Red in tooth and claw

… and beak. Acorn Woodpeckers (Melanerpes formicivorus), it turns out, can be fierce fighters when defending a granary tree.

Each combat site lured up to 50 helper females representing a dozen or more competing coalitions. The birds spread their wings to put on a show of superiority and strength and engaged in incessant bickering; at times the war got bloody. “We’ve seen birds with eyes gouged out, wings broken, bloody feathers, and birds that fell to the ground fighting each other,” Dr. [Sahas] Barve said. “It’s the real stuff.”

What’s that I hear?

Antonio de Luca, Dave Taft and Umi Syam have assembled a very good primer on birds that you might see in the New York metro (or any eastern city, for that matter). The integration of Donald Kroodsma’s sonograms with the audio playback is a great touch, especially for those of us who really haven’t learned how to use sonograms effectively.

And anyone who reminds us,

And as for that iconic cry: As impressive as bald eagles look, their high-pitched chirps can be underwhelming. When an eagle cries in a car commercial or a cowboy movie, you’re probably hearing the dubbed scream of a red-tailed hawk.

has won my heart.

Pair bond

almost readyA pair of Carolina Wrens (Thryothorus ludovicianus) is building a nest in an overgrown plant container at the back of my house. They’ve been working on it since at least Friday, so I’m expecting eggs and incubation (14 days, according to Baicich and Harrison) any time now.

Two ounces

High tech-low tech-biotech: Fitting albatrosses with radar detectors to catch stealth fishermen.

Albatrosses are ideal sentinels of the open ocean, said Henri Weimerskirch, a marine ecologist at a French National Center for Scientific Research in Chizé, France, and the lead author of the new study published on Monday in Proceedings of the National Academy of Sciences. “They are large birds, they travel over huge distances and they are very attracted by fishing vessels.”

Some links: 86

  • Converting 35% of the acreage of a coffee farm to shade-grown culture can maximize revenue, according to new research by Amanda Rodewald et al. and summarized by Gustave Axelson. Depending on the premium paid for shade-grown coffee, that percentage can go as high as 85%.
  • A smartphone attachment can test for the presence of norovirus in a drinking water sample and produce results in five minutes. The promising prototype comes from the biomedical engineering lab of Jeong-Yeol Yoon. Joe Palca reports.

    In the wake of hurricanes and other storms, flooding can cause sewage systems to overflow, potentially mixing with water intended for drinking. Municipal water system managers would breathe easier if they could be certain they didn’t have to worry at all about norovirus contamination.

  • How to cross a river. The water at Huntley Meadows Park is never this fast or cold.
  • Melissa Errico submits a “self-tape” audition.

Carry on

On that same field trip today, Alonso reported seeing a Wood Duck (Aix sponsa) carrying an egg. The bird was at some distance to him, and I didn’t see the bird. We discussed the sighting, and concluded that it was possible, but somewhat unusual.

There is a bit in the literature: Robert W. Strader et al. (The Wilson Bulletin 90:1, March 1978, pp. 131-132) report an observation and suggest that the purpose of egg carrying is to remove eggs damaged by a woodpecker, another animal, or mishap. Larry J. Hindman (The Wilson Journal of Ornithology 127:4, December 2015, pp. 759-761) reports an observation of a male Wood Duck carrying an egg, and discusses some other possible explanations for the behavior.

The removal behavior might be more common than we think. In our boxes, it’s sometimes been the case that we count x eggs on a given Sunday, with high certainty, and we count x-1 eggs the next Sunday.

Some links: 81

Some links, Coffee and Birds Edition:

  • Jodi Helmer reports on the nascent coffee industry in California. Even in this non-tropical climate, at least one farmer is going the shade-grown route:

    Andy Mullins of Mullins Family Farm in Temecula… planted 1,000 coffee trees under the canopies of the avocado trees on his 4-acre farm.

  • A study from India by Charlotte H. Chang et al. indicates that coffee plantations given over to robusta supported nearly the same level of biodiversity as arabica farms, as summarized by the Wildlife Conservation Society.