Birding spot · Boulder County, Colorado
Birding at Boulder Reservoir: What You'll See Each Week In November, the birds most often reported at Boulder Reservoir are Ring-billed Gull (86%), Canada Goose (69%), and Western Grebe (65%). It is busiest in spring, when 69 species turn up on at least 1 in 20 checklists, and species counts peak in the second week of May (80 species). 181 species have been reported here across 1,795 complete checklists from 398 birders.
Species by week 0 20 40 60 80 Jan 1-7: 36 species on 5%+ of 24 checklists Jan 8-14: 35 species on 5%+ of 11 checklists Jan 15-21: 34 species on 5%+ of 39 checklists Jan 22-31: 38 species on 5%+ of 15 checklists Feb 1-7: 43 species on 5%+ of 15 checklists Feb 8-14: 38 species on 5%+ of 16 checklists Feb 15-21: 38 species on 5%+ of 11 checklists Feb 22-28: 40 species on 5%+ of 10 checklists Mar 1-7: 43 species on 5%+ of 13 checklists Mar 8-14: 41 species on 5%+ of 27 checklists Mar 15-21: 44 species on 5%+ of 25 checklists Mar 22-31: 60 species on 5%+ of 66 checklists Apr 1-7: 58 species on 5%+ of 56 checklists Apr 8-14: 61 species on 5%+ of 77 checklists Apr 15-21: 69 species on 5%+ of 117 checklists Apr 22-30: 68 species on 5%+ of 155 checklists May 1-7: 76 species on 5%+ of 53 checklists May 8-14: 80 species on 5%+ of 33 checklists May 15-21: 61 species on 5%+ of 22 checklists May 22-31: 59 species on 5%+ of 25 checklists Jun 1-7: low data (7 checklists) Jun 8-14: low data (9 checklists) Jun 15-21: low data (7 checklists) Jun 22-30: 55 species on 5%+ of 13 checklists Jul 1-7: 52 species on 5%+ of 11 checklists Jul 8-14: low data (7 checklists) Jul 15-21: low data (9 checklists) Jul 22-31: 66 species on 5%+ of 14 checklists Aug 1-7: 58 species on 5%+ of 18 checklists Aug 8-14: 68 species on 5%+ of 15 checklists Aug 15-21: 55 species on 5%+ of 14 checklists Aug 22-31: 58 species on 5%+ of 65 checklists Sep 1-7: 67 species on 5%+ of 16 checklists Sep 8-14: 54 species on 5%+ of 73 checklists Sep 15-21: 51 species on 5%+ of 43 checklists Sep 22-30: 65 species on 5%+ of 72 checklists Oct 1-7: 53 species on 5%+ of 34 checklists Oct 8-14: 57 species on 5%+ of 44 checklists Oct 15-21: 49 species on 5%+ of 13 checklists Oct 22-31: 62 species on 5%+ of 97 checklists Nov 1-7: 61 species on 5%+ of 87 checklists Nov 8-14: 53 species on 5%+ of 65 checklists Nov 15-21: 52 species on 5%+ of 30 checklists Nov 22-30: 48 species on 5%+ of 37 checklists Dec 1-7: 47 species on 5%+ of 51 checklists Dec 8-14: 44 species on 5%+ of 78 checklists Dec 15-21: 42 species on 5%+ of 33 checklists Dec 22-31: 43 species on 5%+ of 23 checklists Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 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 Ring-billed Gull 86% 2 Canada Goose 69% 3 Western Grebe 65% 4 American Coot 63% 5 Red-tailed Hawk 55% 6 Common Merganser 46% 7 Black-billed Magpie 41% 8 Eared Grebe 39% 9 Mallard 37% 10 Bald Eagle 35% 11 Cackling Goose 32% 12 Pied-billed Grebe 31% 13 Common Goldeneye 31% 14 Gadwall 27% 15 European Starling 26% 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 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 .
Ring-billed Gull86%
Canada Goose69%
Western Grebe65%
American Coot63%
Red-tailed Hawk55%
Common Merganser46%
Black-billed Magpie41%
Eared Grebe39%
Mallard37%
Bald Eagle35%
Cackling Goose32%
Pied-billed Grebe31%
Common Goldeneye31%
Gadwall27%
European Starling26%