scholarly journals Conformity to Bergmann’s rule in birds depends on nest design and migration

2019 ◽  
Author(s):  
Mark C. Mainwaring ◽  
Sally E. Street
Keyword(s):  
Body Mass ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Migratory Behaviour ◽  
Migratory Species ◽  
Long Distance ◽  
Environmental Selection ◽  
Western Palearctic ◽  
Nest Design ◽  
And Migration

AbstractSpecies’ geographic ranges and range limits are thought to be determined by climate, and across climatic gradients the morphology of populations varies non-randomly. Ecogeographic rules seek to characterise such variation, with Bergmann’s rule positing that organisms inhabiting colder environments are typically larger-bodied than those inhabiting warmer environments. While Bergmann’s rule has been supported across a range of taxonomic groups, how organisms’ behaviour may moderate its effect remains unclear. Here we investigate whether conformity to Bergmann’s rule among birds of the Western Palearctic varies in relation to nest design and migratory behaviour, using phylogenetic comparative analyses. We test predictions using data on nest structure and location, migration, body mass, latitudinal distribution, annual mean temperature and phylogenetic relatedness for a sample of >500 species. We find that conformity to Bergmann’s rule depends strongly on migratory behaviour: non-migratory species breeding at colder, more northerly latitudes are larger-bodied, while body mass is unaffected by climate in short- and long-distance migrants. Among non-migratory species, conformity to Bergmann’s rule depends, further, on nest design: species with more open nests, who are thus most exposed to adverse climatic conditions while breeding, conform most strongly to Bergmann’s rule. Our findings suggest that enclosed nesting and migration allow smaller bodied species to breed in colder environments than their body size would otherwise allow. Therefore, we conclude that organisms’ behaviour can strongly affect exposure to environmental selection pressures.

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 Bergmann's rule is followed at multiple stages of postembryonic development in a long‐distance migratory songbird

2020 ◽  
Vol 10 (19) ◽  
pp. 10672-10686
Author(s):  
Joseph Youtz ◽  
Kelly D. Miller ◽  
Emerson K. Bowers ◽  
Samantha L. Rogers ◽  
Lesley P. Bulluck ◽  
...  
Keyword(s):  
Postembryonic Development ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Long Distance ◽  
Migratory Songbird ◽  
Multiple Stages

Biogeographical effects on body mass of native Australian and introduced mice, Pseudomys hermannsburgensis and Mus domesticus: an inquiry into Bergmann's Rule

2008 ◽  
Vol 56 (6) ◽  
pp. 423 ◽  
Author(s):  
Sean Tomlinson ◽  
Philip C. Withers
Keyword(s):  
Ambient Temperature ◽  
Body Mass ◽  
Rainfall Variability ◽  
Negative Influence ◽  
Bergmann’S Rule ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Mus Domesticus ◽  
Arid Areas ◽  
Bergmann's Rule

We investigated interactions of body mass with geographical location, and five climatic measures for two Australian rodents, the native Australian sandy inland mouse (Pseudomys hermannsburgensis) and the introduced house mouse (Mus domesticus). Correlation and regression analyses identified interactions of body mass with latitude, longitude, average highest maximum and lowest minimum temperatures, average annual rainfall, rainfall variability, and aridity. There was a significant correlation of body mass with latitude and longitude for Mus domesticus and P. hermannsburgensis. House mice were heavier in the south and east, and sandy inland mice were heavier in the north and east. M. domesticus conforms to Bergmann’s Rule, while P. hermannsburgensis does not. Maximum temperature, aridity and rainfall variability significantly influenced body mass of M. domesticus, which was heavier at cooler maxima, in less arid areas, and in areas of greater rainfall variability. Only aridity significantly influenced body mass of P. hermannsburgensis, which was heavier in more arid areas. Temperature did not interact significantly with body mass. After accounting for climatic variables, there was still a significant relationship between the residuals of body mass with locality for both species, with a negative influence of latitude and a positive influence of longitude in both; the latitudinal interaction for both species was converse to Bergmann’s Rule. We suggest that latitude, ambient temperature and other selection pressures (such as aridity or productivity) can act in opposing directions, and speculate that the influence of other factors, such as food availability or sociality, may be more important than latitude or ambient temperature.

