Survey 2 of the Dundas IBA (ON005): Report

The second Dundas IBA Bird Survey was conducted on November 24, 2018. In stark contrast to Survey 1’s sunny and hot June weather, the day was quite cold and overcast with light rain throughout the day, reaching a high of 6?C.

The survey, which can also be more lengthily referred to as a “Dundas Valley & Dundas Marsh Important Bird & Biodiversity Area Survey” was conducted exclusively within natural lands found inside the boundary of the IBA, which in short covers the Dundas Valley from Summit Muskeg through to Spencer Creek into Cootes Paradise, extending to Burlington Heights.

To read more about this IBA, see

For those familiar with the Christmas Bird Counts, this survey followed a similar methodology, but did not include urban areas or backyard birdfeeders. Lists are submitted and compiled via eBird.

This count included 11 volunteer counters who are to be commended for covering so much ground this time around with much worse weather condition and fewer boots on the ground. While we did not cover all mapped zones, we did cover all key areas, with a total of 29 checklists submitted, very close to the 31 we had for our first count. Counters experienced a full spectrum of results in various locations, ranging from numbers that could be counted on one hand to hundreds.

Since the survey follows a staggered five-month schedule which consequently results in a five-year cycle, we do not have previous results in the same season to compare with as of yet. That being stated, there are still some comparisons that can be made between the first two datasets.

A total of 5,269 birds were counted (+17.9% change from Survey 1) with 73 species identified (-29.8%) in 29 locations.

Of the six “criteria species” (species that have at one time been present in significant numbers within the IBA) that occur within the season, only one was observed — the Red-breasted Merganser (8). This is not very surprising as those species on the list are a mix of very rare species and those one might expect much earlier in the season.

Our “top twelve” for total numbers this time around were: Canada Goose (901), Ring-billed Gull (839), Mallard (772), Black-capped Chickadee (375), Cedar Waxwing (215), Herring Gull (185), Dark-eyed Junco (161), Common Merganser (136), American Robin (135), Blue Jay (102), House Sparrow (100), and Northern Cardinal (92). Of these, the only repeats in the top twelve list from Survey 1 are American Robin (-49% change), Ring-billed Gull (+605%), and Black-capped Chickadee (+223%).

Survey 1’s top bird, the Red-winged Blackbird, dropped to the absolute bottom with only one individual counted this time around.

There were only 2 species with 80% or higher distribution for reported zones, Black-capped Chickadee (97%), Blue Jay (83%). This is in contrast to the 10 in Survey 1, of which only the Blue Jay (+2% change) achieved such wide distribution then as well.

An additional 5 species can be noted if the criteria is lowered to at 60% distribution: Downy Woodpecker (79%), White-breasted Nuthatch (72%), Red-bellied Woodpecker (66%), Northern Cardinal (66%), Hairy Woodpecker (62%).

In stark contrast, there were 21 species that were highly localized; that is, occurring in one checklist only: Snow Goose, Cackling Goose, Trumpeter Swan, Common Goldeneye, Red-breasted Merganser, Wild Turkey, Lesser Black-backed Gull, Double-crested Cormorant, Bald Eagle, Red-shouldered Hawk, American Kestrel, Tufted Titmouse, Ruby-crowned Kinglet, Northern Mockingbird, Common Redpoll, Pine Siskin, Snow Bunting, Field Sparrow, Swamp Sparrow, Red-winged Blackbird, Yellow-rumped Warbler.

It’s possible to see some useful comparisons between the surveys when looking at non-migratory species.

Red-bellied Woodpecker (+5%) have had a relatively similar count, as did Blue Jay (+10%) and Wild Turkey (+12.50%). White-breasted Nuthatch (+51%) and Carolina Wren (+50%) have seen a small boost, while Black-capped Chickadee (+223%) saw a boom in numbers.

Also of note, raptors in general are very likely artificially low in this count due to the poor visibility throughout the day, which included fog in many areas. Had the weather been clearer many more Red-tailed Hawks would have been expected, as well as a Turkey Vulture or two.

There are a few highlights of note, despite the dreary weather.

Winter Wren (2) was present in two locations, possibly indicating more wintering locations for the species in this region.

A flock of Snow Goose (15) was observed flying over Dundas Valley, and a lone Cackling Goose was seen in Caroll’s Bay.

