scholarly journals Brain Size Associated with Foot Preferences in Australian Parrots

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 867
Author(s):  
Gisela Kaplan ◽  
Lesley J. Rogers
Keyword(s):  
Executive Function ◽  
Brain Size ◽  
Relative Size ◽  
Whole Brain ◽  
Brain Mass

Since foot preference of cockatoos and parrots to hold and manipulate food and other objects has been associated with better ability to perform certain tasks, we predicted that either strength or direction of foot preference would correlate with brain size. Our study of 25 psittacine species of Australia found that species with larger absolute brain mass have stronger foot preferences and that percent left-footedness is correlated positively with brain mass. In a sub-sample of 11 species, we found an association between foot preference and size of the nidopallial region of the telencephalon, an area equivalent to the mammalian cortex and including regions with executive function and other higher-level functions. Our analysis showed that percent left-foot use correlates positively and significantly with size of the nidopallium relative to the whole brain, but not with the relative size of the optic tecta. Psittacine species with stronger left-foot preferences have larger brains, with the nidopallium making up a greater proportion of those brains. Our results are the first to show an association between brain size and asymmetrical limb use by parrots and cockatoos. Our results support the hypothesis that limb preference enhances brain capacity and higher (nidopallial) functioning.

scholarly journals Brain regions associated with visual cues are important for bird migration

2015 ◽  
Vol 11 (11) ◽  
pp. 20150678 ◽  
Author(s):  
Orsolya Vincze ◽  
Csongor I. Vágási ◽  
Péter L. Pap ◽  
Gergely Osváth ◽  
Anders Pape Møller
Keyword(s):  
Visual Cues ◽  
Optic Lobe ◽  
Brain Size ◽  
Relative Size ◽  
Bird Species ◽  
Interspecific Variation ◽  
Brain Regions ◽  
Long Distance ◽  
Migration Distance ◽  
Whole Brain

Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.

TOOLS AND BRAINS IN BIRDS

Behaviour ◽  
2002 ◽  
Vol 139 (7) ◽  
pp. 939-973 ◽  
Author(s):  
Denis Boire ◽  
Nektaria Nicolakakis ◽  
Louis Lefebvre
Keyword(s):  
Cognitive Processes ◽  
Tool Use ◽  
Brain Size ◽  
Short Note ◽  
Relative Size ◽  
The Body ◽  
Whole Brain ◽  
Strong Concentration ◽  
The World ◽  
Innovation Rate

AbstractTools are traditionally defined as objects that are used as an extension of the body and held directly in the hand or mouth. By these standards, a vulture breaking an egg by hitting it with a stone uses a tool, but a gull dropping an egg on a rock does not. This distinction between true and borderline (or proto-tool) cases has been criticized for its arbitrariness and anthropocentrism. We show here that relative size of the neostriatum and whole brain distinguish the true and borderline categories in birds using tools to obtain food or water. From two sources, the specialized literature on tools and an innovation data base gathered in the short note sections of 68 journals in 7 areas of the world, we collected 39 true (e.g. use of probes, hammers, sponges, scoops) and 86 borderline (e.g. bait fishing, battering and dropping on anvils, holding with wedges and skewers) cases of tool use in 104 species from 15 parvorders. True tool users have a larger mean residual brain size (regressed against body weight) than do users of borderline tools, confirming the distinction in the literature. In multiple regressions, residual brain size and residual size of the neostriatum (one of the areas in the avian telencephalon thought to be equivalent to the mammalian neocortex) are the best predictors of true tool use reports per taxon. Innovation rate is the best predictor of borderline tool use distribution. Despite the strong concentration of true tool use cases in Corvida and Passerida, independent constrasts suggest that common ancestry is not responsible for the association between tool use and size of the neostriatum and whole brain. Our results demonstrate that birds are more frequent tool users than usually thought and that the complex cognitive processes involved in tool use may have repeatedly co-evolved with large brains in several orders of birds.

scholarly journals Quantitative genetic analysis of brain size variation in sticklebacks: support for the mosaic model of brain evolution

