scholarly journals Body size affects immune cell proportions in birds and non-volant mammals, but not bats

2021 ◽  
Author(s):  
Emily Cornelius Ruhs ◽  
Daniel J. Becker ◽  
Samantha J. Oakey ◽  
Ololade Ogunsina ◽  
M. Brock Fenton ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Immune Cell ◽  
White Blood Cells ◽  
Bird Species ◽  
Immune Defense ◽  
Mammal Species ◽  
Zoonotic Infections ◽  
Neotropical Bats ◽  
Similar Body

Powered flight has evolved several times in vertebrates and constrains morphology and physiology in ways that likely have shaped how organisms cope with infections. Some of these constraints likely have impacts on aspects of immunology, such that larger fliers might prioritize risk reduction and safety. Addressing how the evolution of flight may have driven relationships between body size and immunity could be particularly informative for understanding the propensity of some taxa to harbor many virulent and sometimes zoonotic pathogens without showing clinical disease. Here, we used a comparative framework to quantify scaling relationships between body mass and the proportions of two types of white blood cells--lymphocytes, and granulocytes (neutr-/heterophils)--across 63 bat species, 400 bird species, and 251 non-volant mammal species. By using phylogenetically-informed statistical models on field-collected data from wild Neotropical bats and from captive bats, non-volant mammals and birds, we show that lymphocyte and neutrophil proportions do not vary systematically with body mass among bats. In contrast, larger birds and non-volant mammals have disproportionately higher granulocyte proportions than expected for their body size. Our inability to distinguish bat lymphocyte scaling from birds and bat granulocyte scaling from all other taxa suggest there may be other ecological explanations (i.e. not flight-related) for the cell proportion scaling patterns. Future comparative studies of wild bats, birds, and non-volant mammals of similar body mass should aim to further differentiate evolutionary effects and other aspects of life history on immune defense and its role in tolerance of (zoonotic) infections.

scholarly journals Body size affects immune cell proportions in birds and non-volant mammals, but not bats

2020 ◽  
Author(s):  
Emily Cornelius Ruhs ◽  
Daniel J. Becker ◽  
Samantha J. Oakey ◽  
Ololade Ogunsina ◽  
M. Brock Fenton ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Immune Cell ◽  
White Blood Cells ◽  
Bird Species ◽  
Immune Defense ◽  
Mammal Species ◽  
Scaling Relationships ◽  
Neotropical Bats ◽  
Similar Body

AbstractPowered flight has evolved several times in vertebrates and constrains morphology and physiology in ways that likely have shaped how organisms cope with infections. Some of these constraints likely have impacts on aspects of immunology, such that larger fliers might prioritize risk reduction and safety. Addressing how the evolution of flight may have driven relationships between body size and immunity could be particularly informative for understanding the propensity of some taxa to harbor many virulent and sometimes zoonotic pathogens without showing clinical disease. Here, we used a scaling framework to quantify scaling relationships between body mass and the proportions of two types of white blood cells--lymphocytes, and granulocytes (neutr-/heterophils)--across 60 bat species, 414 bird species, and 256 non-volant mammal species. By using phylogenetically-informed statistical models on field-collected data from wild Neotropical bats, data gleaned from other wild bats available in the literature, and data from captive non-volant mammals and birds, we show that lymphocyte and neutrophil proportions do not vary systematically with body mass among bats. In contrast, larger birds and non-volant mammals have disproportionately higher granulocyte proportions than expected for their body size. Future comparative studies of wild bats, birds, and non-volant mammals of similar body mass should aim to further differentiate evolutionary effects and other aspects of life history on immune defense.Summary statementPowered flight might constrain morphology such that certain immunological features are prioritized. We show that bats largely have similar cell proportions across body mass compared to strong allometric scaling relationships in birds and non-flying mammals.

Acyl composition of muscle membranes varies with body size in birds

2002 ◽  
Vol 205 (22) ◽  
pp. 3561-3569 ◽  
Author(s):  
A. J. Hulbert ◽  
S. Faulks ◽  
W. A. Buttemer ◽  
P. L. Else
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Acyl Chain ◽  
Bird Species ◽  
Unsaturation Index ◽  
Pectoral Muscle ◽  
Muscle Membrane ◽  
Index Number ◽  
Acyl Composition ◽  
Metabolic Intensity