A Lesser Black-Backed Gull was observed in Cootes Paradise, as were a number of late Great Blue Heron (11), and one late Ruby-crowned Kinglet.

A lone Tufted Titmouse was observed in Dundas Valley, and a single Yellow-rumped Warbler was observed along the Spencer Creek Trail in Dundas.

A surprise for the day was not just one, but two Eastern Phoebe found at Spencer Creek Trail in Dundas first, then along Coldwater Creek at McMaster University’s west campus.

Thank you to all whom have assisted in this second survey, including the Royal Botanical Gardens and Hamilton Conservation Authority for their assistance. Our next two surveys are tentatively scheduled for April 14, 2019 and September 14, 2019.

Feel free to contact me with any questions you may have.

Rob Porter
Compiler, Dundas IBA Survey 2


IBA Criteria Species for Autumn

Observed in Survey 2

Red-breasted Merganser (8)

Not found in Survey 2

Barn Owl
Chimney Swift
Little Gull
Prothonotary Warbler
Rusty Blackbird

Survey 2 Count Totals

Each line follows the format: species name, count, distribution (% of checklists present within)

List is in taxonomic order.

Snow Goose    15    (3%)
Cackling Goose    1    (3%)
Canada Goose    901    (52%)
Mute Swan    4    (7%)
Trumpeter Swan    6    (3%)
swan sp.    2    (3%)
Northern Shoveler    18    (7%)
Mallard    772    (41%)
Mallard (Domestic type)    1    (3%)
American Black Duck    20    (10%)
Greater/Lesser Scaup    20    (3%)
Bufflehead    29    (7%)
Common Goldeneye    1    (3%)
Hooded Merganser    45    (14%)
Common Merganser    136    (21%)
Red-breasted Merganser    8    (3%)
duck sp.    230    (10%)
Wild Turkey    9    (3%)
Rock Pigeon    21    (14%)
Mourning Dove    12    (34%)
Ring-billed Gull    839    (55%)
Herring Gull    185    (38%)
Lesser Black-backed Gull    1    (3%)
Great Black-backed Gull    6    (10%)
gull sp.    120    (7%)
Double-crested Cormorant    1    (3%)
Great Blue Heron    11    (17%)
Sharp-shinned Hawk    2    (7%)
Bald Eagle    2    (3%)
Red-shouldered Hawk    1    (3%)
Red-tailed Hawk    7    (21%)
Great Horned Owl    3    (10%)
Belted Kingfisher    5    (14%)
Red-bellied Woodpecker    38    (66%)
Downy Woodpecker    61    (79%)
Hairy Woodpecker    39    (62%)
Downy/Hairy Woodpecker    5    (3%)
Pileated Woodpecker    8    (21%)
Northern Flicker    5    (10%)
American Kestrel    1    (3%)
Eastern Phoebe    2    (7%)
Blue Jay    102    (83%)
American Crow    64    (59%)
Black-capped Chickadee    375    (97%)
Tufted Titmouse    1    (3%)
Red-breasted Nuthatch    7    (14%)
White-breasted Nuthatch    53    (72%)
Brown Creeper    20    (34%)
Winter Wren    2    (7%)
Carolina Wren    30    (45%)
Golden-crowned Kinglet    20    (28%)
Ruby-crowned Kinglet    1    (3%)
Eastern Bluebird    3    (7%)
American Robin    135    (45%)
Northern Mockingbird    2    (3%)
European Starling    45    (17%)
Cedar Waxwing    215    (21%)
House Finch    9    (17%)
Purple Finch    4    (7%)
Common Redpoll    28    (3%)
Pine Siskin    4    (3%)
American Goldfinch    69    (59%)
Snow Bunting    2    (3%)
Field Sparrow    2    (3%)
American Tree Sparrow    44    (31%)
Dark-eyed Junco    161    (55%)
White-throated Sparrow    73    (41%)
Song Sparrow    8    (17%)
Swamp Sparrow    3    (3%)
Red-winged Blackbird    1    (3%)
Yellow-rumped Warbler    1    (3%)
Northern Cardinal    92    (66%)
House Sparrow    100    (28%)

TOTAL birds counted     5269

Species counted    73
Other taxa counted (spuh, slash, or hybrid)    6