Tree Swallows in Arizona

Tree Swallows are summer residents in Arizona, arriving shortly before nesting begins in April and leaving after the young are independent. Through the season they feed on flies, mayflies and dragonflies.

Hot Sonoran and Mojave deserts in the south and west, with pine-oak sky islands and the Colorado Plateau rising above 7,000 ft.

Across Arizona, tree swallows typically nest from April–June. Nest site: nest box or tree cavity lined with feathers. Females lay 4–7 eggs, incubate for 11–20 days, and young leave the nest after 15–25 days.

Summer highs above 110°F in Phoenix and Tucson make water the single strongest attractant; the July monsoon triggers a second breeding pulse.

• Have boxes cleaned and mounted before March — tree swallows begin prospecting ahead of egg-laying.
• Use a 1 1/2 in entrance on a 5 × 5 in floor, mounted 5–10 ft.
• Fit a pole baffle or hole guard; ventilation gaps and drainage holes are essential.
• Clean out old nests after each brood and again after June.

Of the regional native plants we track for Arizona, these 8 provide food or cover tree swallows use:

Tree swallows readily take bluebird-style nest boxes; mount boxes in pairs 15–25 ft apart to share with bluebirds.

• Best foods: Crushed eggshells in spring.
• In Arizona's summer: offer water and insect foods; natural food is abundant.

Full diet breakdown for tree swallows · Best feeder for tree swallows