scholarly journals Variability and repeatability of noctule bat migration in Central Europe: evidence for partial and differential migration

2018 ◽  
Vol 285 (1893) ◽  
pp. 20182174 ◽  
Author(s):  
Linn S. Lehnert ◽  
Stephanie Kramer-Schadt ◽  
Tobias Teige ◽  
Uwe Hoffmeister ◽  
Ana Popa-Lisseanu ◽  
...  
Keyword(s):  
Central Europe ◽  
Migratory Behaviour ◽  
Natal Philopatry ◽  
Differential Migration ◽  
Long Distance ◽  
Migration Strategy ◽  
Migration Patterns ◽  
Bat Migration ◽  
Source Populations ◽  
And Migration

Each year, large numbers of bats move across Europe between their summer and winter areas, yet even though many of them are endangered and legally protected, we are unaware about many aspects of their migratory behaviour. Here, taking Nyctalus noctula as a model species, we used stable hydrogen isotopic values in fur ( δ 2 H f ) as an endogenous marker to shed light on the migratory behaviour of more than 1000 bats from hibernacula across Central Europe. Specifically, we asked the following questions: how flexible is migration in temperate zone bats? Which general migration pattern do noctule bats follow? How repeatable and thus predictable is the migratory behaviour of individuals? Do morphological correlates of migration occur in bats? Our study confirmed that noctule bats engage in partial and female-biased migration across Europe, suggesting the strongest migration pressures for northern populations. Further, we revealed a combination of partial and differential migration patterns with highly variable migration distances which lead to a pronounced mixing of different source populations in hibernacula where mating occurs. Most individuals were consistent in their migration strategy over time, i.e. 86% could be repeatedly assigned to either long-distance or regional origin across years. This is consistent with our finding that the between-individual component explained 84% of the variation in δ 2 H f values, suggesting specialized individual migratory behaviours and a strong natal philopatry. We discovered a positive correlation between forearm length and migration distance and support for sex-specific effects of migration on body condition. Our study elucidated migration patterns over large geographical scales, demonstrating that considerable numbers of migratory bats originating from distant populations depend on hibernacula across Central Europe, calling for international conservation management.

scholarly journals The Elevation does not strongly influence interspecific variation in body size of small Tropical endotherms

2020 ◽  
Vol 68 (4) ◽  
Author(s):  
Oscar E. Murillo-García ◽  
Maria E. De la vega ◽  
Katherine Pérez-Castillo
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Environmental Changes ◽  
Large Body ◽  
Interspecific Variation ◽  
Bergmann’S Rule ◽  
Distribution Data ◽  
Bergmann's Rule ◽  
Altitudinal Distribution ◽  
Altitudinal Gradients

Introduction: Body size is an essential trait for endotherms to face the physiological requirements of cold, so there is a tendency to large body size at high altitudes and latitudes, known as Bergmann's rule. However, the validity of this ecomorphological rule to small-bodied endotherms across altitudinal gradients is poorly known. Objective: To understand the effects of environmental variation on body size, we assessed whether interspecific variation in body size of small tropical endotherms follows Bergmann's rule along tropical altitudinal gradients. Methods: We compiled data on elevational ranges and body masses for 133 species of hummingbirds of Colombia. We then assessed the association between body mass and mid-point of the altitudinal distribution using phylogenetic generalized least squares (PGLS) analyses under different evolutionary models. Results: We found a decelerating rate of evolution for body size since the Early Burst model of evolution provided a better fit to body mass data. For elevational range, we found a slow and constant rate since Pagel's lambda model provided a better fit to the mid-point of the altitudinal distribution data. Besides, phylogenetic regression analysis indicated that body mass and the altitudinal range of hummingbirds are associated through the phylogeny, with a positive but slight association (R2= 0.036). Conclusions: We found that body mass and altitude of hummingbirds are positively related, which is in agreement with expectations under Bergmann's rule. However, this association was weaker than expected for small and non-passerine birds like hummingbirds. Thus, our results suggest that environmental changes across altitudinal gradients do not strongly influence body mass in small tropical endotherms as hummingbirds.

