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Charles C. Eriksen - One of the best experts on this subject based on the ideXlab platform.
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Fortuitous Encounters between Seagliders and Adult Female Northern Fur Seals (Callorhinus ursinus) off the Washington (USA) Coast: Upper Ocean Variability and Links to Top Predator Behavior
2015Co-Authors: Noel A. Pell, Jeremy T. Sterling, Mary-anne Lea, Nicholas A. Bond, Rolf R. Ream, Craig M. Lee, Charles C. EriksenAbstract:Behavioral responses by top marine Predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect Predators ’ prey, foraging Behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and Predator Behavior. In this study, migratory movements and, in some cases, diving Behavior of 40 adult female northern fur seals (NFS; Callorhinus ursinus) were quantified across their range and compared to remotely-sensed environmental data in the Gulf of Alaska and California Current ecosystems, with a particular focus off the coast of Washington State (USA) – a known foraging ground for adult female NFS and where autonomous glider sampling allowed opportunistic comparison of seal Behavior to subsurface biophysical measurements. The results show that in these ecosystems, adult female habitat utilization was concentrated near prominent coastal topographic, riverine, or inlet features and within 200 km of the continental shelf break. Seal dive depths, in most ecosystems, were moderated by surface light level (solar or lunar), mirroring known Behaviors of diel vertically-migrating prey. However, seal dives differed in the California Current ecosystem due to a shift to more daytime diving concentrated at or below the surface mixed layer base. Seal movement models indicate Behavioral responses to season, ecosystem, and surface win
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fortuitous encounters between seagliders and adult female northern fur seals callorhinus ursinus off the washington usa coast upper ocean variability and links to top Predator Behavior
PLOS ONE, 2014Co-Authors: Noel A Pelland, Jeremy T. Sterling, Nicholas A. Bond, Rolf R. Ream, Charles C. EriksenAbstract:Behavioral responses by top marine Predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect Predators' prey, foraging Behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and Predator Behavior. In this study, migratory movements and, in some cases, diving Behavior of 40 adult female northern fur seals (NFS; Callorhinus ursinus) were quantified across their range and compared to remotely-sensed environmental data in the Gulf of Alaska and California Current ecosystems, with a particular focus off the coast of Washington State (USA) – a known foraging ground for adult female NFS and where autonomous glider sampling allowed opportunistic comparison of seal Behavior to subsurface biophysical measurements. The results show that in these ecosystems, adult female habitat utilization was concentrated near prominent coastal topographic, riverine, or inlet features and within 200 km of the continental shelf break. Seal dive depths, in most ecosystems, were moderated by surface light level (solar or lunar), mirroring known Behaviors of diel vertically-migrating prey. However, seal dives differed in the California Current ecosystem due to a shift to more daytime diving concentrated at or below the surface mixed layer base. Seal movement models indicate Behavioral responses to season, ecosystem, and surface wind speeds; individuals also responded to mesoscale eddies, jets, and the Columbia River plume. Foraging within small scale surface features is consistent with utilization of the inner coastal transition zone and habitats near coastal capes, which are known eddy and filament generation sites. These results contribute to our knowledge of NFS migratory patterns by demonstrating surface and subsurface Behavioral responses to a spatially and temporally dynamic ocean environment, thus reflecting its influence on associated NFS prey species.
Richard G Coss - One of the best experts on this subject based on the ideXlab platform.
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effects of risk assessment Predator Behavior and habitat on escape Behavior in columbian black tailed deer
Behavioral Ecology, 2007Co-Authors: Theodore Stankowich, Richard G CossAbstract:The relationship between preflight risk assessment by prey and the escape Behaviors they perform while fleeing from Predators is relatively unexplored. To examine this relationship, a human observer approached groups of Columbian black-tailed deer (Odocoileus hemionus columbianus), varying his Behavior to simulate more or less threatening Behavior. We measured the focal deer's angle of escape, distance moved during flight, duration of trotting and stotting Behavior, and change in elevation during flight. Analyses revealed positive relationships between the distance moved during flight and the distance at which they fled. When flight was initiated when the approacher was close, deer fled relatively shorter distances and took flight paths at more acute angles, a property that would force a real Predator to change direction suddenly. Our results indicate that deer do not compensate for allowing the observer to approach more closely by fleeing greater distances. Rather, distance moved and flight initiation distance are linked by level of reactivity and habituation: more reactive or less habituated deer both flee at a greater distance and move away to a greater distance during flight. More threatening Behavior by the approacher led to longer durations of rapid flight Behavior (e.g., trotting and stotting), and deer tended to flee uphill and into taller vegetation, using these landscape features as refuge from danger. Finally, we provide the first evidence for Pitcher's untested “antiambush” hypothesis for the function of stotting and discuss its significance. In general, both preflight Predator Behavior and habitat features influence both duration and direction of escape.
