scholarly journals BODY SIZE, ENERGY USE, AND COMMUNITY STRUCTURE OF SMALL MAMMALS

Ecology ◽  
2005 ◽  
Vol 86 (6) ◽  
pp. 1407-1413 ◽  
Author(s):  
S. K. Morgan Ernest
2014 ◽  
Vol 281 (1797) ◽  
pp. 20142103 ◽  
Author(s):  
Marlee A. Tucker ◽  
Tracey L. Rogers

Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial ( n = 51) and marine ( n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities.


1994 ◽  
Vol 42 (4) ◽  
pp. 527 ◽  
Author(s):  
PA Marquet

Species diversity patterns of small mammals (sigmodontine rodents) in the Chilean-Peruvian Pacific coastal desert and adjacent Andean area (Puna) were analysed by means of latitudinal and altitudinal transects. The statistical analyses of the patterns show: (1) a wide variation in latitudinal species diversity, with a peak in the region where the Puna reaches its greatest areal extent; (2) the differentiation of at least four groups of distinct faunal elements resulting from the interaction of large-scale biogeographic, geological and evolutionary processes; (3) a positive correlation between species richness and altitude for the altitudinal transects located within the Pacific coastal desert area and Puna; and (4) a highly individualistic pattern of community structure at a regional scale. These results are discussed considering biogeographic, palaeoclimatic and evolutionary processes, such as the establishment of the Pacific coastal desert, and the existence of a major centre of species diversification in the Puna area. Similarities and differences between these community-level patterns and those in North American deserts are discussed.


2011 ◽  
Vol 278 (1721) ◽  
pp. 3135-3141 ◽  
Author(s):  
Montserrat Gomendio ◽  
Maximiliano Tourmente ◽  
Eduardo R. S. Roldan

The hypothesis that sperm competition should favour increases in sperm size, because it results in faster swimming speeds, has received support from studies on many taxa, but remains contentious for mammals. We suggest that this may be because mammalian lineages respond differently to sexual selection, owing to major differences in body size, which are associated with differences in mass-specific metabolic rate. Recent evidence suggests that cellular metabolic rate also scales with body size, so that small mammals have cells that process energy and resources from the environment at a faster rate. We develop the ‘metabolic rate constraint hypothesis’ which proposes that low mass-specific metabolic rate among large mammals may limit their ability to respond to sexual selection by increasing sperm size, while this constraint does not exist among small mammals. Here we show that among rodents, which have high mass-specific metabolic rates, sperm size increases under sperm competition, reaching the longest sperm sizes found in eutherian mammals. By contrast, mammalian lineages with large body sizes have small sperm, and while metabolic rate (corrected for body size) influences sperm size, sperm competition levels do not. When all eutherian mammals are analysed jointly, our results suggest that as mass-specific metabolic rate increases, so does maximum sperm size. In addition, species with low mass-specific metabolic rates produce uniformly small sperm, while species with high mass-specific metabolic rates produce a wide range of sperm sizes. These findings support the hypothesis that mass-specific metabolic rates determine the budget available for sperm production: at high levels, sperm size increases in response to sexual selection, while low levels constrain the ability to respond to sexual selection by increasing sperm size. Thus, adaptive and costly traits, such as sperm size, may only evolve under sexual selection when metabolic rate does not constrain cellular budgets.


Nature ◽  
1987 ◽  
Vol 328 (6126) ◽  
pp. 117-118 ◽  
Author(s):  
DAVID GRIFFITHS

Ecography ◽  
2012 ◽  
Vol 36 (4) ◽  
pp. 508-517 ◽  
Author(s):  
Natalia P. Korallo-Vinarskaya ◽  
Maxim V. Vinarski ◽  
Irina S. Khokhlova ◽  
Boris R. Krasnov

Oikos ◽  
1998 ◽  
Vol 81 (3) ◽  
pp. 525 ◽  
Author(s):  
Paul Eggleton ◽  
Richard G. Davies ◽  
David E. Bignell
Keyword(s):  

2014 ◽  
Vol 281 (1783) ◽  
pp. 20133122 ◽  
Author(s):  
Jonathan L. Payne ◽  
Noel A. Heim ◽  
Matthew L. Knope ◽  
Craig R. McClain

Brachiopods and bivalves feed in similar ways and have occupied the same environments through geological time, but brachiopods were far more diverse and abundant in the Palaeozoic whereas bivalves dominate the post-Palaeozoic, suggesting a transition in ecological dominance 250 Ma. However, diversity and abundance data alone may not adequately describe key changes in ecosystem function, such as metabolic activity. Here, we use newly compiled body size data for 6066 genera of bivalves and brachiopods to calculate metabolic rates and revisit this question from the perspective of energy use, finding that bivalves already accounted for a larger share of metabolic activity in Palaeozoic oceans. We also find that the metabolic activity of bivalves has increased by more than two orders of magnitude over this interval, whereas brachiopod metabolic activity has declined by more than 50%. Consequently, the increase in bivalve energy metabolism must have occurred via the acquisition of new food resources rather than through the displacement of brachiopods. The canonical view of a mid-Phanerozoic transition from brachiopod to bivalve dominance results from a focus on taxonomic diversity and numerical abundance as measures of ecological importance. From a metabolic perspective, the oceans have always belonged to the clams.


Sign in / Sign up

Export Citation Format

Share Document