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Author Degen, T.; Hovestadt, T.; Mitesser, O.; Hölker, F. url  doi
openurl 
  Title Altered sex-specific mortality and female mating success: ecological effects and evolutionary responses Type Journal Article
  Year 2017 Publication Ecosphere Abbreviated Journal Ecosphere  
  Volume 8 Issue 5 Pages e01820  
  Keywords Insects; nocturnal insects; mating behaviour  
  Abstract Theory predicts that males and females should often join the mating pool at different times (sexual dimorphism in timing of emergence [SDT]) as the degree of SDT affects female mating success. We utilize an analytical model to explore (1) how important SDT is for female mating success, (2) how mating success might change if either sex's mortality (abruptly) increases, and (3) to what degree evolutionary responses in SDT may be able to mitigate the consequences of such mortality increase. Increasing male pre-mating mortality has a non-linear effect on the fraction of females mated: The effect is initially weak, but at some critical level a further increase in male mortality has a stronger effect than a similar increase in female mortality. Such a change is expected to impose selection for reduced SDT. Increasing mortality during the mating season has always a stronger effect on female mating success if the mortality affects the sex that emerges first. This bias results from the fact that enhancing mortality of the earlier emerging sex reduces femaleâ??male encounter rates. However, an evolutionary response in SDT may effectively mitigate such consequences. Further , if considered independently for females and males, the predicted evolutionary response in SDT could be quite dissimilar. The difference between female and male evolutionary response in SDT leads to marked differences in the fraction of fertilized females under certain conditions. Our model may provide general guidelines for improving harvesting of populations, conservation management of rare species under altered environmental conditions, or maintaining long-term efficiency of pest-control measures.  
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  ISSN 2150-8925 ISBN Medium  
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  Notes Approved no  
  Call Number LoNNe @ schroer @ Serial 1663  
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Author Tan, M.K. url  doi
openurl 
  Title Why do nocturnal grasshoppers and katydids “salute” to flash photography? Type Journal Article
  Year 2019 Publication Entomological Science Abbreviated Journal Entomological Science  
  Volume 22 Issue 2 Pages 216-219  
  Keywords Animals; Insects; grasshoppers; katydids; orthoptera  
  Abstract Nocturnal animals can be sensitive to powerful light from the environment. Anthropogenically induced perturbation to natural light regimes, including ecological light pollution and flash photography, can have wide‐reaching implications on the ecology and behavior. Ecological ramifications of strong lights were traditionally focused on vertebrates although there is now more focus on invertebrates. Nonetheless, there are still unanswered questions on visual ecology and evolution, particularly on individual‐level effects and of tropical species. Specifically, how invertebrate individuals react to strong light is generally undocumented. Based on opportunistic surveys around Southeast Asia, orthopterans, spotted using concentrated torchlight and exposed to sudden strong light intensity during flash macrophotography, were observed to screen themselves by positioning their foreleg over the dorsum of the compound eye. This resembled the orthopteran “saluting” to the camera. These observations provided empirical evidence of how high intensity light can unsettle orthopterans and other insects and further ecological and evolutionary hypotheses and questions can be raised to understand the effect of light pollution.  
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  ISSN 1343-8786 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2324  
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Author Smit, B.; Boyles, J.G.; Brigham, R.M.; McKechnie, A.E. url  doi
openurl 
  Title Torpor in dark times: patterns of heterothermy are associated with the lunar cycle in a nocturnal bird Type Journal Article
  Year 2011 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms  
  Volume 26 Issue 3 Pages 241-248  
  Keywords Animals; *Biological Clocks; Birds/*physiology; *Body Temperature Regulation; Ecosystem; *Feeding Behavior; Insects; *Moon; Seasons; South Africa  
  Abstract Many studies have shown that endotherms become more heterothermic when the costs of thermoregulation are high and/or when limited energy availability constrains thermoregulatory capacity. However, the roles of many ecological variables, including constraints on foraging opportunities and/or success, remain largely unknown. To test the prediction that thermoregulatory patterns should be related to foraging opportunities in a heterothermic endotherm, we examined the relationship between the lunar cycle and heterothermy in Freckled Nightjars (Caprimulgus tristigma), which are visually orienting, nocturnal insectivores that are dependent on ambient light to forage. This model system provides an opportunity to assess whether variation in foraging opportunities influences the expression of heterothermy. The nightjars were active and foraged for insects when moonlight was available but became inactive and heterothermic in the absence of moonlight. Lunar illumination was a much stronger predictor of the magnitude of heterothermic responses than was air temperature (T(a)). Our data suggest that heterothermy was strongly related to variation in foraging opportunities associated with the lunar cycle, even though food abundance appeared to remain relatively high throughout the study period. Patterns of thermoregulation in this population of Freckled Nightjars provide novel insights into the environmental and ecological determinants of heterothermy, with the lunar cycle, and not T(a), being the strongest predictor of torpor use.  
