When do grackles and blackbirds leave Arizona?

Most Brown-headed Cowbirds have left Arizona by early August, when reports fall below half their usual rate. Stragglers are still reported until the second week of November.

When is the best time to see grackles and blackbirds in Arizona?

The Brown-headed Cowbird is reported most often in late May, on about 25% of Arizona checklists.

Which grackles and blackbirds are in Arizona?

Brown-headed Cowbird, Red-winged Blackbird, Yellow-headed Blackbird, and Western Meadowlark are reported regularly; the Brown-headed Cowbird is the most common.

4 blackbird species in Arizona

When Do Grackles and blackbirds Arrive in Arizona?

Photo: Nicole, CC BY 4.0 via iNaturalist

Brown-headed Cowbirds, Red-winged Blackbirds, and Yellow-headed Blackbirds are the grackles and blackbirds you are most likely to see in Arizona. Brown-headed Cowbirds reach Arizona in the second week of March, are common by late April, peak in late May (25% of checklists), and most are gone by early August.

When to look

First arrivalsMar 8-14the second week of March

Common byApr 22-30late April

PeakMay 22-31late May

Most gone byAug 1-7early August

Best: late May. First arrivals the second week of March; most are gone by early August. Peak: on about 25% of Arizona checklists.

Janrare
Febrare
Maruncommon
Aprcommon
Maypeak season
Junpeak season
Julpeak season
Augcommon
Sepuncommon
Octuncommon
Novrare
Decrare

Darker months: more checklists report it. Outlined: peak month.

Grackles and blackbirds in Arizona, species by species

Species	First arrivals	Common by	Peak	Most gone by	Peak %
Brown-headed Cowbird	Mar 8-14	Apr 22-30	May 22-31	Aug 1-7	25%
Red-winged Blackbird	all year	–	Mar 15-21	–	15%
Yellow-headed Blackbird	Jun 15-21	Jun 22-30	Sep 8-14	May 8-14	8.2%
Western Meadowlark	Sep 15-21	Sep 22-30	Oct 22-31	Mar 22-31	5.0%

Brown-headed Cowbird
Red-winged Blackbird
Yellow-headed Blackbird
Western Meadowlark

Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in Arizona that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

Where in Arizona

Best counties for Brown-headed Cowbird

Share of checklists at the peak

Santa Cruz CountyBest early July · 1896 checklists that week, 162,726 in all43%
La Paz CountyBest mid May · 124 checklists that week, 7,279 in all36%
Maricopa CountyBest the second week of May · 5935 checklists that week, 269,896 in all35%
Yavapai CountyBest the second week of July · 1053 checklists that week, 83,606 in all33%
Yuma CountyBest the second week of July · 124 checklists that week, 14,687 in all33%
Mohave CountyBest the second week of May · 593 checklists that week, 18,083 in all28%

Common questions

When do grackles and blackbirds arrive in Arizona?: Brown-headed Cowbirds reach Arizona in the second week of March, are common by late April, peak in late May (25% of checklists), and most are gone by early August.
When do grackles and blackbirds leave Arizona?: Most Brown-headed Cowbirds have left Arizona by early August, when reports fall below half their usual rate. Stragglers are still reported until the second week of November.
When is the best time to see grackles and blackbirds in Arizona?: The Brown-headed Cowbird is reported most often in late May, on about 25% of Arizona checklists.
Which grackles and blackbirds are in Arizona?: Brown-headed Cowbird, Red-winged Blackbird, Yellow-headed Blackbird, and Western Meadowlark are reported regularly; the Brown-headed Cowbird is the most common.