Fifth and Final Season Summary

By Nick Anich October 8, 2019
Long-eared Owl Asio otus

The fifth and final year of field work is now complete for the Wisconsin Breeding Bird Atlas!

We owe a sincere THANK YOU to the more than 2,000 atlasers who have contributed to Wisconsin Breeding Bird Atlas II. It is simply not possible to accomplish a project of this scale without the dedication of atlasers in every corner of the state. We had almost 500 blocks to finish in the final year and we did it!

We just released this cool infographic and a DNR news release highlighting results through Season 5, but let’s dig even deeper into this year’s results to get a better understanding of the impact of our efforts.

Number of Species Confirmed

We have now recorded 243 possibly breeding species and confirmed 226 of those, which is similar to the 237 possibly breeding species and 226 confirmed species reported by Wisconsin Breeding Bird Atlas I (WBBA I; 1995–2000).

New Species Confirmed this Year

Glossy Ibis, Horicon Marsh, by Jack Bartholmai

Our big find was Aaron Haycraft’s discovery of an apparent family group of Glossy Ibis at Horicon. Two birds showed up there in spring, were seen by many observers through summer, and then later were found with young ibis. Considering the primary season of ibis dispersal to Wisconsin is in spring, and the oversummering pair, this ticks the boxes for the state’s first nesting record, well out of range for this coastal breeder, but understandable at a marsh the quality of Horicon.

Also overdue was our first confirmation of Northern Pintail. We are not in the core breeding range of pintail, but it was nevertheless fun to see this find from Jim Frank. Towards the end of the season, Dan Belter turned up another brood.

Assorted Interesting Finds and Photo Highlights

We heard stories from hundreds of people who had a great time atlasing this year. Everyone came away with some great personal highlights, whether it was confirming a new species, learning something new about a familiar species, discovering a new location, or savoring the accomplishment of finishing off a block. Here are a few of the major highlights and a few fun photos on our radar:

We finally got the Apostle Islands covered this year, with the intrepid Anne Geraghty, Brian Collins, and Karl Bardon leading the charge (see Anne’s  wonderful photo gallery of the experience!) This effort turned up high densities of Swainson’s Thrush and Black-throated Blue Warbler, which are uncommon local breeders on the mainland. A few vagrants were found, like this late June White-winged Dove! Rare breeders seen included: a family of Northern Goshawks; a Long-eared Owl; and Boreal Chickadees on Sand Island and confirmed (see picture) on Devil’s Island. Unfortunately we did not confirm any northern warblers like Tennessee, Bay-breasted, or Wilson’s.

Boreal Chickadee carrying food. Photo by Brian Collins.


We saw great numbers of LeConte’s Sparrows up north in 2019, perhaps a result of high water levels creating unsuitable habitat in preferred sedge meadows throughout the region. For example, a remarkable total of 24 singing males were found in a 3-square mile area near Port Wing, Bayfield County, on July 19.

The ever-mysterious Long-eared Owl (see cover photo) was found breeding in a number of locations in the north this year. Local densities of this species seem to shift year to year, and they are never easy to find. Nevertheless, atlasers ran into 3 confirmations this year, out of the 5 total for the project, with several other individuals or pairs discovered as well but not confirmed as breeding.

It was a banner year for Piping Plovers, although high water reduced favored beach/dune habitat and caused a few birds to shift around the Apostle Islands. Overall, 10 pairs nested at 4 sites on Lakes Superior and Michigan, producing 26 young.

Piping Plover, somewhere in the Apostle Islands, Photo by Anne Geraghty.

Northern Saw-whet Owls seemed unusually vocal this spring, although in many cases we don’t know what became of them, as they are quite secretive, and singing (along with nocturnal effort) drops off through the summer.

Black-necked Stilt continues to increase in the Horicon area, with 31 nesting pairs discovered by DNR biologists in the interior of the marsh!

Horned Grebes nested in Dane County, only the second observation for this atlas.

Acadian Flycatcher was documented in Sawyer County, well north of the usual range, in fact the northernmost observation in eBird for Wisconsin.

Red-shouldered Hawk was confirmed in Ashland County, also well north of the usual range.

Northern Mockingbird was confirmed in Rusk County, only the 4th confirmation for this atlas, and quite far north.

Video of a cute baby Blackburnian Warbler in Menominee County.

Ruffed Grouse chicks just hatched, about to leave the nest, in Vilas County.

Carolina Wren nest in a typically weird location, Walworth County.

Not Confirmed as Breeding during WBBA II

There was only 1 species confirmed in more than 2 blocks during WBBA I that was not confirmed in WBBA II: White-winged Crossbill, a finch that breeds in northern conifer bogs, but primarily after irruption years. No major irruption occurred for this species during this atlas period.

There remains a list of very rare breeders found during Atlas I that we did not confirm (number of WBBA I confirmed blocks in parentheses, zero means it was a possible or probable breeder in WBBA I):

Yellow-crowned Night-Heron (2)
Yellow Rail (2)
Barn Owl (2)
Philadelphia Vireo (2)
Nelson’s Sparrow (2)
Lesser Scaup (1)
Western Grebe (1)
Snowy Egret (1)
Great Black-backed Gull (1)
Great Gray Owl (1)
Western Kingbird (1)
Rusty Blackbird (1)
Eared Grebe (0)
Tennessee Warbler (0)
Bay-breasted Warbler (0)
Wilson’s Warbler (0)

We did not uncover breeding evidence for any Great Black-backed Gulls during this atlas period, Photo by Nick Anich.

Visualizing the Effort

Over 5 years, 58,000 individual locations were plotted for 161,000 Atlas eBird checklists. Once Atlas Point Counts and other datasets are imported, this map will fill in even more! Note that there is no background to this map — this is simply the pattern made by our collective locations, and you can make out atlas blocks, as well as major roads, rivers, lakes, and a few folks’ BBS routes! Consider that during atlas I, all data was assigned to the block center. You can envision how increased spatial precision will add quite a bit to the value of our results.

Here are all the checklists plotted on a map, representing over 58,000 unique locations. View it really big here.

Top Atlasers

And lastly, just for fun, here’s the top atlaser (by number of species confirmed) in each county. These are just a few of the very dedicated atlasers helping us all across the state. Great work, folks!


What happens next?

If you see any late season breeding observations that involve family groups with dependent young (we’ve been getting reports of American Goldfinch, Mourning Dove, Northern Cardinal, and Wild Turkey), you can continue to submit those.

Here at Atlas HQ, we are commencing the long and intensive process of data review.  If you still have a backlog of checklists, please buckle down and get those in ASAP! Data entry will not be available in 2020. We will be involving everyone in data review at some point, but we are waiting on some eBird functionality to get built before we are quite ready for that.

For details on the eventual atlas book, and what you can do with your life now that atlasing is winding down, see our Q&A entitled Life After WBBA II.

Stay up to date on the latest project news by signing up for our email list, liking our main facebook page, and/or joining our photos and discussion facebook group. We will continue to keep our email list and facebook page active (at a less-frequent level) until the book comes out, trying to keep this community abreast of our progress, preliminary results, and other pertinent bird news.

Again, A HUGE THANKS TO ALL WHO ATLASED! We could not have done this without you.