When do grackles and blackbirds leave Missouri?

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

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

The Brown-headed Cowbird is reported most often in early May, on about 47% of Missouri checklists.

Which grackles and blackbirds are in Missouri?

Brown-headed Cowbird, Red-winged Blackbird, Common Grackle, Eastern Meadowlark, Rusty Blackbird, Bobolink, and Western Meadowlark are reported regularly; the Brown-headed Cowbird is the most common.

7 blackbird species in Missouri

When Do Grackles and blackbirds Arrive in Missouri?

Photo: Nicole, CC BY 4.0 via iNaturalist

Brown-headed Cowbirds, Red-winged Blackbirds, and Common Grackles are the grackles and blackbirds you are most likely to see in Missouri. Brown-headed Cowbirds reach Missouri in mid February, are common by late March, peak in early May (47% of checklists), and most are gone by the second week of July.

When to look

First arrivalsFeb 15-21mid February

Common byMar 22-31late March

PeakMay 1-7early May

Most gone byJul 8-14the second week of July

Best: early May. First arrivals mid February; most are gone by the second week of July. Peak: on about 47% of Missouri checklists.

Janrare
Febrare
Marcommon
Aprpeak season
Maypeak season
Junpeak season
Julcommon
Augrare
Seprare
Octrare
Novrare
Decrare

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

Grackles and blackbirds in Missouri, species by species

Species	First arrivals	Common by	Peak	Most gone by	Peak %
Brown-headed Cowbird	Feb 15-21	Mar 22-31	May 1-7	Jul 8-14	47%
Red-winged Blackbird	Mar 1-7	Mar 1-7	Apr 15-21	Jul 22-31	39%
Common Grackle	Mar 8-14	Mar 8-14	May 22-31	Jul 8-14	36%
Eastern Meadowlark	Mar 1-7	Mar 1-7	Apr 1-7	Jul 15-21	15%
Rusty Blackbird	Nov 1-7	Nov 8-14	Mar 8-14	Apr 8-14	4.2%
Bobolink	Apr 15-21	Apr 15-21	May 8-14	Jul 1-7	2.0%
Western Meadowlark	Oct 8-14	Oct 8-14	Mar 8-14	Apr 8-14	1.1%

Brown-headed Cowbird
Red-winged Blackbird
Common Grackle
Eastern 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 Missouri 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 Missouri

Best counties for Brown-headed Cowbird

Share of checklists at the peak

Randolph CountyBest late May · 20 checklists that week, 838 in all79%
Wright CountyBest late April · 37 checklists that week, 638 in all75%
Moniteau CountyBest the second week of April · 13 checklists that week, 614 in all74%
Miller CountyBest late April · 56 checklists that week, 1,190 in all72%
Lewis CountyBest late April · 34 checklists that week, 1,047 in all71%
Daviess CountyBest mid May · 24 checklists that week, 1,354 in all70%

Common questions

When do grackles and blackbirds arrive in Missouri?: Brown-headed Cowbirds reach Missouri in mid February, are common by late March, peak in early May (47% of checklists), and most are gone by the second week of July.
When do grackles and blackbirds leave Missouri?: Most Brown-headed Cowbirds have left Missouri by the second week of July, when reports fall below half their usual rate. Stragglers are still reported until mid August.
When is the best time to see grackles and blackbirds in Missouri?: The Brown-headed Cowbird is reported most often in early May, on about 47% of Missouri checklists.
Which grackles and blackbirds are in Missouri?: Brown-headed Cowbird, Red-winged Blackbird, Common Grackle, Eastern Meadowlark, Rusty Blackbird, Bobolink, and Western Meadowlark are reported regularly; the Brown-headed Cowbird is the most common.