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.

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.

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 Relative Brain Size and Its Relation with the Associative Pallium in Birds

2016 ◽  
Vol 87 (2) ◽  
pp. 69-77 ◽  
Author(s):  
Ferran Sayol ◽  
Louis Lefebvre ◽  
Daniel Sol
Keyword(s):  
Brain Size ◽  
Large Fraction ◽  
Biological Significance ◽  
Size Variation ◽  
Brain Structures ◽  
Brain Regions ◽  
Whole Brain ◽  
Small Areas ◽  
Mosaic Evolution ◽  
The Brain

Despite growing interest in the evolution of enlarged brains, the biological significance of brain size variation remains controversial. Much of the controversy is over the extent to which brain structures have evolved independently of each other (mosaic evolution) or in a coordinated way (concerted evolution). If larger brains have evolved by the increase of different brain regions in different species, it follows that comparisons of the whole brain might be biologically meaningless. Such an argument has been used to criticize comparative attempts to explain the existing variation in whole-brain size among species. Here, we show that pallium areas associated with domain-general cognition represent a large fraction of the entire brain, are disproportionally larger in large-brained birds and accurately predict variation in the whole brain when allometric effects are appropriately accounted for. While this does not question the importance of mosaic evolution, it suggests that examining specialized, small areas of the brain is not very helpful for understanding why some birds have evolved such large brains. Instead, the size of the whole brain reflects consistent variation in associative pallium areas and hence is functionally meaningful for comparative analyses.

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 Combined effects of migration distance, foraging method vegetation density, and population density on wing shapes of boreal songbirds

2018 ◽  
Author(s):  
Flavie Noreau ◽  
André Desrochers
Keyword(s):  
Population Density ◽  
Interspecific Variation ◽  
Breeding Population ◽  
Wing Shape ◽  
Habitat Isolation ◽  
Vegetation Density ◽  
Long Distance ◽  
Migration Distance ◽  
Interspecific Differences ◽  
Foraging Method

AbstractIn birds, migration distance is known to influence morphological attributes that influence flight performance, especially wing shape. However, wing shape is under the likely influence of less documented factors such as foraging method, vegetation density and isolation of individuals and populations. To better understand factors leading to interspecific differences in wing shape, we measured the pointedness of wings (Kipp’s distance) of 1017 live birds of 22 species in an eastern Canadian boreal forest. We modeled wing pointedness as a function of migration distances from eBird records, foraging, habitat, and population density data fromBirds of North Americamonographs. Long-distance migrants and species living in low-density vegetation had more pointed wings than shorter-distance migrants and dense-vegetation dwellers, in accordance to our predictions. After accounting for vegetation density and migration distance, we found no link between the extent of aerial foraging or mean breeding population density, an indicator of isolation, and wing pointedness. Those results are consistent with a tradeoff between sustained flight efficiency and maneuverability, but suggest that interspecific variation in wing shape due specifically to foraging method or habitat isolation is nonexistent or obscured by other factors.

Differences in the proportional volume of different brain regions relative to the whole brain size

2011 ◽  
Vol 42 (01) ◽  
Author(s):  
M. Belke ◽  
D.H. Salat ◽  
E. Wehrmann ◽  
K. Menzler ◽  
W.H. Oertel ◽  
...  
Keyword(s):  
Brain Size ◽  
Brain Regions ◽  
Whole Brain

scholarly journals Parental provisioning drives brain size in birds

2021 ◽  
Author(s):  
Michael Griesser ◽  
Szymon M Drobniak ◽  
Sereina M Graber ◽  
Carel van Schaik
Keyword(s):  
Cognitive Abilities ◽  
Brain Size ◽  
Bird Species ◽  
Behavioral Flexibility ◽  
Interspecific Variation ◽  
Adult Brain ◽  
Egg Mass ◽  
Adult Body Mass ◽  
Parental Provisioning ◽  
Relative Brain Size

