Breeders Choice





imageedit_5_3949838586

Website Investments

Breeders Choice

Pet Bird - Bird Health - Bird Feed - Birds

Wild Birds - Bird Bath - Attracting Birds - Bird Watching





imageedit_5_3949838586

A Study Of The Incubation Periods Of Birds

RRP $16.99

Click on the Google Preview image above to read some pages of this book!

Dr. Bergtold bravely attacks a problem which has ever aroused the interest of ornithologists, by assembling all the available facts and theories relating to it. This evidence, with the many attempts which have been made to determine its significance, he weighs carefully, and finally presents his own conclusions.

The authentic incubation periods recorded vary from ten days in the Cowbirds, Bobolinks, certain Warblers and some others, to as many as fifty-six or fifty-eight days in the Emu and sixty days in the Black-eye-browed Albatross.

To account for this wide difference in time is the object of Dr. Bergtold's studies. Lack of satisfactory data concerning many of the factors involved prevent him, he writes, from presenting other than tentative conclusions.

While admitting that the incubation period "is loosely related to the size of the species, and still more loosely to the size of the egg," Dr. Bergtold believes that this period is primarily determined by thetemperature of the bird. The existing information in regard to the temperature of birds indicates that the 'lowest' forms (that is, those most nearly related to their reptilian ancestors) have the lowest temperatures (averaging 100° - 104°) while the 'highest' birds have the highest temperatures (averaging 106° - 110°). Here, apparently, we have a physiologically reasonable explanation of why the higher birds (Thrushes, Warblers, Finches, etc.) have the shortest incubation periods.

Dr. Bergtold has assembled more information concerning this fascinating and important subject than has before been available in a single volume, and his work marks the starting-place for all future investigators of the phenomena he so ably discusses.

-Bird-Lore: An Illustrated Bi-monthly Magazine, Volume 19 [1917]


"their Eyes Were Watching God"

RRP $8.99

Click on the Google Preview image above to read some pages of this book!

REA's MAXnotes for Zora Neale Hurston's Their Eyes Were Watching God

MAXnotes offer a fresh look at masterpieces of literature, presented in a lively and interesting fashion. Written by literary experts who currently teach the subject, MAXnotes will enhance your understanding and enjoyment of the work. MAXnotes are designed to stimulate independent thought about the literary work by raising various issues and thought-provoking ideas and questions.

MAXnotes cover the essentials of what one should know about each work, including an overall summary, character lists, an explanation and discussion of the plot, the work's historical context, illustrations to convey the mood of the work, and a biography of the author. Each chapter is individually summarized and analyzed, and has study questions and answers.



Search

Breeders Choice Articles

Pet Bird Bird Health Bird Feed Birds
Wild Birds Bird Bath Attracting Birds Bird Watching

Breeders Choice Books

Pet Bird Bird Health Bird Feed Birds
Wild Birds Bird Bath Attracting Birds Bird Watching

Breeders Choice





imageedit_5_3949838586

Website Investments