Escape behavior in gravid and non-gravid females of Gonatodes albogularis (Squamata: Sphaerodactylidae)

Comportamento de fuga em fêmeas grávidas e não-grávidas de Gonatodes albogularis (Squamata: Sphaerodactylidae). Modelos teóricos de relações predador-presa descrevem balanços entre custos de fuga (energéticos e de outros tipos), efciência do comportamento de fuga e risco de predação. Esses modelos preveem que um animal escapará quando o custo esperado em termos de sucesso reprodutivo devido ao risco de predação quando for igual ao custo de fuga ou quando o sucesso reprodutivo após o encontro for maximizado, dependendo do modelo. Nesse cenário, demonstrou-se que diversas variáveis individuais e ecológicas afetam os padrões de fuga, mas o efeito do status reprodutivo foi estudado em poucas espécies. Nós avaliamos diferenças no comportamento de fuga entre fêmeas grávidas e não-grávidas de Gonatodes albogularis. Os lagartos foram estudados aplicando-se um método de procura livre ao longo de transectos independentes. Para cada fêmea, determinamos o status reprodutivo como grávida ou não-grávida e registramos diversas variáveis relacionadas ao comportamento de fuga. Desenvolvemos uma análise discriminante para verifcar se o estado dos indivíduos afetavam o comportamento de fuga. Nossos resultados mostram que as variáveis distância percorrida na fuga, distância fnal e distância para o refúgio diferem entre fêmeas grávidas e não-grávidas. Essas descobertas sustentam previsões baseadas em risco e custo, mas não sustentam modelos de distância de início de fuga. Tais diferenças poderiam estar relacionadas como um processo conhecido como compensação comportamental, por meio do qual alguns indivíduos (as fêmeas grávidas, no nosso caso) modifcam seu comportamento para compensar risco de predação. Estudos adicionais são necessários para verifcar se a compensação comportamental pode ser explicada em termos de processos adaptativos em G. albogularis.Escape behavior in gravid and non-gravid females of Gonatodes albogularis (Squamata: Sphaerodactylidae). Theoretical models of predator-prey relationships describe tradeoffs between energetic and other costs of escape, effectiveness of escape behavior, and predation risk. These models predict that an animal will fee when the expected ftness cost due to risk of predation becomes equal to the the cost of the escape or post-encounter ftness is maximized, depending on the model. In this framework, several individual and ecological variables have been shown to affect escape patterns, but the effect of reproductive status has been studied in few species. We assess differences in escape behavior between gravid and non-gravid females of Gonatodes albogularis. Lizards were surveyed by applying a free search method along independent transects. For each lizard, we determined reproductive status as gravid or non-gravid and recorded several variables related to escape behavior. We made a discriminant function analysis to see whether the state of individuals affect escape behavior. Our results show that the escape variables distance fed, the fnal distance and the distance to refuge differ between gravid and non-gravid females. These fndings support predictions based on risk and cost, but do not support models of fight initiation distance. Such differences could be related to a physiological process known as behavioral compensation, through which some individuals (gravid females in our case) modify their behavior to offset predation risk. Further studies are needed to see if behavioral compensation can be explained in terms of adaptive processes in G. albogularis

Tail autotomy effects on the escape behavior of the lizard Gonatodes albogularis (Squamata: Sphaerodactylidae), from Córdoba, Colombia

Background: Caudal autotomy appears to be an adaptation strategy to reduce the risk of being preyed upon. In an encounter with a predator, the prey must reduce the risk of being preyed upon, and one of the strategies that has exerted a strong pressure on selection has been tail loss. In lizards, it has been demonstrated that tail loss reduces the probability of survival in the event of a second attack; therefore, they must resort to new escape strategies to reduce the risk of falling prey. In order to evaluate the effect of tail loss on the escape behavior of Gonatodes albogularis in natural conditions, we took samples from a forest interior population. We expected that individuals that had not lost their tails would allow the predator to get closer than those that had lost it. For each sample, we recorded the following: (1) escape behavior, measured through three distances (e.g., approach distance, escape distance, and final distance); (2) distance to shelter; and (3) length of tail. We included only males in the study since we did not record any females without a tail and far fewer with a regenerated tail. Results: We found that tail loss does have an effect on the escape behavior of G. albogularis. Males that have their tails intact allow the predator to come closer, and we found a negative correlation between the approach distance and the length of the tail. Conclusion: Our results support the escape behavior theory, in which G. albogularis males drop their tails when the risk of predation is much higher than the cost of fleeing.Facultad de Ciencias Naturales y Muse

