THE ONTARIO WINTER BIRD LIST

is an

annual checklist of bird species seen in On-

tario between december 1 an

d the end of

February in the following year. The online

sources searched to determine sightings

include, but are not limited to, eBird, Ont-

birds, Birdnews and the relatively new

Ontario Birds

discor

d group.

The Ontario Winter Bird List is long-

established, with Blake Maybank launch-

ing the online version approximately 20

years ago. The checklist is now a publicly

accessible spreadsheet (tinyurl.com/my

yulvs) which details the yearly totals of

species seen, and the average number seen

across years. The data displayed here date

back to 2007-08. The species are organized

into three categories based on the likeli-

hood of being seen. These categories, from

regular to extreme rarity, make it easier to

visually assess the probability of any

species being present within a given winter.

While no statistical analyses have been

applied yet to the Winter Bird List data, an

eyeball test for species seen in the last five

years shows that there has been a decline

from 220 species in 2015-16 to 202 species

in 2019-20. But the number has jumped

back up for 2020-21. By February 11 the

total reached 217. Check online for the final

number.

analysis of how or if weather and

climate change impact winter bird species

diversity may be completed in the future.

Weather parameters such as snow depth

and temperature could inﬂuence species

numbers. Other factors affecting winter

bird species numbers include the number

of active birders, their communication av-

enues and changes to bird watching equip-

ment. addition

al analyses of the list, using

the current information, could also deter-

mine what guilds of species are likely to

be seen in winter.

due to the time an

d effort limitations,

some information that could have been

useful in future studies has not been

recorded. For example, the date each

species is first seen each winter is

unknown. This information gap prevents

us from seeing when each species should

be expected each winter. Some rare birds

seen right at the beginning of the study

period may have lingered from the end of

fall migration, while other species aren’t

found at first as they require more search-

ing. In addition, many rare species seem to

occur randomly.

If you want to become involved in On-

tario winter bird listing in 2021-2022, the

OFO is co-sponsoring the Ontario Breeding

Bird atl

as.

atl

as-3 already started on Jan-

uary 1, and will run until

december 31,

2025. This project encourages Ontario bird-

ers to look for birds in under-searched

areas and could result in more species be-

ing added to the Ontario Winter Bird List.

Similarly, OFO set up its Winter Birding

Challenge to encourage birders to get out

more this winter. The goal was to see how

many species of birds could be found

within an eight-kilometre radius of your

home during the winter months. Partici-

pation could have contributed to the in-

crease in total numbers of birds observed

this winter, compared to 2019-20.

Subscribe to Ontario Birdnews through

the OFO website (ofo.ca) to receive emails

with updates and information about the

Ontario Winter Bird List. To learn how to

receive eBird rare bird updates, and how

to join Ontario Birds

discor

d, check the

OFO website under the sub-heading Find-

ing Birds and look under Rare Bird

alerts

and

news.

Todd Hagedorn lives in Ayr, southwest of

Cambridge, where he enjoys keeping a

Winter Bird List for his local patch. Todd is

coordinator of the Ontario Winter Bird List.

The Gist of the

Winter Bird List

List coordinator explains how to add to

community science through winter birding

BY TODD HAGEDORN

Evening Grosbeak, while known to be

declining in Ontario, is among the yellow-

coded species on the Ontario Winter Bird

List, indicating that it is a regular winter

species and seen every year.

Photo by Sherwood McLernon

OFO News February 2021