Latitudinal variation in snowshoe hare (Lepus americanus) body mass: a test of Bergmann’s rule

2020 ◽  
Vol 98 (2) ◽  
pp. 88-95 ◽  
Author(s):  
Laura C. Gigliotti ◽  
Nathan D. Berg ◽  
Rudy Boonstra ◽  
Shawn M. Cleveland ◽  
Duane R. Diefenbach ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Snow Depth ◽  
Large Body ◽  
Geographic Location ◽  
Growing Season ◽  
Lepus Americanus ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
The North

The relationship between body size and latitude has been the focus of dozens of studies across many species. However, results of testing Bergmann’s rule — that organisms in colder climates or at higher latitudes possess larger body sizes — have been inconsistent across studies. We investigated whether snowshoe hares (Lepus americanus Erxleben, 1777) follow Bergmann’s rule by investigating differences in body mass using data from six published studies and from data of 755 individual hares captured from 10 populations across North America covering 26° of north latitude. We also explored alternative hypotheses related to variation in hare body mass, including winter severity, length of growing season, elevation, and snow depth. We found body mass of hares varied throughout their range, but the drivers of body mass differed based on geographic location. In northern populations, females followed Bergmann’s rule, whereas males did not. In northern populations, male mass was related to mean snow depth. In contrast, in southern populations, body mass of both sexes was related to length of the growing season. These differences likely represent variation in the drivers of selection. Specifically, in the north, a large body size is beneficial to conserve heat because of low winter temperatures, whereas in the south, it is likely due to increased food supply associated with longer growing seasons.

Oligo-Miocene climate change and mammal body-size evolution in the northwest United States: a test of Bergmann's Rule

Paleobiology ◽  
10.1666/13006 ◽  
2013 ◽  
Vol 39 (4) ◽  
pp. 648-661 ◽  
Author(s):  
John D. Orcutt ◽  
Samantha S. B. Hopkins
Keyword(s):  
United States ◽  
Body Size ◽  
Body Mass ◽  
Global Climate ◽  
Climatic Conditions ◽  
Bergmann’S Rule ◽  
Bergmann's Rule ◽  
Complex Interactions ◽  
Size Evolution ◽  
Body Size Evolution

Whether or not climate plays a causal role in mammal body-size evolution is one of the longest-standing debates in ecology. Bergmann's Rule, the longest-standing modeladdressing this topic, posits that geographic body-mass patterns are driven by temperature, whereas subsequent research has suggested that other ecological variables, particularly precipitation and seasonality, may be the major drivers of body-size evolution. While paleoecological data provide a unique and crucial perspective on this debate, paleontological tests of Bergmann's rule and its corollaries have been scarce. We present a study of body-size evolution in three ecologically distinct families of mammal (equids, canids, and sciurids) during the Oligo-Miocene of the northwest United States, an ideal natural laboratory for such studies because of its rich fossil and paleoclimatic records. Body-size trends are different in all three groups, and in no case is a significant relationship observed between body size and any climatic variable, counter to what has been observed in modern ecosystems. We suggest that for most of the Cenozoic, at least in the Northwest, body mass has not been driven by any one climatic factor but instead has been the product of complex interactions between organisms and their environments, though the nature of these interactions varies from taxon to taxon. The relationship that exists between climate and body size in many groups of modern mammals, therefore, is the exception to the rule and may be the product of an exceptionally cool and volatile global climate. As anthropogenic global warming continues and ushers in climatic conditions more comparable to earlier intervals of the Cenozoic than to the modern day, models of corresponding biotic variables such as body size may lose predictive power if they do not incorporate paleoecological data.

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