saguaro cactus and bird nest

arizona arms bird birding build cacti cactus close construct construction crook desert ecology eggs hole home lay mojave natural nest nesting open saguaro sonora sonoran spiny territory thorns thorny wildlife wren wrens birding birder home thorned cacti desierto migrant passerine ecological adaptation eco conservation mohave mexico deserted birder nesting home wren cacti spine espinas renew regrow regrowth