2015 ◽  
Vol 282 (1810) ◽  
pp. 20151008 ◽  
Author(s):  
Kristina Noreikiene ◽  
Gábor Herczeg ◽  
Abigél Gonda ◽  
Gergely Balázs ◽  
Arild Husby ◽  
...  
Keyword(s):  
Body Size ◽  
Brain Size ◽  
Additive Genetic Variance ◽  
Genetic Correlations ◽  
Relative Size ◽  
Strong Support ◽  
Brain Evolution ◽  
Brain Regions ◽  
Independent Evolution ◽  
Mosaic Model

The mosaic model of brain evolution postulates that different brain regions are relatively free to evolve independently from each other. Such independent evolution is possible only if genetic correlations among the different brain regions are less than unity. We estimated heritabilities, evolvabilities and genetic correlations of relative size of the brain, and its different regions in the three-spined stickleback ( Gasterosteus aculeatus ). We found that heritabilities were low (average h 2 = 0.24), suggesting a large plastic component to brain architecture. However, evolvabilities of different brain parts were moderate, suggesting the presence of additive genetic variance to sustain a response to selection in the long term. Genetic correlations among different brain regions were low (average r G = 0.40) and significantly less than unity. These results, along with those from analyses of phenotypic and genetic integration, indicate a high degree of independence between different brain regions, suggesting that responses to selection are unlikely to be severely constrained by genetic and phenotypic correlations. Hence, the results give strong support for the mosaic model of brain evolution. However, the genetic correlation between brain and body size was high ( r G = 0.89), suggesting a constraint for independent evolution of brain and body size in sticklebacks.

scholarly journals Do Different Methods Yield Equivalent Estimations of Brain Size in Birds?

2020 ◽  
Vol 95 (2) ◽  
pp. 113-122
Author(s):  
Diego Ocampo ◽  
César Sánchez ◽  
Gilbert Barrantes
Keyword(s):  
Body Size ◽  
Brain Size ◽  
Brain Mass ◽  
Wide Range ◽  
Evolutionary Studies ◽  
Relative Brain Size ◽  
Using Data ◽  
Endocranial Volume ◽  
The Brain ◽  
Size Estimates

The ratio of brain size to body size (relative brain size) is often used as a measure of relative investment in the brain in ecological and evolutionary studies on a wide range of animal groups. In birds, a variety of methods have been used to measure the brain size part of this ratio, including endocranial volume, fixed brain mass, and fresh brain mass. It is still unclear, however, whether these methods yield the same results. Using data obtained from fresh corpses and from published sources, this study shows that endocranial volume, mass of fixed brain tissue, and fresh mass provide equivalent estimations of brain size for 48 bird families, in 19 orders. We found, however, that the various methods yield significantly different brain size estimates for hummingbirds (Trochilidae). For hummingbirds, fixed brain mass tends to underestimate brain size due to reduced tissue density, whereas endocranial volume overestimates brain size because it includes a larger volume than that occupied by the brain.

scholarly journals Brain size and the risk of getting shot

2016 ◽  
Vol 12 (11) ◽  
pp. 20160647 ◽  
Author(s):  
Anders Pape Møller ◽  
Johannes Erritzøe
Keyword(s):  
Random Effects ◽  
Body Condition ◽  
Selection Pressure ◽  
Brain Size ◽  
Selective Advantage ◽  
Sampling Effort ◽  
Human Beings ◽  
Large Database ◽  
Random Effects Models ◽  
Brain Mass

Hunting kills hundreds of millions of animals annually, potentially constituting an important selection pressure on hunted species. We hypothesized that hunted individuals differing from survivors by having better ability to distinguish between dangerous humans and other human beings would be at a selective advantage. We tested whether shot individual birds had smaller brains than survivors, under the assumption that individuals with larger brains had superior escape ability. We used a large database on birds from Denmark to test whether getting shot was predicted by brain mass, while controlling statistically for the potentially confounding effects of age, sex, body mass and body condition. Analyses based on all species, or only species that were hunted, while controlling for differences in sampling effort in random effects models, showed consistently that shot individuals had smaller brains than survivors.

scholarly journals Comparison of Dolphins' Body and Brain Measurements with Four Other Groups of Cetaceans Reveals Great Diversity

