LARVAL SALAMANDER RESPONSE TO UV RADIATION AND PREDATION RISK: COLOR CHANGE AND MICROHABITAT USE

2004 ◽  
Vol 14 (4) ◽  
pp. 1055-1064 ◽  
Author(s):  
Tiffany S. Garcia ◽  
Jodi Stacy ◽  
Andrew Sih
Keyword(s):  
Predation Risk ◽  
Uv Radiation ◽  
Color Change ◽  
Microhabitat Use

scholarly journals Influence of UV Radiation on the Color Change of the Surface of Steamed Maple Wood with Saturated Water Steam

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 217
Author(s):  
Ladislav Dzurenda ◽  
Michal Dudiak ◽  
Eva Výbohová
Keyword(s):  
Uv Radiation ◽  
Color Change ◽  
Color Space ◽  
Color Stability ◽  
Color Difference ◽  
Saturated Steam ◽  
Water Steam ◽  
Saturated Water ◽  
Red Color ◽  
Uv Lamp

The wood of maple (Acer Pseudopatanus L.) was steamed with a saturated steam-air mixture at a temperature of t = 95 °C or saturated steam at t = 115 °C and t = 135 °C, in order to give a pale pink-brown, pale brown, and brown-red color. Subsequently, samples of unsteamed and steamed maple wood were irradiated with a UV lamp in a Xenotest Q-SUN Xe-3-H after drying, in order to test the color stability of steamed maple wood. The color change of the wood surface was evaluated by means of measured values on the coordinates of the color space CIE L* a* b*. The results show that the surface of unsteamed maple wood changes color markedly under the influence of UV radiation than the surface of steamed maple wood. The greater the darkening and browning color of the maple wood by steaming, the smaller the changes in the values at the coordinates L*, a*, b* of the steamed maple wood caused by UV radiation. The positive effect of steaming on UV resistance is evidenced by the decrease in the overall color difference ∆E*. While the value of the total color diffusion of unsteamed maple wood induced by UV radiation is ∆E* = 18.5, for maple wood steamed with a saturated steam-air mixture at temperature t = 95 °C the ∆E* decreases to 12.6, for steamed maple wood with saturated water steam with temperature t = 115 °C the ∆E* decreases to 10.4, and for saturated water steam with temperature t = 135 °C the ∆E* decreases to 7.2. Differential ATR-FTIR spectra declare the effect of UV radiation on unsteamed and steamed maple wood and confirm the higher color stability of steamed maple wood.

The effect of cover and food on space use by wintering Song Sparrows and Field Sparrows

1997 ◽  
Vol 75 (10) ◽  
pp. 1636-1641 ◽  
Author(s):  
Christopher W. Beck ◽  
Bryan D. Watts
Keyword(s):  
Predation Risk ◽  
Positive Response ◽  
Distribution Patterns ◽  
Microhabitat Use ◽  
Vegetative Cover ◽  
Song Sparrows ◽  
Trade Offs ◽  
Resource Requirements ◽  
Woody Cover ◽  
Species Specific

The distribution of birds among microhabitats may reflect species-specific resource requirements. Both food availability and predation risk have been shown to influence patterns of microhabitat use by sparrows during winter. We investigated the influence of vegetative cover and food on microhabitat use using a 2 × 2 factorial design. Both woody cover and food were manipulated at the plot level. The presence of screening cover (weed stems) was manipulated within plots. Sparrows showed a positive response to the presence of both cover and food. Within plots, sparrows selected areas with screening cover. The distribution of birds between areas with and without screening cover was influenced by the presence of woody cover and food. Conversely, the presence of screening cover reduced the influence of woody cover on the distribution of birds within patches. Song Sparrows (Melospiza melodia) and Field Sparrows (Spizella pusilla) differed in their response to treatments both within and across plots, suggesting that trade-offs between foraging and predation risk may be important in the structuring of winter sparrow assemblages. Additionally, screening cover appears to moderate predation risk and therefore to affect distribution patterns.

scholarly journals Polymer materials with controlled degradation time

2018 ◽  
Vol 44 ◽  
pp. 00122 ◽  
Author(s):  
Ewelina Niedzielska ◽  
Anna Masek
Keyword(s):  
Mechanical Properties ◽  
Uv Radiation ◽  
Color Change ◽  
Polymer Materials ◽  
Effect Of Temperature ◽  
Oxygen Effect ◽  
Cyclic Olefin Copolymer ◽  
Cyclic Olefin ◽  
Before And After

The aim of this work was carry out accelarated process of ageing for cyclic olefin copolymer ethylene – norbornene (Topas). The Topas cyclic olefin copolymer (COC) family characterize high transparency, excellent mechanical properties and low water permeability. The influence of external factors such as UV radiation, elevated temperature, oxygen effect and humidity causing degradation of polymer macroparticles was also investigated. The properties of the polymer before and after weathering and UV radiation were also compared. Degradability was examinated by measuring color change, FTIR spectrum analysis and determination of the ageing factor k. The tensile strength, elongation at break and hardness of composites by Shore A method were measured. The synergistic effect of temperature, humidity and UV radiation reduces the mechanical properties of the samples tested, while the interaction of only UV radiation on the samples causes a significant change color.

scholarly journals Microhabitat use and behavior of voles under weasel and raptor predation risk: predator facilitation?

