What is Wisconsin Fat Bird Week?

Welcome to the Natural Resources Foundation of Wisconsin’s first ever Fat Bird Week! What better way to celebrate Wisconsin’s native birds than by admiring the chonkiest of the chonkers? Because after all, a fat bird is a healthy bird.

Every day from Friday, April 19th to Friday, April 26th you will get the chance to vote for your favorite bulbous bird.


Following Fat Bird Week, join NRF and SOS Save Our Songbirds for a free webinar: “Four Ways to keep Wisconsin’s Birds Fat and Healthy” where the winner of Wisconsin Fat Bird Week will be officially announced!


Only one chonk will reign supreme. Only the floofiest of the floofs will floof their way to victory. We love all of Wisconsin’s birds, but only one will hoist itself to the top of the bracket. Who will win the 1st annual Wisconsin Fat Bird Week? Only you can decide…

Introducing the contestants:

Bountiful barn swallow

A barn swallow perched on a plant with its beak wide open. Photo by Joe Riederer

Meet the bountiful barn swallow! Known for their impressive swooping displays, these birds are a sign of spring in Wisconsin. This neotropical migrant tends to feed on various insects while in flight and almost exclusively nests in man-made structures.


Gluttonous golden-crowned kinglet

A golden-crowned kinglet mid-jump in a field of grass. Photo by Charlotte Catalano

Introducing the gluttonous golden-crowned kinglet! Don’t be fooled by this chunker – the golden-crowned kinglet is actually considered one of the smallest birds in North America! They love dense conifer forests and migrate through Wisconsin in early spring on their way to their breeding grounds in the northern bit of the state and Canada.


Hefty horned lark

A horned lark standing in the snow. Photo by Andy Raupp

The hefty horned lark would like to make your acquaintance! This round fella is quite special, as horned larks are the only native lark species in North America. Horned larks are also some of the earliest nesting birds in the southern part of Wisconsin, nesting on the ground, in agricultural fields, and prairies. Horned larks love to munch on seeds and insects, which make up 50% of their diet in the summer! So yummy…


Top heavy tree swallow

A tree swallow perched on top of a bird house. Photo by Richard Albert

Hello there, top heavy tree swallow! Ah, another insect-loving birdie. You could say they have a more refined palate than others, however, as they also enjoy the occasional berry. Tree swallows can be seen migrating in large flocks, with the Wisconsin record being a flock of 50,000 tree swallows in 1977! During breeding season, they tend to stay close to bodies of water, such as ponds or marshes.


Dumpy dark-eyed junco

A dark-eyed junco sitting in the snow. Photo by Warren Lynn

Introducing the dumpy dark-eyed junco (aka, the “snowbird”). They arrive during Wisconsin’s fall as a friendly reminder that winter is on its way, and head to northern Wisconsin and Canada for breeding season. Dark-eyed juncos enjoy conifer and mixed woods as habitat but will make their way to bird feeders for a seedy snack (although, they lazily prefer to eat on the ground)!


Rotund ruby-crowned kinglet

A ruby-crowned kinglet perched on a thin branch. Photo by Andy Raupp

Meet the rotund ruby-crowned kinglet! A common migratory bird for Wisconsin, the ruby-crowned kinglet enjoys staying low in the woods during migration season before going up high into conifers for the summer breeding season. This kinglet isn’t a picky eater (as you probably can tell…) and has a diet of insects, spiders, berries, and even sap or nectar!


Chonky Canada warbler

A Canada warbler standing on wood. Photo by Ken & Barb Wardius

It’s nice to meet you, chonky Canada warbler! You’ll be able to find these warblers in spruce, hemlock, and balsam fir across northern Wisconsin counties during breeding season. This neotropical migrant travels all the way to Peru and Ecuador during the winter. You can thank them for eating mosquitoes, as well as other insects, such as beetles, flies, and moths.


Plump pine warbler

A pine warbler perched on a branch. Photo by Andy Raupp

Last but certainly not least, the plump pine warbler! As you could probably guess by the name, pine warblers love to stay near pine trees! Their breeding range in Wisconsin consists mostly of the northern part of the state. These bright yellow songbirds are fans of bird feeders, unlike other warblers.

How does voting work?

Our 8 chubby contestants will compete in a single elimination, bracket-style tournament. The first round of voting opens at 9am CST on Friday, April 19th and voting will remain open for 48 hours. The second round of voting will open at 9am CST on Sunday, April 21st and remain open for 24 hours. The following rounds will all open at 9am CST and last 24 hours until the final round on Friday, April 26th. The winner will be crowned at the webinar on Tuesday, April 30th!

Join our webinar: “Four Ways to keep Wisconsin’s Birds Fat and Healthy ”

Want to be one of the first to know who won Wisconsin Fat Bird Week? Join our free webinar, presented by NRF and SOS Save Our Songbirds, on Tuesday, April 30th at 12pm on Zoom! Learn all about the easiest ways to help keep our native bird population fat, healthy, and flying. The four biggest actions people can take: plant native species, prevent window strikes, buy bird-friendly coffee, and participate in the Great Wisconsin Birdathon. At the webinar, the winner of Wisconsin Fat Bird Week will be officially announced! You’ll hear from the following speakers:

  1. Amy Alstad (Holy Wisdom Monastery)
  2. Brenna Marsicek (Southern Wisconsin Bird Alliance)
  3. Lisa Gaumnitz (SOS Save Our Songbirds)
  4. Soumika Gaddameedi (Natural Resources Foundation of Wisconsin)

Why do we want our birds to be fat?

We talked with Ryan Brady, a conservation biologist at the Wisconsin Department of Natural Resources, to get the scoop on fat birds.

In birds, fat is a good thing, and the more the better. Simply put, fat is energy and the fuel birds need to survive, especially during migration.
Ryan Brady

WDNR conservation biologist

Now, before we dive into the impressive chunkiness of birds, a few housekeeping things. While many people call birds “fat,” what we are often referring to is the fluffiness of the feathers. Birds can manipulate the contours of their feathers to regulate their own body temperature! They will fluff out their feathers to create air spaces between them. This helps insulate the bird to stay nice and warm. That’s why we often see “fat birds” during the winter. Those floofs are just trying to stay cozy!

Migratory birds store fat prior to migration, too. However, fat stores are hidden underneath the bird’s feathers, so it is difficult to tell just how much weight a bird has by looking at it. Nevertheless, “fluffy” and “fat” birds are all beautiful and worth celebrating during #FatBirdWeek!

Fat is fuel

In preparation for migration, many birds will pack on 50-100% of their body weight to store up enough energy for their long journey. This process is known as hyperphagia. For example, the male ruby-throated hummingbird, which weighs on average 3.0 grams, can double their body mass prior to migration. Fat contains twice as much energy in it than carbs or protein. It is also a lot lighter and less bulky, perfect for the tiny birds that require heaps of lightweight energy for their long-distance travels. After bulking up, both the blackpoll and the Connecticut warbler will embark on a 2-3 day non-stop flight over the Atlantic Ocean towards their South American wintering grounds!

Fat is fuel in the world of bird migration.
Ryan Brady

WDNR conservation biologist

What’s on the menu for fat birds?

Invertebrates. Think caterpillars, beetles, and flies, oh my! Spiders, worms, and crustaceans also make a delicious entrée. Another key source of nutrients for birds are berries of native plants, such as dogwoods, viburnums, and Virginia creeper. Tree seeds and nuts, too. Want to serve these birds the most delectable dishes at your bird feeder? Try high fat foods, such as suet, sunflower and nyjer seeds, and peanuts.

How you can help keep Wisconsin’s native birds fat and healthy

The number one way to support Wisconsin’s birds is by planting native plants. Ryan Brady shares that “plants native to your area will harbor far more insect food, provide more nutritious fruits, and supply the seeds or nectar that native birds need.” Non-native plants can create an ecological desert because they do not provide nutritional resources for birds, crowd out native vegetation, and thus do not attract birds. Other action items include minimal use of pesticides, reducing the size of your lawn, leaving snags (dead trees) standings when safe to do so, keeping cats indoors, and adding deterrents to prevent bird-window collisions.

Everyone can – and must – play a role in helping birds!
Ryan Brady

WDNR conservation biologist

People birdwatching and pointing at birds while standing on a hiking trail in the woods

Wayfarers Millennial Falcons Birdathon Outing. Photo by Cait Williamson

NRF’s work with birds

The Natural Resources Foundation of Wisconsin is proud to partner with organizations like SOS Save Our Songbirds to protect Wisconsin’s native birds. SOS encourages Wisconsinites to take action at home in three major ways:

  • Plant native species
  • Reduce window threats
  • Buy bird-friendly coffee

SOS is a campaign of the Wisconsin Bird Conservation Partnership and is funded by NRF. Bird-lover Lisa Gaumnitz runs SOS, and also happens to be a member of NRF’s board of directors!

Additionally, NRF hosts the Great Wisconsin Birdathon to raise funds for bird conservation. The Great Wisconsin Birdathon is Wisconsin’s largest fundraiser for bird conservation. Each year bird enthusiasts from across the state form teams with the goal of finding as many bird species as possible within a 24-hour period while raising important funds for bird conservation. Since its inception in 2012, the Birdathon has raised over $800,000 for bird protection in Wisconsin.

The funds are collected and managed by NRF through the Bird Protection Fund. Projects supported by the Bird Protection Fund include conservation of Wisconsin’s most threatened and endangered bird species; creation and protection of crucial breeding, stopover, and overwintering habitat; research and monitoring; and education and outreach. Check out the projects supported by birders in 2023.

In 2023, more than 500 birders participated statewide. Interested in joining the flock this year? Birdathon teams can participate any day from April 15th to June 15th and all skill levels are welcome to join!