Male aggression and colour in divergent populations of the threespine stickleback: experiments with animations

1996 ◽  
Vol 74 (9) ◽  
pp. 1727-1733 ◽  
Author(s):  
Jeffrey S. McKinnon ◽  
J. D. McPhail
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Agonistic Behaviour ◽  
Western North America ◽  
Colour Discrimination ◽  
Male Aggression ◽  
Nuptial Coloration ◽  
Negative Findings

We investigated the evolution of male agonistic behaviour and nuptial coloration in populations of the threespine stickleback, Gasterosteus aculeatus, with either monomorphic red or monomorphic black coloration. Specifically, we examined the responses of males from the two population types to computer-generated animations of males with black, red, or dull grey throats on otherwise identically coloured bodies. Males varied greatly in their aggressive responses among individuals and among trials, and did not show statistically significant discrimination towards the differently coloured animations. These results, therefore, do not suggest a role for interactions among males in the evolution of divergent male nuptial coloration. In addition, these negative findings are consistent with other studies of stickleback from western North America, suggesting that geographic variation in agonistic colour discrimination may account, in part, for the discrepancies between the results of earlier studies. Given the diverse methods of studies on this topic, however, methodological differences may also have contributed to the inconsistent results.

A morphometric study of geographic variation in the snowshoe hare (Lepus americanus)

1985 ◽  
Vol 63 (3) ◽  
pp. 567-579 ◽  
Author(s):  
David W. Nagorsen
Keyword(s):  
North America ◽  
Great Lakes ◽  
Geographic Variation ◽  
Principal Component ◽  
Lepus Americanus ◽  
Morphometric Study ◽  
Western North America ◽  
Environmental Selection ◽  
Local Selection ◽  
Central Canada

Geographic variation in Lepus americanus was studied by multivariate analyses of 15 cranial measurements. A total of 1494 specimens from the entire geographic range were grouped into 37 geographic samples of males and females. Principal component analyses demonstrated that hares are largest in eastern North America, Alaska, and northwestern Canada, and smallest in the Pacific Northwest. Size clines exist in the Appalachian Mountains and western North America but size is relatively uniform throughout central Canada and the Great Lakes. A multiple regression of size with 16 climatic variables factors demonstrated that size and climate are strongly correlated; the size trends may reflect environmental selection. The differentiation of hares from the western Cordillera and Pacific coast, the similarity of populations from central Canada and the Great Lakes, and the clines in the Appalachians and western North America were evident in discriminant analyses. These patterns of variation among populations can be attributed to both gene flow and local selection. There is no evidence from the morphometric analyses for classifying populations into the 15 subspecies currently recognized.

Geographic Variation in Fluted Projectile Points: A Hemispheric Perspective

1999 ◽  
Vol 64 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Juliet E. Morrow ◽  
Toby A. Morrow
Keyword(s):  
North America ◽  
South America ◽  
Geographic Variation ◽  
Great Plains ◽  
North American ◽  
South American ◽  
Western North America ◽  
Radiocarbon Dates ◽  
Projectile Points ◽  
Fluted Points

This paper examines geographic variation in fluted point morphology across North and South America. Metric data on 449 North American points, 31 Central American points, and 61 South American points were entered into a database. Ratios calculated from these metric attributes are used to quantify aspects of point shape across the two continents. The results of this analysis indicate gradual, progressive changes in fluted point outline shape from the Great Plains of western North America into adjacent parts of North America as well as into Central and South America. The South American “Fishtail” form of fluted point is seen as the culmination of incremental changes in point shape that began well into North America. A geographically gradual decline in fluting frequency also is consistent with the stylistic evolution of the stemmed “Fishtail” points. Although few in number, the available radiocarbon dates do suggest that “Fishtail” fluted points in southern South America are younger than the earliest dates associated with Clovis points in western North America. All of these data converge on the conclusion that South American “Fishtail” points evolved from North American fluted points.

Meristic variation in the threespine stickleback, Gasterosteus aculeatus L., in eastern Canadian waters

1973 ◽  
Vol 51 (5) ◽  
pp. 547-551 ◽  
Author(s):  
E. T. Garside ◽  
T. Hamor
Keyword(s):  
Nova Scotia ◽  
North America ◽  
Species Complex ◽  
Vertebral Column ◽  
Gasterosteus Aculeatus ◽  
Lake Ontario ◽  
Threespine Stickleback ◽  
Meristic Variation ◽  
La Madeleine ◽  
Lateral Plates

Samples of threespine stickleback, Gasterosteus aculeatus L., collected from several areas of Newfoundland and Nova Scotia, and single sites from Iles de la Madeleine, Quebec, and eastern Lake Ontario, were analyzed for variation in numbers of anterior lateral plates and vertebrae. Counts of vertebrae varied from 28 to 35 and mean counts from 30.3 to 33.4, without being related to any obvious geographic gradients. Trunk and caudal segments of the vertebral column had about the same degree of variation. Counts of lateral plates exclusive of ossicles of the caudal keel ranged from 0 to 31 with a range of means from 1.6 to 24.7. Incomplete development of potential plate number and absence of caudal keels were observed in 1st-year individuals. These results are discussed in relation to information about this species complex from populations of Pacific North America and Europe.

Geographic Variation of the Screech Owls of the Deserts of Western North America

The Condor ◽  
1951 ◽  
Vol 53 (4) ◽  
pp. 161-177 ◽  
Author(s):  
Alden H. Miller ◽  
Loye Miller
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Western North America

Polymorphism for plate morphs in Gasterosteus aculeatus on the east coast of Canada and an hypothesis for their global distribution

1982 ◽  
Vol 60 (5) ◽  
pp. 1032-1042 ◽  
Author(s):  
D. W. Hagen ◽  
G. E. E. Moodie
Keyword(s):  
North America ◽  
New Brunswick ◽  
Prince Edward Island ◽  
Gasterosteus Aculeatus ◽  
East Coast ◽  
Threespine Stickleback ◽  
Global Distribution ◽  
High Frequencies ◽  
Virtual Absence ◽  
Associated Variable

In the threespine stickleback (Gasterosteus aculeatus) three plate morphs, controlled by major genes, are easily distinguished: the low-plated, partially plated, and completely plated morphs. We give the results of a geographic survey for these morphs, with 177 samples from New Brunswick, Prince Edward Island, and adjacent regions. The low-plated morph is virtually absent. Most sites are either monomorphic for the completely plated morph or polymorphic with high frequencies of that morph. Polymorphic sites are most frequent in fresh water where the frequency of partials is much higher. Polymorphic sites are also more than twice as frequent on Prince Edward Island than on the mainland. But sites with high frequencies of the partial morph, with one exception, occur only on the mainland. Populations with high frequencies of partials predominate in lakes and their tributaries near the sea. Hybridization between the low-plated leiurus and completely plated trachurus cannot account for most of the polymorphism in North America. The global distribution of plate morphs shows an association with climate, and the virtual absence of the low-plated morph in this survey can be accounted for by the action of climatic selection or an associated variable.

Parasites of the Threespine Stickleback (Gasterosteus aculeatus) in Newfoundland and Labrador

1970 ◽  
Vol 27 (5) ◽  
pp. 901-907 ◽  
Author(s):  
George Hanek ◽  
William Threlfall
Keyword(s):  
North America ◽  
Newfoundland And Labrador ◽  
Gasterosteus Aculeatus ◽  
New Records ◽  
Threespine Stickleback ◽  
New Host ◽  
Parasitic Copepods ◽  
Threespine Sticklebacks ◽  
New Host Records

Fifteen genera of helminths (19 species) and two genera of parasitic copepods (2 species) were recovered from 375 threespine sticklebacks (Gasterosteus aculeatus Linnaeus, 1758) taken in 10 sampling areas in Newfoundland and Labrador during 1968 and 1969. Two new host records and two new records for North America are included.

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