Sympatry Changes and Hybridization Incidence in Mallards and Black Ducks

Johnsgard, Paul A.

doi:10.2307/2423425

Cited by 41 publications

(26 citation statements)

References 7 publications

(4 reference statements)

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“…First, Brodsky et al used mallards from Manitoba and black ducks from Ontario, Quebec and New Brunswick. Because the frequency of hybridization between mallards and black ducks increases in an east-to-west gradient (Johnsgard 1967), 'black ducks' in our study (all from Ontario) may have possessed mallard genes, whereas black ducks in Brodsky et al's study were more likely to have been genetically 'pure'. Also, Ontario mallards are more likely to possess black duck genes than are Manitoba mallards.…”

Section: Discussionmentioning

confidence: 52%

Correlates of behavioural dominance in mallards and American black ducks

Hoysak

Ankney

1996

Animal Behaviour

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Section: Discussionmentioning

confidence: 52%

Correlates of behavioural dominance in mallards and American black ducks

Hoysak

Ankney

1996

Animal Behaviour

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“…For instance, in North America, hybridization with Mallards has been implicated as one factor in the population decline of American Black Ducks (A. rubrifes;Johnsgard 1967, Heusmann 1974, Ankney et al 1987, Hawaiian Ducks {A. wyvilliana; Griffin et al 1989), and Mexican Ducks (A. platyrhynchos diazi;Hubbard 1977 (Mazourek and Gray 1994). In fact, the AOU (1983) declared the Mexican Duck to be conspecific with the Mallard because of extensive hybridization between them.…”

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confidence: 99%

Mitochondrial Analysis of Gene Flow between New Zealand Mallards (Anas platyrhynchos) and Grey Ducks (A. superciliosa)

Rhymer

Braun

1994

The Auk

138

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ABSTRACT.•One of the more well-known examples of hybridization in birds is the frequently documented occurrence between sexually dimorphic Mallards (Anas platyrhynchos) and several closely related nondimorphic species in the mallard complex. In New Zealand, the Grey Duck (Anas superciliosa superciliosa) is the indigenous, nondimorphic Mallardlike species, and extensive hybridization with introduced Mallards has been implicated in the population decline of Grey Ducks. Individuals from throughout the country were classified phenotypically as parentals or hybrids based on variation in plumage, bill color, and leg color. We confirmed species-specific mitochondrial DNA haplotypes by comparing restrictionenzyme fragment patterns in Grey Ducks and New Zealand Mallards to those of Pacific Black Ducks (A, superciliosa rogersi) from Australia and Mallards from North America, respectively. Our data indicate that hybridization has led not only to introgression of Grey Duck mtDNA into Mallard populations (the predicted direction of gene flow), but also to significant introgression of Mallard mtDNA into Grey Duck populations. Thus, the contention that hybridization between Mallards and nondimorphic species involves primarily Mallard males with females of the other species is not upheld for this example from New Zealand. The speciation process appears to be undergoing reversal.

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confidence: 99%

“…Much debate has focused on possible reasons for the decline, such as competitive exclusion, overhunting, or genetic swamping of the Black Duck's gene pool by introgressive hybridization with the Mallard (Goodwin, 1956;Johnsgard, 1961;Heusmann, 1974;Dennis et al, 1984;Ankney et al, 1987). The species now hybridize frequently in nature (Brodsky and Weatherhead, 1984;Goodwin, 1956;Johnsgard, 1960Johnsgard, , 1967Heusmann, 1974), and various hybrid and backcross classes appear viable and fertile (though to an unknown degree compared to nonhybrids) (Cade, 1983;Phillips, 1915). The reproductive compatibility of Mallard and Black Ducks, and their similarities in other attributes such as courtship display (Johnsgard, 1960), have generated controversy concerning whether the forms warrant recognition as distinct species (Ankney et al, 1986;Hepp et al 1988).…”

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confidence: 99%