The Experts below are selected from a list of 2076 Experts worldwide ranked by ideXlab platform

Joah R. Madden - One of the best experts on this subject based on the ideXlab platform.

  • A novel continuous inhibitory-control task: variation in individual performance by young pheasants (Phasianus colchicus)
    Animal Cognition, 2017
    Co-Authors: Christina Meier, Ja ,van Horik, Pr Laker, Sara Raj Pant, Ellis J. G. Langley, Mark A. Whiteside, Frederick Verbruggen, Joah R. Madden
    Abstract:

    Inhibitory control enables subjects to quickly react to unexpectedly changing external demands. We assessed the ability of young (8 weeks old) pheasants Phasianus colchicus to exert inhibitory control in a novel response-inhibition task that required subjects to adjust their movement in space in pursuit of a reward across changing target locations. The difference in latencies between trials in which the target location did and did not change, the distance travelled towards the initially indicated location after a change occurred, and the change-signal reaction time provided a consistent measure that could be indicative of a pheasant’s inhibitory control. Between individuals, there was a great variability in these measures; these differences were not correlated with motivation either to access the reward or participate in the test. However, individuals that were slower to reach rewards in trials when the target did not change exhibited evidence of stronger inhibitory control, as did males and small individuals. This novel test paradigm offers a potential assay of inhibitory control that utilises a natural feature of an animal’s behavioural repertoire, likely common to a wide range of species, specifically their ability to rapidly alter their trajectory when reward locations switch.

Andrew N Hoodless - One of the best experts on this subject based on the ideXlab platform.

  • synergistic effects of supplementation of dietary antioxidants during growth on adult phenotype in ring necked pheasants Phasianus colchicus
    Functional Ecology, 2012
    Co-Authors: Josephine M. Orledge, Andrew N Hoodless, Jonathan D. Blount, Thomas W. Pike, Nick J. Royle
    Abstract:

    Summary 1. Oxidative stress may provide a proximate link between investment in growth and/or reproduction and investment in self-maintenance. Dietary antioxidants, such as carotenoids and vitamin E, provide potentially important roles in regulating these trade-offs. Recent work suggests that carotenoids may have synergistic effects in combination with non-pigmentary antioxidants (e.g. vitamin E) on the expression of sexually selected traits in adulthood. However, these studies involved the supplementation of antioxidants to adults so did not take account of early life-history effects. 2. Here, we test the independent and combined roles of supplementation of carotenoids and vitamin E during early growth in regulating the expression of traits in adulthood, in ring-necked pheasants, Phasianus colchicus. Individuals supplemented with a combination of carotenoids and vitamin E were larger at adulthood than individuals receiving other treatment diets (including vitamin E or carotenoids alone), but there were no differences in ornament expression, immune function, the swelling response to phytohaemagglutinin or levels of oxidative damage. 3. This shows that there are synergistic early life-history effects of these dietary antioxidants on body size at adulthood and suggest that the allocation of limited antioxidant resources are prioritized towards traits that increase competitive ability rather than sexual attractiveness in this strongly sexually selected species.

  • Synergistic effects of supplementation of dietary antioxidants during growth on adult phenotype in ring‐necked pheasants, Phasianus colchicus
    Functional Ecology, 2011
    Co-Authors: Josephine M. Orledge, Andrew N Hoodless, Jonathan D. Blount, Thomas W. Pike, Nick J. Royle
    Abstract:

    1. Oxidative stress may provide a proximate link between investment in growth and/or reproduction and investment in self-maintenance. Dietary antioxidants, such as carotenoids and vitamin E, provide potentially important roles in regulating these trade-offs. Recent work suggests that carotenoids may have synergistic effects in combination with non-pigmentary antioxidants (e.g. vitamin E) on the expression of sexually selected traits in adulthood. However, these studies involved the supplementation of antioxidants to adults so did not take account of early life-history effects. 2. Here, we test the independent and combined roles of supplementation of carotenoids and vitamin E during early growth in regulating the expression of traits in adulthood, in ring-necked pheasants, Phasianus colchicus. Individuals supplemented with a combination of carotenoids and vitamin E were larger at adulthood than individuals receiving other treatment diets (including vitamin E or carotenoids alone), but there were no differences in ornament expression, immune function, the swelling response to phytohaemagglutinin or levels of oxidative damage. 3. This shows that there are synergistic early life-history effects of these dietary antioxidants on body size at adulthood and suggest that the allocation of limited antioxidant resources are prioritized towards traits that increase competitive ability rather than sexual attractiveness in this strongly sexually selected species

  • nest predation of common pheasants Phasianus colchicus
    Ibis, 2008
    Co-Authors: Roger A H Draycott, Andrew N Hoodless, Maureen I A Woodburn, Rufus B Sage
    Abstract:

