105th Hamilton Christmas Bird Count Preliminary Report

[Rob Porter]

The 105th Hamilton Christmas Bird Count was held on December 26, 2025. This is a preliminary report where some details will be missing or a bit more generalized. A later final report will fill in these details in full.

The count circle centres upon Dundurn Castle; it is bounded in the west by Christie Lake, in the east by Lake Ontario, in the north by Lake Medad, and in the south by Hamilton International Airport. It includes two Key Biodiversity Areas (KBAs): the West End of Lake Ontario (WELO) KBA, and Hamilton Harbour Waterbird Colonies KBA.

The day’s weather was challenging for birding, starting off with overcast, -6° C and ENE winds of 30 km/h, leading to later snow, sleet, then freezing rain and a high of -2° C. Most field counters called it a day by about 1:30 pm in the afternoon due to this weather. Some locations important to the count, such as the RBG’s Arboretum, were closed completely and inaccessible.

At least 53 separate parties of counters were active on the count day. With almost all reports in by the time of writing, 95 species were counted on the day. Add to this an additional 7 species from the count week period brings the total in at 102 species for the count period. (Remaining reports may affect this, and add to further data below.)

A total of 28,901 individual birds were counted, making for a substantially below-average count, 8,151 less than the ten-year average of 37,052.

Despite the challenging circumstances, five species managed to have record-high counts this year.

Trumpeter Swan came in strong with 211 individuals counted in 9 different locations. This beats the previous record of 193 in 2010.

While most waterfowl had below-average counts this year, a total of 1,843 Red-breasted Mergansers were found, setting a record two years in a row (1,301 last year). The vast majority of these (1,711) were in a single location, Windermere Basin.

The Yellow-bellied Sapsucker has now been present for five years in a row, the longest streak it has ever maintained in the history of the count. With 5 individuals counted by 4 separate count groups this year, it has set a new record.

Once again we have counted 7 Merlins on count day, and this is the third time this exact record has been matched (2015, 2021, 2025). The species has been seen every year since 1998, and in the last 25 years the average has been 4 found per count. This species was seen by six different groups.

The most impressive record of the year is the discovery of 12 Hermit Thrush, seen by 7 different groups, beating out a record of 11 seen in 2002 and being only the second count on record to have double-digit counts of this species.

As expected with count with a low total, some species hit record lows not seen in the count since the very early days of the count where only a few participants were involved.

While our count circle began in 1921, it wasn’t until 1955 that it was standardized for scientific purposes with a set circle. Since that time, we have never had as few House Sparrows as this year, with a count of 841. Song Sparrow also hit a record low, with only 9 observed, the first single-digit report in the 70 counts since 1955.

Species with a 25-year low included: Bufflehead (103), Mourning Dove (189), Ring-billed Gull (298), Downy Woodpecker (111), Black-capped Chickadee (584), White-breasted Nuthatch (115), Northern Mockingbird (4), House Finch (99), and Northern Cardinal (319).

Count week species included: Glaucous Gull, Lesser Black-backed Gull, Snowy Owl, Great Horned Owl, Fox Sparrow, Common Grackle, Yellow-rumped Warbler.

A lot of these lows are likely due to the very poor weather making observation conditions challenging. (A later final report will be able to comment on whether hours-effort was affected by weather conditions.)

Thank you to the dozens of participants this year, especially given our poor weather conditions! We consistently see between 90 to 110 participants each year making this one of the biggest counts in the province and it is evident from the results that our counters are very determined to find all they can.

If you have any questions about this report or the Hamilton count, please feel free to reach out to me. 

For exact numbers of each species, see the raw data below this written section.

Happy New Year,

Rob Porter
Hamilton Christmas Bird Count Compiler
Hamilton Naturalists’ Club

Additional Notes:

Last year’s report can be seen at: https://ebird.org/tripreport/311739

CBC Hamilton wrote an article about our count (using early preliminary data): https://www.cbc.ca/news/canada/hamilton/hamilton-bird-count-2025-9.7029182

Species Count Data

Count Day Species: 95
Count Week Species: 7
Total Species Countable: 102
Spuh/Slash Species: 4
Hybrid Species: 0

* Record high (105 years)
*10y 10-year high
CW denotes "Count Week" species (3 days before or after the count day but not observed the day-of)

Cackling Goose   3 

Canada Goose   6,584 

Mute Swan   44 

*Trumpeter Swan   211 

Tundra Swan   9 

Wood Duck   2 

Northern Shoveler   66 

Gadwall   49 

American Wigeon   1 

Mallard   5,019 

American Black Duck   204 

Northern Pintail   6 

Green-winged Teal   6 

Canvasback   45 

Redhead   26 

Ring-necked Duck   85 

Greater Scaup   732 

Lesser Scaup   36 

Surf Scoter   5 

White-winged Scoter   117 

Black Scoter   4 

Long-tailed Duck   548 

Bufflehead   103 

Common Goldeneye   833 

Hooded Merganser   87 

Common Merganser   1,438 

*Red-breasted Merganser   1,843 

Ruddy Duck   55 

duck sp.   14 

Wild Turkey   106 

Rock Pigeon   1,471 

Mourning Dove   189 

American Coot   44 

Ring-billed Gull   298 

American Herring Gull   331 

Great Black-backed Gull   11 

Glaucous Gull CW 

Lesser Black-backed Gull CW 

Iceland Gull   1 

gull sp.   15 

Pied-billed Grebe   1 

Horned Grebe   2 

Common Loon   2 

Double-crested Cormorant   54 

Black-crowned Night Heron   1 

Great Blue Heron   3 

Turkey Vulture   9 

Sharp-shinned Hawk   2 

Cooper's Hawk   14 

Northern Harrier   1 

Bald Eagle   13 

Red-shouldered Hawk   1 

Red-tailed Hawk   66 

Rough-legged Hawk   1 

hawk sp.   1 

*10y Eastern Screech-Owl   10 

Snowy Owl CW 

Great Horned Owl CW 

Belted Kingfisher   2 

*Yellow-bellied Sapsucker   5 

Red-bellied Woodpecker   83 

Downy Woodpecker   111 

Hairy Woodpecker   45 

Pileated Woodpecker   2 

Northern Flicker   10 

American Kestrel   1 

*Merlin   7 

Peregrine Falcon   3 

Northern Shrike   1 

Blue Jay   235 

American Crow   331 

Common Raven   16 

Black-capped Chickadee   584 

Tufted Titmouse   1 

Golden-crowned Kinglet   9 

White-breasted Nuthatch   115 

Red-breasted Nuthatch   40 

Brown Creeper   19 

Winter Wren   2 

Carolina Wren   30 

European Starling   2,433 

Gray Catbird   1 

Northern Mockingbird   4 

Eastern Bluebird   30 

*Hermit Thrush   12 

American Robin   671 

Cedar Waxwing   169 

House Sparrow   841 

House Finch   99 

Purple Finch   2 

Pine Siskin   46 

American Goldfinch   526 

finch sp.   10 

American Tree Sparrow   160 

Fox Sparrow CW 

Dark-eyed Junco   968 

White-crowned Sparrow   16 

White-throated Sparrow   104 

Song Sparrow   9 

Swamp Sparrow   1 

Red-winged Blackbird   4 

Brown-headed Cowbird   1 

Common Grackle CW 

Orange-crowned Warbler   1 

Yellow-rumped Warbler CW 

Northern Cardinal   319 

TOTAL 28,901