Larger brains should be adaptive because they support numerous eco- and socio-cognitive benefits, but these benefits explain only a modest part of the interspecific variation in brain size. Notably underexplored are the high energetic costs of developing brains, and thus the possible role of parental provisioning in the evolution of adult brain size. We explore this idea in birds, which show considerable variation in both socio-ecological traits and the energy transfer from parents to offspring. Comparative analyses of 1,176 bird species show that the combination of adult body mass, mode of development at hatching, relative egg mass, and the time spent provisioning the young in combination strongly predict relative brain size across species. Adding adult eco- and socio-cognitive predictors only marginally adds explanatory value. We therefore conclude that parental provisioning enabled bird species to evolve into skill-intensive niches, reducing interspecific competition and consequently promoting survival prospects and population stability. Critically, parental provisioning also explains why precocial bird species have smaller brains than altricial ones. Finally, these results suggest that the cognitive adaptations that provide the behavioral flexibility to improve reproductive success and survival are intrinsically linked to successful parental provisioning. Our findings also suggest that the traditionally assessed cognitive abilities may not predict relative brain size.

scholarly journals Nocturnal giants: evolution of the sensory ecology in elephant birds and other palaeognaths inferred from digital brain reconstructions

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181540 ◽  
Author(s):  
Christopher R. Torres ◽  
Julia A. Clarke
Keyword(s):  
Visual Cues ◽  
Bird Species ◽  
Sensory Ecology ◽  
Interspecific Variation ◽  
Avian Brain ◽  
Olfactory Bulbs ◽  
Visual Systems ◽  
Auditory Systems ◽  
Brain Shape ◽  
Shed Light

The recently extinct Malagasy elephant birds (Palaeognathae, Aepyornithiformes) included the largest birds that ever lived. Elephant bird neuroanatomy is understudied but can shed light on the lifestyle of these enigmatic birds. Palaeoneurological studies can provide clues to the ecologies and behaviours of extinct birds because avian brain shape is correlated with neurological function. We digitally reconstruct endocasts of two elephant bird species, Aepyornis maximus and A. hildebrandti , and compare them with representatives of all major extant and recently extinct palaeognath lineages. Among palaeognaths, we find large olfactory bulbs in taxa generally occupying forested environments where visual cues used in foraging are likely to be limited. We detected variation in olfactory bulb size among elephant bird species, possibly indicating interspecific variation in habitat. Elephant birds exhibited extremely reduced optic lobes, a condition also observed in the nocturnal kiwi. Kiwi, the sister taxon of elephant birds, have effectively replaced their visual systems with hyperdeveloped olfactory, somatosensory and auditory systems useful for foraging. We interpret these results as evidence for nocturnality among elephant birds. Vision was likely deemphasized in the ancestor of elephant birds and kiwi. These results show a previously unreported trend towards decreased visual capacity apparently exclusive to flightless, nocturnal taxa endemic to predator-depauperate islands.

MACRODYNAMICS OF ELECTRICAL ACTIVITY IN THE WHOLE BRAIN

2004 ◽  
Vol 14 (02) ◽  
pp. 363-381 ◽  
Author(s):  
EROL BAŞAR
Keyword(s):  
Electrical Activity ◽  
Brain Function ◽  
Dynamic Properties ◽  
Large Population ◽  
Brain Regions ◽  
Long Distance ◽  
Distance Measurements ◽  
Whole Brain ◽  
Brain Theory ◽  
The Brain

The general problem of brain mechanisms involved in perception can now be studied directly by means of new analysis–methods for the activity of large population of neurons. These methods range from indirect means of measuring changes in cerebral blood flow in local regions of the human cortex (functional magnetic resonance imaging, fMRI), or changes in the electrical activity of the human brain with EEG-recording with topological distributed macroelectrodes, to the use of chronically implanted multiple microelectrodes in primates. f MRI has the disadvantage of low temporal resolution and with multiple microelectrodes long distance measurements cannot yet be properly performed. Accordingly, recording of macro-activity (EEG/ERP or MEG) with a time resolution of millisecond-range is the most possibly adequate method to measure the dynamic properties of memory and the integrative brain function. Since neuroscientists have come to the general conclusion that large numbers of different brain regions have to cooperate for any brain function, the analysis of relationships between different regions of the brain is becoming more and more important. Before new progresses and importance of EEG studies research became clear, scientists working with macrodynamics of the brain had a long way to go, in order to elucidate brain functioning. In this tutorial report we explain in a narrative way the developments leading to the concept of Macrodynamics in search of an integrative brain function. Moreover, elements of a brain theory, which we call neurons-brain theory describing the dynamics of electrical activity in the whole brain, are introduced. The concept of superbinding in integrative brain function, which emerged from experimental data, is a consequence of this theory.

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