Birding spot · Jefferson County, Colorado
Birding at Main Reservoir: What You'll See Each Week In November, the birds most often reported at Main Reservoir are Mallard (95%), Hooded Merganser (93%), and American Coot (92%). It is busiest in spring, when 73 species turn up on at least 1 in 20 checklists, and species counts peak in the second week of May (84 species). 206 species have been reported here across 3,436 complete checklists from 582 birders.
Species by week 0 20 40 60 80 100 Jan 1-7: 40 species on 5%+ of 31 checklists Jan 8-14: 44 species on 5%+ of 30 checklists Jan 15-21: 38 species on 5%+ of 23 checklists Jan 22-31: 41 species on 5%+ of 51 checklists Feb 1-7: 40 species on 5%+ of 29 checklists Feb 8-14: 41 species on 5%+ of 30 checklists Feb 15-21: 36 species on 5%+ of 27 checklists Feb 22-28: 39 species on 5%+ of 43 checklists Mar 1-7: 45 species on 5%+ of 74 checklists Mar 8-14: 46 species on 5%+ of 55 checklists Mar 15-21: 52 species on 5%+ of 65 checklists Mar 22-31: 56 species on 5%+ of 136 checklists Apr 1-7: 62 species on 5%+ of 126 checklists Apr 8-14: 65 species on 5%+ of 147 checklists Apr 15-21: 67 species on 5%+ of 148 checklists Apr 22-30: 73 species on 5%+ of 263 checklists May 1-7: 77 species on 5%+ of 252 checklists May 8-14: 84 species on 5%+ of 198 checklists May 15-21: 77 species on 5%+ of 140 checklists May 22-31: 75 species on 5%+ of 143 checklists Jun 1-7: 56 species on 5%+ of 37 checklists Jun 8-14: 50 species on 5%+ of 32 checklists Jun 15-21: 45 species on 5%+ of 24 checklists Jun 22-30: 50 species on 5%+ of 38 checklists Jul 1-7: 50 species on 5%+ of 27 checklists Jul 8-14: 50 species on 5%+ of 23 checklists Jul 15-21: 53 species on 5%+ of 30 checklists Jul 22-31: 55 species on 5%+ of 33 checklists Aug 1-7: 50 species on 5%+ of 28 checklists Aug 8-14: 59 species on 5%+ of 34 checklists Aug 15-21: 61 species on 5%+ of 28 checklists Aug 22-31: 57 species on 5%+ of 52 checklists Sep 1-7: 63 species on 5%+ of 65 checklists Sep 8-14: 61 species on 5%+ of 63 checklists Sep 15-21: 52 species on 5%+ of 52 checklists Sep 22-30: 44 species on 5%+ of 41 checklists Oct 1-7: 55 species on 5%+ of 54 checklists Oct 8-14: 54 species on 5%+ of 71 checklists Oct 15-21: 52 species on 5%+ of 58 checklists Oct 22-31: 48 species on 5%+ of 67 checklists Nov 1-7: 50 species on 5%+ of 48 checklists Nov 8-14: 56 species on 5%+ of 115 checklists Nov 15-21: 49 species on 5%+ of 122 checklists Nov 22-30: 54 species on 5%+ of 84 checklists Dec 1-7: 44 species on 5%+ of 45 checklists Dec 8-14: 49 species on 5%+ of 40 checklists Dec 15-21: 44 species on 5%+ of 51 checklists Dec 22-31: 39 species on 5%+ of 63 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 Mallard 95% 2 Hooded Merganser 93% 3 American Coot 92% 4 Ring-billed Gull 91% 5 Gadwall 78% 6 American Crow 75% 7 Bufflehead 74% 8 Canada Goose 73% 9 Black-capped Chickadee 71% 10 Common Goldeneye 67% 11 House Finch 61% 12 American Wigeon 58% 13 Northern Flicker 57% 14 Black-billed Magpie 51% 15 Northern Shoveler 49% 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 .
Mallard95%
Hooded Merganser93%
American Coot92%
Ring-billed Gull91%
Gadwall78%
American Crow75%
Bufflehead74%
Canada Goose73%
Black-capped Chickadee71%
Common Goldeneye67%
House Finch61%
American Wigeon58%
Northern Flicker57%
Black-billed Magpie51%
Northern Shoveler49%