2016 ◽  
Vol 88 (3-4) ◽  
pp. 235-257 ◽  
Author(s):  
Sam H. Ridgway ◽  
Kevin P. Carlin ◽  
Kaitlin R. Van Alstyne ◽  
Alicia C. Hanson ◽  
Raymond J. Tarpley
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Body Length ◽  
Brain Volume ◽  
Brain Size ◽  
The Other ◽  
Vascular Networks ◽  
Data Set ◽  
Brain Mass ◽  
Endocranial Volume

We compared mature dolphins with 4 other groupings of mature cetaceans. With a large data set, we found great brain diversity among 5 different taxonomic groupings. The dolphins in our data set ranged in body mass from about 40 to 6,750 kg and in brain mass from 0.4 to 9.3 kg. Dolphin body length ranged from 1.3 to 7.6 m. In our combined data set from the 4 other groups of cetaceans, body mass ranged from about 20 to 120,000 kg and brain mass from about 0.2 to 9.2 kg, while body length varied from 1.21 to 26.8 m. Not all cetaceans have large brains relative to their body size. A few dolphins near human body size have human-sized brains. On the other hand, the absolute brain mass of some other cetaceans is only one-sixth as large. We found that brain volume relative to body mass decreases from Delphinidae to a group of Phocoenidae and Monodontidae, to a group of other odontocetes, to Balaenopteroidea, and finally to Balaenidae. We also found the same general trend when we compared brain volume relative to body length, except that the Delphinidae and Phocoenidae-Monodontidae groups do not differ significantly. The Balaenidae have the smallest relative brain mass and the lowest cerebral cortex surface area. Brain parts also vary. Relative to body mass and to body length, dolphins also have the largest cerebellums. Cortex surface area is isometric with brain size when we exclude the Balaenidae. Our data show that the brains of Balaenidae are less convoluted than those of the other cetaceans measured. Large vascular networks inside the cranial vault may help to maintain brain temperature, and these nonbrain tissues increase in volume with body mass and with body length ranging from 8 to 65% of the endocranial volume. Because endocranial vascular networks and other adnexa, such as the tentorium cerebelli, vary so much in different species, brain size measures from endocasts of some extinct cetaceans may be overestimates. Our regression of body length on endocranial adnexa might be used for better estimates of brain volume from endocasts or from endocranial volume of living species or extinct cetaceans.

scholarly journals High-throughput whole-brain mapping of rhesus monkey at micron resolution

2020 ◽  
Author(s):  
Fang Xu ◽  
Yan Shen ◽  
Lufeng Ding ◽  
Chao-Yu Yang ◽  
Heng Tan ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Large Scale ◽  
High Efficiency ◽  
Brain Size ◽  
Integrative Approach ◽  
Whole Brain ◽  
3 Dimensional ◽  
Large Brain ◽  
Thalamocortical Projections ◽  
Distinct Features

AbstractWhole-brain mesoscale mapping of primates has been hindered by large brain size and the relatively low throughput of available microscopy methods. Here, we present an integrative approach that combines primate-optimized tissue sectioning and clearing with ultrahigh-speed, large-scale, volumetric fluorescence microscopy, capable of completing whole-brain imaging of a rhesus monkey at 1 µm × 1 µm × 2.5 µm voxel resolution within 100 hours. A progressive strategy is developed for high-efficiency, long-range tracing of individual axonal fibers through the dataset of hundreds of terabytes, establishing a “Serial sectioning and clearing, 3-dimensional Microscopy, with semi-Automated Reconstruction and Tracing” (SMART) pipeline. This system supports effective connectome-scale mapping of large primates that reveals distinct features of thalamocortical projections of the rhesus monkey brain at the level of individual axonal fibers.

scholarly journals Using relative brain size to better understand trophic interactions and phenotypic plasticity of invasive lionfish (Pterois volitans)

2020 ◽  
Author(s):  
McKenna Becker
Keyword(s):  
Body Mass ◽  
Brain Size ◽  
Predation Pressure ◽  
Mass Ratio ◽  
Pterois Volitans ◽  
Predator Prey ◽  
Brain Mass ◽  
Body Mass Ratio ◽  
Relative Brain Size ◽  
The Brain