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effects of Predator Behavior and proximity on risk assessment by columbian black tailed deer
Behavioral Ecology, 2006Co-Authors: Theodore Stankowich, Richard G CossAbstract:In Predator-prey encounters, many factors influence risk perception by prey and their decision to flee. Previous studies indicate that prey take flight at longer distances when they detect Predators at longer distances and when the Predator’s Behavior indicates the increased likelihood of attack. We examined the flight decisions of Columbian black-tailed deer (Odocoileus hemionus columbianus) using an approaching human whose speed, directness of approach, directness of gaze, and simulated gun carrying varied. Deer fled at greater distances when approached more quickly and directly, and there was a concave-down quadratic trend in the relationship between the distances at which the Predator began its approach and at which the deer became alert (alert distance [AD]), indicating that deer have a zone of awareness beyond which there is a delay in detecting an approaching Predator. Time spent assessing the approacher (assessment time) was shorter during faster approaches and was positively related with AD. Deer fled at longer distances and had shorter assessment times when they were already alert to the Predator at the initiation of approach. Males fled at shorter distances than females when approached during the gun-holding condition, and males had shorter assessment times than females when the approacher averted his gaze. Such sex differences in risk assessment might reflect male motivation during the mating season as well as exposure to human hunting. We suggest that risk assessment is affected the by the Predator’s Behavior, the state of awareness of the prey, and the distance at which they detect the Predator.
Jeremy J Wrigh - One of the best experts on this subject based on the ideXlab platform.
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adaptive significance of venom glands in the tadpole madtom noturus gyrinus siluriformes ictaluridae
The Journal of Experimental Biology, 2012Co-Authors: Jeremy J WrighAbstract:SUMMARY Piscine venom glands have implicitly been assumed to be anti-Predatory adaptations, but direct examinations of the potential fitness benefits provided by these structures are relatively sparse. In previous experiments examining this question, alternative phenotypes have not been presented to ecologically relevant Predators, and the results are thus potentially confounded by the presence of sharp, bony fin spines in these species, which may also represent significant deterrents to predation. Here, I present the results of experiments exposing Micropterus salmoides (largemouth bass) to tadpole madtoms ( Noturus gyrinus ) with one of several fin spine phenotypes (intact, stripped, absent), which indicate that the venom glands of this species do provide a significant fitness benefit, relative to individuals having fin spines without venom glands or no spines at all. Intact madtoms were repeatedly rejected by the bass and were almost never consumed, while alternative phenotypes were always consumed. Madtoms with stripped fin spines showed increases in Predator rejections relative to spineless madtoms and control minnows, but non-significant increases in handling time, contrasting with previous results and predictions regarding the adaptive benefit of these structures. Comparisons with a less venomous catfish species ( Ameiurus natalis ) indicate that a single protein present in the venom of N. gyrinus may be responsible for providing the significant selective advantage observed in this species. These results, considered in conjunction with other studies of ictalurid biology, suggest that venom evolution in these species is subject to a complex interplay between Predator Behavior, phylogenetic history, life history strategy and adaptive responses to different Predatory regimes.
Noel A Pelland - One of the best experts on this subject based on the ideXlab platform.
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fortuitous encounters between seagliders and adult female northern fur seals callorhinus ursinus off the washington usa coast upper ocean variability and links to top Predator Behavior
PLOS ONE, 2014Co-Authors: Noel A Pelland, Jeremy T. Sterling, Nicholas A. Bond, Rolf R. Ream, Charles C. EriksenAbstract:Behavioral responses by top marine Predators to oceanographic features such as eddies, river plumes, storms, and coastal topography suggest that biophysical interactions in these zones affect Predators' prey, foraging Behaviors, and potentially fitness. However, examining these pathways is challenged by the obstacles inherent in obtaining simultaneous observations of surface and subsurface environmental fields and Predator Behavior. In this study, migratory movements and, in some cases, diving Behavior of 40 adult female northern fur seals (NFS; Callorhinus ursinus) were quantified across their range and compared to remotely-sensed environmental data in the Gulf of Alaska and California Current ecosystems, with a particular focus off the coast of Washington State (USA) – a known foraging ground for adult female NFS and where autonomous glider sampling allowed opportunistic comparison of seal Behavior to subsurface biophysical measurements. The results show that in these ecosystems, adult female habitat utilization was concentrated near prominent coastal topographic, riverine, or inlet features and within 200 km of the continental shelf break. Seal dive depths, in most ecosystems, were moderated by surface light level (solar or lunar), mirroring known Behaviors of diel vertically-migrating prey. However, seal dives differed in the California Current ecosystem due to a shift to more daytime diving concentrated at or below the surface mixed layer base. Seal movement models indicate Behavioral responses to season, ecosystem, and surface wind speeds; individuals also responded to mesoscale eddies, jets, and the Columbia River plume. Foraging within small scale surface features is consistent with utilization of the inner coastal transition zone and habitats near coastal capes, which are known eddy and filament generation sites. These results contribute to our knowledge of NFS migratory patterns by demonstrating surface and subsurface Behavioral responses to a spatially and temporally dynamic ocean environment, thus reflecting its influence on associated NFS prey species.
