Why kingfishers sometimes turn themselves into aerial battering rams

6/7/2013 | 0

A female Belted Kingfisher perches on a stump. Photo by Kelly Colgan Azar (Creative Commons)

A female Belted Kingfisher perches on a stump. Photo by Kelly Colgan Azar (Creative Commons)

It’s well known that Belted Kingfishers are champion diggers, famous for sending plumes of soil into the air as they excavate their nest burrows.

Less well known is how the kingfishers get their burrows started. Published reports suggest the birds typically stab at the soil with their bill while they hover near a potential site or cling to a perch beneath it.

Occasionally, though, kingfishers locate their nests in banks that are vertical or overhanging, leaving no place to perch, or that are packed with rocks or other substances that resist pecking. How are these burrows started?

Paul Hendricks, a zoologist with the Montana Natural Heritage Program, knows. In April 2010, he and two colleagues watched a pair of Belted Kingfishers take turns hovering and then rushing toward the bank of Rattlesnake Creek in Missoula County, Montana. The birds repeatedly hit the bank bill-first, either directly or at an upward angle, then returned to a perch near the stream.

“Sometimes a kingfisher struck with such force that it struggled to remain airborne after impact as it bounced backwards and fluttered down to a creek-side perch,” Hendricks writes. “We saw debris fall down the face of the bank after several of these collisions.“

So-called aerial ramming — into banks, termitaria, or trees — has been reported in 13 other species of kingfishers (listed below), including two kookaburras, and birds have suffered broken bills and even died in the collisions. Given the potential hazards, Hendricks concludes, aerial ramming is probably the least desirable option available to Belted Kingfishers for initiating burrow excavations.

His observations appeared in the March 2013 issue of the Wilson Journal of Ornithology, the quarterly journal of the Wilson Ornithological Society. — Chuck Hagner, Editor

14 kingfisher species reported to perform aerial ramming:

Common Kingfisher (Alcedo atthis)
Belted Kingfisher (Megaceryle alcyon)
Blue-winged Kookaburra (Dacelo leachii)
Laughing Kookaburra (D. novaeguineae)
Woodland Kingfisher (Halcyon senegalensis)
White-throated Kingfisher (H. smyrnensis)
Stork-billed Kingfisher (Pelargopsis capensis)
Common Paradise-kingfisher (Tanysiptera galatea)
Collared Kingfisher (Todiramphus chloris)
Micronesian Kingfisher (T. cinnamominus)
Tuamotu Kingfisher (T. gambieri)
Forest Kingfisher (T. macleayii)
Sacred Kingfisher (T. sanctus)
Society Kingfisher (T. veneratus)

Read it yourself:

Paul Hendricks, Deborah Richie, and Lisa M. Hendricks (2013) Aerial Ramming, a Burrow Excavation Behavior by Belted Kingfishers, with a Review of Its Occurrence among the Alcedinidae. The Wilson Journal of Ornithology: March 2013, Vol. 125, No. 1, pp. 197-201. Abstract.

A version of this article appeared in the June 2013 issue of BirdWatching magazine.