FRIENDS OF WILDLIFE SOUND AT NSA

ABSTRACT

The problem of categorization arises in any classification system because classes should be discrete while the characteristics of most natural objects and aspects of nature are more or less gradual. In systematics, this problem usually is solved by creating several levels of categories, such as class, order, family, genus and species. In the existing killer whale discrete call classification, only two levels occur—call type and call subtype. In this paper we describe structural categories at a broader level than call type in the discrete sounds of killer whales and compare these categories between and within vocal clans in a community of resident killer whales from Southeast Kamchatka, Russian Far East, and also with killer whales outside this community. We found four main classes of discrete calls in the repertoire of resident killer whales from Southeast Kamchatka. The calls of Southeast Kamchatka transient killer whales and Sakhalin killer whales do not fall into these classes. This suggests that the resident killer whale community from Southeast Kamchatka has some rules defining the structure of calls which are typical for this community. Consequently, all resident killer whales from Southeast Kamchatka can be said to share the same vocal tradition.     

Adaptation of Avian Eggs to Incubation Period Variability Around Allometric Regressions Is Correlated with Time

Many morphological and physiological parameters of avian eggsare known to be correlated with fresh egg weight, i.e, to exhibitallometric relationships. It has been predicted that part ofthe variability around some of these allometric relationshipsis the result of adaptations to incubation periods of differentlengths. I performed multiple regressions of three of theseparameters (the rate of water loss in the nest, conductanceof the shell to gases and the rate of O₂ consumption just priorto hatching) versus weight and incubation period to test thesepredictions. All these parameters were significantly correlatedwith weight and for eggs of the same weight inversely correlatedwith the length of the incubation period. Other investigatorshave reported allometric interrelations between weight, lifespan and other parameters. For example the average number ofheartbeats is the same in mammals of all weights. The kind ofinterrelation reported in this study appears similar to thiskind of allometric interrelation but is actually quite differentbecause it concerns organisms of the same weight. I refer tothis kind of interrelation between various parameters for eggsof the same weight as an isometric interrelation. The two kindsof interrelations are quite independent the existence of anallometric interrelation does not prove the existence of anisometric interrelation.