scholarly journals Microhabitat Use Affects Brain Size and Structure in Intertidal Gobies

2015 ◽  
Vol 85 (2) ◽  
pp. 107-116 ◽  
Author(s):  
Gemma E. White ◽  
Culum Brown
Keyword(s):  
Spatial Learning ◽  
Brain Size ◽  
Microhabitat Use ◽  
Rocky Shores ◽  
Rock Pool ◽  
Environmental Complexity ◽  
Learning Abilities ◽  
Trade Offs ◽  
Species Specific ◽  
Dorsal Medulla

The ecological cognition hypothesis poses that the brains and behaviours of individuals are largely shaped by the environments in which they live and the associated challenges they must overcome during their lives. Here we examine the effect of environmental complexity on relative brain size in 4 species of intertidal gobies from differing habitats. Two species were rock pool specialists that lived on spatially complex rocky shores, while the remainder lived on dynamic, but structurally simple, sandy shores. We found that rock pool-dwelling species had relatively larger brains and telencephalons in particular, while sand-dwelling species had a larger optic tectum and hypothalamus. In general, it appears that various fish species trade off neural investment in specific brain lobes depending on the environment in which they live. Our previous research suggests that rock pool species have greater spatial learning abilities, enabling them to navigate their spatially complex environment, which may account for their enlarged telencephalon, while sand-dwelling species likely have a reduced need for spatial learning, due to their spatially simple habitat, and a greater need for visual acuity. The dorsal medulla and cerebellum size was unaffected by the habitat in which the fish lived, but there were differences between species indicative of species-specific trade-offs in neural investment.

The effect of cover and food on space use by wintering Song Sparrows and Field Sparrows

1997 ◽  
Vol 75 (10) ◽  
pp. 1636-1641 ◽  
Author(s):  
Christopher W. Beck ◽  
Bryan D. Watts
Keyword(s):  
Predation Risk ◽  
Positive Response ◽  
Distribution Patterns ◽  
Microhabitat Use ◽  
Vegetative Cover ◽  
Song Sparrows ◽  
Trade Offs ◽  
Resource Requirements ◽  
Woody Cover ◽  
Species Specific

The distribution of birds among microhabitats may reflect species-specific resource requirements. Both food availability and predation risk have been shown to influence patterns of microhabitat use by sparrows during winter. We investigated the influence of vegetative cover and food on microhabitat use using a 2 × 2 factorial design. Both woody cover and food were manipulated at the plot level. The presence of screening cover (weed stems) was manipulated within plots. Sparrows showed a positive response to the presence of both cover and food. Within plots, sparrows selected areas with screening cover. The distribution of birds between areas with and without screening cover was influenced by the presence of woody cover and food. Conversely, the presence of screening cover reduced the influence of woody cover on the distribution of birds within patches. Song Sparrows (Melospiza melodia) and Field Sparrows (Spizella pusilla) differed in their response to treatments both within and across plots, suggesting that trade-offs between foraging and predation risk may be important in the structuring of winter sparrow assemblages. Additionally, screening cover appears to moderate predation risk and therefore to affect distribution patterns.

scholarly journals Brain morphology predicts social intelligence in wild cleaner fish

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zegni Triki ◽  
Yasmin Emery ◽  
Magda C. Teles ◽  
Rui F. Oliveira ◽  
Redouan Bshary
Keyword(s):  
Social Intelligence ◽  
Brain Plasticity ◽  
Decision Rules ◽  
Brain Morphology ◽  
Brain Anatomy ◽  
Environmental Complexity ◽  
Learning Abilities ◽  
Cleaner Fish ◽  
High Performing ◽  
Selective Pressures

AbstractIt is generally agreed that variation in social and/or environmental complexity yields variation in selective pressures on brain anatomy, where more complex brains should yield increased intelligence. While these insights are based on many evolutionary studies, it remains unclear how ecology impacts brain plasticity and subsequently cognitive performance within a species. Here, we show that in wild cleaner fish (Labroides dimidiatus), forebrain size of high-performing individuals tested in an ephemeral reward task covaried positively with cleaner density, while cerebellum size covaried negatively with cleaner density. This unexpected relationship may be explained if we consider that performance in this task reflects the decision rules that individuals use in nature rather than learning abilities: cleaners with relatively larger forebrains used decision-rules that appeared to be locally optimal. Thus, social competence seems to be a suitable proxy of intelligence to understand individual differences under natural conditions.

scholarly journals The energy allocation trade-offs underlying life history traits in hypometabolic strepsirhines and other primates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Simmen ◽  
Luca Morino ◽  
Stéphane Blanc ◽  
Cécile Garcia
Keyword(s):  
Life History ◽  
Energy Expenditure ◽  
Body Mass ◽  
Life History Traits ◽  
Brain Size ◽  
Energy Allocation ◽  
Interbirth Interval ◽  
Energy Investment ◽  
Litter Mass ◽  
Trade Offs