  Address DST/NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa. smitbe@gmail.com  
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  Language (up) English Summary Language Original Title  
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  ISSN 0748-7304 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21628551 Approved no  
  Call Number IDA @ john @ Serial 59  
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Author Dacke, M.; Baird, E.; Byrne, M.; Scholtz, C.H.; Warrant, E.J. url  doi
openurl 
  Title Dung beetles use the Milky Way for orientation Type Journal Article
  Year 2013 Publication Current Biology : CB Abbreviated Journal Curr Biol  
  Volume 23 Issue 4 Pages 298-300  
  Keywords Animals; Beetles/*physiology; *Behavior, Animal; Cues; Feces; *Galaxies; Locomotion; Moon; Motor Activity; Orientation/*physiology; *Stars, Celestial; Vision, Ocular/physiology; Milky Way; insects  
  Abstract When the moon is absent from the night sky, stars remain as celestial visual cues. Nonetheless, only birds, seals, and humans are known to use stars for orientation. African ball-rolling dung beetles exploit the sun, the moon, and the celestial polarization pattern to move along straight paths, away from the intense competition at the dung pile. Even on clear moonless nights, many beetles still manage to orientate along straight paths. This led us to hypothesize that dung beetles exploit the starry sky for orientation, a feat that has, to our knowledge, never been demonstrated in an insect. Here, we show that dung beetles transport their dung balls along straight paths under a starlit sky but lose this ability under overcast conditions. In a planetarium, the beetles orientate equally well when rolling under a full starlit sky as when only the Milky Way is present. The use of this bidirectional celestial cue for orientation has been proposed for vertebrates, spiders, and insects, but never proven. This finding represents the first convincing demonstration for the use of the starry sky for orientation in insects and provides the first documented use of the Milky Way for orientation in the animal kingdom.  
  Address Department of Biology, Lund University, 223 62 Lund, Sweden. marie.dacke@biol.lu.se  
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  Language (up) English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0960-9822 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23352694 Approved no  
  Call Number IDA @ john @ Serial 116  
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Author Narendra, A.; Reid, S.F.; Raderschall, C.A. url  doi
openurl 
  Title Navigational efficiency of nocturnal Myrmecia ants suffers at low light levels Type Journal Article
  Year 2013 Publication PloS one Abbreviated Journal PLoS One  
  Volume 8 Issue 3 Pages e58801  
  Keywords Adaptation, Biological/*physiology; Animals; Ants/*physiology; Australian Capital Territory; *Cues; Geographic Information Systems; Homing Behavior/*physiology; *Light; Locomotion/*physiology; Orientation/*physiology; insects  
  Abstract Insects face the challenge of navigating to specific goals in both bright sun-lit and dim-lit environments. Both diurnal and nocturnal insects use quite similar navigation strategies. This is despite the signal-to-noise ratio of the navigational cues being poor at low light conditions. To better understand the evolution of nocturnal life, we investigated the navigational efficiency of a nocturnal ant, Myrmecia pyriformis, at different light levels. Workers of M. pyriformis leave the nest individually in a narrow light-window in the evening twilight to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, while few attempt to return to the nest throughout the night. We found that as light levels dropped, ants paused for longer, walked more slowly, the success in finding the nest reduced and their paths became less straight. We found that in both bright and dark conditions ants relied predominantly on visual landmark information for navigation and that landmark guidance became less reliable at low light conditions. It is perhaps due to the poor navigational efficiency at low light levels that the majority of foragers restrict navigational tasks to the twilight periods, where sufficient navigational information is still available.  
  Address ARC Centre of Excellence in Vision Science, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia. ajay.narendra@anu.edu.au  
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  Language (up) English Summary Language Original Title  
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  ISSN 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23484052; PMCID:PMC3590162 Approved no  
  Call Number IDA @ john @ Serial 117  
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