    The Common Pheasant Phasianus colchicus is currently the most abundant, widespread and economically important gamebird in Europe. The Game and Wildlife Conservation Trust has undertaken several recent studies of Pheasant breeding ecology to improve the management of this species. Although predation is often the most important cause of nest failure in declining ground-nesting birds in agricultural landscapes, the causes of predation and the identity of predators are often unknown. In this paper, we analyse data from approximately 450 nests of radiotagged hen Pheasants collected from six sites between 1990 and 2003 and present results on the fate and survival rates of Pheasant nests in relation to habitat, predation control and other covariates. Survival rates during the laying stage and incubation stage were 28 and 37%, respectively, and overall nest survival was 10%. Nest predation rates were significantly lower on two sites where intensive predation control was undertaken than on four sites with only low levels of predation control. Red Foxes Vulpes vulpes and corvids were the most important nest predators, accounting for at least half of all predation events. We assess these results in the context of other ground-nesting farmland birds.

  • effects of tick ixodes ricinus infestation on pheasant Phasianus colchicus breeding success and survival
    Wildlife Biology, 2003
    Co-Authors: Andrew N Hoodless, Klaus Kurtenbach, Patricia A Nuttall, Sarah E Randolph
    Abstract:

    In some parts of Britain, pheasants Phasianus colchicus are infested by Ixodes ricinus ticks in the spring and summer. The effects of experimental reduction of tick infestation levels on the breeding success and survival of reared female pheasants were studied on two estates in southern England during 1995–1997. Females were radio-tagged and half of the birds, selected at random, were fitted with a slow-release acaricide, which substantially reduced their tick burdens. Clutch survival was significantly higher for treated females throughout the three-year study period, and hence more chicks were hatched by treated females (3.30 ± 0.86) than by control females (0.70 ± 0.36), even though treated and control birds produced the same numbers of clutches and eggs. During April-July, the female survival rate was significantly higher for acaricide-treated birds, showing an improvement of 10–15% over that of control birds each year. While these impacts will be of minor importance where annual pheasant releasing takes place to supplement autumn stocks for shooting, they might reduce the potential harvest on estates with wild pheasants or on those aiming to re-establish self-sustaining naturalised populations.

Ja ,van Horik - One of the best experts on this subject based on the ideXlab platform.

  • A novel continuous inhibitory-control task: variation in individual performance by young pheasants (Phasianus colchicus)
    Animal Cognition, 2017
    Co-Authors: Christina Meier, Ja ,van Horik, Pr Laker, Sara Raj Pant, Ellis J. G. Langley, Mark A. Whiteside, Frederick Verbruggen, Joah R. Madden
    Abstract:

    Inhibitory control enables subjects to quickly react to unexpectedly changing external demands. We assessed the ability of young (8 weeks old) pheasants Phasianus colchicus to exert inhibitory control in a novel response-inhibition task that required subjects to adjust their movement in space in pursuit of a reward across changing target locations. The difference in latencies between trials in which the target location did and did not change, the distance travelled towards the initially indicated location after a change occurred, and the change-signal reaction time provided a consistent measure that could be indicative of a pheasant’s inhibitory control. Between individuals, there was a great variability in these measures; these differences were not correlated with motivation either to access the reward or participate in the test. However, individuals that were slower to reach rewards in trials when the target did not change exhibited evidence of stronger inhibitory control, as did males and small individuals. This novel test paradigm offers a potential assay of inhibitory control that utilises a natural feature of an animal’s behavioural repertoire, likely common to a wide range of species, specifically their ability to rapidly alter their trajectory when reward locations switch.

  • A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus) (dataset)
    University of Exeter Press, 2017
    Co-Authors: Meier C, Raj Pant S, Ja ,van Horik, Pr Laker, Langley Ejg, Verbruggen F
    Abstract:

    The article associated with this dataset is in ORE: http://hdl.handle.net/10871/29175Dataset to accompany the article "A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus)" to be published in Animal CognitionFV was supported by a starting grant from the European Research Council (ERC; Grant Agreement No. 312445), and a Royal Society Wolfson Research Merit Award. JRM, PL, EJGL, MAW and JOvH were supported by a consolidator grant to JRM from the European Research Council (ERC; Grant Agreement No. 616474). SRP was supported by a grant from the University of Exeter Research Fund to FV

Pr Laker - One of the best experts on this subject based on the ideXlab platform.