AbstractPredator-prey dynamics provide critical insight into overall coral reef health. It has been shown that predator-prey relationships link the relative brain size of predators to their prey. Predation pressure forces prey to use decision-making skills that require higher cognition by inspecting and identifying predators and then adjusting their behavior to achieve the highest chance for survival. However, the predation pressure that prey face outweighs the pressure predators face to find prey, resulting in prey having larger relative brain sizes than their predators. There is little data on the relative brain size of fishes with few natural predators such as Pterois volitans. This study compared the brain mass to body mass ratio of Pterois volitans, which have very few natural predators and thus very little predation pressure, to the brain mass to body mass ratio of their prey, possible predators, competitors, and taxonomically similar fish. Lionfish had a significantly smaller relative brain size than their predators, prey, and competitors, but was not significantly smaller than taxonomically similar fish. These results demonstrate that the morphological anti-predator adaptation of venomous spines causes little predation pressure. Thus, lionfish do not use the same cognitive skills as other prey or predators and, in turn, have smaller relative brain sizes.

Predation impacts brain allometry and offspring production in female guppies (Poecilia reticulata)

2021 ◽  
Author(s):  
Regina Vega-Trejo ◽  
David Joseph Mitchell ◽  
Catarina Vila Pouca ◽  
Alexander Kotrschal
Keyword(s):  
Poecilia Reticulata ◽  
Brain Size ◽  
Relative Size ◽  
Reproductive Traits ◽  
Brain Evolution ◽  
Predation Pressure ◽  
Control Fish ◽  
Brain Anatomy ◽  
Offspring Production ◽  
The Impact

Survivorship under predation exerts strong selection on reproductive traits as well as on brain anatomy of prey. However, how exactly predation and brain evolution are linked has not been resolved as current empirical evidence is inconclusive. This may be due to predation pressure having different effects across life stages and/or due to confounding factors in ecological comparisons of predation pressure. Here, we used adult guppies (Poecilia reticulata) to experimentally test the impact of a period of strong predation on brain anatomy and reproduction of surviving individuals. We compared the survivors to control fish, which were exposed to visual and olfactory predator cues but could not be predated on, and found that predation impacted the relative size of female brains. This effect was dependent on body size as larger female survivors showed relatively larger brains, while smaller survivors showed relatively smaller brains when compared to control animals. There were no differences in male relative brain size between the treatments, nor for any specific relative brain region sizes for either sex. Moreover, survivors produced more offspring, but did not show shorter interbrood intervals than controls. Our results corroborate the important, yet complex, role of predation as an important factor behind variation in brain anatomy.

scholarly journals Neocortex expansion is linked to size variations in gene families with chemotaxis, cell–cell signalling and immune response functions in mammals

Open Biology ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 160132
Author(s):  
Atahualpa Castillo-Morales ◽  
Jimena Monzón-Sandoval ◽  
Alexandra A. de Sousa ◽  
Araxi O. Urrutia ◽  
Humberto Gutierrez
Keyword(s):  
Immune Response ◽  
Adult Development ◽  
Brain Size ◽  
Mammalian Species ◽  
Cell Signalling ◽  
Relative Size ◽  
Brain Evolution ◽  
Gene Families ◽  
Evolutionary Innovation ◽  
Cell Cell

Increased brain size is thought to have played an important role in the evolution of mammals and is a highly variable trait across lineages. Variations in brain size are closely linked to corresponding variations in the size of the neocortex, a distinct mammalian evolutionary innovation. The genomic features that explain and/or accompany variations in the relative size of the neocortex remain unknown. By comparing the genomes of 28 mammalian species, we show that neocortical expansion relative to the rest of the brain is associated with variations in gene family size (GFS) of gene families that are significantly enriched in biological functions associated with chemotaxis, cell–cell signalling and immune response. Importantly, we find that previously reported GFS variations associated with increased brain size are largely accounted for by the stronger link between neocortex expansion and variations in the size of gene families. Moreover, genes within these families are more prominently expressed in the human neocortex during early compared with adult development. These results suggest that changes in GFS underlie morphological adaptations during brain evolution in mammalian lineages.

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