scholarly journals Incubation under climate warming affects learning ability and survival in hatchling lizards

2017 ◽  
Vol 13 (3) ◽  
pp. 20170002 ◽  
Author(s):  
Buddhi Dayananda ◽  
Jonathan K. Webb

Despite compelling evidence for substantial individual differences in cognitive performance, it is unclear whether cognitive ability influences fitness of wild animals. In many animals, environmental stressors experienced in utero can produce substantial variation in the cognitive abilities of offspring. In reptiles, incubation temperatures experienced by embryos can influence hatchling brain function and learning ability. Under climate warming, the eggs of some lizard species may experience higher temperatures, which could affect the cognitive abilities of hatchlings. Whether such changes in cognitive abilities influence the survival of hatchlings is unknown. To determine whether incubation-induced changes in spatial learning ability affect hatchling survival, we incubated velvet gecko, Amalosia lesueurii , eggs using two fluctuating temperature regimes to mimic current (cold) versus future (hot) nest temperatures. We measured the spatial learning ability of hatchlings from each treatment, and released individually marked animals at two field sites in southeastern Australia. Hatchlings from hot-incubated eggs were slower learners than hatchlings from cold-incubated eggs. Survival analyses revealed that hatchlings with higher learning scores had higher survival than hatchlings with poor learning scores. Our results show that incubation temperature affects spatial learning ability in hatchling lizards, and that such changes can influence the survival of hatchlings in the wild.

2012 ◽  
Vol 8 (6) ◽  
pp. 946-948 ◽  
Author(s):  
Daniel W. A. Noble ◽  
Pau Carazo ◽  
Martin J. Whiting

Spatial cognition is predicted to be a fundamental component of fitness in many lizard species, and yet some studies suggest that it is relatively slow and inflexible. However, such claims are based on work conducted using experimental designs or in artificial contexts that may underestimate their cognitive abilities. We used a biologically realistic experimental procedure (using simulated predatory attacks) to study spatial learning and its flexibility in the lizard Eulamprus quoyii in semi-natural outdoor enclosures under similar conditions to those experienced by lizards in the wild. To evaluate the flexibility of spatial learning, we conducted a reversal spatial-learning task in which positive and negative reinforcements of learnt spatial stimuli were switched. Nineteen (32%) male lizards learnt both tasks within 10 days (spatial task mean: 8.16 ± 0.69 (s.e.) and reversal spatial task mean: 10.74 ± 0.98 (s.e.) trials). We demonstrate that E. quoyii are capable of flexible spatial learning and suggest that future studies focus on a range of lizard species which differ in phylogeny and/or ecology, using biologically relevant cognitive tasks, in an effort to bridge the cognitive divide between ecto- and endotherms.


2016 ◽  
Vol 82 (6) ◽  
pp. 1859-1867 ◽  
Author(s):  
Ching-Lian Chen ◽  
Shin-yuan Fen ◽  
Chun-Hui Chung ◽  
Shu-Chuan Yu ◽  
Cheng-Lun Chien ◽  
...  

ABSTRACTThe marine foodborne enteropathogenVibrio parahaemolyticushas four putative catalase genes. The functions of twokatE-homologous genes,katE1(VPA1418) andkatE2(VPA0305), in the growth of this bacterium were examined using gene deletion mutants with or without complementary genes. The growth of the mutant strains in static or shaken cultures in a rich medium at 37°C or at low temperatures (12 and 4°C), with or without competition fromEscherichia coli, did not differ from that of the parent strain. When 175 μM extrinsic H2O2was added to the culture medium, bacterial growth of the ΔkatE1strain was delayed and growth of the ΔkatE1ΔkatE2and ΔkatE1ΔahpC1double mutant strains was completely inhibited at 37°C for 8 h. The sensitivity of the ΔkatE1strain to the inhibition of growth by H2O2was higher at low incubation temperatures (12 and 22°C) than at 37°C. The determined gene expression of these catalase andahpCgenes revealed thatkatE1was highly expressed in the wild-type strain at 22°C under H2O2stress, while thekatE2andahpCgenes may play an alternate or compensatory role in the ΔkatE1strain. This study demonstrated thatkatE1encodes the chief functional catalase for detoxifying extrinsic H2O2during logarithmic growth and that the function of these genes was influenced by incubation temperature.


Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 430-435 ◽  
Author(s):  
C. Chungu ◽  
J. Gilbert ◽  
F. Townley-Smith

