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Articles 61 - 88 of 88
Full-Text Articles in Ornithology
Sympatry Changes And Hybridization Incidence In Mallards And Black Ducks, Paul A. Johnsgard
Sympatry Changes And Hybridization Incidence In Mallards And Black Ducks, Paul A. Johnsgard
Papers in Ornithology
Changes in general fall and winter distributions of Mallards and Black Ducks over the past century have resulted in markedly increased sympatric contact during pair formation between these two forms, and have been responsible for increased opportunities for hybridization. Bureau of Sport Fisheries and Wildlife records of hybrids from 34 states indicate a minimal current hybridization rate that is about 4% of the frequency expected on the basis of mating according to mathematical probabilities of chance contact. Thus, hybridization is most frequent where both forms are almost equally abundant, indicating that no reinforcement of differences reducing hybridization in the primary …
Behavior Of The Australian Musk Duck And Blue-Billed Duck, Paul A. Johnsgard
Behavior Of The Australian Musk Duck And Blue-Billed Duck, Paul A. Johnsgard
Papers in Ornithology
Sexual displays of the Musk Duck and Blue-billed Duck are described and illustrated. The displays of male Musk Ducks comprise a series of three forms exhibiting increasing ritualization, complexity, and time-interval constancy. All of them have conspicuous auditory characteristics as well as variously conspicuous visual features. Displays in the species appear to have evolved under the influence of intense sexual selection resulting from what is probably a more completely promiscuous mating system than occurs in any other species of Anatidae. These selective pressures have also probably promoted the evolution of such features as large size and extreme sexual dimorphism that …
The Elusive Musk Ducks, Paul A. Johnsgard
The Elusive Musk Ducks, Paul A. Johnsgard
Papers in Ornithology
If one were to try to choose the most remarkable duck in the world, serious consideration would have to be given the Australian Musk Duck (Biziura lobata) of the family Anatidae. Among its unusual features are the great dimorphism of the sexes (males weigh eight pounds or more and are about three feet from bill to tail; females weigh two to three pounds and measure about two feet), the leathery pendent lobe that is located on the lower mandible, the strong odor of musk that is prominent in males during the breeding season, and the remarkably large eggs (averaging one-half …
Comparative Behavior And Relationships Of The Eiders, Paul A. Johnsgard
Comparative Behavior And Relationships Of The Eiders, Paul A. Johnsgard
Papers in Ornithology
Pair-forming and copulatory displays of the four species of eiders are described and illustrated, based on observations of captive and wild specimens. Behavioral differences indicate that two genera (Polysticta and Somateria) of eiders should be recognized, and that Lamponetta should be considered a synonym of Somateria. Racial differences in the displays of Somateria mollissima mollissima and S. m. v. nigra are explained on the basis of sympatry between the latter and S. fischeri, producing selection for display divergence that has not affected S. m. mollissima. Similarities in the behavior patterns of the eiders and the …
Comparative Behavior And Relationships Of The Eiders, Paul A. Johnsgard
Comparative Behavior And Relationships Of The Eiders, Paul A. Johnsgard
Papers in Ornithology
One of the more controversial systematic problems existing in the family Anatidae concerns the taxonomic rank and evolutionary relationships of the four species of eiders, which are currently considered by the American Ornithologists’ Union (1957) to comprise three genera (Somateria, Lampronetta, and Polysticta) in the diving duck subfamily Aythyinae. In 1945, however, Delacour and Mayr included the eiders in a single genus (Somateria) within the sea duck tribe Mergini. At present, Delacour (1959) considers the eiders a separate tribe, Somateriini, distinct from the other sea ducks, and placed near the dabbling duck tribe Anatini. The erection …
Review Of Sex Ratios And Age Ratios In North American Ducks, Paul A. Johnsgard
Review Of Sex Ratios And Age Ratios In North American Ducks, Paul A. Johnsgard
Papers in Ornithology
This bulletin is by far the most elaborate and comprehensive of any of the publications dealing with waterfowl age and sex ratios that have appeared to date, and represents the presentation and analysis of sex and age ratio data accumulated by the Illinois Natural History Survey over the last 24 years. The several people concerned are to be congratulated for bringing this material into publishable form, and it is commendable that the National Science Foundation undertook the printing costs of this extensively tabulated and illustrated bulletin.