SUMMARYThe acyl composition of phospholipids from pectoral muscle of eight species of birds, ranging in size from the 13 g zebra finch to the 34 kg emu, were measured and combined with recent published results for a 3 g hummingbird. This represents an approximately 11000-fold range in body mass. Muscle phospholipids, and thus muscle membrane bilayers, from birds had a relatively constant unsaturated acyl chain content of 62% but exhibited a significant allometric decline in unsaturation index (number of double bonds per 100 acyl chains) with increasing body mass. There was a significant allometric increase in the percentage of mono-unsaturates and a significant allometric decline in the percentage of n-3 polyunsaturates with increasing body mass,whilst there were no significant allometric trends in either percentage of n-6 or percentage of total polyunsaturates in bird muscle. The relative content of the highly polyunsaturated docosahexaenoic acid (22:6 n-3) showed the greatest scaling with body mass, having an allometric exponent of -0.28. The contribution of this n-3 polyunsaturate to the unsaturation index varied with body size, ranging from less than a 6%contribution in the emu to approximately 70% in the hummingbird. Such allometric variation in the acyl composition of bird muscle phospholipids is similar to that observed in mammals, although birds have fewer n-3 polyunsaturates and more n-6 polyunsaturates than do mammalian phospholipids. This allometric variation in phospholipid acyl composition is discussed with respect to both the metabolic intensity and lifespan of different sized bird species.

scholarly journals Do Life History Traits Influence Patterns of Maternal Immune Elements in New World Blackbirds (Icteridae)?

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
C A Fassbinder-Orth ◽  
L D Igl ◽  
D C Hahn ◽  
K M Watts ◽  
T E Wilcoxen ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Immune Responses ◽  
Life History Traits ◽  
New World ◽  
Bird Species ◽  
Immune Defense ◽  
Closely Related Species ◽  
Brood Parasites ◽  
Comparative Immunity

Abstract Avian immunology developed originally by investigating domesticated poultry species (Galliformes), but in recent decades eco-immunological studies of wild bird species have revealed that avian immune systems are more diverse than initially assumed. This study compares six immunological elements in eggs of six species within the same family, the New World blackbirds (Icteridae),whose members differ most notably in two life history parameters, brood parasitism and body size. We measured the maternal immune investment of passive immune components in both yolk and albumen: lysozyme, ovotransferrin, and immunoglobulins (Igs), and LPS-specific Igs. We predicted that brood parasites would have higher levels of immune activity for both innate and adaptive immunity compared with non-brood parasites, and that increased body size could increase microbial exposure of larger animals, resulting in an increase in some adaptive immune responses, such as LPS-specific Igs. We found that brood parasites had significantly higher levels of Igs and lysozyme levels in albumen, but significantly lower levels of Igs in yolk compared with non-brood parasites. Igs in yolk scaled according to body size, with the smallest organisms (the brood parasites) having the lowest levels, and the largest organism (common grackle) having the highest. Our results confirm the findings of other studies of comparative immunity among species in a single taxon that (1) similarities in immune investment cannot be assumed among closely related species and (2) single measures of immune defense cannot be assumed to be indicators of a species’ overall immune strategy, as life history traits can differentially affect immune responses.

CLIMBING PERFORMANCE OF MIGRATING BIRDS AS A BASIS FOR ESTIMATING LIMITS FOR FUEL-CARRYING CAPACITY AND MUSCLE WORK

1992 ◽  
Vol 164 (1) ◽  
pp. 19-38 ◽  
Author(s):  
ANDERS HEDENSTRÖM ◽  
THOMAS ALERSTAM
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Bird Species ◽  
Flapping Flight ◽  
Fuel Load ◽  
Total Power ◽  
Total Body Mass ◽  
Muscle Work ◽  
Total Power Consumption ◽  
Migrating Birds

Sustained climb rates and airspeeds in flapping flight were measured by radar tracking fifteen species of migrating birds ranging in body mass between 10 g and 10 kg. There was an inverse correlation between body size and climb rate: the lowest mean climb rate, 0.32 m s−1, was observed in the mute swan and the highest mean value, 1.63ms−1, in the dunlin. Some dunlin flocks achieved sustained climb rates exceeding 2ms−1, up to 2.14ms−1. Assuming that the migrants expend maximum sustained power during their climbs, the climbing power can be used as a conservative estimate of the power margin. Estimates of climbing power for the species tracked by radar were used, in conjunction with aerodynamic theory, to calculate the amount of extra load the migrants should be able to carry if their power margin was used for load transportation rather than for climbing. Calculated ratios of total body mass with maximum load to lean body mass ranged between 1.28 and 2.75, showing an overall negative correlation with body size. There was a broad agreement with maximum fuel loads observed among freeliving birds, indicating that the upper limits of fuel-carrying capacities and flight ranges in migrating birds are determined by power margin constraints in sustained flapping flight. Markedly reduced climb rates have been recorded for shorebirds departing with very large fuel reserves from W. Africa and Iceland, supporting the calculated trade-off between climb rate and fuel load. Total power consumption was estimated as the sum of calculated aerodynamic power for forward flight and climbing power. The ratio of total power to the expected minimum aerodynamic power was 1.1-1.3 in the three largest species, increasing to 2–4 in the smallest species. Medium- and small-sized species seem to allocate power in excess of the minimum aerodynamic power not only for climbing but also for maintaining a forward speed faster than the minimum power speed. Given provisional estimates of flight muscle masses and wingbeat frequencies, the mass-specific sustained muscle work for the different climbing bird species was calculated to be in the range 16–41 joules per kilogram muscle mass, showing a significant positive correlation with body mass