The effects of incubation temperature, leaf-wetness duration, inoculum concentration, and interaction between leaf-wetness duration and inoculum concentration on the development of Septoria tritici blotch were evaluated at the seedling stage in two bread wheats (Katepwa and 6 Lacos-78) and two durum wheats (AC Melita and Kyle). The study was conducted to assess if bread and durum cultivars widely grown in Manitoba and a resistant cultivar from South America react differently to the disease at temperatures characteristic of Manitoba summers, and to obtain information on conditions that would be used in differentiating resistant and susceptible cultivars under controlled conditions. The experiments were carried out under three temperature regimes. Factors that evaluated included inoculum concentration and duration of leaf wetness. Increasing incubation temperature, duration of leaf wetness, and inoculum concentration resulted in an increase in disease severity. There were significant (P < 0.05) differences for duration of leaf wetness and inoculum concentration within each cultivar. Pycnidia were observed 4 days earlier when incubation temperature increased from 18°C day/15°C night to 22°C day/15°C night or when inoculum concentration increased from 1 × 106 spores/ml to 1 × 107 spores/ml. There were more pycnidia when duration of leaf wetness was 72 h as opposed to 48 h and 60 h. The cultivar that was presumed to be resistant maintained its resistance under environmental conditions that are characteristic of Manitoba summers. We found that the optimal conditions for screening spring wheats for Septoria tritici blotch reaction were incubation temperatures of 18°C day/15°C night, and 22°C day/15°C night. Leaf wetness duration of 48 or 72 h and inoculum concentration of 1 × 107 spores/ml consistently produced a susceptible reaction on Katepwa, AC Melita, and Kyle the three cultivars that were susceptible to Septoria tritici blotch.


Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 595-598 ◽  
Author(s):  
T. V. Toai ◽  
D. L. Linscott

We studied the effects of temperature (5, 10, 20, and 30 C) on the phytotoxic activity of decaying quackgrass [Agropyron repens (L.) Beauv.] leaves and rhizomes that were incubated in soils for 0, 1, 2, 4, and 6 weeks. Alfalfa (Medicago sativa L.) seeds were grown for 96 h in water, water extracts of control soils, and water extracts of soil with quackgrass rhizomes or leaves. Dried quackgrass rhizomes and leaves contained water-soluble toxins that inhibited alfalfa seedling development and growth. There was a strong interaction between incubation time and temperature on the development of additional toxins by decomposing quackgrass. High incubation temperature (30 C) accelerated toxin formation and ultimate decay. Intermediate temperature (20 C) delayed toxin formation and decay. Low incubation temperatures (5 C and 10 C) prevented formation of additional toxin. In all extracts of quackgrass and soil that had been incubated for 6 weeks, normal alfalfa seedling number equaled that in water. However, seedling growth varied with incubation temperatures.Treatment of quackgrass with glyphosate [N-(phosphonomethyl) glycine] in the greenhouse did not influence the toxicity of decaying quackgrass leaves. The highest toxic effect was noted after 1 week of decay on the soil surface.


2018 ◽  
Vol 373 (1740) ◽  
pp. 20160508 ◽  
Author(s):  
Sarah Benson-Amram ◽  
Geoff Gilfillan ◽  
Karen McComb

Playback experiments have proved to be a useful tool to investigate the extent to which wild animals understand numerical concepts and the factors that play into their decisions to respond to different numbers of vocalizing conspecifics. In particular, playback experiments have broadened our understanding of the cognitive abilities of historically understudied species that are challenging to test in the traditional laboratory, such as members of the Order Carnivora. Additionally, playback experiments allow us to assess the importance of numerical information versus other ecologically important variables when animals are making adaptive decisions in their natural habitats. Here, we begin by reviewing what we know about quantity discrimination in carnivores from studies conducted in captivity. We then review a series of playback experiments conducted with wild social carnivores, including African lions, spotted hyenas and wolves, which demonstrate that these animals can assess the number of conspecifics calling and respond based on numerical advantage. We discuss how the wild studies complement those conducted in captivity and allow us to gain insights into why wild animals may not always respond based solely on differences in quantity. We then consider the key roles that individual discrimination and cross-modal recognition play in the ability of animals to assess the number of conspecifics vocalizing nearby. Finally, we explore new directions for future research in this area, highlighting in particular the need for further work on the cognitive basis of numerical assessment skills and experimental paradigms that can be effective in both captive and wild settings. This article is part of a discussion meeting issue ‘The origins of numerical abilities’.


1989 ◽  
Vol 35 (4) ◽  
pp. 474-480 ◽  
Author(s):  
Christon J. Hurst ◽  
William H. Benton ◽  
Kim A. McClellan

The long-term survival of three human enterovirus serotypes, Coxsackievirus B3, echovirus 7, and poliovirus 1 was examined in samples of surface freshwater collected from five sites of physically different character. These were an artificial lake created by damming a creek, a small groundwater outlet pond, both a large- and a medium-sized river, and a small suburban creek. Survival was studied at temperatures of −20, 1, and 22 °C. The average amount of viral inactivation was 6.50–7.0 log10 units over 8 weeks at 22 °C, 4–5 log10 units over 12 weeks at 1 °C, and 0.4–0.8 log10 units over 12 weeks at −20 °C. The effect of incubation temperature upon viral inactivation rate was statistically significant (p < 0.00001). As determined by pairing tests, survival was also significantly related to both viral serotype and water source at each of the three incubation temperatures (p ≤ 0.05). Efforts were made to determine whether the rate of viral inactivation observed at the different incubation temperatures was related to characteristics inherent to the water that was collected from the different locations. The characteristics examined included physical and chemical parameters, indigenous bacterial counts, and the amount of bacterial growth that the waters would support (measured as the maximum number of generations which seeded bacteria could undergo after being placed into either pasteurized or sterile-filtered water samples). Analysis of viral inactivation rate versus these characteristics revealed three apparent effectors of viral persistence. These were (i) hardness and conductivity, both of which strongly correlated with one another; (ii) turbidity and suspended solids content, both of which strongly correlated with one another; and (iii) the number of generations of bacterial growth that a sample was capable of supporting, which also correlated with hardness and conductivity.Key words: virus, survival, inactivation rate, water.


