In preparation for returning to Wisconsin from Central or South America, many birds will pack on 50-100% of their body weight to store up enough energy for their long journey, Brady says. For example, the male ruby-throated hummingbird, which weighs on average 3.0 grams, about as much as a penny, can double its body mass before migration. “Fat is fuel in the world of bird migration,” he says. “It’s what lets them overcome challenges like storms and loss of stopover habitat and still get to their breeding territories on time and in good condition.” Fat contains twice as much energy as carbs or protein. It is also a lot lighter and less bulky, perfect for the tiny birds that require lightweight energy for their long-distance travels, Brady says. After bulking up, both the Blackpoll and the Connecticut warblers embark on a two-to three-day non-stop flight over the Atlantic Ocean towards their South American wintering grounds. That’s a distance of 1,000 to 1,700 miles! Fat stores are hidden underneath birds’ feathers, so birds’ rotund appearance often actually reflects that they’ve fluffed up their feathers to stay warm. “Fat Bird Week is a great way to look at fun pictures and consider that birds are something more than just pretty to look at,” he says. “And in the end, we all like a winner!” See the matchups and learn more about how Wisconsin birds prepare for migration in this NRF blog post. Winner Announcement Webinar
Fat Bird Week’s winning bird will be announced at a webinar on April 30th at noon, where attendees will also learn the top four ways that Wisconsinites can help keep our state’s birds fat and healthy. Presented by SOS Save Our Songbirds and the Natural Resources Foundation of Wisconsin. Register here. |