Measuring colours
 

The most popular, and objective method for measuring plumage colouration is to use a reflectance spectrometer. The following companies make instruments that are portable enough for field use:

OCEAN OPTICS: their USB4000 UV-VIS spectrometer (as of 1 jan 2006 this replaces the old USB2000) coupled to a PX-2 Pulsed Xenon lamp provides a good system for field use. Various configurations are available depending upon the application. We will summarize here a typical good configuration for bird colour work SOON—as soon as we get a chance to test the new USB4000 and their new cross-platform software

AVANTES: the AvaSpec-256 Fiber Optic Spectrometer connected to a AvaLight-DHc light source would seem to be suitable for bird colour measurements but we have not used this instrument ourselves

X-RITE: this company bought out and discontinued the ColorTron that waas used by some people to measure bird colours. they continue to make a variety of portable spectrometers but they do not measure very far into the UV-region that birds can see (nor did the ColorTron, for that matter). Their spectrometers are very easy to use and might be suitable for species that do not have significant plumage reflectance in the UV

 

ALSO

JOHN ENDLER has produced a very useful summary of the sorts of equipment needed to measure bird colouration in the filed. You can download it here