WhenToBird

Astur cooperii · Accipitridae

When Do Cooper's Hawks Arrive in Maine?

Adult male Cooper's Hawk
Photo: Shirley Zundell, CC BY 4.0 via iNaturalist

Cooper's Hawks reach Maine in early July, are common by the second week of July, peak in mid September (3.7% of checklists), and most are gone by late February.

When to look

First arrivalsJul 1-7early July
Common byJul 8-14the second week of July
PeakSep 15-21mid September
Most gone byFeb 22-28late February

Best: mid September. First arrivals early July; most are gone by late February. Peak: on about 3.7% of Maine checklists.

  1. Jancommon
  2. Febcommon
  3. Maruncommon
  4. Aprcommon
  5. Maycommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Deccommon

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

0%1%2%3%4%Jan 1-7: 2.0% of 15499 checklistsJan 8-14: 2.1% of 11141 checklistsJan 15-21: 2.1% of 10729 checklistsJan 22-31: 2.0% of 15084 checklistsFeb 1-7: 2.4% of 9403 checklistsFeb 8-14: 1.6% of 11268 checklistsFeb 15-21: 1.4% of 14061 checklistsFeb 22-28: 0.9% of 9977 checklistsMar 1-7: 0.9% of 9649 checklistsMar 8-14: 1.1% of 11781 checklistsMar 15-21: 1.2% of 11613 checklistsMar 22-31: 1.4% of 17798 checklistsApr 1-7: 1.9% of 14638 checklistsApr 8-14: 2.3% of 16511 checklistsApr 15-21: 2.2% of 17164 checklistsApr 22-30: 2.7% of 22602 checklistsMay 1-7: 2.9% of 22556 checklistsMay 8-14: 2.3% of 27842 checklistsMay 15-21: 1.4% of 27748 checklistsMay 22-31: 1.1% of 38715 checklistsJun 1-7: 0.8% of 26916 checklistsJun 8-14: 0.9% of 23737 checklistsJun 15-21: 1.0% of 22733 checklistsJun 22-30: 0.9% of 28248 checklistsJul 1-7: 1.1% of 20290 checklistsJul 8-14: 1.1% of 18534 checklistsJul 15-21: 1.4% of 17319 checklistsJul 22-31: 1.5% of 22815 checklistsAug 1-7: 1.9% of 15004 checklistsAug 8-14: 2.1% of 14603 checklistsAug 15-21: 2.7% of 14972 checklistsAug 22-31: 2.8% of 19813 checklistsSep 1-7: 3.3% of 14567 checklistsSep 8-14: 3.7% of 14520 checklistsSep 15-21: 4.0% of 14339 checklistsSep 22-30: 3.6% of 16879 checklistsOct 1-7: 3.1% of 12959 checklistsOct 8-14: 3.2% of 13168 checklistsOct 15-21: 2.9% of 11184 checklistsOct 22-31: 2.5% of 13717 checklistsNov 1-7: 1.9% of 9823 checklistsNov 8-14: 2.0% of 9007 checklistsNov 15-21: 2.1% of 8528 checklistsNov 22-30: 2.1% of 10228 checklistsDec 1-7: 3.1% of 7505 checklistsDec 8-14: 2.5% of 7982 checklistsDec 15-21: 2.6% of 10455 checklistsDec 22-31: 2.5% of 14285 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 Maine 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 Maine

Best counties

Share of checklists at the peak
  1. York CountyBest the second week of September · 1999 checklists that week, 101,844 in all8.4%
  2. Cumberland CountyBest mid September · 2865 checklists that week, 169,501 in all5.5%
  3. Waldo CountyBest mid September · 618 checklists that week, 33,433 in all4.7%
  4. Sagadahoc CountyBest the second week of December · 177 checklists that week, 21,736 in all3.8%
  5. Androscoggin CountyBest late January · 390 checklists that week, 16,955 in all3.5%
  6. Kennebec CountyBest mid December · 777 checklists that week, 48,185 in all3.4%

Best spots

Share of checklists at the peak
  1. Baxter WoodsCumberland County, best late July · 23 checklists that week, 1,002 in all78%
  2. Bradbury Mountain State ParkCumberland County, best the second week of April · 50 checklists that week, 377 in all51%
  3. Deering OaksCumberland County, best late November · 41 checklists that week, 661 in all27%
  4. Mount AgamenticusYork County, best mid September · 38 checklists that week, 1,103 in all27%
  5. Town Thatch BedYork County, best the second week of September · 20 checklists that week, 440 in all26%

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

Best time of day

In Maine, the Cooper's Hawk is most often listed on checklists started between 6 and 8 am (2.7% of those checklists).

0%1%2%3%12 am: too few checklists (510) to judge1 am: too few checklists (517) to judge2 am: too few checklists (581) to judge3 am: too few checklists (3242) to judge4 am: too few checklists (7221) to judge5 am: 1.8% of 19895 checklists6 am: 2.8% of 54578 checklists7 am: 2.6% of 92775 checklists8 am: 2.4% of 86962 checklists9 am: 2.1% of 78989 checklists10 am: 2.0% of 70954 checklists11 am: 1.8% of 59331 checklists12 pm: 1.8% of 50943 checklists1 pm: 1.7% of 49775 checklists2 pm: 1.7% of 49001 checklists3 pm: 1.6% of 43252 checklists4 pm: 1.5% of 33413 checklists5 pm: 1.4% of 25547 checklists6 pm: 1.3% of 18309 checklists7 pm: too few checklists (14287) to judge8 pm: too few checklists (5336) to judge9 pm: too few checklists (2253) to judge10 pm: too few checklists (1518) to judge11 pm: too few checklists (720) 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
January2.0%2.1%2.1%2.0%
February2.4%1.6%1.4%0.9%
March0.9%1.1%1.2%1.4%
April1.9%2.3%2.2%2.7%
May2.9%2.3%1.4%1.1%
June0.8%0.9%1.0%0.9%
July1.1%1.1%1.4%1.5%
August1.9%2.1%2.7%2.8%
September3.3%3.7%4.0%3.6%
October3.1%3.2%2.9%2.5%
November1.9%2.0%2.1%2.1%
December3.1%2.5%2.6%2.5%

Neighboring states

  • New Hampshire: arrives late June, 1 week earlier than Maine
  • Massachusetts: arrives late August, 7 weeks later than Maine
  • Vermont: arrives mid July, 2 weeks later than Maine
  • Rhode Island: arrives late July, 3 weeks later than Maine

Common questions

When do Cooper's Hawks arrive in Maine?
Cooper's Hawks reach Maine in early July, are common by the second week of July, peak in mid September (3.7% of checklists), and most are gone by late February.
When do Cooper's Hawks leave Maine?
Most Cooper's Hawks have left Maine by late February, when reports fall below half their usual rate.
When is the best time to see a Cooper's Hawk in Maine?
The Cooper's Hawk is reported most often in mid September, on about 3.7% of Maine checklists.
Where in Maine are Cooper's Hawks seen most often?
By county, York County, Cumberland County, and Waldo County have the highest peak reporting rates for the Cooper's Hawk (counties with at least 200 checklists).