Chemometric approach to chromatic spatial variance. Case study: patchiness of the Skyros wall lizard

Brydegaard, Mikkel; Runemark, Anna; Bro, Rasmus

doi:10.1002/cem.2444

Cited by 7 publications

(5 citation statements)

References 41 publications

(49 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To capture the colour variance within each sample, the chromaticities of individual pixels were summarized in 2‐D histogram planes (Drew & Au, ; Brydegaard et al ., ; Fig. e,f).…”

Section: Methodsmentioning

confidence: 83%

“…the bimodal colour distribution reflecting the presence of both green and black scales in the histograms in Fig. c,e) is preferable if the spectral region of interest is covered by the RGB imager (Brydegaard et al ., ). All lizards were photographed with a DMC FX01 Panasonic colour camera (a RGB imaging system) in an optical isolated box with a white background reference, using the built‐in xenon flash.…”

Section: Methodsmentioning

confidence: 97%

“…The entire method for the colour analysis procedure is described in detail in Brydegaard et al . (). Matlab ® (MathWorks, Natick, MA, USA) was used for all image analyses.…”

Section: Methodsmentioning

confidence: 97%

See 2 more Smart Citations

Does relaxed predation drive phenotypic divergence among insular populations?

Runemark

Brydegaard

Svensson

2014

J of Evolutionary Biology

View full text Add to dashboard Cite

The evolution of striking phenotypes on islands is a well-known phenomenon, and there has been a long-standing debate on the patterns of body size evolution on islands. The ecological causes driving divergence in insular populations are, however, poorly understood. Reduced predator fauna is expected to lower escape propensity, increase body size and relax selection for crypsis in small-bodied, insular prey species. Here, we investigated whether escape behaviour, body size and dorsal coloration have diverged as predicted under predation release in spatially replicated islet and mainland populations of the lizard species Podarcis gaigeae. We show that islet lizards escape approaching observers at shorter distances and are larger than mainland lizards. Additionally, we found evidence for larger between-population variation in body size among the islet populations than mainland populations. Moreover, islet populations are significantly more divergent in dorsal coloration and match their respective habitats poorer than mainland lizards. These results strongly suggest that predation release on islets has driven population divergence in phenotypic and behavioural traits and that selective release has affected both trait means and variances. Relaxed predation pressure is therefore likely to be one of the major ecological factors driving body size divergence on these islands.

show abstract

“…To capture the colour variance within each sample, the chromaticities of individual pixels were summarized in 2‐D histogram planes (Drew & Au, ; Brydegaard et al ., ; Fig. e,f).…”

Section: Methodsmentioning

confidence: 83%

Section: Methodsmentioning

confidence: 97%

See 1 more Smart Citation

Does relaxed predation drive phenotypic divergence among insular populations?

Runemark

Brydegaard

Svensson

2014

J of Evolutionary Biology

View full text Add to dashboard Cite

show abstract

“…This would be the case if several clusters share the same chromophores, but in different discrete concentrations [1], [2]. The four groups of damselflies (males and females of C. splendens and C. virgo) share the same melanin pigment, but are differently melanised in discrete quantities [3], [24]. The most prominent signature, however, arises from the structural phenomenon and this does not decompose linearly because the center wavelength and feature width relate to the size and ordering of the nanostructures, respectively, rather than to specific spectral transition energy.…”

Section: Unsupervised Clustering and Classificationmentioning

confidence: 99%

Rare Events in Remote Dark-Field Spectroscopy: An Ecological Case Study of Insects

Runemark

Wellenreuther

Jayaweera

et al. 2012

IEEE J. Select. Topics Quantum Electron.

View full text Add to dashboard Cite

Abstract-In this paper, a novel detection scheme for the monitoring of insect ecosystems is presented. Our method is based on the remote acquisition of passive sunlight scattering by two insect species. Procedures to identify rare events in remote dark-field spectroscopy are explained. We further demonstrate how to reduce the spectral representation, and how to discriminate between sexes, using a hierarchical clustering analysis. One-day cycle showing the temporal activities of the two sexes as well as data on activity patterns in relation to temperature and wind is presented. We also give a few examples of the potential use of the technique for studying interactions between sexes on a time scale of milliseconds.

show abstract

“…Therefore a close to a top-hat beam profile can be obtained with any radius, simply by adjusting the focal stage of the expanding telescope. This is ideal for imaging applications, e.g., for spatial chromatic variance 47 of vegetation. A test target made with light marker pens on white paper demonstrates the principle with images recorded remotely and directly at the target as shown in Fig.…”

Section: Imaging Recording Of Laser-induced Fluorescence Using An Rgbmentioning

confidence: 99%

Realistic Instrumentation Platform for Active and Passive Optical Remote Sensing

et al. 2016

Self Cite

View full text Add to dashboard Cite

We describe the development of a novel versatile optical platform for active and passive remote sensing of environmental parameters. Applications include assessment of vegetation status and water quality. The system is also adapted for ecological studies, such as identification of flying insects including agricultural pests. The system is based on two mid-size amateur astronomy telescopes, continuous-wave diode lasers at different wavelengths ranging from violet to the near infrared, and detector facilities including quadrant photodiodes, two-dimensional and line scan charge-coupled device cameras, and a compact digital spectrometer. Application examples include remote Ramanlaser-induced fluorescence monitoring of water quality at 120 m distance, and insect identification at kilometer ranges using the recorded wing beat frequency and its spectrum of overtones. Because of the low cost this developmental platform is very suitable for advanced research projects in developing countries and has, in fact, been multiplied during hands-on workshops and is now being used by a number of groups at African universities.

show abstract

Chemometric approach to chromatic spatial variance. Case study: patchiness of the Skyros wall lizard

Cited by 7 publications

References 41 publications

Does relaxed predation drive phenotypic divergence among insular populations?

Does relaxed predation drive phenotypic divergence among insular populations?

Rare Events in Remote Dark-Field Spectroscopy: An Ecological Case Study of Insects

Realistic Instrumentation Platform for Active and Passive Optical Remote Sensing

Contact Info

Product

Resources

About