Black or white? Physiological implications of roost colour and choice in a microbat

Doty, Anna C.; Stawski, Clare; Currie, Shannon E.; Geiser, Fritz

doi:10.1016/j.jtherbio.2016.07.015

Cited by 19 publications

(25 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only one other study to date has examined variation in thermal properties of nest boxes painted typically-used colors [43], and our findings suggest that they may have failed to detect any influence of brown versus green on maximum daytime temperatures because these two colors had similar solar reflectance. Second, our data indicate that box colors commonly used in nest box programs, for example various shades of dark-green [44], may potentially have reflectance values that are very similar to black paint, the color with the lowest possible reflectance, and thereby the largest influence on the difference between box temperatures and ambient conditions [40–42,53]. These two novel findings highlight the benefit of measuring the reflectance spectrum of color treatments, and examining the resultant variation in box thermal profiles, prior to painting and installing boxes.…”

Section: Discussionmentioning

confidence: 99%

“…As we were interested in comparing two shades of green with markedly different reflectance spectra, we selected the white-based light-green paint for the nest box temperature trials. As previous studies have used nest boxes painted black (the color with the lowest reflectance) to achieve the greatest possible difference between box and ambient temperatures [38,40–42,53], we also tested a sample of black paint. This analysis revealed that the dark-green paint treatment used in this study had a reflectance spectrum that was almost identical to black paint (total solar reflectance = 2.9%, Fig 3).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Surface reflectance drives nest box temperature profiles and thermal suitability for target wildlife

et al. 2017

View full text Add to dashboard Cite

Thermal properties of tree hollows play a major role in survival and reproduction of hollow-dependent fauna. Artificial hollows (nest boxes) are increasingly being used to supplement the loss of natural hollows; however, the factors that drive nest box thermal profiles have received surprisingly little attention. We investigated how differences in surface reflectance influenced temperature profiles of nest boxes painted three different colors (dark-green, light-green, and white: total solar reflectance 5.9%, 64.4%, and 90.3% respectively) using boxes designed for three groups of mammals: insectivorous bats, marsupial gliders and brushtail possums. Across the three different box designs, dark-green (low reflectance) boxes experienced the highest average and maximum daytime temperatures, had the greatest magnitude of variation in daytime temperatures within the box, and were consistently substantially warmer than light-green boxes (medium reflectance), white boxes (high reflectance), and ambient air temperatures. Results from biophysical model simulations demonstrated that variation in diurnal temperature profiles generated by painting boxes either high or low reflectance colors could have significant ecophysiological consequences for animals occupying boxes, with animals in dark-green boxes at high risk of acute heat-stress and dehydration during extreme heat events. Conversely in cold weather, our modelling indicated that there are higher cumulative energy costs for mammals, particularly smaller animals, occupying light-green boxes. Given their widespread use as a conservation tool, we suggest that before boxes are installed, consideration should be given to the effect of color on nest box temperature profiles, and the resultant thermal suitability of boxes for wildlife, particularly during extremes in weather. Managers of nest box programs should consider using several different colors and installing boxes across a range of both orientations and shade profiles (i.e., levels of canopy cover), to ensure target animals have access to artificial hollows with a broad range of thermal profiles, and can therefore choose boxes with optimal thermal conditions across different seasons.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Surface reflectance drives nest box temperature profiles and thermal suitability for target wildlife

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The deployment of bat box designs that differ in thermal profiles and the use of boxes that offer a thermal gradient within the box itself is likely an important factor for boxes to be a suitable artificial roost resource for heterothermic bats. Box microclimate is considered particularly important during ambient temperature extremes [32,41,56] and for energy conservation, such as through passive rewarming from torpor [28,57] and through warm roosts for dependent young and lactating females [14,43].…”

Section: Discussionmentioning

confidence: 99%

“…Investigating temperature among & within box designs during the periods of investigation (i.e., warmest day, coolest day & 5-day period) is of particular relevance to test whether boxes have the potential to cause heat stress (i.e., box temperatures exceeding the upper thermal tolerance limit) in summer [32,41] and/or provide beneficial conditions for bats to passively rewarm in summer & winter [28,42] during both average ambient temperatures & ambient temperature extremes.…”