AbstractLife history, brain size and energy expenditure scale with body mass in mammals but there is little conclusive evidence for a correlated evolution between life history and energy expenditure (either basal/resting or daily) independent of body mass. We addressed this question by examining the relationship between primate free-living daily energy expenditure (DEE) measured by doubly labeled water method (n = 18 species), life history variables (maximum lifespan, gestation and lactation duration, interbirth interval, litter mass, age at first reproduction), resting metabolic rate (RMR) and brain size. We also analyzed whether the hypometabolic primates of Madagascar (lemurs) make distinct energy allocation tradeoffs compared to other primates (monkeys and apes) with different life history traits and ecological constraints. None of the life-history traits correlated with DEE after controlling for body mass and phylogeny. In contrast, a regression model showed that DEE increased with increasing RMR and decreasing reproductive output (i.e., litter mass/interbirth interval) independent of body mass. Despite their low RMR and smaller brains, lemurs had an average DEE remarkably similar to that of haplorhines. The data suggest that lemurs have evolved energy strategies that maximize energy investment to survive in the unusually harsh and unpredictable environments of Madagascar at the expense of reproduction.

scholarly journals Brain size is correlated with endangerment status in mammals

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152772 ◽  
Author(s):  
Eric S. Abelson
Keyword(s):  
Brain Size ◽  
Extinction Risk ◽  
Small Body ◽  
Cost Benefit ◽  
Metabolic Cost ◽  
Trade Offs ◽  
Extant Species ◽  
Body Sizes ◽  
The Cost ◽  
The Relationship

Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost–benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.

Corrigendum to: Size, depth and position affect the diversity and structure of rock pool communities in an urban estuary

2019 ◽  
Vol 70 (7) ◽  
pp. 1045
Author(s):  
Nina Schaefer ◽  
Katherine A. Dafforn ◽  
Emma L. Johnston ◽  
Mariana Mayer-Pinto
Keyword(s):  
Species Diversity ◽  
Environmental Conditions ◽  
Outer Zone ◽  
Ecological Niches ◽  
Rocky Shores ◽  
Rock Pools ◽  
Rock Pool ◽  
Taxa Richness ◽  
Urban Estuary ◽  
Sydney Harbour

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.

Assessment of spatial learning abilities of mice in a new circular maze

2003 ◽  
Vol 79 (4-5) ◽  
pp. 683-693 ◽  
Author(s):  
G KOOPMANS ◽  
A BLOKLAND ◽  
P VANNIEUWENHUIJZEN ◽  
J PRICKAERTS
Keyword(s):  
Spatial Learning ◽  
Learning Abilities

scholarly journals Midsagittal Brain Variation among Non-Human Primates: Insights into Evolutionary Expansion of the Human Precuneus

2017 ◽  
Vol 90 (3) ◽  
pp. 255-263 ◽  
Author(s):  
Ana Sofia Pereira-Pedro ◽  
James K. Rilling ◽  
Xu Chen ◽  
Todd M. Preuss ◽  
Emiliano Bruner
Keyword(s):  
Homo Sapiens ◽  
Brain Size ◽  
Anatomical Variation ◽  
General Pattern ◽  
Dorsal Surface ◽  
Modern Human ◽  
Brain Morphology ◽  
Functional Region ◽  
Medial Side ◽  
Species Specific

The precuneus is a major element of the superior parietal lobule, positioned on the medial side of the hemisphere and reaching the dorsal surface of the brain. It is a crucial functional region for visuospatial integration, visual imagery, and body coordination. Previously, we argued that the precuneus expanded in recent human evolution, based on a combination of paleontological, comparative, and intraspecific evidence from fossil and modern human endocasts as well as from human and chimpanzee brains. The longitudinal proportions of this region are a major source of anatomical variation among adult humans and, being much larger in Homo sapiens, is the main characteristic differentiating human midsagittal brain morphology from that of our closest living primate relative, the chimpanzee. In the current shape analysis, we examine precuneus variation in non-human primates through landmark-based models, to evaluate the general pattern of variability in non-human primates, and to test whether precuneus proportions are influenced by allometric effects of brain size. Results show that precuneus proportions do not covary with brain size, and that the main difference between monkeys and apes involves a vertical expansion of the frontal and occipital regions in apes. Such differences might reflect differences in brain proportions or differences in cranial architecture. In this sample, precuneus variation is apparently not influenced by phylogenetic or allometric factors, but does vary consistently within species, at least in chimpanzees and macaques. This result further supports the hypothesis that precuneus expansion in modern humans is not merely a consequence of increasing brain size or of allometric scaling, but rather represents a species-specific morphological change in our lineage.