  • A novel continuous inhibitory-control task: variation in individual performance by young pheasants (Phasianus colchicus)
    Animal Cognition, 2017
    Co-Authors: Christina Meier, Ja ,van Horik, Pr Laker, Sara Raj Pant, Ellis J. G. Langley, Mark A. Whiteside, Frederick Verbruggen, Joah R. Madden
    Abstract:

    Inhibitory control enables subjects to quickly react to unexpectedly changing external demands. We assessed the ability of young (8 weeks old) pheasants Phasianus colchicus to exert inhibitory control in a novel response-inhibition task that required subjects to adjust their movement in space in pursuit of a reward across changing target locations. The difference in latencies between trials in which the target location did and did not change, the distance travelled towards the initially indicated location after a change occurred, and the change-signal reaction time provided a consistent measure that could be indicative of a pheasant’s inhibitory control. Between individuals, there was a great variability in these measures; these differences were not correlated with motivation either to access the reward or participate in the test. However, individuals that were slower to reach rewards in trials when the target did not change exhibited evidence of stronger inhibitory control, as did males and small individuals. This novel test paradigm offers a potential assay of inhibitory control that utilises a natural feature of an animal’s behavioural repertoire, likely common to a wide range of species, specifically their ability to rapidly alter their trajectory when reward locations switch.

  • A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus) (dataset)
    University of Exeter Press, 2017
    Co-Authors: Meier C, Raj Pant S, Ja ,van Horik, Pr Laker, Langley Ejg, Verbruggen F
    Abstract:

    The article associated with this dataset is in ORE: http://hdl.handle.net/10871/29175Dataset to accompany the article "A novel continuous inhibitory-control task: Variation in individual performance by young pheasants (Phasianus colchicus)" to be published in Animal CognitionFV was supported by a starting grant from the European Research Council (ERC; Grant Agreement No. 312445), and a Royal Society Wolfson Research Merit Award. JRM, PL, EJGL, MAW and JOvH were supported by a consolidator grant to JRM from the European Research Council (ERC; Grant Agreement No. 616474). SRP was supported by a grant from the University of Exeter Research Fund to FV

Nick J. Royle - One of the best experts on this subject based on the ideXlab platform.

  • synergistic effects of supplementation of dietary antioxidants during growth on adult phenotype in ring necked pheasants Phasianus colchicus
    Functional Ecology, 2012
    Co-Authors: Josephine M. Orledge, Andrew N Hoodless, Jonathan D. Blount, Thomas W. Pike, Nick J. Royle
    Abstract:

    Summary 1. Oxidative stress may provide a proximate link between investment in growth and/or reproduction and investment in self-maintenance. Dietary antioxidants, such as carotenoids and vitamin E, provide potentially important roles in regulating these trade-offs. Recent work suggests that carotenoids may have synergistic effects in combination with non-pigmentary antioxidants (e.g. vitamin E) on the expression of sexually selected traits in adulthood. However, these studies involved the supplementation of antioxidants to adults so did not take account of early life-history effects. 2. Here, we test the independent and combined roles of supplementation of carotenoids and vitamin E during early growth in regulating the expression of traits in adulthood, in ring-necked pheasants, Phasianus colchicus. Individuals supplemented with a combination of carotenoids and vitamin E were larger at adulthood than individuals receiving other treatment diets (including vitamin E or carotenoids alone), but there were no differences in ornament expression, immune function, the swelling response to phytohaemagglutinin or levels of oxidative damage. 3. This shows that there are synergistic early life-history effects of these dietary antioxidants on body size at adulthood and suggest that the allocation of limited antioxidant resources are prioritized towards traits that increase competitive ability rather than sexual attractiveness in this strongly sexually selected species.

  • Synergistic effects of supplementation of dietary antioxidants during growth on adult phenotype in ring‐necked pheasants, Phasianus colchicus
    Functional Ecology, 2011
    Co-Authors: Josephine M. Orledge, Andrew N Hoodless, Jonathan D. Blount, Thomas W. Pike, Nick J. Royle
    Abstract:

    1. Oxidative stress may provide a proximate link between investment in growth and/or reproduction and investment in self-maintenance. Dietary antioxidants, such as carotenoids and vitamin E, provide potentially important roles in regulating these trade-offs. Recent work suggests that carotenoids may have synergistic effects in combination with non-pigmentary antioxidants (e.g. vitamin E) on the expression of sexually selected traits in adulthood. However, these studies involved the supplementation of antioxidants to adults so did not take account of early life-history effects. 2. Here, we test the independent and combined roles of supplementation of carotenoids and vitamin E during early growth in regulating the expression of traits in adulthood, in ring-necked pheasants, Phasianus colchicus. Individuals supplemented with a combination of carotenoids and vitamin E were larger at adulthood than individuals receiving other treatment diets (including vitamin E or carotenoids alone), but there were no differences in ornament expression, immune function, the swelling response to phytohaemagglutinin or levels of oxidative damage. 3. This shows that there are synergistic early life-history effects of these dietary antioxidants on body size at adulthood and suggest that the allocation of limited antioxidant resources are prioritized towards traits that increase competitive ability rather than sexual attractiveness in this strongly sexually selected species