Wisconsin Breeding Bird Atlas Year 1

By Team eBird October 15, 2015

Kirtland’s Warbler. Photo by Nick Anich.

The inaugural year of the Wisconsin Breeding Bird Atlas II is complete—marking the first year that a breeding bird atlas has had the data collection process run entirely through eBird. Wisconsin Atlasers submitted more than 24,000 checklists documenting the location and breeding activity of more than 1.7 million individuals of 229 species. It’s been a great first season! You can explore some of the results on the official Wisconsin Breeding Bird Atlas II eBird portal, where you can view species maps with breeding evidence, or see summaries of the effort across the state, a county, or a single atlas block. To learn more about the summary of the first year, provided by the WI Atlas team, read on!

This below article is thanks to the Wisconsin Atlas team, and can also be seen on the WI Atlas II portal.

First off, a HUGE THANKS to the over 700 atlasers that contributed to Wisconsin Breeding Bird Atlas II so far!

Those of you who have signed up for our email list or have liked our Facebook page, probably already saw this cool infographic showing how we’ve covered over 2,600 atlas blocks and submitted over 23,900 checklists, totaling 1.7 million birds! But we thought we’d delve even deeper into some of those statistics to get a better understanding of the impact of our efforts.

This year we recorded 229 possibly breeding species, and confirmed 212 species, which already brings us very close to the 237 possibly breeding species and 226 confirmed species reported by the first atlas.

This year we found 8 species that were not confirmed during the six years of Wisconsin Breeding Bird Atlas I (1995–2000).

Bufflehead (1 confirmation)
Whooping Crane (Multiple confirmations)
Eurasian Collared-Dove (4 confirmations)
White-eyed Vireo (1 confirmation)
Great Tit (2 confirmations)
Kirtland’s Warbler (Multiple confirmations)
Yellow-throated Warbler (1 confirmation)
European Goldfinch (4 confirmations)

There were lots of exciting finds this season of other uncommon Wisconsin breeders! Check out these checklists with fantastic embedded photos:

Northern Mockingbird
Black-necked Stilt
Long-eared Owl

However, we have not yet confirmed a number of species that were confirmed breeding in more than one block during the first atlas:

American Wigeon
Northern Pintail
Northern Bobwhite
Yellow Rail
Short-eared Owl
Philadelphia Vireo
Swainson’s Thrush
Worm-eating Warbler
Yellow-breasted Chat
Le Conte’s Sparrow
Nelson’s Sparrow
White-winged Crossbill

Philadelphia Vireo

Philadelphia Vireo

Here’s the breakdown of confirmed species by county:


Although confirming a species is fun and a major component of the project, we do want to emphasize that records of probable and possible breeding also contribute important information to the atlas.

It’s also important to recognize that the distribution of confirmed species is related to how much coverage each county got. Let’s take a look at the effort this year, broken down by hours per county:


You can see that Madison, Milwaukee, and Green Bay are well covered. Coverage varies across the rest of the state, but clearly over the next four years we’ll be in need of additional help in some gaps, especially in the north-central, and western regions.

All these statistics, as well as species maps are available on the Explore Data tools. We encourage you to poke around the Explore Data tools yourself, and learn more about which species are breeding near you and where the gaps in coverage are. One reminder that the totals on the Explore a Region tool are still preliminary; there are a few species listed as probable that need to come off (because the observations in question were of migrants) and a few hidden species which are not tallying, which is why the total count of confirmed species doesn’t currently add up to 212.

And lastly, just for fun, here’s the top atlaser (by number of species confirmed) in each county. Great work folks!


Again, A HUGE THANKS TO ALL WHO ATLASED THIS YEAR! Here at Atlas HQ, we will continue sifting through the data and preparing for the next season.