants in the desert as a nest site, the curve-billed thrasher accepts a personal risk of injury in exchange for a level of protection from predators that few other nesting locations could offer.
Status
Least Concern — widespread and abundant across suitable desert scrub habitat throughout the southwestern United States and much of Mexico.
Curve-Billed Thrasher: common questions
Why does the curve-billed thrasher nest inside a spiny cactus?
Building a nest deep within a spiny cholla cactus provides strong physical protection from most predators, which are deterred or injured trying to reach through the dense spines, and while the thrasher itself must carefully navigate the same sharp spines to access its own nest, the trade-off generally favours the added safety for eggs and young over the risk of injury to the adult birds.
What is the curve-billed thrasher's bill used for?
This species has a notably long, downcurved bill that it uses to probe into soil and sweep through leaf litter, dislodging insects, small invertebrates, and other hidden food items, a specialised foraging tool well suited to searching through the loose desert ground it typically forages on.
How aggressive is the curve-billed thrasher?
This species can be notably bold and aggressive when defending its nest and territory, sometimes directly confronting animals considerably larger than itself that venture too close, a level of defensive assertiveness that is somewhat unusual compared with many other similarly sized desert songbirds.
How can you identify a curve-billed thrasher?
Look for a greyish-brown bird with a long, distinctly downcurved bill and a striking yellow-orange iris, features that together make it fairly straightforward to distinguish from other desert songbirds, combined with its sharp, whistled "whit-wheet" call commonly heard across the desert Southwest.