The Sexual Behavior And Systematic Position Of The Hooded Merganser, Paul A. Johnsgard
The Sexual Behavior And Systematic Position Of The Hooded Merganser, Paul A. Johnsgard
Papers in Ornithology
It has been over 15 years since Delacour and Mayr (1945) first urged that the mergansers (Mergus)and the goldeneye-Bufflehead group (Bucephala) be merged into a single tribe (Mergini) rather than being maintained in separate subfamilies (Aythyinae and Merginae). Their reasons for this change were several, and included such points as the similarities in the downy young, female color patterns, occurrence of wild hybrids between the two genera, and tracheal structure. Indeed, except for the shape of the bill in these two groups there is no good means of distinguishing the two subfamilies. As Delacour and Mayr pointed out, bill shape …
Correspondence About "Evolutionary Relationships Among The North American Mallards", Allan R. Phillips, Paul A. Johnsgard
Correspondence About "Evolutionary Relationships Among The North American Mallards", Allan R. Phillips, Paul A. Johnsgard
Papers in Ornithology
The confusing leading article of the 1961 Auk calls for comment. Despite his title, "Evolutionary Relationships among the North American Mallards," the author discusses primarily geographic distributions, population sizes, egg-white proteins( !), and certain behavioral patterns. Maps are based on ". . . the literature, personal communications, and the major United States collections," " . and from additional sight and specimen records available to me"; yet only two museums other than Cornell University are mentioned in the acknowledgments. These maps show many records of platyrhynchos far to the south; sometimes (Figure 1) the reader must search hard for any hint …
Wintering Distribution Changes In Mallards And Black Ducks, Paul A. Johnsgard
Wintering Distribution Changes In Mallards And Black Ducks, Paul A. Johnsgard
Papers in Ornithology
Through the use of data compiled by the Audubon Society's annual Christmas Counts, an attempt has been made to trace the distributional changes of wintering Mallards and Black Ducks in the eastern states from 1900 to the present. During this period the Black Duck has increased relative to the Mallard in few if any states (the Great Lakes region), whereas the Mallard has increased nearly everywhere else (except in the extreme northeast), particularly in the southern coastal states. Deforestation and changes in land use are sug- gested as probable reasons for this trend, which is not likely to be reversed.
Evolutionary Relationships Among The North American Mallards, Paul A. Johnsgard
Evolutionary Relationships Among The North American Mallards, Paul A. Johnsgard
Papers in Ornithology
A comparative morphological, behavioral, and electrophoretic study was undertaken on six populations of North American mallards that are currently considered by the A.O.U. Check-list to comprise four species and two additional subspecies. These include Anas p. platyrhynchos, A. d. diaxi, A. d. novimexicana, A. f. fulvigula, A. f. maculosa, and A. rubripes. These forms are essentially allopatric in their breeding distributions, with the major exception of A. p. platyrhynchos and A. rubripes, which overlap throughout a several-hundred-mile zone in east-central United States.
