Great Basin Naturalist

Volume 53 Number 2 Article 10

6-4-1993

Autumn and winter foods of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) (Galliformes: Tetraonidae)

Terry Z. Riley Iowa Department of Natural Resources, Chariton Research Station, Chariton, Iowa

Charles A. Davis New Mexico State University, Las Cruces, New Mexico

Randall A. Smith Forest Service, USDA, Coronado National Forest, Tucson, Arizona

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Recommended Citation Riley, Terry Z.; Davis, Charles A.; and Smith, Randall A. (1993) "Autumn and winter foods of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) (Galliformes: Tetraonidae)," Great Basin Naturalist: Vol. 53 : No. 2 , Article 10. Available at: https://scholarsarchive.byu.edu/gbn/vol53/iss2/10

This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. (;reat Basin N ,\tllrali.~t ,'53(2), pp, 1H6-J89

AUTUMN AND WINTER FOODS OF THE LESSER PRAIRIE-CHICKEN (TYMPANUCHUS PALLlDICINCTUS) (GALLIFORMES: TETHAONIDAE)

2 Terry Z. Rilc/, Charles A. Davis , and Handall A. Smith:)

ABSTBA<:r.-Dt'scriptiollS of Lesser Prairie-Chicken (TymparIuchus }Hlllidicinclus) foods in New Mexico havc not included comparison hetween alltullm and winter seasons, \\ie analyzed and compared prairie-chicken crop contents in autumn] 97h (n = 9) and 1977 (n = J7) and winter J977 (n = 4) and 1978 (n = 2) in a shinJ1(~ry oak (QuC1Tn~ havanlii) grassland in sOllthe,t~tern Kew Mexico. Autumn foods were a mixtnre of seeds (x = 4,1%), vegetative material (x = 39%), and insects (x = 1k%), especially shillllery oak acorns and insect ~alls IX = 49%). Short-horned grasshoppers (Acrididae, x= ],')%) aL~o W(~]'(~ an important food, Winter foods were shinncry oak acorns (i: = h9%) antI \vikJ buckwheat (Eriogonwn amJlIIIIH,."t = 14%). Use of v(~getative material and insccts decreased from autumn to winter, WhtOre'ls use of ac'Orns increased. High Plains Hluestem SnbtYlxo in the Sonthem Mixed Prairie is an important habitat that provides many of the foods l~atcn hy prairie-chickens. Tlwrefore, hroad-scale distnrbances of t}lis comlIIunity shou1 d btO avoided.

Key Ivrm!s: .{Ilod, feeding, I.esser Prairie-Chicken, New Mexico, shinlw!'y oak, 'lympamlChlls pallidicindus.

L::~sser Prairie-Chickens (Tympanuchus pal­ t\veen autumn and winter. The pu:rpose of this lidicindus) occupy sernimid grasslands that study was to prOVide a description of autumn typically include a large component of shrubs, and v.inter foods of Lesser Prairie-Chickens. either shinnel)' oak (Quen'us havardiI) or sand The objectives were to collect crops ofprairie­ sagebrush (Artemisia filifolia) , A description of chickens dming autumn and winter, to analyze foods used by prairie-chickens in the shinnery crop contents to determine the type and amount oak grasslands is incornpletc. Davis et al. (1981) off()()ds consumed, and to compare and contrast compamd spling and summer diets in shinnery diets between seasons and ,vears. oak grasslands of castem New Mexico. They found that praiJie-chickens feed on green, leafy STUDY AHEA vegetation in spring but ch'lIlge to insects in summer. Fnu)' (19,57) found that insects are The study arca is approximately 15,500 haof impOltant in emlyautumn (Sep-Oct) in eastern Bureau of Land Management lands in Chaves New Mexico. Crmvford :md Bolen (1976) evalu­ County in southeastell1 New Mexico. Topogra­ atedautumn diets of90 Lesser Prairie-Chickens phy is gently undulating. Climate is semiarid collected in mid-October from shinnery oak with distinct seasons and wide ranges ofdiumal habitats ofwest Texas. ])espite the bct that their and annual temperatures. Nearly 75% of the study area included cultivated grains, shinnery annual precipitation (30-year x ~ 345 mm/yr) oak and insects were the prinCipal natural foods. falls dUring the growing scason, May through A seasonal description and comparison of October, mainly from brief but often intense f()och used bv, Lesser Prairie-Chickens in shin- thunderstorms (U.S. Department of Com­ nery oak grasslands through the entire annual merce 1976, 1977), cycle could be used to assist land managers in The study area is in the Southern Mixed manipulating hahitats to provide food resources PraiIie Type, where the High Plains Bluestem throughout the year. However, published de­ Subtype grades westward into the Desert Prai­ sCliptions of Lesser PraiIie-Chicken foods in rie Subtype (Holechek et al. 1989:79), Most of shinnery oak grasslands do not differentiate bc- the study area (89%) is on deep, sandy soils

.: ;,,,n ;),'I ~"I,,,,.nt 0[' NaIll ",I I" ''''Ll ''''''. ( :hnJ'i ton 11, '-,<"m,h S lill; [In, 1l'1m; Ho'tl[- #.1. Box ZO\), Ch"riton. IOWl> .'}(J(/1fJ. -I )"1'''1'111 l('"t ,l Vi ,I"'ri'" nl ,eI \Vil dl ii" Sci ('I flee'"~ N,w ~'l(',i co Slale Uni""I'.'it\', r"., (_'nlC~'_ New M",,; m &'HX).1, :1 110 1'(',1- S<.'lV; ('(', US IlA, (~lf()n"d() Nati ,,,oa[ I'or",t, .'J(lO \V, Co, 'gf",", T I K'''''';_Arizoll" SS70 1

186 1993] PHAJHIE-CmCKE:-.i FooDs IN AUTUMN AKD WI"JTEH 187 where vegetation is dominated by various com­ trapping were similar to those mllected by other binations ofbluestem grasses (Andrapogoll haI­ methods ,vithin the same seanimal materialx = 7%, vegetative are conspkUOIL"i invaders ofthis subtypein sum~ material x= 28%). part; ofthe study area. \Vinter samples were comhined hctween year.; because of the small sample size (1977 METHODS 11 = 4, 197811. = 2). Foods mnsumed by Lesser })mirie-Chickens in winter primarily consisted Crop oontents were fmm birds collected of shinne!)' oak aeams (x ~ 69%), with lesser dUlingautllmn (Oct-Dec 1976,11 ~ 9, and 1977, amounts of hrreen vegetation (x = 26%) and 11 = 17) and winter (Jan-Feb 1977 and 1978,11 insects (x = 5%, Table 1). No differences (P > = 6), mostly by shotgu11 or small-caliber rine. .05) were detected in crop contents bet'vveen Two were taken from hird." that died as a result autumn 1976 and winter 1977-78. Shinne!)'oak of trapping in autumn 1977, and hvo were do­ acorn composition of winter crops (x = 69%) nated hy hunters in antumn 1978. Data from was greater(P < .n!)) than in autumn 1977crops. empty crops were not used in the analysis. \Ve Use ofvegetative material and insects (resulting storeu the frozen crops in IOO-ml plastic storage prirnaIily from lack of short-horned grasshop­ bottles until analysi.s. Contents from each crop pers in winter) was lower (P < .0,5) in winter were analyzed separately. Foodswere measured crops than in crops collected in autumn 1977. by volumetlic clisplacement to the nearest O.l ml, and items measuring <0.1 ml were classified as "trace," Composition ofdiet was determined Dl SClJSSJON by the aggregate percent method (Martin "t al. 1946). We used Borror and White (1970) and Differences in illltllmn diets ofpmitie-chick­ Correll and Johnston (1970) to identify food ens between year~ might be explained hy the items. fact that annual precipitation was nearly 100 Means and standard eJTors were C'dlculated mm (27%) below normal in 1977 (X ~ 250 mm; when an individual food item was detected in U.S. Department of Commerce 1976, 1977). two or more crops. Small sample sizes reduced Lower-than-normal precipitation in 1977 might the power of statistiC'dI tests, but we used Stu­ have arfeeted the a\Oulability offood resources. dent's t test to test the hypothesis that there were Shinne!)' oak provided amlTIS, insect galls, no differences in the composition offood items and leaves, which together constituted 50% of between seasons emd yeerrs (Snedecor and the autumn diet in our study and 36% ofnatuml Cochran 1989). Differences were mnsidered foods in Cmwford and Bolen's (1976) study. significant at P < .05. De~1)ite the fact that Crawford and Bo]en:~ (1976) studyarea included gmin fielth, shinne!)' RESULTS oak was the principal natural food in autumn. In both studies short-homed grasshoppers were Auhunn diets primatily consisted of shin­ the prinCipal animal food in autumn. )7 ra!)' ne!)' oak amms, sbort-homed grasshopperx (1957) reported crop mntents fmlll 17 Lesser (AcIididae), broom groundsel (Senecio spar­ Prairie-Chickenscollected in eastern New Mex­ tioid.es) leaves, ilnd insect galls from shinnery ieo about 45 km nOitheast ofollr study area. His oak (Table 1). Thirty different food items were sample vvas pooled across 6 months, and so identified, nearly halfofwhich were bJTCen vege­ seasonal comparisons with our data arc not pos­ talion. Crop contents from birds wlleeted by sible. He did find, however, that in.'iccts were hunters and from birds that died '" a result of important in early autumn (Sep-Oct). 188 GaEAT BASIN NATURALIST [Volume 53

TABLE 1. Mean composition (%) of autumn (Oct-Dec) and winter (Jan-Feb) crop contents of Lesser Prairie-Chickens, Chaves County, New Mexico, 1976-78. ------Autumn

1976 1977 Winter Food item (n ~ 9) (n ~ 17) (n = 6)

Mast and seeds Quercus ha1xlnlii Acorns 61 (12-7)" 17 (6_9) 69 (6.4) EUlJ!torhia spp. 4 (2-2) Utlwspermum irwhwn 4 b lJUhymef/ wislizeni t Total 6.5 (13.0) 21 (68) 69 (6.4) Vegetative material Quercus luwanlii Insel't galls 5 (1.7) Leaves 2 Senecio spartioirh,s' 12 (6.1) 5 (HI Dalen tlflt/.({ 7 (2.4) Hriof!,on1l1n annum 7 (2.7) 14 (4.2) Phlm.: "'pp. 4 (19) 4 (2.0) b Lit!tospennum indsum 4 t Composite 4 Oenothcrrt "'pp. 4 t" EU}Jluwhul spp. 3 I tb JiYllwlUn~/s spp. 2 tIl Xantlwcephalwn sarothrac I t" Penstmlum buckelyi t" 2 h Others ," t Tota] 28 03.8) 49 (9.3) 26 (6..1) Animal material Acrididae 2 oA) 2H (R.2) Glyllidae 3 (0 ..1) Lepidoptera 2 Carabidae .5 (3.6) Others t], t" Total 7 (.1.6) .5 (3.7)

":;1<: "Ih~",«l%)

Similarities between autumn 1976 and win­ MANAGEMENT IMPLICATIONS ter 1977-78 diets probably were a result of the fact that most (416) crops collected in winter Lesser Prairie-Chickens are closely associ­ were from 1977 ,Old the availability of acorns ated with the shinnery oak-grassland commu­ was similar between seasons. Differences be­ nity in much oftheiroL'Cupied range. Within this tween autumu 1977 and winter 1977-78 diets community, in New Mexico, Lesser Prairie­ probably resulted trom the factthat winterdiets Chickens obtain most oftheir autumn and win­ were more a reflection of winter 1977 than ter diets from a rather small number of plants and associated insects that are common in the 1978, and below-nonnal precipitation in 1977 less grassy habitat. Shinnery oak is the most might have reduced acorn production in the heavily utilized food of prairie-chickens on an area and increased the demand on other food annual basis. Shinnery oak acorns, catkins, sources during autumn. Frary (1957) fouud that leaves, and galls in various combi.nations provide vegetative material is important in winter diets adult birds with >50% of their diet in autumn and that acorns are important in winter. Jones and winter. Because of the importanc'C of shin­ (1963), working with prairie chickens in Okla­ nery oak grassland to prailie-chickens for both homa, showedthe importance ofmast andseed" food and cover, broad-scale eradication of this in the winter diet. community should be avoided. 1993] PRAlRIE-CfIlCKEN FOODS IN AlJrUMN AND WINTER 189

ACKNOWLEDGM,:NTS in New Mexico, Pages 7~O in P A. Vohs and F, L. Knopf, eds., Pl"Oceeding.~ of the prairie grouse ~)'mpo­ sium. Oklahoma State University. Stillwater. This research w,,, funded in part by the u.s. FIIAKY. L. C. 1957. EVd.Iu;lt;on of prairie-chicken nmges. Bureau ofLand Management (BLM). The ew P-R c;ompletion report. project l1umber W· 77·R-3, Mexico Department of Game and Fish pro­ New Mexico J>epartmcnt orCamc and Fi.~h, Santa Fe. vicled collection permits. We are indebted to 81 pp. HOLECllF,K. J. L., It D. Pll'ElI, AND GII, HEIUlEr., .1989. W. J. Wisdom, H. R. Suminski, and other for­ Range mal1agemt~nt principles and practices. Prflnliee mer wildlife students at New Mexico State Uni­ H,\ll, ElLgbvood Cliffs, New Jersey. 501 pp. versity for field and lah assistance. This is a New JONF;~. R. E. 1963. t