Section: Microclimate Monitoringmentioning

confidence: 99%

Variation in Summer and Winter Microclimate in Multi-Chambered Bat Boxes in Eastern Australia: Potential Eco-Physiological Implications for Bats

Rueegger

2019

Environments

View full text Add to dashboard Cite

Bat boxes are commonly used as a conservation tool. Detailed knowledge on the influence of box elements on microclimate is lacking, despite eco-physiological implications for bats. Summer and winter box temperature and relative humidity patterns were studied in narrow multi-chambered plywood and wood-cement boxes in eastern Australia. Box exteriors were black or white and plywood boxes comprised vents. Relative humidity was higher in white boxes than black boxes and box colour, construction material, chamber sequence and vents influenced temperatures. Maximum box temperature differences between designs varied by up to 9.0 • C in summer and 8.5 • C in winter. The black plywood box consistently recorded the warmest temperatures. This design comprised a temperature gradient between chambers and within the front chamber (influenced by vent). During the 32-day summer sampling period, the front chamber rarely recorded temperatures over 40.0 • C (postulated upper thermal tolerance limit of bats), while the third and fourth chamber never reached this threshold. At the study site, the tested black boxes are considered most thermally suitable for bats during average summer conditions. However, during temperature extremes black boxes likely become too hot. Wood-cement, a durable material not previously tested in Australia should be considered as an alternative construction material.

show abstract

“…Tree roosts and roofs of buildings are less insulated than caves or burrows and therefore are 372 impacted by daily fluctuations in T a , which can be dramatic on mild winter days (Law & Chidel 373 2007;Turbill 2008;Doty, Stawski, Currie & Geiser 2016). In these circumstances, bats are 374 exposed to potential passive rewarming, thus mitigating much of the cost of arousal from low 375 T a /T b .…”

Section: Discussion 268mentioning

confidence: 99%

Cold-hearted bats: Cardiac function and metabolism of small bats during torpor at subzero temperatures

Stawski

Geiser

2017

Preprint

Self Cite

View full text Add to dashboard Cite

20Despite their small size and large relative surface area, many hibernating bats have the 21 ability to thermoregulate and defend their body temperature (T b ) often below 10°C by an 22 increase in metabolic rate. Above a critical temperature (T crit ) animals usually thermoconform. 23We investigated the physiological responses above and below T crit for a small tree dwelling 24 bat (Chalinolobus gouldii, ~14g) that is often exposed to subzero temperatures during winter. 25Through simultaneous measurement of 2 ) we 26 show that the relationship between oxygen transport and cardiac function is substantially 27 altered in thermoregulating torpid bats down to -2°C, compared with thermoconforming torpid 28 bats at mild ambient temperatures (T a 5-20°C). T crit for this species was T a 0.7 ± 0.4°C, with 29 a corresponding T b of 1.8 ± 1.2°C. Below this T crit animals began to thermoregulate, indicated 30 by a considerable but disproportionate 2 . The maximum increase 31 in HR was only 4-fold greater than the average 32 -2 . 2 to low T a was represented 33 by a 15-fold increase in oxygen delivery per heart beat (cardiac oxygen pulse). During torpor 34 at low T a , thermoregulating bats maintain a relatively slow HR and compensate for increased 35 metabolic demands by significantly increasing stroke volume and tissue oxygen extraction. 36Our study provides valuable new information on the relationship between metabolism and 37 HR in an unstudied physiological state and further advances our knowledge of the 38 thermogenic capacity of small bats. 39 40

show abstract

Black or white? Physiological implications of roost colour and choice in a microbat

Cited by 19 publications

References 59 publications

Surface reflectance drives nest box temperature profiles and thermal suitability for target wildlife

Surface reflectance drives nest box temperature profiles and thermal suitability for target wildlife

Variation in Summer and Winter Microclimate in Multi-Chambered Bat Boxes in Eastern Australia: Potential Eco-Physiological Implications for Bats

Cold-hearted bats: Cardiac function and metabolism of small bats during torpor at subzero temperatures

Contact Info

Product

Resources

About