WhenToBird

Anser rossii · Anatidae

When Do Ross's Geese Arrive in California?

Adult Ross's Goose
Photo: Andrew Cannizzaro, CC BY 4.0 via iNaturalist

Ross's Geese are winter birds in California: they arrive in early November, peak in the second week of January (1.0% of checklists), and most are gone by early March.

When to look

First arrivalsNov 1-7early November
Common byNov 1-7early November
PeakJan 8-14the second week of January
Most gone byMar 1-7early March

Best: the second week of January. First arrivals early November; most are gone by early March. Peak: on about 1.0% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Mayrare
  6. Junrare
  7. Julnot usually seen
  8. Augnot usually seen
  9. Seprare
  10. Octuncommon
  11. Novpeak season
  12. Decpeak season

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

0%0.5%1%1.5%Jan 1-7: 1.0% of 112336 checklistsJan 8-14: 1.0% of 85518 checklistsJan 15-21: 1.0% of 86488 checklistsJan 22-31: 0.9% of 116174 checklistsFeb 1-7: 0.8% of 75171 checklistsFeb 8-14: 0.6% of 84467 checklistsFeb 15-21: 0.5% of 105683 checklistsFeb 22-28: 0.6% of 83396 checklistsMar 1-7: 0.5% of 77470 checklistsMar 8-14: 0.4% of 75180 checklistsMar 15-21: 0.3% of 80770 checklistsMar 22-31: 0.2% of 114116 checklistsApr 1-7: 0.1% of 84057 checklistsApr 8-14: 0.1% of 83692 checklistsApr 15-21: 0.1% of 89242 checklistsApr 22-30: 0.1% of 114289 checklistsMay 1-7: 0.1% of 85728 checklistsMay 8-14: 0.1% of 91984 checklistsMay 15-21: 0.1% of 75478 checklistsMay 22-31: 0.1% of 106250 checklistsJun 1-7: 0.1% of 70051 checklistsJun 8-14: 0.1% of 67485 checklistsJun 15-21: 0.1% of 66269 checklistsJun 22-30: 0.1% of 79172 checklistsJul 1-7: 0.1% of 62877 checklistsJul 8-14: 0.1% of 60328 checklistsJul 15-21: 0.1% of 59705 checklistsJul 22-31: 0.1% of 83796 checklistsAug 1-7: 0.1% of 60215 checklistsAug 8-14: 0.1% of 60172 checklistsAug 15-21: 0.1% of 59877 checklistsAug 22-31: 0.1% of 89107 checklistsSep 1-7: 0.1% of 72000 checklistsSep 8-14: 0.1% of 71228 checklistsSep 15-21: 0.1% of 76808 checklistsSep 22-30: 0.1% of 100204 checklistsOct 1-7: 0.1% of 76571 checklistsOct 8-14: 0.1% of 80874 checklistsOct 15-21: 0.1% of 74581 checklistsOct 22-31: 0.3% of 97498 checklistsNov 1-7: 0.4% of 70851 checklistsNov 8-14: 0.6% of 72431 checklistsNov 15-21: 0.8% of 66767 checklistsNov 22-30: 0.9% of 94737 checklistsDec 1-7: 1.0% of 65393 checklistsDec 8-14: 0.8% of 67449 checklistsDec 15-21: 0.7% of 83421 checklistsDec 22-31: 0.9% of 124993 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 California 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 California

Best counties

Share of checklists at the peak
  1. Colusa CountyBest late November · 251 checklists that week, 7,653 in all39%
  2. Glenn CountyBest late November · 230 checklists that week, 5,189 in all24%
  3. Merced CountyBest the second week of January · 337 checklists that week, 13,095 in all17%
  4. Imperial CountyBest the second week of January · 778 checklists that week, 24,551 in all16%
  5. Sutter CountyBest early January · 169 checklists that week, 4,996 in all9.6%
  6. Butte CountyBest mid November · 507 checklists that week, 33,693 in all7.4%

Best spots

Share of checklists at the peak
  1. Santa Fe Dam Recreation AreaLos Angeles County, best the second week of January · 43 checklists that week, 1,659 in all75%
  2. Colusa National Wildlife RefugeColusa County, best late November · 95 checklists that week, 1,370 in all74%
  3. Colusa National Wildlife Refuge (Powell Slough)Colusa County, best mid November · 23 checklists that week, 795 in all73%
  4. Merced National Wildlife RefugeMerced County, best the second week of January · 24 checklists that week, 667 in all73%
  5. Merced National Wildlife Refuge (northeast)Merced County, best the second week of February · 21 checklists that week, 516 in all65%
  6. Fairbanks Country Club Open SpaceSan Diego County, best the second week of January · 27 checklists that week, 339 in all57%

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

Best time of day

In California, the Ross's Goose is most often listed on checklists started between 1 and 3 pm (0.5% of those checklists).

0%0.5%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 0.3% of 186053 checklists7 am: 0.3% of 444086 checklists8 am: 0.3% of 535846 checklists9 am: 0.3% of 486061 checklists10 am: 0.4% of 411130 checklists11 am: 0.4% of 325798 checklists12 pm: 0.4% of 269132 checklists1 pm: 0.5% of 244762 checklists2 pm: 0.5% of 235420 checklists3 pm: 0.5% of 232365 checklists4 pm: 0.4% of 208688 checklists5 pm: 0.1% of 146104 checklists6 pm: 0.1% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) 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
January1.0%1.0%1.0%0.9%
February0.8%0.6%0.5%0.6%
March0.5%0.4%0.3%0.2%
April0.1%0.1%0.1%0.1%
May0.1%0.1%0.1%0.1%
June0.1%0.1%0.1%0.1%
July0.1%0.1%0.1%0.1%
August0.1%0.1%0.1%0.1%
September0.1%0.1%0.1%0.1%
October0.1%0.1%0.1%0.3%
November0.4%0.6%0.8%0.9%
December1.0%0.8%0.7%0.9%

Neighboring states

  • Nevada: arrives mid November, 2 weeks later than California
  • Idaho: arrives the second week of February, 13 weeks later than California
  • New Mexico: arrives early November, in the same week than California
  • Colorado: arrives early November, in the same week than California

Common questions

When do Ross's Geese arrive in California?
Ross's Geese are winter birds in California: they arrive in early November, peak in the second week of January (1.0% of checklists), and most are gone by early March.
When do Ross's Geese leave California?
Most Ross's Geese have left California by early March, when reports fall below half their usual rate.
When is the best time to see a Ross's Goose in California?
The Ross's Goose is reported most often in the second week of January, on about 1.0% of California checklists.
Where in California are Ross's Geese seen most often?
By county, Colusa County, Glenn County, and Merced County have the highest peak reporting rates for the Ross's Goose (counties with at least 200 checklists).