Purple Martins in Arizona

Purple Martins are summer residents in Arizona, arriving shortly before nesting begins in April and leaving after the young are independent. Desert subspecies nests in saguaro cavities, not martin houses. Through the season they feed on dragonflies, flies, beetles and moths; flying ants and wasps.

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, purple martins typically nest from April–July. Nest site: in the East, nests almost entirely in human-supplied martin houses and gourds. Females lay 3–6 eggs, incubate for 15–18 days, and young leave the nest after 26–32 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 — purple martins begin prospecting ahead of egg-laying.
• Use a 1 3/4–2 1/8 in round, or starling-resistant crescent (3 × 1 3/16 in) entrance on a 6 × 6 in minimum (6 × 12 in preferred) floor, mounted 10–20 ft on a telescoping pole, 40+ ft from trees.
• Fit a pole baffle or hole guard; ventilation gaps and drainage holes are essential.
• Clean out old nests after each brood and again after July.

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

Purple Martins do not use feeders. Supporting them means supplying correctly built colony housing in the open and managing House Sparrows and starlings.

• Best foods: Crushed eggshells (calcium) offered on a tray near housing.
• Avoid: Seed and suet feeders — martins will not use them.
• In Arizona's summer: offer water and insect foods; natural food is abundant.

Full diet breakdown for purple martins