WhenToBird

Oxyura jamaicensis · Anatidae

When Do Ruddy Ducks Arrive in Illinois?

Adult male Ruddy Duck
Photo: Anne Parsons, CC0 1.0 via iNaturalist

Ruddy Ducks are winter birds in Illinois: the first arrive in early October, they are common by the second week of October, peak in early November (5.5% of checklists), and most are gone by late April.

When to look

First arrivalsOct 1-7early October
Common byOct 8-14the second week of October
PeakNov 1-7early November
Most gone byApr 22-30late April

Best: early November. First arrivals early October; most are gone by late April. Peak: on about 5.5% of Illinois checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Mayuncommon
  6. Junrare
  7. Julrare
  8. Augrare
  9. Seprare
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%2%4%6%Jan 1-7: 2.6% of 29700 checklistsJan 8-14: 2.4% of 20189 checklistsJan 15-21: 2.5% of 19784 checklistsJan 22-31: 2.2% of 26641 checklistsFeb 1-7: 2.4% of 20478 checklistsFeb 8-14: 1.9% of 21967 checklistsFeb 15-21: 1.9% of 28735 checklistsFeb 22-28: 3.6% of 24223 checklistsMar 1-7: 4.3% of 26775 checklistsMar 8-14: 4.5% of 27579 checklistsMar 15-21: 5.2% of 27193 checklistsMar 22-31: 5.4% of 42278 checklistsApr 1-7: 4.6% of 34579 checklistsApr 8-14: 3.7% of 38290 checklistsApr 15-21: 3.7% of 39261 checklistsApr 22-30: 2.0% of 59584 checklistsMay 1-7: 1.1% of 60485 checklistsMay 8-14: 0.6% of 59647 checklistsMay 15-21: 0.5% of 43173 checklistsMay 22-31: 0.5% of 47913 checklistsJun 1-7: 0.3% of 31151 checklistsJun 8-14: 0.2% of 27692 checklistsJun 15-21: 0.2% of 23983 checklistsJun 22-30: 0.1% of 28448 checklistsJul 1-7: 0.1% of 21273 checklistsJul 8-14: 0.3% of 19284 checklistsJul 15-21: 0.2% of 17712 checklistsJul 22-31: 0.3% of 24500 checklistsAug 1-7: 0.3% of 18498 checklistsAug 8-14: 0.3% of 19331 checklistsAug 15-21: 0.2% of 19983 checklistsAug 22-31: 0.1% of 31892 checklistsSep 1-7: 0.1% of 26396 checklistsSep 8-14: 0.1% of 25011 checklistsSep 15-21: 0.3% of 23597 checklistsSep 22-30: 0.7% of 30638 checklistsOct 1-7: 1.2% of 23949 checklistsOct 8-14: 2.1% of 24412 checklistsOct 15-21: 3.8% of 22359 checklistsOct 22-31: 5.2% of 29794 checklistsNov 1-7: 5.8% of 21877 checklistsNov 8-14: 5.4% of 19742 checklistsNov 15-21: 5.0% of 18989 checklistsNov 22-30: 4.4% of 23905 checklistsDec 1-7: 3.9% of 16935 checklistsDec 8-14: 3.8% of 16687 checklistsDec 15-21: 2.6% of 20931 checklistsDec 22-31: 2.5% of 29011 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 Illinois 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 Illinois

Best counties

Share of checklists at the peak
  1. Putnam CountyBest late October · 91 checklists that week, 3,333 in all71%
  2. Richland CountyBest early December · 10 checklists that week, 580 in all69%
  3. Moultrie CountyBest the second week of November · 15 checklists that week, 1,367 in all51%
  4. Mason CountyBest the second week of November · 45 checklists that week, 5,020 in all42%
  5. Edgar CountyBest mid November · 13 checklists that week, 914 in all39%
  6. Calhoun CountyBest early March · 14 checklists that week, 786 in all38%

Best spots

Share of checklists at the peak
  1. Carbondale ReservoirJackson County, best the second week of December · 34 checklists that week, 1,735 in all100%
  2. Chautauqua National Wildlife RefugeMason County, best late March · 22 checklists that week, 1,092 in all93%
  3. Lake RenwickWill County, best early April · 20 checklists that week, 582 in all90%
  4. Sue and Wes Dixon Waterfowl Refuge at Hennepin & Hopper LakesPutnam County, best late November · 49 checklists that week, 1,924 in all90%

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

Best time of day

In Illinois, the Ruddy Duck is most often listed on checklists started between 2 and 4 pm (2.9% of those checklists).

0%1%2%3%12 am: too few checklists (484) to judge1 am: too few checklists (631) to judge2 am: too few checklists (485) to judge3 am: too few checklists (610) to judge4 am: too few checklists (2321) to judge5 am: too few checklists (23536) to judge6 am: 1.2% of 95511 checklists7 am: 1.9% of 164584 checklists8 am: 2.1% of 163654 checklists9 am: 2.2% of 141804 checklists10 am: 2.4% of 122882 checklists11 am: 2.5% of 100640 checklists12 pm: 2.4% of 89894 checklists1 pm: 2.6% of 82729 checklists2 pm: 2.8% of 79801 checklists3 pm: 3.0% of 82169 checklists4 pm: 2.5% of 75124 checklists5 pm: 1.7% of 57708 checklists6 pm: 1.1% of 41843 checklists7 pm: too few checklists (20943) to judge8 pm: too few checklists (6131) to judge9 pm: too few checklists (1677) to judge10 pm: too few checklists (843) to judge11 pm: too few checklists (448) 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
January2.6%2.4%2.5%2.2%
February2.4%1.9%1.9%3.6%
March4.3%4.5%5.2%5.4%
April4.6%3.7%3.7%2.0%
May1.1%0.6%0.5%0.5%
June0.3%0.2%0.2%0.1%
July0.1%0.3%0.2%0.3%
August0.3%0.3%0.2%0.1%
September0.1%0.1%0.3%0.7%
October1.2%2.1%3.8%5.2%
November5.8%5.4%5.0%4.4%
December3.9%3.8%2.6%2.5%

Neighboring states

  • Indiana: arrives the second week of October, 1 week later than Illinois
  • Wisconsin: arrives early March, 20 weeks later than Illinois
  • Michigan: arrives early March, 20 weeks later than Illinois
  • Iowa: arrives late September, 1 week earlier than Illinois

Common questions

When do Ruddy Ducks arrive in Illinois?
Ruddy Ducks are winter birds in Illinois: the first arrive in early October, they are common by the second week of October, peak in early November (5.5% of checklists), and most are gone by late April.
When do Ruddy Ducks leave Illinois?
Most Ruddy Ducks have left Illinois by late April, when reports fall below half their usual rate. Stragglers are still reported until early May.
When is the best time to see a Ruddy Duck in Illinois?
The Ruddy Duck is reported most often in early November, on about 5.5% of Illinois checklists.
Where in Illinois are Ruddy Ducks seen most often?
By county, Putnam County, Richland County, and Moultrie County have the highest peak reporting rates for the Ruddy Duck (counties with at least 200 checklists).