A comparison of animal color measurements using a commercially available digital color sensor and photograph analysis

An animal's pelage,feather,or skin color can serve a variety of functions,so it is important to have multiple standardized methods for measuring color.One of the most common and reliable methods for measuring animal coloration is the use of standardized digital photographs of animals.New tech no logy in the form of a commercially available handheld digital color sensor could provide an alter native to photography-based animal color measurements.To determine whether a digital color sensor could be used to measure animal coloration,we tested the ability of a digital color sensor to measure coloration of mammalian,avian,and lepidopteran museums specimens.We compared results from the sensor to measurements taken using traditional photography methods.Our study yielded significant differences between photography-based and digital color sensor measurements of brightness(light to dark)and colors along the green to red spectrum.There was no difference between photographs and the digital color sensor measurements for colors along the blue to yellow spectrum.The average difference in recorded color(AE)by the 2 methods was above the threshold at which humans can perceive a difference.There were sign讦icant correlations between the sensor and photographs for all measurements indicating that the sensor is an effective animal coloration measuring tool.However,the sensor's small aperture and narrow light spectrum range designed for human-vision limit its value for ecological research.We discuss the conditions in which a digital color sensor can be an effective tool for measuring animal coloration in both laboratory settings and in the field.

Adult bobcat(Lynx rufus)habitat selection in a longleaf pine savanna

Background:Pine savannas are primarily managed with frequent prescribed fire(≤3 years)to promote diversity of flora and fauna,and to maintain open,park-like conditions needed by species such as the endangered red-cockaded woodpecker(Picoides borealis).However,a knowledge gap exists in our understanding of bobcat(Lynx rufus)habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions.Methods:We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales(i.e.,study area boundary[hereafter,landscape scale])and annual area of use[95%kernel density;local scale],and assessed effects of prescribed fire on bobcat habitat selection.Specifically,we monitored 45 bobcats(16 males and 29 females)during 2001–2007.Results:We found differential habitat selection by sex.At the landscape scale,female bobcats were closer to mixed pine-hardwoods,young pine,and secondary roads,but farther from mature pine and hardwoods stands relative to males.We found no difference in selection of agriculture,shrub-scrub,and primary roads between sexes.At the annual area of use scale,female bobcats were closer to secondary roads,but farther from agriculture and shrub-scrub relative to males.We found no difference in selection of mature pine,mixed pine-hardwoods,hardwoods,young pine,and primary roads between sexes.Bobcats primarily selected for stands burned≤1.1 years post-fire.Conclusions:Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands(≤1.1 year post-fire),suggesting prey in many areas of this system are at risk of bobcat predation.Additionally,we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.