Season 2 Preliminary Results and Stats

By Nick Anich September 26, 2016

Here are all the checklists plotted on a map, representing over 20,000 individual locations. The pink squares are atlas priority and specialty blocks, so you can see which blocks have sightings and which still need coverage. View it really big here.

It’s been a great second season!

First off, a HUGE THANKS to the over 1,100 atlasers that contributed to Wisconsin Breeding Bird Atlas II so far! This project would not be possible without your contributions. We now have two years under our belt, with three more to go.

You may have already seen our recent news release and this cool infographic highlighting results so far. But let’s delve even deeper into this year’s results to get a better understanding of the impact of our efforts.

Number of Species Confirmed
After this year we have recorded 239 possibly breeding species, and confirmed 220 species, which already brings us near the 237 possibly breeding species and 226 confirmed species reported by the first atlas.


New Species Confirmed this Year
This year we added 3 species that were not confirmed during the six years of Wisconsin Breeding Bird Atlas I (WBBA I; 1995–2000), Mississippi Kite, Blue Grosbeak, and Canvasback (actually a late 2015 record we did not hear about until early this year).

Probably the most exciting, is the first recorded Wisconsin nest of Mississippi Kite found near Janesville.  Although we are now up to 11 species recorded breeding that were not confirmed as breeders during WBBA I, this is the first instance of a completely new breeding record for the state during the current atlas period. This was a species we were keeping our eye out for, and it fits in with the known pattern of range expansion as kites push north and west and colonize increasingly suburban habitat.

An adult Mississippi Kite feeds a cicada to the recently fledged chick. Photo by Scott Weberpal.

An adult Mississippi Kite feeds a cicada to the recently fledged chick. Photo by Scott Weberpal.

The Blue Grosbeaks were found at Spring Green Preserve SNA, and the report of a successful nest is, to our knowledge, the first since 1970. We also have a pending report of a fledged Blue Grosbeak further east in Sauk County. We are just a bit north of their regular breeding range.

The Canvasback record comes from Rush Lake, a high-quality marsh for nesting waterbirds, and interestingly, the same observer and location produced the only Possible Canvasback record for WBBA I. The bulk of the Canvasbacks nest to the northwest of us.

Another surprise confirmation was a brood of Horned Grebe reported from Crex Meadows. The core of this species’ breeding range is also well to the northwest of us, but quality marshes like Crex can turn just about anything up!

White-winged Dove by Quentin Yoerger

White-winged Dove by Quentin Yoerger

Unexpected Finds
An unexpected atlas record from this summer was this Lafayette County White-winged Dove. Although it seems unlikely that it would find a mate, this bird was singing on territory for most of the summer, thus earning itself a Probable atlas code and an interesting footnote. Normally a bird of the southwest US and Central America, this species has been straying to Wisconsin in summer with increasing frequency, so as unlikely as it seems to us right now, maybe it will eventually nest here.

Another record of note was a singing Summer Tanager. This bird is becoming an increasing find in May as they overshoot their typical breeding grounds. It may be just a matter of time before we find a pair breeding here.

Yet to be Confirmed
We are now down to only 3 species confirmed in more than 2 blocks during WBBA I that we have not yet confirmed: Le Conte’s Sparrow, an especially secretive sedge-meadow nester; American Wigeon, a duck that only uncommonly breeds in the state; and White-winged Crossbill, a finch that breeds in northern confier bogs, but primarily after irruption years.

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

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

But compared to some of those rare breeders, we’re just as likely to find another first state breeding record – What will 2017 bring? Eurasian Tree Sparrow, Prairie Warbler, Chuck-will’s-widow, Laughing Gull, Black-billed Magpie, White-faced Ibis, Great-tailed Grackle, Boreal Owl, American Three-toed Woodpecker, or some other unexpected surprise?

Progress to Date
Here are a few maps showing our progress so far. This is 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. We were seeing far too many checklists last year where people were not using possible and probable codes, and leaving important information out of the atlas.

It’s also important to recognize that the distribution of confirmed species is related to a number of factors including county size, species diversity present (in general more species in the northern counties) and, of course, how much coverage each county got. Let’s take a look at the effort this year, broken down by hours per county and then corrected by county area:


You can see that Milwaukee is pretty much done (except for nighttime effort!), and the southeast in general is well-covered, but much of the state is sorely lacking. Our success in the years to come will depend upon getting people to leave completed blocks and move on to blocks that need effort. You’ll be hearing more about how you can help on this issue in the offseason.

Where to Find Data Year-Round
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 errors displaying that have not yet been corrected, and a few hidden species which are not tallying, which is why the total tallies may not match what is reported elsewhere.

Top Atlasers
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.  If you’ve still got a backlog of checklists, it’s not too late, buckle down and get those records in!

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