Tuesday, March 28, 2017

Toad Tales



The greater prairie chicken or pinnated grouse (Tympanuchus cupido), sometimes called a boomer, is a large bird in the grouse family. This North American species was once abundant, but has become extremely rare and extirpated over much of its range due to habitat loss. Conservation measures are underway to ensure the sustainability of existing small populations. One of the most famous aspects of these creatures is the mating ritual called booming.

Adults of both sexes are medium to large chicken-like bird, stocky, with round-wings. They have short tails which are typically rounded and blue in color. Adult males have orange comb-like feathers over their eyes and dark, elongated head feathers that can be raised or lain along neck. They also possess a circular, un-feathered neck patch which can be inflated while displaying; this, like their comb feathers, is also orange. As with many other bird species, the adult females have shorter head feathers and also lack the male's yellow comb and orange neck patch.
Charles Wheeler took this gorgeous shot of a Greater Prairie-Chicken displaying in Nebraska.
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The greater prairie chicken was almost extinct in the 1930s due to hunting pressure and habitat loss. They now only live on small parcels of managed prairie land. It is thought that their current population is approximately 459,000 individuals. In May 2000, the Canadian Species at Risk Act listed the greater prairie chicken as extirpated in its Canadian range (AlbertaSaskatchewanManitobaOntario). It was again confirmed by the Committee on the Status of Endangered Wildlife in Canada in November 2009. Nonetheless, sightings and encounters continue to occur in the south-central regions of Alberta and Saskatchewan, along with southern Ontario where sightings are extremely rare.
In states such as Iowa and Missouri that once had thriving prairie chicken populations (estimated to be hundreds of thousands, total numbers have dropped to about 500. However, the Missouri Department of Conservation has started a program to import prairie chickens from Kansas in the hopes that they will be able to repopulate the state and increase that number to 3,000.
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Greater prairie chickens do not migrate. They are territorial birds and often defend their booming grounds. These booming grounds are the area in which they perform their displays in hopes of attracting females. Their displays consist of inflating air sacs located on the side of their neck and snapping their tails. These booming grounds usually have very short or no vegetation. The male prairie-chickens stay on this ground displaying for almost two months. The breeding season usually begins in the United States starting in Late March throughout April. During this time the males establish booming sites where they display for the females. The one or two most dominant males will do about 90% of the mating. Due to their now small populations and habitat fragmentation the greater prairie chickens often undergo inbreeding causing observable inbreeding depression: with fewer offspring and a decreased survival rate within these limited offspring further aiding their population decrease.




After mating has taken place, the females will move about one mile from the booming grounds and begin to build their nests. Hens lay between 5 and 17 eggs per clutch and the eggs take between 23 and 24 days to hatch. There are between five and 10 young per brood. (INRIN, 2005). The young are raised by the female and fledge in one to four weeks, are completely independent by the tenth to twelfth week, and reach sexual maturity by age one (Ammann, 1957). A study of female greater prairie chickens in Kansas found that their survival rates were 1.6 to 2.0 times higher during the non-breeding season compared to the breeding season; this was due to heavy predation during nesting and brood-rearing. [8] One problem facing prairie chickens is competition with the ring-necked pheasants. Pheasants will lay their eggs in prairie-chicken nests. The pheasant eggs hatch first; this causes the prairie chickens to leave the nest thinking that the young have hatched. In reality the eggs did not hatch and the young usually die because the mother is not there to incubate the eggs.




http://www.thenaturalistsnotebook.com/

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