WhenToBird

Birding spot · Boulder County, Colorado

Birding at Lagerman Reservoir: What You'll See Each Week

In November, the birds most often reported at Lagerman Reservoir are American Coot (86%), Bufflehead (83%), and Ruddy Duck (81%). It is busiest in spring, when 77 species turn up on at least 1 in 20 checklists, and species counts peak in the second week of May (81 species). 205 species have been reported here across 8,357 complete checklists from 1,337 birders.

Species by week

020406080100Jan 1-7: 41 species on 5%+ of 121 checklistsJan 8-14: 35 species on 5%+ of 59 checklistsJan 15-21: 31 species on 5%+ of 51 checklistsJan 22-31: 31 species on 5%+ of 66 checklistsFeb 1-7: 31 species on 5%+ of 60 checklistsFeb 8-14: 35 species on 5%+ of 47 checklistsFeb 15-21: 38 species on 5%+ of 109 checklistsFeb 22-28: 38 species on 5%+ of 73 checklistsMar 1-7: 38 species on 5%+ of 96 checklistsMar 8-14: 44 species on 5%+ of 100 checklistsMar 15-21: 43 species on 5%+ of 169 checklistsMar 22-31: 50 species on 5%+ of 376 checklistsApr 1-7: 52 species on 5%+ of 276 checklistsApr 8-14: 60 species on 5%+ of 353 checklistsApr 15-21: 74 species on 5%+ of 512 checklistsApr 22-30: 74 species on 5%+ of 605 checklistsMay 1-7: 80 species on 5%+ of 471 checklistsMay 8-14: 81 species on 5%+ of 277 checklistsMay 15-21: 77 species on 5%+ of 174 checklistsMay 22-31: 71 species on 5%+ of 356 checklistsJun 1-7: 59 species on 5%+ of 114 checklistsJun 8-14: 58 species on 5%+ of 83 checklistsJun 15-21: 68 species on 5%+ of 54 checklistsJun 22-30: 71 species on 5%+ of 69 checklistsJul 1-7: 60 species on 5%+ of 57 checklistsJul 8-14: 66 species on 5%+ of 72 checklistsJul 15-21: 64 species on 5%+ of 69 checklistsJul 22-31: 62 species on 5%+ of 183 checklistsAug 1-7: 73 species on 5%+ of 141 checklistsAug 8-14: 76 species on 5%+ of 186 checklistsAug 15-21: 76 species on 5%+ of 211 checklistsAug 22-31: 72 species on 5%+ of 225 checklistsSep 1-7: 72 species on 5%+ of 178 checklistsSep 8-14: 77 species on 5%+ of 257 checklistsSep 15-21: 67 species on 5%+ of 185 checklistsSep 22-30: 68 species on 5%+ of 185 checklistsOct 1-7: 69 species on 5%+ of 174 checklistsOct 8-14: 76 species on 5%+ of 179 checklistsOct 15-21: 58 species on 5%+ of 139 checklistsOct 22-31: 58 species on 5%+ of 212 checklistsNov 1-7: 48 species on 5%+ of 138 checklistsNov 8-14: 48 species on 5%+ of 154 checklistsNov 15-21: 47 species on 5%+ of 92 checklistsNov 22-30: 47 species on 5%+ of 196 checklistsDec 1-7: 45 species on 5%+ of 143 checklistsDec 8-14: 43 species on 5%+ of 83 checklistsDec 15-21: 47 species on 5%+ of 79 checklistsDec 22-31: 40 species on 5%+ of 148 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
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. 1American Coot86%
  2. 2Bufflehead83%
  3. 3Ruddy Duck81%
  4. 4Mallard76%
  5. 5Canada Goose75%
  6. 6Ring-billed Gull69%
  7. 7Northern Pintail61%
  8. 8Killdeer56%
  9. 9American Wigeon55%
  10. 10Redhead52%
  11. 11Cackling Goose52%
  12. 12Red-tailed Hawk51%
  13. 13Eared Grebe50%
  14. 14Bald Eagle50%
  15. 15Green-winged Teal50%

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 42 species

  1. Canada Goose69%
  2. Common Goldeneye69%
  3. Mallard54%
  4. Bald Eagle54%
  5. Cackling Goose52%

Spring 77 species

  1. Killdeer86%
  2. Mallard81%
  3. American Avocet79%
  4. Ruddy Duck78%
  5. Green-winged Teal74%

Summer 73 species

  1. Killdeer94%
  2. Double-crested Cormorant87%
  3. Mallard84%
  4. Canada Goose78%
  5. Ring-billed Gull71%

Fall 68 species

  1. American Coot88%
  2. Ring-billed Gull82%
  3. Mallard80%
  4. Ruddy Duck79%
  5. Killdeer79%

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.