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Abstract
Human speech shows an unparalleled richness in geographic variation. However, few attempts have been made to understand this linguistic diversity from an evolutionary and comparative framework. Here, we a) review extensively what is known about geographic variation of acoustic signals in terrestrial mammals, using common terminology adopted from linguistics to define different forms of variation (i.e. accents and dialects), and b) examine which factors may determine this variation (i.e. genetic, environmental and/or social). Heretofore, terminology has been used inconsistently within and across taxa, and geographic variation among terrestrial mammals has never been defined as in human speech. Our results show that accents, phonologically different varieties, occur widely in terrestrial mammals. Conversely, dialects, lexically and phonologically different varieties, have only been documented thus far in great white-lined bats, red deer, chimpanzees and orangutans. Although relatively rare among terrestrial mammals, dialects are thus not unique to humans. This finding also implies that such species possess the capacity for acoustic learning. Within primates, the two great apes showing dialects are those who also show extensive cultures in the wild, suggesting that, in hominoids, intricacy of acoustic geographic variation is potentially associated with cultural complexity; namely, both have derived from selection increasingly favoring social learning across varied contexts, including the acoustic domain.
Morphology of the lymph nodes was examined in six bottlenose dolphins (Tursiops truncatus) and three striped dolphins (Stenella coeruleoalba) from the Adriatic Sea. All animals had been found dead in nature. One group of the nodes was taken from the tracheal branching area and was marked as bifurcational lymph node, and the other group was taken from the mesenteric root and was marked as mesenteric lymph node. Microscopic analysis showed that the lymph nodes in both dolphin specieswere surrounded by a connective tissue capsule comprising smooth muscle cells. The parenchyma of the mesenteric and bifurcational lymph nodes in bottlenose dolphinwas divided into the peripherally situated cortex with the lymphatic nodules and diffuse lymphatic tissue, and the centrally situated medulla structured of the medullary cords separated by the medullary sinuses. These lymph nodes structurally correspond to the lymph nodes in the majority of terrestrial mammals. The mesenteric lymph node of striped dolphin also had a peripherally situated cortex and a centrally positioned medulla as the majority of terrestrial mammals. In the bifurcational lymph nodes of striped dolphin, there was a central dense lymphatic tissue with the lymphatic nodules and a peripheral less dense lymphatic tissue structured of the cell cords and sinuses. The bifurcational lymph node in striped dolphinresembledporcine lymph nodes and belonged to the inverse lymph nodes.
Seed dispersal is a limiting factor in the maintenance and distribution of plant communities, especially in rainforest ecosystems where a major proportion of plant species are dispersed by animals. Knowledge of seed removal by terrestrial mammals (particularly small mammals) in Araucaria forest patches scattered in Campos grassland is relatively sparse. In this study, we assessed: (1) whether the removal rate of Araucaria angustifolia seeds differs in different successional stages of Araucaria forest advancing over grassland, and (2) the importance of small mammals and others vertebrates for seed removal rates in each environment type. We used seed removal experiments and camera trapping to answer these questions. Our results showed that seed removal was higher in more-forested sites than in open ones and in control treatment in 2006, we found an interaction between successional stage and treatment in 2007 and, in 2008, only treatments differed significantly. Our photographic records were mostly of small cricetid rodents. Seed-removal increment as a function of forested area suggests increased use of these sites by terrestrial mammals as patches develop in grassland. The use of large patches by mammals may increase the probability of mammal-dispersed plants colonizing patches as they attain a given structural development, which might determine to some degree the future patch nucleation dynamics.
. 2004. Occurrence of Conepatus chinga (Molina) (Mammalia, Carnivora, Mustelidae) and other terrestrial mammals in the Serra do Mar, Parana, Brazil. Revista Brasileira de Zoologia 21: 577–579. Cáceres N. C
lesser extent ( Gehler et al., 2011 ). From all these factors, the ingested environmental water plays the most significant role in the water‒tissue oxygen-equilibrium process in the body of the terrestrial mammal. Due to the correlation between isotopic
