Julie Craves answers readers’ questions about Eastern Bluebird, Great Horned Owl, and more

 

In every issue of BirdWatching, Contributing Editor Julie Craves answers readers’ questions about birds and bird behavior in her column “Since You Asked.” Julie is supervisor of avian research at the Rouge River Bird Observatory at the University of Michigan Dearborn and a research associate at the university’s Environmental Interpretive Center. She blogs about her research at net-results.blogspot.com, and she maintains the website Coffee & Conservation, a thorough resource on where coffee comes from and its impact on wild birds.

In our August 2013, Julie answered questions about Eastern Bluebird, Great Horned Owl, and more. Here are the questions and her answers:

I live in south-central Nebraska, and every birdwatching book I’ve seen shows that Eastern Bluebird does not reside much west of Lincoln. If that is true, why do I see bluebird boxes on fence lines in parks and pasture land? Are we trying to encourage the bird to expand its range? — Jerry Culver, Kearney, Nebraska

While it’s possible that the boxes are intended for other cavity-nesting species, Eastern Bluebirds do, indeed, nest in western Nebraska. According to the Nebraska Bird Library, Eastern Bluebirds nest locally in the west, but they’re not as common as in the eastern part of the state.

Range maps in field guides can be out of date. The best source for current information on breeding birds is a state ornithological or birding society or a breeding bird atlas.

A breeding bird atlas compiles statewide nesting data gathered by volunteers. An effort is made to cover all habitats, often down to the township level. Atlas projects typically span five years and are repeated every 20 years, offering a snapshot of where each species nests and how ranges change over time. The atlases can be powerful tools for conservation.

Most states have completed at least one atlas, and many states are now working on their second. Nebraska recently completed the fifth year of its second atlas.

Can thunder kill the embryos in bird eggs? — Mark Kelliott, Boston, Massachusetts

I have heard this old wives’ tale mostly in connection with chickens. There is no reason why thunder would harm eggs unless the parent incubating the eggs abandoned the nest after being disturbed by the noise or if the associated lightning destroyed the nest somehow.

I have heard that Great Horned Owls can take prey as large as a porcupine. Does that mean they can catch a porcupine? How can they eat a porcupine? — Bud Green, Chapel Hill, North Carolina

Great Horned Owl is one of the Western Hemisphere’s most powerful and largest owls, weighing from two to five pounds; females are larger than males. The owls typically feed on small rodents or medium-size prey such as rabbits and ducks. However, they have been known to attack prey much heavier than themselves, including porcupines, which can weigh from 12 to 35 pounds.

Usually owls swallow mice and other small prey whole. When they catch large prey, they tear it apart with their bills and strong talons. Because of this habit, and because of the large size and ample spiny defenses of porcupines, not all encounters end well for the owl.

I have seen several accounts of Great Horned Owls found with porcupine quills embedded in their faces and bodies, a situation that can be fatal. Porcupines are not armed with quills on the front halves of their bodies, so it’s possible an owl could successfully attack a sleeping or unwary porcupine, but the likelihood that the owl would end up with quills in it seems pretty high.

What was your spark bird? — Stan Ortsag, Baltimore, Maryland

I have loved birds for as long as I can remember, an interest passed on to me from my mother. One of my first bird books was rather crude by today’s standards: The Bird Guide by Chester Reed, published in 1905. (It was a gift from an elderly neighbor and is not an indication of my age!)

I can still remember browsing through the little red leather-bound book, looking at the eye-popping painting of Scarlet Tanager. I honestly did not believe a bird so brilliant could be found near me, and finding one became my quest. It took me a while to see my first, but I was hooked on birds well before that day. I consider Scarlet Tanager my spark bird. It still takes my breath away.

 

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

Originally Published August 2, 2013