. Advances in the study of mammalian behavior. Mammals. Caf,e Studies 493. Fig. 2. Breeding colony of northern elephant seals (Mirounga anguslirostns); note high density of parturient females and presence of competing adult males. polygyny, apparently only two polar species have done so (the wal- rus, Odobenus rosmarus, and the Weddell seal, Leptonychotes wed- delli). One consequence of these two overlooked aspects has been that marked sexual dimorphism and highly developed polygyny is generally considered to be more characteristic of pinnipeds than is the case. In fact, almost half of the liv
. Advances in the study of mammalian behavior. Mammals. Caf,e Studies 493. Fig. 2. Breeding colony of northern elephant seals (Mirounga anguslirostns); note high density of parturient females and presence of competing adult males. polygyny, apparently only two polar species have done so (the wal- rus, Odobenus rosmarus, and the Weddell seal, Leptonychotes wed- delli). One consequence of these two overlooked aspects has been that marked sexual dimorphism and highly developed polygyny is generally considered to be more characteristic of pinnipeds than is the case. In fact, almost half of the living species of pinnipeds do not exhibit these characteristics. Bartholomew's (1970) model explains the evolution of terrestrial polygyny but it assumes that the gregariousness of females and terrestrial mating are already-evolved characters. The purpose of this paper is to evaluate and discuss on a broader scale the most important factors influencing the evolution of the spectrum of mat- ing systems in pinnipeds today. I will sacrifice a certain amount of detail because the information available is voluminous and the life cycles of each species (and even of subpopulations of the same species) have their own distinct characteristics. Also, much of this paper will be speculative because of gaps in information on critical points. Consequently, wherever possible, I will emphasize unanswered questions and discussions of species in ecological contexts that. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Eisenberg, John Frederick; Kleiman, Devra G; American Society of Mammalogists. [Shippensburg, Pa?] : American Society of Mammalogists
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectmammals
