The biophysics of Bergmann's rule: a comparison of the effects of pelage and body size variation on metabolic rate

1994 ◽  
Vol 72 (1) ◽  
pp. 70-77 ◽  
Author(s):  
K. Steudel ◽  
W. P. Porter ◽  
D. Sher
Keyword(s):  
Body Size ◽  
Metabolic Rate ◽  
Small Mammals ◽  
Seasonal Changes ◽  
Size Variation ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Large Mammals ◽  
Size Change ◽  
Biomechanical Constraints

Should an animal extending its range into a cooler climate rely most on pelage or on body size change to minimize its mass-specific metabolic rate? The various examples of animals following Bergmann's rule support the latter. The fact that an increase in size will result in an increase in total metabolic rate (though coupled to the decrease in the mass-specific metabolic rate) suggests that increases in the insulative value of the pelage would be the preferred strategy. We used a thermal simulation model to compare the relative effects of increasing body mass versus increasing pelage insulative properties on the mass-specific metabolic rate. We found that even the fur of summer-adapted small mammals from temperate climates is extremely dense compared with that of larger mammals and is near the point at which increases in density increase, rather than decrease, heat loss as a result of the high conductivity of individual hairs compared with the layer of still air that it encloses. Small mammals also have lower fur depths, presumably as a result of biomechanical constraints. Seasonal changes in pelage observed in small mammals have very modest effects on mass-specific metabolism. Summer-adapted temperate large mammals, however, are less heavily insulated and, consequently, have substantial latitude for increasing insulation as a means of minimizing mass-specific metabolism. Thus, Bergmann's rule should be more relevant to small mammals than to large ones.

Glacial/Interglacial Size Variation in Fossil Spotted Hyenas (Crocuta crocuta) from Britain

1989 ◽  
Vol 32 (1) ◽  
pp. 88-95 ◽  
Author(s):  
Richard G. Klein ◽  
Katharine Scott
Keyword(s):  
Body Size ◽  
Temperature Variation ◽  
Late Pleistocene ◽  
Size Variation ◽  
Crocuta Crocuta ◽  
Bergmann’S Rule ◽  
Spotted Hyena ◽  
Bergmann's Rule ◽  
Spotted Hyenas ◽  
The Relationship

AbstractThe lower carnassial lengths of spotted hyenas (Crocuta crocuta) in 12 late Pleistocene samples from Britain indicate that, on average, local hyenas of the last (Devensian) glaciation were significantly larger than their last-interglaciation (Ipswichian) counterparts. Together with the tendency for spotted hyena carnassial length to increase with latitude in present-day Africa, this suggests that spotted hyena body size is inversely related to temperature, as predicted by Bergmann's rule. The implication is that spotted hyena carnassial length can be used as an independent gauge of Pleistocene temperature variation, though the combined African and British data imply that the relationship between carnassial length and temperature is curvilinear, such that as temperature declines, equal amounts of further decline produce progressively smaller increases in average carnassial length.

Dichroplus vittatus(Orthoptera: Acrididae) follows the converse to Bergmann's rule although male morphological variability increases with latitude

2007 ◽  
Vol 97 (1) ◽  
pp. 69-79 ◽  
Author(s):  
C.J. Bidau ◽  
D.A. Martí
Keyword(s):  
Body Size ◽  
Morphological Variability ◽  
Size Variation ◽  
Bergmann’S Rule ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
South American ◽  
Bergmann's Rule ◽  
Number Of Factors ◽  
Positive Correlations

AbstractGeographic body size variation was analysed in males and females of 19 populations of the South American grasshopperDichroplus vittatusBruner spanning 20 degrees of latitude and 2700 m of altitude. Using mean and maximum body length of each sex and factors obtained from principal components analyses of six morphometric linear characters it was shown thatD. vittatusfollowed the converse to Bergmann's rule latitudinally but not altitudinally where no significant trends were observed. For males, variability of body size increased with latitude but not with altitude. Both types of trends were significantly correlated with mean annual temperature and minimum annual temperature (positive correlations), and two estimators of seasonality, the coefficients of variation of mean annual temperature (negative) and mean annual precipitation (positive). Some allometric relationships also showed geographic variation. It is suggested that the observed decrease in size with latitude together with the increase in morphological variability is a consequence of a number of factors: the shortening of the growing season southwards; the increasing seasonality and climatic unpredictability; and the fact that the species exhibits protandry which contributes to smaller and more variable size in males and smaller but more constant body size in females.

Bergmann's rule is invalid

1987 ◽  
Vol 65 (4) ◽  
pp. 1035-1038 ◽  
Author(s):  
Valerius Geist
Keyword(s):  
Body Size ◽  
Surface Area ◽  
Small Body ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Large Mammals ◽  
Annual Productivity ◽  
Body Sizes ◽  
Growth Correlations

Bergmann's rule, claiming that in homeotherms body size increases inversely with temperature so that, intraspecifically, body size increases latitudinally, is not valid, nor is the explanation of this rule. In large mammals body size at first increases with latitude, but then reverses between 53 and 65° N, so that small body sizes occur at the lowest and highest latitudes. This is predicted by the hypothesis that body size follows the duration of the annual productivity pulse, so that body size is a function of availability of nutrients and energy during periods of growth. Correlations between body size and temperature are shown to be spurious. If reduction in relative surface area is indeed an adaptation to conserve heat, then mammals should increase in size from south to north at rates two orders of magnitude greater than they do. Bergmann's rule has no basis in fact or theory.

An interspecific test of Bergmann's rule reveals inconsistent body size patterns across several lineages of water beetles (Coleoptera: Dytiscidae)

2018 ◽  
Vol 44 (2) ◽  
pp. 249-254 ◽  
Author(s):  
Susana Pallarés ◽  
Michele Lai ◽  
Pedro Abellán ◽  
Ignacio Ribera ◽  
David Sánchez-Fernández
Keyword(s):  
Body Size ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Water Beetles

Latitudinal body-mass trends in Oligo-Miocene mammals

Paleobiology ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 643-658
Author(s):  
John D. Orcutt ◽  
Samantha S. B. Hopkins
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Regional Scale ◽  
Latitudinal Gradients ◽  
Bergmann’S Rule ◽  
Strongly Correlated ◽  
Bergmann's Rule ◽  
Deep Time ◽  
Causal Factors ◽  
Primary Driver

AbstractPaleecological data allow not only the study of trends along deep-time chronological transects but can also be used to reconstruct ecological gradients through time, which can help identify causal factors that may be strongly correlated in modern ecosystems. We have applied such an analysis to Bergmann’s rule, which posits a causal relationship between temperature and body size in mammals. Bergmann’s rule predicts that latitudinal gradients should exist during any interval of time, with larger taxa toward the poles and smaller taxa toward the equator. It also predicts that the strength of these gradients should vary with time, becoming weaker during warmer periods and stronger during colder conditions. We tested these predictions by reconstructing body-mass trends within canid and equid genera at different intervals of the Oligo-Miocene along the West Coast of North America. To allow for comparisons with modern taxa, body mass was reconstructed along the same transect for modernCanisandOdocoileus. Of the 17 fossil genera analyzed, only two showed the expected positive relationship with latitude, nor was there consistent evidence for a relationship between paleotemperature and body mass. Likewise, the strength of body-size gradients does not change predictably with climate through time. The evidence for clear gradients is ambiguous even in the modern genera analyzed. These results suggest that, counter to Bergmann’s rule, temperature alone is not a primary driver of body size and underscore the importance of regional-scale paleoecological analyses in identifying such drivers.

scholarly journals Why mammalian lineages respond differently to sexual selection: metabolic rate constrains the evolution of sperm size

2011 ◽  
Vol 278 (1721) ◽  
pp. 3135-3141 ◽  
Author(s):  
Montserrat Gomendio ◽  
Maximiliano Tourmente ◽  
Eduardo R. S. Roldan
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Metabolic Rate ◽  
Sperm Competition ◽  
Small Mammals ◽  
High Mass ◽  
Metabolic Rates ◽  
Wide Range ◽  
Low Mass ◽  
Sperm Size

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.

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