Geographic ranges and population sizes are estimated, and evidence is presented to indicate that the …
A Quantitative Study Of Sexual Behavior Of Mallards And Black Ducks, Paul A. Johnsgard
A Quantitative Study Of Sexual Behavior Of Mallards And Black Ducks, Paul A. Johnsgard
Papers in Ornithology
In recent years an increased interest in the use of behavioral characteristics in evolutionary studies has developed, and this is particularly true in the case of waterfowl. The classical studies of Heinroth (1911), who was one of the first to apply knowledge of waterfowl behavior to systematics, have been elaborated on by Lorenz (1941; 1951-1953) in his important contribution toward the understanding of relationships in the Anatinae. These, and other, studies have stressed the qualitative behavioral differences occurring among different species as providing possible isolating mechanisms through their presumed function of conveying species-specific recognition signals. To the present, no extensive …
Hybridization In The Anatide And Its Taxonomic Implications, Paul A. Johnsgard
Hybridization In The Anatide And Its Taxonomic Implications, Paul A. Johnsgard
Papers in Ornithology
Without doubt, waterfowl of the family Anatidae have provided the greatest number and variety of bird hybrids originating from both natural and captive conditions. The recent compilation by Gray (1958) has listed approximately 400 interspecies hybrid combinations in this group, which are far more than have occurred in any other single bird family. Such a remarkable propensity for hybridization in this group provides a great many possibilities for studying the genetics of speciation and the genetics of plumage and behavior, and it also provides a valuable tool for judging species relationships. It may generally be said that the more closely …
Classification And Evolutionary Relationships Of The Sea Ducks, Paul A. Johnsgard
Classification And Evolutionary Relationships Of The Sea Ducks, Paul A. Johnsgard
Papers in Ornithology
When Delacour and Mayr (1945) revised the classification of the Anatidae, one of their major innovations was the erection of the tribe Mergini, the members of which had in the past (Peters, 193 1) been included in the subfamilies Nyrocinae (=Aythyinae) and Merginae. This separation of the true pochards (Netta and Aythya) from the other diving ducks and the merging of the merganser group into the same tribe with the goldeneyes (Bucephala) and other sea ducks has been accepted by most authorities and incorporated into recent classifications such as those of Kagelmann (1951) and Boetticher ( …
Comments On Species Recognition With Special Reference To The Wood Duck And The Mandarin Duck, William C. Dilger, Paul A. Johnsgard
Comments On Species Recognition With Special Reference To The Wood Duck And The Mandarin Duck, William C. Dilger, Paul A. Johnsgard
Papers in Ornithology
It is well known that closely related, sympatric species have evolved species-specific features which serve to minimize the possibility of "wrong" choices being made during pair formation. The amount of evolution of such species-specific features is roughly proportional to the deleterious effects of the "wrong" choices made in species recognition. Of course, if upon initial contact, the forms interbreed too freely panmixia will occur and both will eventually lose whatever genetic identity they may have had. On the other hand if, by the time of contact, the forms have incidentally developed differences sufficient to serve automatically as isolating mechanisms from …
Review Of A Coloured Key To The Wildfowl Of The World, Paul A. Johnsgard
Review Of A Coloured Key To The Wildfowl Of The World, Paul A. Johnsgard
Papers in Ornithology
The Wildfowl Trust, Slimbridge. Gloucestershire. 96 pp., 23 plates. 1957. Price. 9 s. 6d. This hand·guide to alI the species and subspecies of the Anatidae is an elaborated version of an earlier black and white guide. mainly for use in assisting in the identification of live birds in the incomparable waterfowl coIlection at the Wildfowl Trust, but also of great value as a guide in any zoo or even under field conditions. A total of 147 species, comprising 247 forms, are shown, including both sexes where they differ noticeably. as weIl as major color phases of the polymorphic forms such …
Variability In The Electrophoretic Patterns Of Avian Serum Proteins, Charles G. Sibley, Paul A. Johnsgard
Variability In The Electrophoretic Patterns Of Avian Serum Proteins, Charles G. Sibley, Paul A. Johnsgard
Papers in Ornithology
It has been known for more than 50 years that particular proteins characterize every species of plant and animal and that phylogenetic relationships are reflected in protein structure. The first application of this fact to taxonomic studies was by Nuttall ( 1901; 1904) who used the precipitin reaction of immune sera to test degrees of relationship in over 500 species of animals. With refinements in technique have come many more serological studies and the results have justified the statement by Landsteiner (1945) that “chemical differences parallel the variation in structure” and hence are useful in classification.