Takahisa Miyatake - One of the best experts on this subject based on the ideXlab platform.
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polygene control and trait dominance in death feigning syndrome in the red flour beetle tribolium castaneum
bioRxiv, 2021Co-Authors: Kentarou Matsumura, Takahisa MiyatakeAbstract:Death-feigning Behavior is an anti-Predator Behavior in a wide range of animal taxa, and it often correlates with the movement (i.e. death-feigning syndrome). In the present study, we performed reciprocal crossing among strains with genetically longer (L strain) and shorter (S strain) duration of death feigning, and investigated related heritable factors in the F1 and F2 populations. We also investigated moving activity which negatively responded to artificial selection for death feigning in T. castaneum. Our results showed that death feigning occurred more frequently and for shorter periods in the F1 population. In the F2 population, death feigning and movement showed continuous segregation. The distribution of each trait value in the F2 generation was different from the distribution of trait values in the parental generation, and no individuals transgressing the distribution of trait values in the parental generation emerged in the F2 generation. Chi-square analysis of the observed death feigning and movement of F1 and F2 progenies rejected the hypothesis of mono-major gene inheritance. These results suggest that death-feigning syndrome is controlled in a polygenic manner. Our study indicated that reciprocal crossing experiments are useful in assessing the quantitative inheritance of Behavioral traits.
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responses to relaxed and reverse selection in strains artificially selected for duration of death feigning Behavior in the red flour beetle tribolium castaneum
Journal of Ethology, 2018Co-Authors: Kentarou Matsumura, Takahisa MiyatakeAbstract:Divergent lines selected artificially for many generations make it possible to answer two questions: (1) whether genetic variation still exists within the selected population; and (2) whether the selection itself is costly for the selected strain. In previous studies, the red flour beetle Tribolium castaneum was divergently selected artificially for duration of death-feigning, and strains selected for longer (L-strain) and shorter (S-strain) durations of death-feigning have been established (Miyatake et al. 2004, 2008). Because the selection experiments have been conducted for more than 27 generations, genetic variation may be eroded. Furthermore, because another previous study reported physiological costs to L-strains, the L-strains selected artificially for longer duration of death-feigning may have suffered more costs than the S-strains. In the present study, therefore, we relaxed the selection pressure after the 27th or 30th generation of S- and L-strains. We also carried out reverse selection during the most recent eight generations of S- and L-strains. The results showed that each strain clearly responded to relaxation of selection and reverse selection, suggesting that (1) additive genetic variation still existed in both strains after long-term selection, and (2) selection for shorter and longer duration of death-feigning was costly. These results suggest that anti-Predator Behavior is controlled by many loci, and longer or shorter duration of death-feigning is costly in a laboratory without Predators.
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Positive genetic correlations between life-history traits and death-feigning Behavior in adzuki bean beetle (Callosobruchus chinensis)
Evolutionary Ecology, 2008Co-Authors: Satoshi Nakayama, Takahisa MiyatakeAbstract:Usually, several traits in organisms are genetically linked with each other; thus, correlated responses to selection are generally observed. Anti-Predator Behaviors may be genetically correlated with other traits such as life-history. We compared the life-history traits of individuals derived from two regimes artificially selected for the duration of death feigning in the adzuki bean beetle, Callosobruchus chinensis . The two-way selected regimes include the L-lines with stronger intensity (longer duration and higher frequency) and the S-lines with weaker intensity (shorter duration and lower frequency) of death feigning. L-lines exhibited greater longevity, higher rates of emergence, laid bigger eggs and greater reproductive effort, and also had a tendency of faster development. Fecundity was not significantly different between L- and S-lines. These results provide the novel possibility that death feigning is a potentially advantageous anti-Predator Behavior that, through a positive genetic correlation with some life-history traits, can bring a higher fitness to an individual adopting this Behavior. This novel aspect might explain why death-feigning Behavior is prevalent in various taxonomic animal groups.
