WhenToBird

Larus fuscus · Laridae

When Do Lesser Black-backed Gulls Arrive in Iowa?

Adult Lesser Black-backed Gull
Photo: danielarah, CC0 1.0 via iNaturalist

Lesser Black-backed Gulls are winter birds in Iowa: they arrive in mid November, peak in the second week of December (1.1% of checklists), and most are gone by late March.

When to look

First arrivalsNov 15-21mid November
Common byNov 15-21mid November
PeakDec 8-14the second week of December
Most gone byMar 22-31late March

Best: the second week of December. First arrivals mid November; most are gone by late March. Peak: on about 1.1% of Iowa checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marpeak season
  4. Apruncommon
  5. Maynot usually seen
  6. Junnot usually seen
  7. Julnot usually seen
  8. Augnot usually seen
  9. Sepuncommon
  10. Octcommon
  11. Novcommon
  12. Decpeak season

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

0%0.5%1%1.5%2%Jan 1-7: 1.2% of 5551 checklistsJan 8-14: 0.6% of 3498 checklistsJan 15-21: 0.6% of 3803 checklistsJan 22-31: 0.6% of 4807 checklistsFeb 1-7: 0.6% of 3613 checklistsFeb 8-14: 0.9% of 4173 checklistsFeb 15-21: 0.8% of 5796 checklistsFeb 22-28: 1.2% of 4394 checklistsMar 1-7: 0.8% of 5295 checklistsMar 8-14: 0.9% of 5679 checklistsMar 15-21: 0.6% of 5418 checklistsMar 22-31: 0.4% of 8613 checklistsApr 1-7: 0.3% of 6970 checklistsApr 8-14: 0.1% of 7511 checklistsApr 15-21: 0.1% of 8321 checklistsApr 22-30: 0.1% of 11976 checklistsMay 1-7: 0.1% of 11725 checklistsMay 8-14: 0.1% of 12626 checklistsMay 15-21: 0.1% of 9372 checklistsMay 22-31: 0.1% of 10330 checklistsJun 1-7: 0% of 5472 checklistsJun 8-14: 0% of 4568 checklistsJun 15-21: 0% of 3870 checklistsJun 22-30: 0% of 4780 checklistsJul 1-7: 0% of 4201 checklistsJul 8-14: 0.1% of 3605 checklistsJul 15-21: 0% of 3621 checklistsJul 22-31: 0.1% of 5093 checklistsAug 1-7: 0.1% of 3931 checklistsAug 8-14: 0% of 3488 checklistsAug 15-21: 0.1% of 3802 checklistsAug 22-31: 0% of 6293 checklistsSep 1-7: 0.1% of 5328 checklistsSep 8-14: 0.2% of 4622 checklistsSep 15-21: 0.4% of 4367 checklistsSep 22-30: 0.4% of 6086 checklistsOct 1-7: 0.2% of 4708 checklistsOct 8-14: 0.2% of 4791 checklistsOct 15-21: 0.8% of 4429 checklistsOct 22-31: 0.5% of 5633 checklistsNov 1-7: 0.2% of 4090 checklistsNov 8-14: 0.2% of 3416 checklistsNov 15-21: 0.4% of 3398 checklistsNov 22-30: 0.5% of 4679 checklistsDec 1-7: 1.2% of 3442 checklistsDec 8-14: 1.6% of 3322 checklistsDec 15-21: 0.8% of 4619 checklistsDec 22-31: 1.1% of 5113 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 Iowa 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.

Embed this map on your site

Where in Iowa

Best counties

Share of checklists at the peak
  1. Jackson CountyBest mid February · 32 checklists that week, 1,765 in all17%
  2. Wapello CountyBest late December · 13 checklists that week, 654 in all10%
  3. Lee CountyBest early February · 24 checklists that week, 1,488 in all9.5%
  4. Marion CountyBest mid December · 84 checklists that week, 3,389 in all8.0%
  5. Scott CountyBest early February · 186 checklists that week, 11,116 in all8.0%
  6. Polk CountyBest the second week of December · 597 checklists that week, 37,521 in all5.0%

Best spots

Share of checklists at the peak
  1. Mississippi RiverScott County, best the second week of February · 42 checklists that week, 606 in all44%
  2. AY McDonald ParkDubuque County, best mid October · 20 checklists that week, 311 in all35%
  3. Riverfront ParkwayScott County, best late January · 31 checklists that week, 270 in all21%
  4. Saylorville Recreation Area (Camp Dodge)Polk County, best the second week of December · 47 checklists that week, 690 in all21%
  5. Saylorville Recreation Area (Rock Creek)Polk County, best the second week of December · 68 checklists that week, 1,401 in all20%
  6. Saylorville Recreation Area (northwest)Polk County, best mid March · 20 checklists that week, 1,546 in all17%

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

Best time of day

In Iowa, the Lesser Black-backed Gull is most often listed on checklists started between 1 and 3 pm (0.5% of those checklists).

0%0.5%1%12 am: too few checklists (96) to judge1 am: too few checklists (99) to judge2 am: too few checklists (67) to judge3 am: too few checklists (82) to judge4 am: too few checklists (201) to judge5 am: too few checklists (1888) to judge6 am: 0.1% of 11313 checklists7 am: 0.2% of 25717 checklists8 am: 0.3% of 29755 checklists9 am: 0.3% of 28897 checklists10 am: 0.4% of 26343 checklists11 am: 0.4% of 21210 checklists12 pm: 0.4% of 17662 checklists1 pm: 0.5% of 16595 checklists2 pm: 0.4% of 16405 checklists3 pm: 0.5% of 17030 checklists4 pm: 0.4% of 17378 checklists5 pm: 0.4% of 14251 checklists6 pm: 0.2% of 10349 checklists7 pm: 0.1% of 6233 checklists8 pm: too few checklists (2002) to judge9 pm: too few checklists (392) to judge10 pm: too few checklists (186) to judge11 pm: too few checklists (87) 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
January1.2%0.6%0.6%0.6%
February0.6%0.9%0.8%1.2%
March0.8%0.9%0.6%0.4%
April0.3%0.1%0.1%0.1%
May0.1%0.1%0.1%0.1%
June0%0%0%0%
July0%0.1%0%0.1%
August0.1%0%0.1%0%
September0.1%0.2%0.4%0.4%
October0.2%0.2%0.8%0.5%
November0.2%0.2%0.4%0.5%
December1.2%1.6%0.8%1.1%

Neighboring states

  • Illinois: arrives mid October, 4 weeks earlier than Iowa
  • Nebraska: arrives the second week of September, 9 weeks earlier than Iowa
  • Kansas: arrives late September, 7 weeks earlier than Iowa
  • South Dakota: arrives late September, 7 weeks earlier than Iowa

Common questions

When do Lesser Black-backed Gulls arrive in Iowa?
Lesser Black-backed Gulls are winter birds in Iowa: they arrive in mid November, peak in the second week of December (1.1% of checklists), and most are gone by late March.
When do Lesser Black-backed Gulls leave Iowa?
Most Lesser Black-backed Gulls have left Iowa by late March, when reports fall below half their usual rate.
When is the best time to see a Lesser Black-backed Gull in Iowa?
The Lesser Black-backed Gull is reported most often in the second week of December, on about 1.1% of Iowa checklists.
Where in Iowa are Lesser Black-backed Gulls seen most often?
By county, Jackson County, Wapello County, and Lee County have the highest peak reporting rates for the Lesser Black-backed Gull (counties with at least 200 checklists).