Howard Campbell

A Population Study of Lesser Prairie Chickens in New Mexico

A total of 285 lesser prairie chickens (Tympanuchus pallidicinctus) were mist-netted in the spring on 16 booming grounds (display grounds) in eastern New Mexico during 1962-70. Life tables, based on capture-recapture data from 3 consistently trapped grounds, were constructed for males only, as comparatively few females were trapped and none was recaptured. The male population underwent virtually a complete turnover in about 5 years. The mean annual overall mortality rate of males was calculated at about 65 percent. Inefficiencies inherent in the trapping method (probable failure to recapture all banded birds present on booming grounds each year) presumably magnified the calculated mortality rate, possibly by about 5 to 10 percent. Age and sex ratios indicate that adult females had a higher mortality rate than adult males. The removal by hunting of about 1,100 birds per year, on the average, over a 12-year period had no observed harmful effect on the population. Recaptures of banded birds suggest that adult males are faithful throughout life to the same booming grounds where they initially established territories, but hunter recoveries show that at least some males shift for feeding purposes in fall and winter to harvested grain fields that may be several miles from their accustomed booming grounds. This paper reports the results of a field study of the lesser prairie chicken on its native range in eastern New Mexico. The work was done in the heart of that range in southern Roosevelt and northern Lea counties. Life tables, based on capturerecapture data, were constructed for the male segment of the population. Biological and behavioral data derived from the hunting harvests are also presented. Several general accounts have been published concerning the lesser prairie chicken in New Mexico (Bailey 1928:207-209, Ligon 1961:89-92, Sands 1968), but published reports of specific research studies on the local populations have been few. The first of these reports appears to be that by Lee (1950); it contains data on age and sex ratios, weights, criteria for determining age and sex, habits, and habitats. Campbell (1950) described a typical instance of the 1A contribution from Federal Aid Project W104-R, New Mexico. often-seen persistent harassment of prairie chickens by wintering marsh hawks (Circus cyaneus). Snyder (1967:121-128), in addition to a general account of the species in the state, summarized some of the technical data from a series of unpublished New Mexico P-R reports by W. S. Huey, G. W. Merrill, L. G. Frary, W. A. Snyder, J. F. Johnson, M. G. Wischnofske, and J. L. Sands. The present paper is based chiefly on these reports, and on several of my later unpublished P-R reports. Portions of Colorado, Kansas, Oklahoma, and Texas also have populations of lesser prairie chickens, and investigators in at least the latter two states have published important work on the species. Copelin (1963) published a comprehensive account of lesser prairie chickens in Oklahoma, and Jones (1963) compared in great detail the habitats of the lesser and greater prairie chickens in Oklahoma. Jones (1964) also studied seasonal behavior of various plant species in

Some Observations on the Bursa of Fabricius in Chukars

This paper reports a method to distinguish birds-of-the-year, hereinafter referred to as juveniles, from adults in chukars (Alectoris graeca) during the fall by measuring the depth of the bursa. When young chukars have completed their post-juvenal molt, normally before the end of October, they are difficult to distinguish accurately from adults by external characteristics. The shape and coloration of the juvenal primaries IX and X, which are retained during the first winter of life, have been used as a basis for making this age distinction; but results are uncertain except perhaps with very experienced workers (Smith, 1961). Retention of a few juvenal secondaries (conspicuously mottled) has also been used in the attempt to distinguish young chukars from adults in the fall but the method is unreliable (Smith, 1961). Only 7 (13.7 per cent) of the 51 juveniles included in the present study still retained any mottled secondaries on October 19, and these 7 birds were all from a late hatch. The depth of the bursa of Fabricius is the only known characteristic by which age determination in chukars can be made with certainty during late fall and early winter. The bursa is a blind sac opening antero-dorsally into the cloaca of birds. Bursae tend to be prominent in young birds and to regress with the onset of sexual maturity. The structure has been known to anatomists for centuries, but Gower (1939) was the first to point out its value in wildlife management. Since then it has been studied in numerous species of game birds (Taber, 1960). Measurement of the bursa is of limited value in aging hunter-killed chukars since the bursa is usually removed when birds are field-dressed. Evidence that this method of aging is applicable to Turkish chukars (probably subspecies cypriotes) is shown in Table 1. This table is based on 150 known-age, known-sex birds hatched and reared at the State Game Bird Farm, Carlsbad, New Mexico. The birds were descendants of chukars wild-trapped in Asiatic Turkey in 1951-52. During the period October 19-22, 1960, the experimental birds were sacrificed and a variety of biological data was secured from them. Bursae were measured with a small metal knitting needle marked off into 5-mm intervals. Bursal depths were estimated to the nearest millimeter. Because

Experimental Feeding of Wild Quail in New Mexico

The response of wild populations of scaled and Gambels quail to artificial feeding of grain was studied, mainly during the three-year period 195456. Yearlong feeding was done at water developments in quail habitat of various kinds over a large area. Resultant quail increases, if any, were much too small to justify the high cost of feeding.