scholarly journals Energetic trade-offs: Implications for selection between two bivalve prey species by a carnivorous muricid gastropod

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250937
Author(s):  
A. Averbuj ◽  
J. A. Büchner-Miranda ◽  
L. P. Salas-Yanquin ◽  
J. M. Navarro ◽  
L. M. Pardo ◽  
...  
Keyword(s):  
Prey Species ◽  
Energetic Cost ◽  
Net Energy ◽  
Rocky Shores ◽  
Mixed Diet ◽  
Complex Processes ◽  
Trade Offs ◽  
Metabolic Costs ◽  
Semimytilus Algosus ◽  
Energy Gains

Active predators obtain energy and nutrients from prey through complex processes in which the energy gained must exceed the energy invested in finding and ingesting the prey. In addition, the amount of energy available will vary with the prey that are selected for consumption. The muricid gastropod Acanthina monodon inhabits rocky shores, where it routinely feeds on the mytilids Semimytilus algosus and Perumytilus purpuratus. In this study, S. algosus was highly preferred by the predator (over 90% were eaten) versus P. purpuratus (only 9% were eaten) when offered a mixed diet. The energetic cost of attacking one S. algosus individual was 91 J bivalve-1 while for P. purpuratus it was slightly higher: 95 J bivalve-1. Also, whereas A. monodon required on average 19 h to consume S. algosus, successful attacks on P. purpuratus required about 32% more time (25 h). In addition, a longer resting time was needed by the predator after preying on P. purpuratus before it initiated another attack. Moreover, the active metabolic costs associated with successfully attacking the prey increased 3.2 times over the basal metabolic costs when attacking S. algosus, but only by 2.5 times when attacking P. purpuratus. The calculations associated with preying on each species showed that the energetic gain per unit time likely accounts for the predator’s preference for attacking S. algosus, even though predation on both species provided net energy gains for the predator. However, as S. algosus occurs seasonally at our study site, P. purpuratus would probably also be consumed due to its constant availability throughout the whole year.

scholarly journals Comparing conservation monitoring approaches: traditional and environmental DNA tools for a critically endangered mammal

2017 ◽  
Author(s):  
Chanjuan Qu ◽  
Kathryn A Stewart
Keyword(s):  
Data Collection ◽  
Environmental Dna ◽  
Critically Endangered ◽  
Conventional Pcr ◽  
Aquatic Mammal ◽  
Real Time Quantitative Pcr ◽  
Trade Offs ◽  
Sampling Protocols ◽  
Species Specific ◽  
The Cost

While conservation management has made tremendous strides in the last few decades, the decision of knowing where and how to invest (often) small surveying budgets for biodiversity data collection remains a central hurdle for impactful conservation decision making. New analytical tools, such as environmental DNA (eDNA), are now facilitating broader biodiversity monitoring to take place at unprecedented scales, in part due to its time-efficient, and presumably cost-efficient, premise. eDNA approaches vary from conventional PCR (detecting presence/absence of species), metabarcoding (community structure), to qPCR (relative DNA abundance), and knowing when to employ these techniques over traditional sampling protocols could enable conservation practitioners to make informed trade-offs between cost, accuracy, and speed of data collection. Using 12 species-specific primers designed for conventional PCR use in eDNA analysis of the Yangtze Finless Porpoise (Neophocaena asiaeorientalis asiaeorientalis), a critically endangered aquatic mammal within the Yangtze River, we validated and optimized these same primers for use in real-time Quantitative PCR (qPCR). We tested the repeatability and sensitivity of primer each to detect YFP eDNA and subsequently compared the cost of traditional visual sampling to both conventional PCR and qPCR eDNA tools. Our results suggest qPCR to be substantially more sensitive than conventional PCR eDNA analysis, although the later remains the least-expensive sampling option. Still, due to a lack of sensitivity causing an increased probability of false negatives, conventional PCR may not be the most robust sampling method for this taxa and should only be employed as a supplementary tool or when large populations are expected to be present. Alternatively, utilizing qPCR for eDNA protocols is still less-expensive than visual surveying and represents a highly repeatable and sensitive method for this behaviorally elusive species. Presenting a cost assessment of eDNA to traditional surveying practices has scarcely been discussed, while contrasting deliverables to the cost of different eDNA methods has, to date, been ignored. Yet given budgetary constraints, particularly for developing countries where low-governance and high endemism are present, we encourage managers to carefully consider the trade-offs among data accuracy, cost, coverage and speed for biodiversity collections.

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