WhenToBird

Birding spot · Adams County, Colorado

Birding at Rocky Mountain Arsenal National Wildlife Refuge: What You'll See Each Week

In November, the birds most often reported at Rocky Mountain Arsenal National Wildlife Refuge are Mallard (81%), Ring-billed Gull (78%), and Green-winged Teal (71%). It is busiest in spring, when 80 species turn up on at least 1 in 20 checklists, and species counts peak in the second week of May (95 species). 179 species have been reported here across 1,080 complete checklists from 423 birders.

Species by week

020406080100Jan 1-7: low data (3 checklists)Jan 8-14: low data (6 checklists)Jan 15-21: low data (3 checklists)Jan 22-31: low data (2 checklists)Feb 1-7: low data (1 checklists)Feb 8-14: low data (3 checklists)Feb 15-21: low data (3 checklists)Feb 22-28: low data (9 checklists)Mar 1-7: low data (6 checklists)Mar 8-14: 44 species on 5%+ of 14 checklistsMar 15-21: 57 species on 5%+ of 18 checklistsMar 22-31: 46 species on 5%+ of 30 checklistsApr 1-7: 50 species on 5%+ of 18 checklistsApr 8-14: 53 species on 5%+ of 35 checklistsApr 15-21: 54 species on 5%+ of 35 checklistsApr 22-30: 62 species on 5%+ of 47 checklistsMay 1-7: 69 species on 5%+ of 21 checklistsMay 8-14: 95 species on 5%+ of 33 checklistsMay 15-21: 85 species on 5%+ of 31 checklistsMay 22-31: 77 species on 5%+ of 88 checklistsJun 1-7: 72 species on 5%+ of 29 checklistsJun 8-14: 70 species on 5%+ of 31 checklistsJun 15-21: 70 species on 5%+ of 23 checklistsJun 22-30: 73 species on 5%+ of 37 checklistsJul 1-7: 69 species on 5%+ of 30 checklistsJul 8-14: 69 species on 5%+ of 27 checklistsJul 15-21: 63 species on 5%+ of 21 checklistsJul 22-31: 66 species on 5%+ of 30 checklistsAug 1-7: 80 species on 5%+ of 29 checklistsAug 8-14: 83 species on 5%+ of 18 checklistsAug 15-21: 63 species on 5%+ of 26 checklistsAug 22-31: 85 species on 5%+ of 37 checklistsSep 1-7: 69 species on 5%+ of 25 checklistsSep 8-14: 71 species on 5%+ of 26 checklistsSep 15-21: 57 species on 5%+ of 28 checklistsSep 22-30: 69 species on 5%+ of 49 checklistsOct 1-7: 72 species on 5%+ of 16 checklistsOct 8-14: 65 species on 5%+ of 31 checklistsOct 15-21: 63 species on 5%+ of 39 checklistsOct 22-31: 59 species on 5%+ of 34 checklistsNov 1-7: 47 species on 5%+ of 23 checklistsNov 8-14: low data (6 checklists)Nov 15-21: 45 species on 5%+ of 12 checklistsNov 22-30: 51 species on 5%+ of 17 checklistsDec 1-7: 26 species on 5%+ of 10 checklistsDec 8-14: low data (8 checklists)Dec 15-21: low data (5 checklists)Dec 22-31: low data (7 checklists)JanFebMarAprMayJunJulAugSepOctNovDec
Number of species reported on at least 5% of complete checklists, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

In November: what to expect

  1. 1Mallard81%
  2. 2Ring-billed Gull78%
  3. 3Green-winged Teal71%
  4. 4Bufflehead69%
  5. 5Canada Goose66%
  6. 6Black-billed Magpie62%
  7. 7Gadwall53%
  8. 8Hooded Merganser53%
  9. 9American Crow50%
  10. 10Northern Shoveler50%
  11. 11Rock Pigeon43%
  12. 12Killdeer34%
  13. 13American Tree Sparrow33%
  14. 14Cackling Goose31%
  15. 15Northern Flicker31%

Share of complete checklists at this spot that reported the bird in November. The sparkline is the whole year, with this month highlighted.

Season by season

Winter 34 species

  1. Canada Goose52%
  2. Mallard50%
  3. Ring-billed Gull50%
  4. Black-billed Magpie42%
  5. American Kestrel37%

Spring 80 species

  1. Mallard86%
  2. Western Meadowlark85%
  3. Canada Goose80%
  4. Killdeer75%
  5. Red-winged Blackbird74%

Summer 77 species

  1. Killdeer89%
  2. Mallard84%
  3. Mourning Dove83%
  4. Canada Goose82%
  5. Snowy Egret82%

Fall 72 species

  1. Mallard86%
  2. Killdeer65%
  3. Canada Goose60%
  4. Black-billed Magpie53%
  5. Ring-billed Gull48%

Specialties

Birds reported far more often here than across Colorado.

Nearby spots

Frequency is the share of complete checklists at this location that listed the bird, 2016–2025. Busy places report more of everything, and the weekly chart counts species on at least 5% of checklists so a few stray reports do not inflate it. How to read it.