Size Dimorphism and Food Habits of North American Owls

The Condor ◽  
1970 ◽  
Vol 72 (3) ◽  
pp. 251-264 ◽  
Author(s):  
Caroline M. Earhart ◽  
Ned K. Johnson
Keyword(s):  
North American ◽  
Food Habits ◽  
Size Dimorphism

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

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.

Influence of female-biased sexual size dimorphism on dominance of female Townsend’s chipmunks

2006 ◽  
Vol 84 (12) ◽  
pp. 1859-1863 ◽  
Author(s):  
A.J. Edelman ◽  
J.L. Koprowski
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
North American ◽  
Sexual Size Dimorphism ◽  
Large Female ◽  
Small Female ◽  
Access To Resources ◽  
Size Dimorphism

Female-biased sexual size dimorphism (SSD), a condition common in North American chipmunks, occurs when females are larger than males in a species. We examined the influence of body size on dominance of captive female Townsend’s chipmunks ( Tamias townsendii Bachman, 1839), a species that exhibits female-biased SSD, in all-female and mixed-sex dyadic encounters. In all-female dyads, large female chipmunks were more frequently dominant over small female opponents. In mixed-sex dyads, large females were always dominant over small males. Female-biased SSD in Townsend’s chipmunks appears to indirectly allow large females to more frequently dominate small female and male conspecifics. Greater dominance could increase reproductive success of large female chipmunks by increasing access to resources.

Pythons in the pergola: the ecology of 'nuisance' carpet pythons (Morelia spilota) from suburban habitats in south-eastern Queensland

2001 ◽  
Vol 28 (6) ◽  
pp. 573 ◽  
Author(s):  
S. Fearn ◽  
B. Robinson ◽  
J. Sambono ◽  
R. Shine
Keyword(s):  
Body Size ◽  
Food Habits ◽  
Sexual Size Dimorphism ◽  
Activity Patterns ◽  
Dietary Composition ◽  
Seasonal Activity ◽  
Size Dimorphism ◽  
South Eastern ◽  
Two Cities ◽  
Body Sizes

Carpet pythons (Morelia spilota) are large (to >4 m, 11 kg) non-venomous snakes that are widely distributed across mainland Australia. In many parts of their range, viable populations persist even in highly disturbed urban and suburban habitats. Over a six-year period, we collected 258 ‘nuisance’ pythons from two cities (Brisbane and Ipswich) in south-eastern Queensland. Most of these snakes were reported by members of the general public, often after the snakes had consumed domestic pets or cage-birds. We provide data on seasonal activity patterns, body sizes, sexual size dimorphism, reproduction and food habits of these snakes. Snakes were active and fed year-round, primarily on domestic and commensal birds and mammals. Dietary composition shifted with body size: one small snake consumed a lizard, intermediate-sized snakes took mostly mice, rats and parrots, and large snakes fed on larger items such as cats, brushtail possums and poultry. Adult male pythons engaged in combat bouts during the breeding season, and (perhaps as an adaptation to enhance success in such bouts) grew larger and were more heavy-bodied than conspecific females.

Sexual size dimorphism in relation to resource partitioning in North American dabbling ducks

1984 ◽  
Vol 62 (10) ◽  
pp. 2009-2012 ◽  
Author(s):  
Thomas D. Nudds ◽  
Richard M. Kaminski
Keyword(s):  
North American ◽  
Resource Partitioning ◽  
Sexual Size Dimorphism ◽  
Prey Size ◽  
Dabbling Ducks ◽  
Male And Female ◽  
Size Dimorphism ◽  
Bill Morphology ◽  
Size Dimension ◽  
Bill Length

Data from museum specimens were used to examine patterns of sexual size dimorphism in bill morphology in relation to resource partitioning in seven species of North American dabbling ducks (Anas sp.). All species were dimorphic with respect to bill length. Male and female bill length distributions were skewed in opposite directions in five of seven species (P < 0.01). Four of seven species were dimorphic with respect to lamellar density, but male and female distributions were skewed in opposite directions in only two species. The four dimorphic species were positioned between other species along a prey size dimension; species which were not dimorphic had only one neighbour on the prey size dimension. These results are consistent with the hypothesis that intersexual competition for food promotes niche divergence between sexes and contributes to sexual size dimorphism in ducks.

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.

scholarly journals Food Habits of North American Diving Ducks

Bird-Banding ◽  
1939 ◽  
Vol 10 (4) ◽  
pp. 178
Author(s):  
Margaret M. Nice ◽  
Clarence Cottam
Keyword(s):  
North American ◽  
Food Habits ◽  
Diving Ducks
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