Sexual Dimorphism and Food Habits in Three North American Accipiters

The Auk ◽  
1966 ◽  
Vol 83 (3) ◽  
pp. 423-436 ◽  
Author(s):  
Robert W. Storer
Keyword(s):  
Sexual Dimorphism ◽  
North American ◽  
Food Habits

The Food Habits of North American Golden Eagles

1976 ◽  
Vol 95 (1) ◽  
pp. 231 ◽  
Author(s):  
Richard R. Olendorff
Keyword(s):  
North American ◽  
Food Habits ◽  
Golden Eagles

Lack of diet segregation between sexes and age groups in feral horses

1985 ◽  
Vol 63 (11) ◽  
pp. 2583-2585 ◽  
Author(s):  
Mark S. Lenarz
Keyword(s):  
Sexual Dimorphism ◽  
Intraspecific Competition ◽  
Food Habits ◽  
Age Groups ◽  
Past Research ◽  
Diet Selection ◽  
Feral Horses ◽  
Range Use

Past research on large ungulates has suggested that species might minimize intraspecific competition by assuming sex- or age-specific diets. Diet segregation has, in fact, been documented in a variety of taxa but tends to be confounded by sexual dimorphism or differential range use. A hypothesis regarding diet selection was tested using food habits data from feral horses. The results indicate that diet segregation does not take place either between sexes or among age groups.

Digestive organ morphology, diet, and guild structure of North American Anatidae

1987 ◽  
Vol 65 (7) ◽  
pp. 1812-1817 ◽  
Author(s):  
Gregory G. Barnes ◽  
Vernon G. Thomas
Keyword(s):  
North American ◽  
Food Habits ◽  
Feeding Habits ◽  
Feeding Guilds ◽  
Canada Geese ◽  
Guild Structure ◽  
Diet Diversity ◽  
Branta Bernicla ◽  
Carnivorous Species ◽  
Clangula Hyemalis

Discriminant function, cluster, and covariate analyses of gizzard, small intestine, and ceca weights were used to quantify the structure of feeding guilds and the effects of diet on gut morphology for 18 species of North American anatids. Guild structure based on gut measurements closely approximated that identified by generalized feeding habits. Herbivorous species such as Brant (Branta bernicla), Gadwall (Anas strepera), Redheads (Aythya americana), Canada Geese (Branta canadensis), and Mallards (Anas platyrhynchos) consistently had heavier gizzards and ceca than carnivorous species such as Common Goldeneye (Bucephala clangula), Bufflehead (Bucephala albeola), Oldsquaw (Clangula hyemalis), and Common Mergansers (Mergus merganser). Omnivorous species such as Lesser Scaup (Aythya afftnis), Greater Scaup (Aythya marila), and American Black Ducks (Anas rubripes) were characterized by heavy gizzards, intermediate ceca, and heavy intestines. The results provide further evidence that intestine size is primarily influenced by overall diet diversity and suggest that gut size may be used to indicate general food habits. The ability of waterfowl to adjust gut sizes and accommodate dietary changes is restricted to ranges dictated by the most frequently eaten foods. Thus, predictions of general food habits can be made without knowledge of the foods being consumed at a particular time and location.

Lower Devonian aulacopleuroidean trilobites from Oklahoma

1997 ◽  
Vol 71 (4) ◽  
pp. 703-712 ◽  
Author(s):  
Jonathan M. Adrain ◽  
Gerald J. Kloc
Keyword(s):  
New Species ◽  
Sexual Dimorphism ◽  
North American ◽  
Lower Devonian ◽  
First Record ◽  
The North ◽  
New Information ◽  
New Material

New aulacopleuroidean trilobites from the Lochkovian of Oklahoma include the otarionine Cyphaspis carrolli new species from the Haragan Formation, and the brachymetopid Cordania wessmani new species from the overlying Bois d'Arc Formation. Cyphaspis carrolli is the first record of the genus from the North American Devonian. It is a highly plesiomorphic species, dissimilar to contemporaries from Europe, but closely related to Silurian species from Northern Laurentia and England. Cordania wessmani had previously been interpreted as a possible sexual dimorph of Cordania falcata Whittington, 1960, but new material and information shows that the forms occur separately with no stratigraphic overlap. New information on trilobite occurrence in the Haragan and Bois d'Arc Formations does not support previous hypotheses of trilobite sexual dimorphism, but rather indicates the presence of distinct, stratigraphically successive faunas.

scholarly journals ON THE FOOD-HABITS OF NORTH AMERICAN RHYNCHOPHORA

1890 ◽  
Vol 22 (12) ◽  
pp. 258-261
Author(s):  
W. M. Beutenmuller
Keyword(s):  
North American ◽  
Food Habits ◽  
Staten Island ◽  
Salix Fragilis

Orchestes niger and O. subhirtus are both found on willow when in bloom. (Harrington Can. Ent, 16, p. 119.)Orchestes niger and O. pallicornis were taken together in July on the leaves of low willows by Mr. Chittenden. O. ephippiatus was found in abundance on willow (Salix fragilis) by Mr. C.W Leng and myself on Staten Island, N.Y.

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