1996 ◽  
Vol 7 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Erkki Korpimaki ◽  
Vesa Koivunen ◽  
Hani Hakkarainen
Keyword(s):  
Predation Risk ◽  
Microhabitat Use ◽  
And Behavior

Effects of Background Color and Predation Risk on Color Change in Fire Salamander Larvae

2009 ◽  
Vol 55 (4) ◽  
pp. 359-367 ◽  
Author(s):  
Ori Segev
Keyword(s):  
Predation Risk ◽  
Perceived Risk ◽  
Color Change ◽  
White Background ◽  
Color Matching ◽  
Background Color ◽  
Background Matching ◽  
Threat Sensitivity ◽  
Risk Of Predation ◽  
Fire Salamander

The threat-sensitivity hypothesis assumes individuals should demonstrate flexibility in response to perceived predation risk and vary the intensity of anti-predator responses in concert with perceived risk of predation. Substrate color matching is adaptive as it enables organisms to become less conspicuous to both their prey and predators. I hypothesized that newborn fire salamander (Salamandra infraimmaculata) larvae will respond fast through physiological color change to contrasting backgrounds, becoming lighter against a white background and darker against a black background. Additionally, in accordance with the threat-sensitivity hypothesis, I expected a background color x predator interaction—i.e., that predator presence will further enhance the focal larvae color-matching response. To explicitly test these hypotheses I conducted a replicated outdoor mesocosm experiment. I used a two-by-two factorial design: pools of black or white background color crossed with the presence or absence of a larger cannibalistic conspecific. Digital photos of the focal larvae's dorsal view revealed that larval brightness and chroma changed accordingly against the contrasting black and white backgrounds to increase background matching. Although not statistically significant, larvae tended to show a stronger color-change response towards enhanced background matching in the presence of the free predator. Larval survival was strongly reduced in the presence of the larger conspecific, with no apparent effect of background color. This study demonstrates that Salamandra larvae are capable of environmentally induced physiological color change and highlights the need for further investigation into the interplay between threat intensity, mechanisms of risk assessment, and physiological antipredator responses.

Habitat deterioration affects antipredatory behavior, body condition, and parasite load of female Psammodromus algirus lizards

2007 ◽  
Vol 85 (6) ◽  
pp. 743-751 ◽  
Author(s):  
Luisa Amo ◽  
Pilar López ◽  
José Martín
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Relative Abundance ◽  
Microhabitat Use ◽  
Health State ◽  
Habitat Deterioration ◽  
Antipredatory Behavior ◽  
Risk Of Predation ◽  
Psammodromus Algirus

Deforestation may increase predation risk for prey because it may make prey more conspicuous and limit the number of refuges suitable to avoid predators. Therefore, prey may need to increase the magnitude of escape responses. However, excessive antipredatory effort might lead to a loss of body mass and a decrease in defense against parasites, with important consequences for short- and long-term fitness. We analyzed whether Psammodromus algirus (L., 1758) lizards that inhabit patches with different levels of deterioration of the vegetation within the same oak forest differed in relative abundance numbers, microhabitat use, antipredatory strategies, and health state. Results showed lizards selected similar microhabitats regardless of the level of deterioration of the vegetation and relative abundance of lizards was similar in both areas. However, habitat deterioration seemed to increase predation risk, at least for females, because they were detected at longer distances in deteriorated areas. Females seemed to adjust their antipredatory behavior accordingly to high risk of predation by increasing approach distances allowed to predators. The costs associated with frequent antipredatory displays might explain why females in deteriorated habitats had lower body condition and greater blood parasite loads than females in natural areas. This loss of body condition and increased parasitemia might have deleterious consequences for female fitness and therefore affect the maintenance of lizard populations in the long-term.

scholarly journals Selected performance indices for assessment of polypropylene susceptibility to dyeing by pigments of different UV resistance

Polimery ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 44-51
Author(s):  
Marek Bieliński ◽  
Artur Kościuszko ◽  
Katarzyna Smolińska
Keyword(s):  
Injection Molding ◽  
Uv Radiation ◽  
Radiation Resistance ◽  
Color Change ◽  
Uv Resistance ◽  
Performance Indices ◽  
Polymer Medium

This study presents an assessment of the effects of usage time for polypropylene (PP) experimental samples including those dyed with pigments of different UV resistance. A standard double cavity mold was used to create the samples by injection molding. Selected indices were analyzed in terms of color change (UV resistance of pigments), and UV radiation resistance of a PP polymer medium. The experiment revealed a significant impact of the accepted usage time and the type of dye concentrates on the indices characterizing the sample color change (CIELab) and a change in the structure and state of the PP medium surface.

Effect of predation risk on microhabitat use by goldfish

2018 ◽  
Vol 31 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Sundararaj Vijayan ◽  
Burt P. Kotler ◽  
Lotan Tamar Tov-Elem ◽  
Zvika Abramsky
Keyword(s):  
Predation Risk ◽  
Microhabitat Use
Sign in / Sign up

Export Citation Format

Share Document