This male Eastern Bluebird is either sunbathing (which may help drive off mites or lice), or doing what is called passive “anting.” They fly down onto the lawn and strike a possum-like pose, lying on the ground with their wings extended and fluffed out, and their heads cocked to one side. Sometimes they actually lie on their sides. They stay in this position for one to several minutes. Afterwards they may preen their belly and wing feathers.
I saw a Black-capped Chickadee doing this on a black shingle roof. I thought it was dead until it flew off. It was probably sunning or sunbathing. (House Sparrows have also been seen doing this on rooftops.) Sunbathing helps absorb solar radiation. The heat may cause feather parasites to mobilize, making it easier for the bird to locate and remove them during preening.
Anting has been observed in more than 250 species of birds (mostly passerines) worldwide. (It has not been seen in Western Bluebirds. Whitaker, who did a resume of anting in 1957, listed all other North American thrushes except bluebirds as anting.) When birds (e.g., Starlings) engage in passive anting over an ant hill, they may first disturb it with their feet or belly. Apparently they want the ants to crawl on them. They don’t eat them. Some people believe this is because the formic acid emitted by ants as a defense mechanism may affect mites which pester them. Bluebirds do not place ants on their feathers like other members of the thrush family (Krieg 1971.)
In other cases, birds actually pick up ants (called “active anting”), kill them, and then rub them on their plumage. Researchers disagree as to why they do this. According to John Eastman in Birds of Forest, Yard, and Thicket: “The traditional view is that ants’ formic acid acts as an insecticide or fungicide against feather and skin parasites. Anting often occurs during periods of high humidity, lending weight to the fungicidal theory. But other investigators find no correlation between anting and parasite or fungal presence; they speculate that anting, like sunning, is simply a comfort activity, stimulating the skin, especially during summer molt. A recent theory suggests that anting forces the insects to expel their formic acid, thus making them more palatable to consume.”
References and More Information:
- Anting (Ecobirds)
- Bluebird_L posts on “anting”
- Feather facts (Sialis.org)
- Cornell Glossary
- Birds of Forest, Yard, and Thicket
by John Eastman
Previous Pictures of the Week: © Original photographs are copyrighted, and may not be used without the permission of the photographer. Please honor their copyright protection. If you would like to use a photo for educational purposes, you can contact me.
- Tips for photographing cavity nesters
- June 11, 2006 – Great Crested Flycatcher
- June 19, 2006 – Snake Lick
- June 26, 2006 – House Finch Nest
- July 3, 2006 – Tree Swallow in Flight
- July 17, 2006 – Bluebird Battle
- July 24, 2006 – Bear Attack
- August 1, 2006 – Neglected Nestboxes (House Sparrow nests)
- August 14, 2006 – Threesome (Bluebird Babes)
- August 28, 2006 – Peering (flicker)
- January 2007 – New Hill Trail (Sialis)
- February 12 2007 – Sharp-shinned? Hawk feeding on dead starling
- February 19, 2007 – Joe’s Cafe (Suet/Mealworm Feeder)
- March 25, 2007 – Sunflower Eater
- February 2007 – Snags & Suet (Pileated Woodpeckers)
- May 2007 – Birdcam Shots and Birdcam Photo Album
- May 12, 2007 – Carolina Wren nest in a boot
- May 25, 2007 – Batman Bird (Tree Swallows)
- June 2007 – Bluebird nest of cattails, one with leaves, and a TRES nest with maple seeds
- June 20, 2007 – Nine Egger (Tree Swallow nest)
- June 27, 2007 – Black-capped Chickadees (funny and serious photos)
- July 7, 2007 – Anting and Sunbathing
- Red-shouldered Hawk perching on nestbox
- November 18, 2007 – Western Bluebirds at the Spa
- March 15, 2008 – Under Construction – Eastern Bluebirds Building a Nest
- April 9, 2008 – Bluebird Battle in PA
- April 10, 2008 – Mouse Surprise
- April 15, 2008 – Bluebird News (nest in paper box)
- April 23, 2008 – My personal nightmare
- April 25, 2008 – Brave White-breasted Nuthatch
- April, 2008 – How an egg hatches
- May 3, 2008 – Newborn Blue (baby hatching)
- May 3, 2008 – Brave Blue (female on nest)
- May 14, 2008 – House Wren Havoc (eggs pecked)
- May 25, 2008 – House Wren Takeover (of nest, more pecked eggs)
- May 29, 2008 – Take Your Pick (parents feeding fledgling)
- June 10, 2008 – That Look Belongs in a Holster (female MOBL)
- August 23, 2008 – Cat on Nestbox
- September 28, 2008 – HOSP on the House
- October 10, 2008 – Cuddling nestlings (taken in summer time)
- October 27, 2008 – HOSP in flight
- October, 2008 – Possible double and dwarf egg in one nest
- December 16, 2008 – The Next Generation (children building boxes)
- January 22, 2009 – Blue with Cold
- January 28, 2009 – Prothonotary Warbler on a camper | Nest building PROW | PROW nesting in tree cavity
- May, 2009 – To Kill a Mockingbird (Snake eating mockingbird – may be disturbing)
- May 21, 2009 – Should I Stay or Should I Go Now? (Titmouse nestling in box)
- May 25, 2009 – Which of these is not like the others? (Cowbird egg)
- May 23, 2009 – The Honeypot at the end of the rainbow (bumblebee nest)
- June 20, 2009 – House Wren nest decorated with Western Bluebird feathers
- June 20, 2009 – Wonderful WEBLS of WA
- June 20, 2009 – Bluebirds of Bickleton
- July 12, 2009 – Hairy Shrimp (newborn bluebirds)
- July 2009 – Diet (bluebird with earthworm in beak)
- July 2009 – Bluebirds nesting outside of cavity
- July 19, 2009 – HOSP on Holiday
- July 20, 2009 – Pink bluebird eggs
- August 2, 2009 – Pinkies (baby mice)
- August 2, 2009 – En garde (male bluebird in box)
- September 29, 2009 – 1917 instructions for bird house construction
- I forget when – Rainbox
- April 11, 2010 – nuthatch bark
- April 12, 2010 – My first white egg
- April 12, 2009 – TUTI nest by Keith Kridler
- May 2010 – TUTI newborns
- May 2010 – Christmas Chickadee
- May 2010 – Bluebird and Chickadee eggs in the same nest
- June 2012 – Paparazzi
- April 2013 – Under Construction – Titmouse nestbuilding
- July 2013 – Pink Bluebird Eggs
- July 2014 – Cowbird egg in Eastern Bluebird nest
- July 2014 – Newborn HOSP
- July 2015: Patience Pays (Male Eastern Bluebird)
A bluebird, famous for the scrap of sky
Borne on his back – an indigo so bright
That just a glimpse of his distinctive flight,
All swoop and flurry, captivates the eye …
– George Bradley, “New Yorker” Mar. 19, 2001