Die wirkung der Mikrohabitat-Temperatur auf das fluchtverhalten des tagaktiven Geckos Gonatodes albogularis (duMéril & bribon, 1836) (Squamata: Sauria: Sphaerodactylidae)

The present study examined the effect of microhabitat air temperature on the escape behavior of Gonatodes albogularis (Duméril & Bribon, 1836) in a tropical dry forest relict of Colombia, south america. results showed negative correlation between both microhabitat air temperature and distance between lizards and predators at the moment in which escape is triggered and between temperature and distance of lizards to the closest shelter.Die vorliegende arbeit untersuchte die wirkung der lufttemperatur auf das fluchtverhalten von Gonatodes albogularis (Duméril & Bribon, 1836) in einem tropischen Trockenwald-relikt kolumbiens. die ergebnisse zeigten negative korrelationen zwischen der Mikrohabitat-lufttemperatur und dem abstand zwischen echse und beutegreifer zum Zeitpunkt, zu dem die flucht ausgelöst wird sowie zwischen der Mikrohabitat-lufttemperatur und dem abstand der echse zum nächstgelegenen unterschlupf zum Zeitpunkt ihrer erstbeobachtung.Facultad de Ciencias Naturales y Muse

Tail autotomy effects on the escape behavior of the lizard Gonatodes albogularis (Squamata: Sphaerodactylidae), from Córdoba, Colombia

Background: Caudal autotomy appears to be an adaptation strategy to reduce the risk of being preyed upon. In an encounter with a predator, the prey must reduce the risk of being preyed upon, and one of the strategies that has exerted a strong pressure on selection has been tail loss. In lizards, it has been demonstrated that tail loss reduces the probability of survival in the event of a second attack; therefore, they must resort to new escape strategies to reduce the risk of falling prey. In order to evaluate the effect of tail loss on the escape behavior of Gonatodes albogularis in natural conditions, we took samples from a forest interior population. We expected that individuals that had not lost their tails would allow the predator to get closer than those that had lost it. For each sample, we recorded the following: (1) escape behavior, measured through three distances (e.g., approach distance, escape distance, and final distance); (2) distance to shelter; and (3) length of tail. We included only males in the study since we did not record any females without a tail and far fewer with a regenerated tail. Results: We found that tail loss does have an effect on the escape behavior of G. albogularis. Males that have their tails intact allow the predator to come closer, and we found a negative correlation between the approach distance and the length of the tail. Conclusion: Our results support the escape behavior theory, in which G. albogularis males drop their tails when the risk of predation is much higher than the cost of fleeing.Facultad de Ciencias Naturales y Muse

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

Compilación de Proyectos de Investigacion de 1984-2002

Instituto Politecnico Nacional. UPIICS

Morphological and spectral properties of the W51 region measured with the MAGIC telescopes

The W51 complex hosts the supernova remnant W51C which is known to interact with the molecular clouds in the star forming region W51B. In addition, a possible pulsar wind nebula CXO J192318.5+140305 was found likely associated with the supernova remnant. Gamma-ray emission from this region was discovered by Fermi/LAT (between 0.2 and 50 GeV) and H.E.S.S. (>1 TeV). The spatial distribution of the events could not be used to pinpoint the location of the emission among the pulsar wind nebula, the supernova remnant shell and/or the molecular cloud. However, the modeling of the spectral energy distribution presented by the Fermi/LAT collaboration suggests a hadronic emission mechanism. We performed observations of the W51 complex with the MAGIC telescopes for more than 50 hours. The good angular resolution in the medium (few hundred GeV) to high (above 1 TeV) energies allow us to perform morphological studies. We detect an extended emission of very-high-energy gamma rays, with a significance of 11 standard deviations. We extend the spectrum from the highest Fermi/LAT energies to \sim 5 TeV and find that it follows a single power law with an index of 2.58 \pm 0.07stat \pm 0.22syst . The main part of the emission coincides with the shocked cloud region, while we find a feature extending towards the pulsar wind nebula. The possible contribution of the pulsar wind nebula, assuming a point-like source, shows no dependence on energy and it is about 20% of the overall emission. The broad band spectral energy distribution can be explained with a hadronic model that implies proton acceleration above 100 TeV. This result, together with the morphology of the source, tentatively suggests that we observe ongoing acceleration of ions in the interaction zone between supernova remnant and cloud. These results shed light on the long-standing problem of the origin of galactic cosmic rays.Comment: 11 pages, 7 figures, accepted by A&A, corresponding authors: J. Krause, I Reichardt, E. Carmon

Global urban environmental change drives adaptation in white clover.

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale