Blog Birding #284

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Blue-winged and Golden-winged Warblers are notorious for their penchant for interbreeding, but the upcoming publication of a study in Current Biology clarifies the relationship between the two “species”, and forces us to question what we think about these birds. Gustave Axelson explains at All About Birds.

 

In many ways, Golden-winged Warblers and Blue-winged Warblers appear to be completely distinct species-they look different, they sing different songs, and in recent history they have lived in different places, with golden-wings in the Northeast and upper Midwest and blue-wings in a band slightly farther south from the Ozarks to the Appalachian Mountains. Where the two species overlap, they produce hybrids-including the forms called Brewster’s and Lawrence’s warblers.

 

The classy Loggerhead Shrike is much loved for its unique plumage and vicious nature. But, as Tom Brown, writing at 10,000 Birds shares, the species has an easy-going family life that belies its grisly reputation.

 

As a boy growing up, I scoured every bird book I could get my hands on. In each of them, I was always fascinated with the shrikes. I guess it is that gruesome boyhood interest in any bird that would use thorns and barbwire to impale its prey on. Years went by, and I had still not been able to track down a real live shrike to add to my list. In 2011, my wife and I sailed into a beautiful little anchorage here in the Sea of Cortez, on Isla Espritu Santos. Out exploring in the dinghy, I got to see my first shrike, a Loggerhead Shrike. There it sat, on the top of a Cordon Cactus, obviously looking for its next prey. Childhood memories flooded back in, and I began my search for the poor victims of this bird, so lovingly nicknamed “The Butcher Bird”. Nothing was found, not a grasshopper, lizard, nothing. Sometimes reality is so unfair!

 

The joke about the chicken and the egg is and old one, but there are still a lot of questions about the evolution of bird and pre-bird reproduction. A new published study, shared at The AOU-COS Publication Blog, seeks to shed some light on that evolution.

 

Fossils of primitive birds and eggs from the Mesozoic era place them midway between their dinosaur ancestors and their modern descendants, with eggs between those of pre-avian dinosaurs and modern birds in term of size and shape. In this way, David Varricchio and Frankie Jackson of the Montana State University are able to trace the evolution of bird reproduction through a series of distinct stages, from pre-avian dinosaurs to the birds of today.

 

At The Nemesis Bird, Ian Gardner writes about a recent trip to the far reaches of Honduras in search of birds and adventure.

 

A Band-tailed Pigeon flock flew overhead as an Azure-crowned Hummingbird darted past my head. I spotted a Brown-capped Vireo, several Yellow-backed Orioles, and a Black-headed Siskin… then one rampaging, blue bird shot down the dirt road we were standing on. We learned to stay vigilant for them from then on. No, it wasn’t an actual bird nor was it blue. Although there are resident Eastern Bluebirds here (one of a surprising number of carryover species from the Eastern US) Blue Bird is an American school bus manufacturer, and this was one of many retired yellow school buses that now have a second life in Honduras. Naturally with absent traffic police, the young and reckless pilots kept their right foot as close to the floor as possible between stops. That evening we stayed at the lodge adjacent to the La Tigra Visitor’s Center. Most of us spent the night shivering, but thankful to not be caught out in the 3am downpour.

 

Fall is coming in the upper midwest, and Laura Erickson is out in the field to experience it, even if fall at this point looks like young warblers, ratty vireos, and hummingbirds.

 

Birds know better. Days are noticeably getting shorter, most baby birds of the year are on their own now, and adults are recovering from the rigors of raising those young birds-many have finished molting into new feathers and are ready to head south. NEXRAD has been showing some migratory events already, and even though birds are quiet, we can’t help but notice that a lot of them are starting to pass through.

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