American Birding Podcast



Blog Birding #416



California Gnatcatcher continues to be the subject of various legal battles against developers in its core southern California range. At 10,000 Birds, Jason Crotty explains.

More recently, a group of developers petitioned FWS to delist the gnatcatcher because the underlying science was allegedly flawed and the coastal gnatcatcher is not really a distinct subspecies. The petition relied on a genetic and ecological analysis by Dr. Robert Zink, a biologist at the University of Nebraska (the “Zink study”). FWS sought the views of six independent scientists and they all rejected the findings in the Zink study. As a result, FWS denied the petition to delist in August 2016.

Kayla Fisk explores the evolutionary history of the beak, which next to feathers is the defining characteristic of Class Aves.

While no matter what color or shape they are they are all made up of the same underlying structure. The very basis of each birds beak are two bony structures, the upper and lower mandible. On top of this is a thin keratin layer of epidermis which is called the rhamphotheca. This layer is what is often referred to as the bill sheath and is what contains the color and structure of the beak.

At the American Ornithological Society’s Wing Beat blog, Joshua Brown summarizes a paper that explores the genetic hegemony of the ubiquitous Mallard.

The “mallard complex” comprises 14 closely related mallard-like species of duck that are uniquely adapted to various habitats and environments around the world. Nearly every species within the complex has come into contact and is known to hybridize with the Mallard. It’s important for wildlife managers to monitor the effects of hybridization on the genetic integrity of both species involved. Our study system, described below, provides a unique opportunity to investigate how hybridization affects the evolutionary trajectory of closely related species under differing environmental and ecosystem pressures.

The passage of Hurricane Dorian meant rare birds in Atlantic Canada, with Nova Scotia the primary recipient. At Cape Sable Birding, Mark Dennis shares the experience.

After a busy time sometimes you just want to chill for a while but circumstance sometimes demands you dredge up that last bit of energy and get on with it. With the Hurricane Dorian fall out this was one of those times, there will be plenty of time for quiet reflection once the birds have all gone and we are back to staring at Herring Gulls and wondering whether they are vaguely Vega.