摘要:

AbstractThe taxonomy of the spotted dolphins has been confused. Two apparent species exist, one endemic to the Atlantic and the other pantropical. They have sharply different color patterns and non‐overlapping vertebral counts. However, the holotype specimens for most of the names that have been applied to the spotted dolphins (includingS. attenuata, S. frontalis, S. plagiodonand others) are skulls only, with no information on coloration or number of vertebrae. The two species overlap in all skull characters; geographical variation in both is pronounced. We used a discriminant analysis based on tooth counts and three skull measurements (standardized to skull width) to identify the type specimens to the two species. We used other criteria for assignment of nominal species for which holotype specimens do not exist. We propose thatStenella frontalis(G. Cuv., 1829) be used for the Atlantic endemic species andStenella attenuata(Gray, 1846) for the pantropical species and here redescribe the species. Proposed common names are Atlantic spotted dolphin and pantropical spotted dolphin.S. frontalisnow includesDelphinus froenatusF. Cuv., 1829,D. dorisGray, 1846 andD. plagiodonCope, 1866.S. attenuata (a nomen conservandum)includesD. veloxG. Cuv., 1829,D. pseudodelphisWiegmann, ≤ 1840,D. brevimanusWagner, 1846,D. microbrachiumGray, 1850,D. albirostratusPeale, 1848,Steno capensisGray, 1865,Clymene punctatusGray, 1866,Steno consimilisMalm, 1871 andProdelphinus graffmaniLönnberg, 1934. Unidentifiable to either of the two valid species areD. dubiusG. Cuv., 1812,D. pernettensisde Blainville, 1817 (suppressed),D. malayanusLesson, 1826 andD. RappiiReichenbach, 1845; these must remainincertae s

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00158.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAdults of long‐lived, birth‐pulse populations (e.g., many cetaceans, polar bears and walrus) may not breed every year because of parental care, long gestation periods or nutritional constraints. Estimates of adult annual recruitment rates for such populations are necessarily an oversimplification since these rates are applied to both breeding and non‐breeding females.The weighted mean of age‐specific recruitment is insufficient for non‐stable age projections of multi‐annual populations beyond the first time interval. Restated, conventional or collapsed Leslie matrix and life‐table projections are not adequate for non‐stable age simulations of populations with multi‐annual reproduction cycles.These difficulties may be avoided by employing a parameterization that accommodates a dynamic age structure and proportion of breeding females within a given age class. This parameterization is a true description of the multiple‐year reproduction schedule.Examples, broadly mimicking the life history of polar bears, were used to identify potential qualitative errors that may occur from using overly simplifie

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00159.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractBowhead whales (Balaena mysticetus) summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry. Photos were taken from a turbine Aerocommander 690 with wingtip‐mounted, calibrated 35‐mm cameras. Photos were measured on an analytical plotter with scale data provided by radar altimeter and focal length of the lenses. Coefficient of variation of known‐sized targets 12 m long was 1.7 percent (n= 25). Potential duplicate photographs of whales were removed from consideration through an algorithm based on whale swim speed and elapsed time between sightings. Significant segregation by bowhead whale length was found between four broad regions (P<0.001, ANOVA, Chi square). Also an inverse correlation appeared between longitude and size of animals (P<0.001), with the larger animals occurring farther east. This unequivocal size‐class segregation confounds an accurate assessment of overall size‐class composition of the population as well as recent attempts to determine calving rate from aerial su

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00160.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractCompared to the anterior surface of the normal human cornea, allTursiopsshowed pronounced random, local curvature changes typical of old keratitis and scarring. Comparable but less severe findings apply toZalophus.These irregularities were superimposed on the mild regular astigmatism of the spoon‐shapedTursiopscornea (mean central power is 26.8 D, SD = 3.8, N = 82). AllZalophuscorneas showed no reliable regular astigmatism (overall mean power is 21.7 D, SD = 4.4, N = 53) but exhibited a flat, circular region about 6.5 mm in diameter along the nasal aspect of the horizontal meridian. Refraction through this cornea1 region showed aerial emmetropia, which accounts for equivalent marine and aerial visual resolution in this specie

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00161.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Book review in this articleINTERNATIONAL REGULATION OF WHALING: FROM CONSERVATION OF WHALING TO CONSERVATION OF WHALES AND REGULATION OF WHALE WATCHING. Patricia BirnieBEHAVIOUR OF WHALES IN RELATION TO MANAGEMENT. G. P. Donovan (ed.).A HANDBOOK FORTHEIDENTIFICATIONOFCEPHALOPODBEAKS. Malcolm R. Clarke(ed.).THE WAR AGAINST THE SEALS: A HISTORY OF THE NORTH AMERICAN SEAL FISHERY. Briton Cooper Busch.THE HARBOR SEAL. Doug Bertran Productions, Box 10340, Olympia, Washington 98502.

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00162.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1987.tb00163.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY