WhenToBird

Molothrus ater · Icteridae

When Do Brown-headed Cowbirds Arrive in Rhode Island?

Adult female Brown-headed Cowbird
Photo: Nicole, CC BY 4.0 via iNaturalist

Brown-headed Cowbirds reach Rhode Island in late February, are common by late March, peak in late April (35% of checklists), and most are gone by the second week of July.

When to look

First arrivalsFeb 22-28late February
Common byMar 22-31late March
PeakApr 22-30late April
Most gone byJul 8-14the second week of July

Best: late April. First arrivals late February; most are gone by the second week of July. Peak: on about 35% of Rhode Island checklists.

  1. Jannot usually seen
  2. Febrare
  3. Marcommon
  4. Aprpeak season
  5. Maypeak season
  6. Juncommon
  7. Julcommon
  8. Auguncommon
  9. Seprare
  10. Octrare
  11. Novrare
  12. Decnot usually seen

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

0%10%20%30%40%Jan 1-7: 0.8% of 5678 checklistsJan 8-14: 0.9% of 4004 checklistsJan 15-21: 1.0% of 3691 checklistsJan 22-31: 1.0% of 4738 checklistsFeb 1-7: 1.0% of 3178 checklistsFeb 8-14: 1.5% of 3262 checklistsFeb 15-21: 2.0% of 4286 checklistsFeb 22-28: 2.1% of 3449 checklistsMar 1-7: 3.6% of 3014 checklistsMar 8-14: 5.6% of 3259 checklistsMar 15-21: 9.6% of 3320 checklistsMar 22-31: 15% of 4692 checklistsApr 1-7: 23% of 3280 checklistsApr 8-14: 30% of 3872 checklistsApr 15-21: 33% of 4037 checklistsApr 22-30: 36% of 5595 checklistsMay 1-7: 36% of 5699 checklistsMay 8-14: 31% of 6089 checklistsMay 15-21: 30% of 4937 checklistsMay 22-31: 27% of 5445 checklistsJun 1-7: 26% of 3031 checklistsJun 8-14: 22% of 2793 checklistsJun 15-21: 22% of 2736 checklistsJun 22-30: 20% of 3318 checklistsJul 1-7: 16% of 2629 checklistsJul 8-14: 12% of 2561 checklistsJul 15-21: 8.8% of 2580 checklistsJul 22-31: 7.4% of 3654 checklistsAug 1-7: 4.9% of 2629 checklistsAug 8-14: 5.3% of 2912 checklistsAug 15-21: 4.6% of 2850 checklistsAug 22-31: 4.1% of 4007 checklistsSep 1-7: 4.3% of 2893 checklistsSep 8-14: 2.5% of 2850 checklistsSep 15-21: 2.9% of 2770 checklistsSep 22-30: 3.2% of 3888 checklistsOct 1-7: 3.5% of 3174 checklistsOct 8-14: 3.8% of 3278 checklistsOct 15-21: 3.6% of 3008 checklistsOct 22-31: 3.4% of 3678 checklistsNov 1-7: 2.9% of 3270 checklistsNov 8-14: 2.0% of 3405 checklistsNov 15-21: 1.6% of 2907 checklistsNov 22-30: 1.3% of 3607 checklistsDec 1-7: 1.0% of 2415 checklistsDec 8-14: 1.1% of 2345 checklistsDec 15-21: 0.7% of 2836 checklistsDec 22-31: 0.9% of 4826 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in Rhode Island 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.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

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Where in Rhode Island

Best counties

Share of checklists at the peak
  1. Washington CountyBest late April · 2376 checklists that week, 65,038 in all40%
  2. Kent CountyBest mid April · 544 checklists that week, 16,966 in all36%
  3. Newport CountyBest early June · 418 checklists that week, 33,574 in all34%
  4. Providence CountyBest early May · 1561 checklists that week, 40,898 in all34%
  5. Bristol CountyBest early May · 431 checklists that week, 15,899 in all31%

Best spots

Share of checklists at the peak
  1. Branch RiverProvidence County, best early May · 25 checklists that week, 526 in all83%
  2. Nicholas Farm Management AreaKent County, best mid April · 43 checklists that week, 602 in all76%
  3. Capwell Mill PondKent County, best late April · 40 checklists that week, 975 in all75%
  4. Barden ReservoirProvidence County, best late April · 30 checklists that week, 376 in all72%
  5. Sachuest Point National Wildlife RefugeNewport County, best the second week of June · 47 checklists that week, 3,685 in all69%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Rhode Island, the Brown-headed Cowbird is most often listed on checklists started between 6 and 8 am (19% of those checklists).

0%10%20%30%12 am: too few checklists (42) to judge1 am: too few checklists (58) to judge2 am: too few checklists (45) to judge3 am: too few checklists (69) to judge4 am: too few checklists (319) to judge5 am: too few checklists (3170) to judge6 am: 22% of 10493 checklists7 am: 17% of 17631 checklists8 am: 15% of 18834 checklists9 am: 13% of 17725 checklists10 am: 9.9% of 16696 checklists11 am: 8.4% of 14799 checklists12 pm: 7.4% of 12580 checklists1 pm: 6.7% of 12779 checklists2 pm: 6.6% of 12302 checklists3 pm: 6.9% of 11884 checklists4 pm: 8.2% of 9762 checklists5 pm: 9.6% of 6442 checklists6 pm: 9.9% of 3947 checklists7 pm: too few checklists (2119) to judge8 pm: too few checklists (452) to judge9 pm: too few checklists (105) to judge10 pm: too few checklists (69) to judge11 pm: too few checklists (53) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January0.8%0.9%1.0%1.0%
February1.0%1.5%2.0%2.1%
March3.6%5.6%9.6%15%
April23%30%33%36%
May36%31%30%27%
June26%22%22%20%
July16%12%8.8%7.4%
August4.9%5.3%4.6%4.1%
September4.3%2.5%2.9%3.2%
October3.5%3.8%3.6%3.4%
November2.9%2.0%1.6%1.3%
December1.0%1.1%0.7%0.9%

Neighboring states

  • Massachusetts: arrives early March, 1 week later than Rhode Island
  • Connecticut: arrives mid January, 5 weeks earlier than Rhode Island
  • New Hampshire: arrives early March, 1 week later than Rhode Island
  • Vermont: arrives early March, 1 week later than Rhode Island

Common questions

When do Brown-headed Cowbirds arrive in Rhode Island?
Brown-headed Cowbirds reach Rhode Island in late February, are common by late March, peak in late April (35% of checklists), and most are gone by the second week of July.
When do Brown-headed Cowbirds leave Rhode Island?
Most Brown-headed Cowbirds have left Rhode Island by the second week of July, when reports fall below half their usual rate. Stragglers are still reported until early November.
When is the best time to see a Brown-headed Cowbird in Rhode Island?
The Brown-headed Cowbird is reported most often in late April, on about 35% of Rhode Island checklists.
Where in Rhode Island are Brown-headed Cowbirds seen most often?
By county, Washington County, Kent County, and Newport County have the highest peak reporting rates for the Brown-headed Cowbird (counties with at least 200 checklists).