Waterfowl Sex Ratios During Spring In Washington State And Their Interpretation, Paul A. Johnsgard, Irven O. Buss
Waterfowl Sex Ratios During Spring In Washington State And Their Interpretation, Paul A. Johnsgard, Irven O. Buss
Papers in Ornithology
Sex-ratio studies have received much attention from research workers in recent years. The contributions of Hochbaum (1944), Petrides (1944) and others have yielded considerable information on sex ratios in waterfowl; Beer (1945) and Yocom (1949) have presented data for the state of Washington. To interpret regional data on waterfowl sex ratios adequately, it is necessary to obtain a series of uninterrupted observations covering the entire migration period of the species concerned. In 1954, an ecologic study was conducted in the Potholes area, Grant County, central Washington (Johnsgard, 1956). During the period February 15 to May 16, sex-ratio data were collected …
Courtship Activities Of The Anatidae In Eastern Washington, Paul A. Johnsgard
Courtship Activities Of The Anatidae In Eastern Washington, Paul A. Johnsgard
Papers in Ornithology
The many interesting and sometimes spectacular aspects of waterfowl courtship have been observed and recorded by several writers. Among the best and most complete descriptions are those of Bent (1923, 1925), Townsend (1910, 1916), Wetmore (1920), and Hochbaum (1944). However, for the most part these are unillustrated, deal with only a few species, or are based on limited observations.
Birds Observed In The Potholes Region During 1953-1954, Paul A. Johnsgard
Birds Observed In The Potholes Region During 1953-1954, Paul A. Johnsgard
Papers in Ornithology
From June 15-August 15, 1953 and from February 15 to August 15, 19 5 4 the writer did extensive field work in the Potholes Region of Grant County,Washington, gathering data for an ecological study of the vegetation and wildlife of that area. During this time considerable observations of the bird life were made, which for the most part were restricted to the area adjacent to O'Sullivan Dam and Potholes Reservoir.
Long-Tailed Jaeger Collected In Eastern Washington, Paul A. Johnsgard
Long-Tailed Jaeger Collected In Eastern Washington, Paul A. Johnsgard
Papers in Ornithology
An adult female Long-tailed Jaeger (Stercorarius longicaudus) was collected on Potholes Reservoir. Grant County. Washington, June 27. 1953. The bird was observed resting on the water near the middle of the reservoir. and as I approached. I noticed it was unable to fly. It attempted to fly several times as I came near, but seemed too exhausted to be able to leave the water. It was readily captured and brought to shore. Although in apparent good health. it refused to eat. and died that night. The bird was skinned, and is specimen number 53-216 in the Charles R. …
Waterfowl Of North Dakota, Paul A. Johnsgard
Waterfowl Of North Dakota, Paul A. Johnsgard
Papers in Ornithology
North Dakota is a great waterfowl state. Within its borders more ducks nest every summer than in any other state. Each fall thousands of hunters share in the excellent duck and goose hunting, and every school child is aware of the immense flocks of migrating waterfowl that are such a common sight. This booklet was written not only to serve as a guide in identifying these birds, but also to point out something of their habits and importance.
Depositor's note (June 2008): Paul seemed delighted when I presented him the source copy of this little pamphlet, which I had found …
Life Histories Of North American Nuthatches, Wrens, Thrashers And Their Allies: Order Passeriformes, Arthur Cleveland Bent
Life Histories Of North American Nuthatches, Wrens, Thrashers And Their Allies: Order Passeriformes, Arthur Cleveland Bent
Papers in Ornithology
An attempt has been made to give as full a life history as possible of the best-known subspecies of each species and to avoid duplication by writing briefly of the others and giving only the characters of the subspecies, its range, and any -habits peculiar to it. In many cases certain habits, probably common to the species as a whole, have been recorded for only one subspecies. Such habits are mentioned under the subspecies on which the observations were made. The distribution gives the range of the species as a whole, with only rough outlines of the ranges of the …
A Preliminary Study Of A Physical Basis Of Bird Navigation, Henry L. Yeagley
A Preliminary Study Of A Physical Basis Of Bird Navigation, Henry L. Yeagley
Papers in Ornithology
The bird navigation theory as presented implies an organ or organs in the bird's physiology which are sensitive to the effect of its motion through the vertical component of the earth's magnetic field and to the effort exerted to overcome the coriolis force, due to the earth's rotation. Both these influences involve a set of lines which together form a navigational gridwork. By correlating its instantaneous land speed with the two above effects, a bird can fly to its home which is a unique point in this gridwork, or to related companion points existing in the gridwork at positions other …
Notes On The Owls Found In Lincoln County, Nebraska, Wilson Tout
Notes On The Owls Found In Lincoln County, Nebraska, Wilson Tout
Papers in Ornithology
During more than a quarter of a century I have been making notes and collecting information about the Owls of Lincoln county and it seemed an opportune time to put this information into print that it might be available to those who are interested in birds and serve as a basis for further study and amplification. Lincoln County is not usually considered a favorable place for Owls to reside on account of the absence of heavy timber over most of its area. But the nine varieties listed will probably be extended as more observations are made by those who are …
Abyssinian Birds And Mammals: Painted From Life By Louis Agassiz Fuertes, Louis Agassiz Fuertes
Abyssinian Birds And Mammals: Painted From Life By Louis Agassiz Fuertes, Louis Agassiz Fuertes
Papers in Ornithology
LIST OF SUBJECTS
Cape Teal. Anas capensis (Gmelin) .
