Some of you might be interested in what sort of measurements etc. I take when I’ve caught a quail. I’ve scaled the process way down from my Ph.D. work. I band them and then measure tarsus length, wing length at the first primary and mass. These measurements will give me a general idea of the size of the bird. For the juveniles, I also determine where they are in the primary and secondary moult which will give me some estimate of their age.
I also take a little bit of blood 10-100ug by clipping a toenail. This is not comfortable for the bird but is, according to some veterinarians, probably less stressful than wing venipuncture or through the jugular vein or carotid artery. I do not need a lot of blood to do a population genetic and kin relationship work up of the birds (using microsatellite markers).
Finally, I give them a little sip of water, make sure their toenail has stopped bleeding and send them on their way. i have not been taking measurements of secondary sexual characteristics (length of crest, size of chest and belly patches, size of black and white markings on face and neck, color of all of these patches). These are measurements I took during my Ph. D. because I was interested in mate choice for plumage characteristics. I am not interested in this anymore, at least not in quail–or rather, this question is a more intractable one at this point than I want to pursue. I realized, during my dissertation work, that yes, we can elicit a preference response (e.g. to elongated vs. normal length crests; females prefer the former) but figuring out what that response means evolutionarily, which is really the next step is extremely complicated.
I believe we need to understand a heck of a lot more what the bird is seeing when it looks at the plumage–we really do not know at this point. First, their eyes are different from ours, so we cannot assume they see what we see (they have 4 cones, we three, they have oil droplets, we don’t, etc). Second, we do not know how they process what they perceive–do they see multiple discrete patches, like a taxonomist, or do they integrate the patches somehow, seeing the gestalt individual. Do some aspects matter more than others depending upon the context? I saw hints of the latter in my analysis of the responses of the quail–gestalt and context dependent responses.
But getting at this stuff is very hard in any species (including our own) and getting at it in a bird in the field, when one is reluctant to do much that is invasive, is prohibitive. Furthemore, if one is interested in evolution, calculating the impact of responses on proportional representation in the next generation, which, after all, is the measure of the traits and the responses effect and affect evolutionary change, is near impossible in a field population of tasty critters such as quail.
My advisor, by the by, has had a lot more success with her captive zebra finches, so I have an idea what can be done….but not by me.
At any rate, it is also not a good time to measure plumage traits, when the birds are moulting, since their plumage is a mix of old ratty feathers, fresh new feathers, and pinfeathers.
I also have found that my interests lie much more in social and family behavior, than in mate choice per se, which is why I think the blood samples will be useful as well as the bands.