Wisconsin Ornithology: Eastern Bluebird
In Wisconsin, United States
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This series highlights several of my favorite birds, all of which can be found in Wisconsin. I have found all of the birds included in the series (with one exception). Each cache is somehow related to the highlighted bird. In many cases you will find hints to finding the cache in the information provided about each bird. Each cache is hidden in roughly the environment the bird can be found. None of the caches are hidden in a nesting box or a fake nest (with one exception of a very non-standard nest), so if you find a nest or nesting box—please leave it alone it has nothing to do with the cache.
The Eastern Bluebird has perhaps the largest non-game fan club of any species of North American bird. As a result of both deliberate and unintentional human intervention the Eastern Bluebird population is at record levels. The Bluebird, a member of the Thrush family (like the Robin), feeds on the ground. Its’ habitat is at the intersection of open areas and woodlands: feeding on the ground of fields and meadows, but nesting in the cavity of trees. The clearing of land in the east and eastern mid-west created more open areas for the Bluebird. Similarly the creation of windbreaks on the prairies bringing trees for nesting allowed the Bluebird’s range to expand west. These developments allowed the population to greatly expand. However, the Eastern Bluebird began to face new competition for nesting spots in the mid-twentieth century from species such as the House Wren, House Sparrow, and European Starling. As a result the population began to decline. Concerned Bluebird lovers stepped in to create thousands of Bluebird nesting boxes. Many of these boxes were constructed with openings large enough for the Bluebird, but too small for its larger competitors. The Bluebirds rapidly adopted these nesting boxes. As a result, the population is as healthy today as it has ever been.
Eastern Bluebird (Sialia sialis )
The Eastern Bluebird is frequently seen perched on telephone wires, fence lines, fence posts, and tree limbs near fields and meadows. While this lofty perch might lead you to believe that the Bluebird is scanning the air for flying insects, as we have already mentioned, the Bluebird feeds mainly on the ground. Its’ primary diet is beetles, crickets, grasshoppers, caterpillars, and spiders. In the fall and winter the Bluebird’s diet is supplemented by a greater proportion of fruit.
The seemingly docile Bluebird can be quite aggressive in defending prime nesting spots. Bluebirds have been known to kill other Bluebirds over choice nesting locations. They have also been known to attack and occasionally kill House Sparrows, Starlings, and Tree Swallows. If there are a number of Bluebird boxes in an area, frequently a female will build a nest in multiple boxes, but use only one. It appears that the remaining nests are built simply to keep other Bluebirds from using the box. While the female builds the nest, the male often selects the location. Part of the mating ritual involves the male going in and out of the hole to the cavity or nesting box with building material in his beak. The pair may remain together for several years raising two broods a summer. Young from the first brood live independent after fledging. However, young from the second brood will after remain with the parents through migration and winter.
The Geocache Notification Form has been submitted to the Wisconsin DNR. Geocaches placed on Wisconsin Department of Natural Resource managed lands require permission by means of a notification form. Please print out a paper copy of the notification form, fill in all required information, then submit it to the land manager. The DNR Notification form and land manager information can be obtained at: http://www.wi-geocaching.com/hiding
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Last Updated: on 12/15/2015 2:17:36 PM (UTC-08:00) Pacific Time (US & Canada) (10:17 PM GMT)
Coordinates are in the WGS84 datum