Investigating the role of environment in pika (Ochotona) body size patterns across taxonomic levels, space, and time

2020 ◽  
Vol 101 (3) ◽  
pp. 804-816
Author(s):  
Marie L Westover ◽  
Felisa A Smith
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Food Availability ◽  
Biotic Interactions ◽  
Mammal Species ◽  
Habitat Variability ◽  
Space And Time ◽  
Important Trait ◽  
Response To Temperature ◽  
Response To Environmental Change

Abstract Body size is an important trait in animals because it influences a multitude of additional life history traits. The causal mechanisms underlying body size patterns across spatial, temporal, and taxonomic hierarchies are debated, and of renewed interest in this era of climate change. Here, we tested multiple hypotheses regarding body mass patterns at the intraspecific and interspecific levels. We investigated body size patterns within a climate-sensitive small mammal species, Ochotona princeps (n = 2,873 individuals), across their range with local environmental variables. We also examined body mass of populations over time to determine if body size has evolved in situ in response to environmental change. At the interspecific level we compared the mean mass of 26 pika species (genus Ochotona) to determine if environmental temperatures, food availability, habitat variability, or range area influence body size. We found correlations between temperature, vegetation, and particularly precipitation variables, with body mass within O. princeps, but no linear relationship between body size and any climate or habitat variable for Ochotona species. Body size trends in relation to climate were stronger at the intraspecific than the interspecific level. Our results suggest that body size within O. princeps likely is related to food availability, and that body size evolution is not always a viable response to temperature change. Different mechanisms may be driving body size at the interspecific and intraspecific levels and factors other than environment, such as biotic interactions, may also be influential in determining body size over space and time.

scholarly journals Large-scale assessment of commensalistic–mutualistic associations between African birds and herbivorous mammals using internet photos

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4520 ◽  
Author(s):  
Peter Mikula ◽  
Jiří Hadrava ◽  
Tomáš Albrecht ◽  
Piotr Tryjanowski
Keyword(s):  
Species Richness ◽  
Body Mass ◽  
Information Technologies ◽  
Large Scale ◽  
Bird Species ◽  
Null Model ◽  
Herd Size ◽  
Mammal Species ◽  
African Mammals ◽  
Herbivorous Mammals

Birds sitting or feeding on live large African herbivorous mammals are a visible, yet quite neglected, type of commensalistic–mutualistic association. Here, we investigate general patterns in such relationships at large spatial and taxonomic scales. To obtain large-scale data, an extensive internet-based search for photos was carried out on Google Images. To characterize patterns of the structural organization of commensalistic–mutualistic associations between African birds and herbivorous mammals, we used a network analysis approach. We then employed phylogenetically-informed comparative analysis to explore whether features of bird visitation of mammals, i.e., their mean number, mass and species richness per mammal species, are shaped by a combination of host mammal (body mass and herd size) and environmental (habitat openness) characteristics. We found that the association web structure was only weakly nested for commensalistic as well as for mutualistic birds (oxpeckers Buphagus spp.) and African mammals. Moreover, except for oxpeckers, nestedness did not differ significantly from a null model indicating that birds do not prefer mammal species which are visited by a large number of bird species. In oxpeckers, however, a nested structure suggests a non-random assignment of birds to their mammal hosts. We also identified some new or rare associations between birds and mammals, but we failed to find several previously described associations. Furthermore, we found that mammal body mass positively influenced the number and mass of birds observed sitting on them in the full set of species (i.e., taking oxpeckers together with other bird species). We also found a positive correlation between mammal body mass and mass of non-oxpecker species as well as oxpeckers. Mammal herd size was associated with a higher mass of birds in the full set of species as well as in non-oxpecker species, and mammal species living in larger herds also attracted more bird species in the full set of species. Habitat openness influenced the mass of birds sitting on mammals as well as the number of species recorded sitting on mammals in the full set of species. In non-oxpecker species habitat openness was correlated with the bird number, mass and species richness. Our results provide evidence that patterns of bird–mammal associations can be linked to mammal and environmental characteristics and highlight the potential role of information technologies and new media in further studies of ecology and evolution. However, further study is needed to get a proper insight into the biological and methodological processes underlying the observed patterns.

scholarly journals A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition

2021 ◽  
pp. 1-12
Author(s):  
Carel P. van Schaik ◽  
Zegni Triki ◽  
Redouan Bshary ◽  
Sandra A. Heldstab
Keyword(s):  
Body Size ◽  
Cognitive Abilities ◽  
Brain Size ◽  
Estimation Error ◽  
Primate Species ◽  
Mammal Species ◽  
Mean Values ◽  
Encephalization Quotient ◽  
Body Sizes ◽  
Size Measure

Both absolute and relative brain sizes vary greatly among and within the major vertebrate lineages. Scientists have long debated how larger brains in primates and hominins translate into greater cognitive performance, and in particular how to control for the relationship between the noncognitive functions of the brain and body size. One solution to this problem is to establish the slope of cognitive equivalence, i.e., the line connecting organisms with an identical bauplan but different body sizes. The original approach to estimate this slope through intraspecific regressions was abandoned after it became clear that it generated slopes that were too low by an unknown margin due to estimation error. Here, we revisit this method. We control for the error problem by focusing on highly dimorphic primate species with large sample sizes and fitting a line through the mean values for adult females and males. We obtain the best estimate for the slope of circa 0.27, a value much lower than those constructed using all mammal species and close to the value expected based on the genetic correlation between brain size and body size. We also find that the estimate of cognitive brain size based on cognitive equivalence fits empirical cognitive studies better than the encephalization quotient, which should therefore be avoided in future studies on primates and presumably mammals and birds in general. The use of residuals from the line of cognitive equivalence may change conclusions concerning the cognitive abilities of extant and extinct primate species, including hominins.

scholarly journals Body mass data set for 1317 bird and 270 mammal species from Colombia

Ecology ◽  
2020 ◽  
Author(s):  
David Ocampo ◽  
Kevin G. Borja‐Acosta ◽  
Julián Lozano‐Flórez ◽  
Sebastián Cifuentes‐Acevedo ◽  
Enrique Arbeláez‐Cortés ◽  
...  
Keyword(s):  
Body Mass ◽  
Mammal Species ◽  
Data Set ◽  
Mass Data

scholarly journals Morphological determinants of jumping performance in the Iberian green frog

2019 ◽  
Vol 66 (4) ◽  
pp. 417-424
Author(s):  
Gregorio Moreno-Rueda ◽  
Abelardo Requena-Blanco ◽  
Francisco J Zamora-Camacho ◽  
Mar Comas ◽  
Guillem Pascual
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Fluctuating Asymmetry ◽  
Hind Limb ◽  
Limb Length ◽  
Age Classes ◽  
Jumping Performance ◽  
Hind Limbs ◽  
Selective Forces ◽  
Pelophylax Perezi

Abstract Predation is one of the main selective forces in nature, frequently selecting potential prey for developing escape strategies. Escape ability is typically influenced by several morphological parameters, such as morphology of the locomotor appendices, muscular capacity, body mass, or fluctuating asymmetry, and may differ between sexes and age classes. In this study, we tested the relationship among these variables and jumping performance in 712 Iberian green frogs Pelophylax perezi from an urban population. The results suggest that the main determinant of jumping capacity was body size (explaining 48% of variance). Larger frogs jumped farther, but jumping performance reached an asymptote for the largest frogs. Once controlled by structural body size, the heaviest frogs jumped shorter distances, suggesting a trade-off between fat storage and jumping performance. Relative hind limb length also determined a small but significant percentage of variance (2.4%) in jumping performance—that is, the longer the hind limbs, the greater the jumping capacity. Juveniles had relatively shorter and less muscular hind limbs than adults (for a given body size), and their jumping performance was poorer. In our study population, the hind limbs of the frogs were very symmetrical, and we found no effect of fluctuating asymmetry on jumping performance. Therefore, our study provides evidence that jumping performance in frogs is not only affected by body size, but also by body mass and hind limb length, and differ between age classes.

Sign in / Sign up

Export Citation Format

Share Document