Author(s):  
Jesús García-Grajales ◽  
Juan Francisco Meraz ◽  
José Luis Arcos García ◽  
Eustacio Ramírez Méndez

The influence of nest incubation temperatures on the carapace shape and morphological traits of Dermochelys coriacea (Vandelli 1761) hatchlings incubated in two hatcheries of Oaxaca, Mexico was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers without association with universities, that protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; later, hatchlings were weighed and their bodies were measured. The mean temperature of 12 nests in each hatchery were recorded, with no significant differences between hatcheries. The principal component analysis (PCA) revealed an overlapping of the carapace shape under different duration of temperature. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low weight, smaller appendage; narrower carapace width and shorter flippers length. Lower mean incubation temperatures produced hatchlings that had greater weight, greater appendage width, wider carapace width and longer flipper length. Results indicate that the D. coriacea hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.


2021 ◽  
Author(s):  
◽  
Alexis Garland

<p>A prominent psychological theory on early cognitive development is Spelke’s Core Knowledge (CK) hypothesis (Spelke, Breinlinger, Macomber, & Jacobson, 1992), which posits that human infants, and possibly other species, are guided by innate understandings of how object movements, classification and quantification are governed by physical laws and, further, how agents are capable of perceptions and purposive action. CK is a set of cognitive building blocks, which serve as the foundation for more complex cognition such as acquisition and use of symbol systems pertaining to language and mathematics (Spelke, 2000). Evidence points to four core systems of knowledge: representation of number, object, space (or geometry) and agency. Investigation of spontaneous CK in nonhuman species in the wild is fundamental to understanding the ecological validity and evolutionary context for a set of systems that is proposed to be universally embedded. The bold, inquisitive manner, naïve fearlessness and unique insect caching behaviour of wild North Island robins (Petroica longipes) presents a unique opportunity to identify and characterise CK in a new model system. Six studies were conducted with the aim of investigating core developmental cognition in robins. The first three studies focused on perception of numerical quantity. Study 1 investigated the ability to discriminate between both large and small quantities, finding that robins successfully discriminate between unusually large quantities independent of ratio. Study 2 explored quantity discrimination in which summation of items is spatially distributed across an array, and found that while robins perform successfully with small numbers, the task presented substantially more cognitive demand. Study 3 measured robins’ reactions to computation by presenting simple addition and subtraction problems in a Violation of Expectancy (VoE) paradigm, finding that robins search longer when presented with a mathematically incongruent scenario. The last three studies focused on perception of agency. Study 4 investigated robins’ response to gaze direction in humans in a competitive paradigm, and found that they were sensitive to human gaze direction in all conditions but one. Study 5 explored perception of physical capability in humans, and results indicated that limb visibility significantly influences pilfering choice. Study 6 examined robins’ perception of animacy in prey, finding that in a VoE paradigm, robins’ expectation of hidden prey continuity varies depending on mobility and animacy. Taken together, the results of these six studies suggest that while supportive of fundamental characteristics defining basic Core Knowledge in many ways, some unique results in the cognitive abilities of this biologically naïve species shed new light on our growing understanding of the shared basis of cognition. A deeper look at avian performance in core developmental tasks, especially in a naïve wild population, can offer new insights into sweeping evolutionary theories that underpin basic cognitive mechanisms.</p>


2021 ◽  
Author(s):  
Mads Kock Pedersen ◽  
Carlos Mauricio Castaño Díaz ◽  
Mario Alejandro Alba-Marrugo ◽  
Ali Amidi ◽  
Rajiv Vaid Basaiwmoit ◽  
...  

Psychology and the social sciences are undergoing a revolution: It has become increasingly clear that traditional lab-based experiments fail to capture the full range of differences in cognitive abilities and behaviours across the general population. Some progress has been made toward devising measures that can be applied at scale across individuals and populations. What has been missing is a broad battery of validated tasks that can be easily deployed, used across different age ranges and social backgrounds, and employed in practical, clinical, and research contexts. Here, we present Skill Lab, a game-based approach allowing the efficient assessment of a suite of cognitive abilities. Skill Lab has been validated outside the lab in a crowdsourced population-size sample recruited in collaboration with the Danish Broadcast Company (Danmarks Radio, DR). Our game-based measures are five times faster to complete than the equivalent traditional measures and replicate previous findings on the decline of cognitive abilities with age in a large population sample. Furthermore, by combining the game data with an in-game survey, we demonstrate that this unique dataset has implication for key questions in social science, challenging the Jack-of-all-Trades theory of entrepreneurship and provide evidence for risk preference being independent of executive functioning.


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