Spur-winged Goose. Plectropterus gambensis (Linnaeus) .
Secretary Bird. Sagittarius serpentarius (Miller).
White-necked Vulture. Pseudogyps africanus (Salvadori) .
Lappet-faced Vulture. Torgos tracheliotus nubicus Smith.
White-headed Vulture. Trigonoceps occipitalis (Burchell) .
Egyptian Vulture. Neophron percnopterus (Linnaeus) .
Abyssinian Lanner. Falco biarmicus abyssinicus Neumann.
African Swallow-tailed Kite. Chelictinea riocourii (Vieillot and Oudart).
Black-shouldered Kite. Elanus caeruleus (Desfontaines) .
African Tawny Eagle. Aquila rapax raptor Brehm.
Bateleur Eagle. Terathopius ecaudatus (Daudin) .
Bateleur Eagle. Terathopius ecaudatus (Daudin) .
African Sea Eagle. Cuncuma vocifer Daudin.
African Sea Eagle (Immature). Cuncuma vocifer Daudin.
Bearded Vulture. Gypaetus barbatus …
A Preliminary Review Of The Birds Of Nebraska With Synopses, Lawrence Bruner, Robert H. Wolcott, Myron H. Swenk
A Preliminary Review Of The Birds Of Nebraska With Synopses, Lawrence Bruner, Robert H. Wolcott, Myron H. Swenk
Papers in Ornithology
In 1896, Prof. Bruner published his list entitled "Some Notes on Nebraska Birds." As a working basis for the study of the ornithology of the state it has proven invaluable and it has also been greatly in demand by people not ornithologists, who desired to "know something about our birds." That edition was exhausted some time ago and its author has been frequently urged to publish another. However, the organization of the Nebraska Ornithologists' Union and the development of ornithology in the University has led to such a rapid increase in our knowledge in the past five years that it …
Some Notes On Nebraska Birds: A List Of The Species And Subspecies Found In The State, With Notes On Their Distribution, Food-Habits, Etc., Lawrence Bruner
Some Notes On Nebraska Birds: A List Of The Species And Subspecies Found In The State, With Notes On Their Distribution, Food-Habits, Etc., Lawrence Bruner
Papers in Ornithology
For upwards of twenty-five years the writer has taken an interest in our birds and made notes relative to their abundance, migrations, nesting, food-habits, etc., simply for personal gratification.
About two years ago, during a conversation in which the relation of birds to horticulture incidentally arose, Professor F. W. Taylor suggested the advisability of devoting a portion of a succeeding annual report to our Nebraska birds. With this object in view both the professor and the writer broached the matter to other members of the Society. Several at once not only became interested in the matter, but suggested its early …
Notes On The Ornithology Of Southern Texas, James C. Merrill
Notes On The Ornithology Of Southern Texas, James C. Merrill
Papers in Ornithology
BEING A LIST OF BIRDS OBSERVED IN THE VICINITY OF FORT BROWN, TEXAS, FROM FEBRUARY, 1876, TO JUNE, 1878.
The post of Fort Brown, Texas, in the immediate vicinity of which most of the following observations were made, is at the extreme southern point of the State, in latitude 25° 53' 16", longitude 97° 13'. It adjoins the town of Brownsville, on the left bank of the Rio Grande, and across the river is Matamoras, in the Mexican State of Tamaulipas. The nearest part of the Gulf coast is about eighteen miles distant. The surrounding country is level, and mostly …