july] 281 LIFE HISTORY OF THE GROOVE-BILLED ANI This paperis a reporton observationsmade on theGroove-billed Ani (Crotophagasulcirostris) in Central America over many years, but chieflyfrom 1930 to 1940,when I livedin regionswhere these birds arc more abundantthan about my presentabode in the Valley of E1 General in CostaRica. In subsequentyears a little additional informationwas gathered. The specieshas a wide rangefrom the lowerRio GrandeValley in Texasthrough Middle America and much of northern South America. Since, as far as I know, no one has ever publisheda comprehensive study of thiscommon and most interesting bird and availableaccounts of its breedinghabits are only compila- tionsfrom scattered sources, it will perhapsbe of valueto studentsof bird behaviorto haveall of my observationsin a singlepaper. CHARACTERISTICS AND DAILY L•FE Appearance.--Althoughthe anishave much to recommendthem to the attention of the naturalist, it is not by their beauty that they attract him. With the exceptionof the vultures,they are the least comelybirds that I know. Yet theyare not absolutelyugly, for being birds, they wear feathersand, as Grey of Fallodononce wrote about anothernot very comelybird, having feathersthey cannotavoid a certaindegree of beauty.The anis are lean and lank and looselyput together,and their long tails, which are almostinvariably frayed and worn, seemso inadequatelyattached to their bodiesthat they are in dangerof being brushedoff as the birds push throughthe tall grasses and weedswhere they forage.In facial expressionthey are especially unfortunate. The Groove-billed Ani's black bill is narrow and very high, with the upper mandiblestrongly arched and furrowedlength- wise by parallel curvedridges and channels.Its black face is largely bare of feathersand prominentlashes shade its dark, beadyeyes. Its plumageis everywhereblack, but the featherson its neck presenta scaledappearance, while greenishand purplish glints play over its body and wings in the sunshineand redeemthe black monotonyof the bird. Foice.--Invoice the anis are hardlymore pleasingthan in appear- ance. Membersof the cuckoofamily, they are not songbirdsand they lack even the stirring callso[ someof their relatives. The call- note of the Groove-billedAni is well paraphrasedby one of the commonnames given to it in Guatemala,Pij•y (pronouncedpe-h•y) or Pichuy. This disyllableis utteredas the anisperch or fly, usually [- Auk 282 SKUTCH,Life Histor),of Groove-billedAni LVol.70 thrice togetherin a soft, high-pitchedvoice, neither unpleasantnor particularlydelightful, and it is usuallypreceded by a few preliminary throatyclucks which one can hear only when closeto the bird, thus: tuc tuc tuc pihuy pihuy pihuy. A CostaRican namefor the ani, Tijo tijo (tdehotdeho) represents another attempt to reproduceits peculiar call in human language. These notes are certainly more attractive than the high-pitchedwhine of the Smooth-billedAni (C. ani) of the West Indies and SouthAmerica. Where the rangesof thesetwo black birds overlap, as in western Ecuador, Colombia, Venezuela and Panam•, they can be distinguishedby their voicesmore readily than by their appearance. Other utterances which I have heard from the Groove-billed Ani include a full, long-continued,mournful call, soft but deep, an ex- pressionof anxiety or distress,which one individual deliveredwhile I examinedits nestand anotherafter it had beenrepeatedly repulsed by someSmooth-billed Anis which it tried to join; a harsh,rasping grrr voicedas the birds attack intrudersat their nests;and a cackling soundwhich parentsused when trying to coax a fallen nestlingto return to its nest. Sociability.--Butif the anis lack beautiful plumageand a melodious voice,they have been amply compensated in otherways. They have beenendowed by naturewith an extraordinarilyaffectionate disposi- tion, a degreeof adaptabilitywhich enablesthem to thrive in a far greaterrange of environmentsthan most other birds, and nesting habits which make them, in the eyesof the bird-watcher,second in interestto none. Few birds crave the companyof their kind more constantlythan the anis. I havenever seen them engage in a quarrel or fight. When one is separatedfrom its flockit callsand callsuntil it findsits companions.Even in hot weather,when there is no need to huddletogether for warmth,two, three, or moreperch side by side asclosely as they can press. If oneof the insidebirds of sucha group fliesoff, the othersat onceclose the gapuntil theytouch each other again. While onestretches up its neckits neighborcarefully bills and nibblesat the feathers,possibly searching for insectpests; and when thefirst has finished its kind office to thesecond, the latter reciprocates the favor. When not nesting,the anisassociate in smallparties which usually includefrom ten to twentyindividuals. Thesetravel over their home rangein a leisurelymanner, foraging as they go, or pausingto reston low perchessingly or in little groups. They do not, as somebirds, form a close flock which moves as a unit and seemsto be motivated by a singlewill, but theystraggle along singly or a fewtogether, often July]•9•9 SKuxcI•,LifeHistory o]Groove-billed dni 283 strungover a distanceof a few hundredfeet, and keep in contactby their voices. Sometimesone ani startsoff on an expeditiononly to find that its companionsdo not care to follow, in which case,after calling to them in vain, it turns again in the direction of the main party. Flight.--The anis'mode of flight is as characteristicas any other of their peculiarhabits. A long journey, say anythingmuch in excess of a hundredyards, is seldommade by a continuousflight, but the bird advanceswith frequentpauses in convenientlysituated trees and bushes. As it alightson one of the lower branches,the momentum of its long tail carriesit forward abovethe bird's head with a jerk. Recoveringits balance,the ani delayshere for somemoments, looking around with caution and calling in a high-pitchedvoice. Then, satisfiedthat the path aheadis clear,with a tuc tuc tuc pihuy pihuy pihuy, it launchesitself upon the next stageof its journey. A few rapid beatsof its shortwings serve to impart the requisitemomentum; then it setsthem for a long glide,by which it may covera surprisingly long distance,on a slightlydescending course, without further muscu- lar exertion. If its ultimate destination is a certain branch in a tree or bush,it will often arrestits flight on anotherlimb considerably lower. Then, by a few queer,rapid, sidewayshops along the bough and somebounds or, better,bounces from limb to limb, it gainsthe desiredposition, where, most likely, it spreadsits wings to the morning sunshine. Sun-bathing.--Inthe cold, wet weatherof the rainy season,the anis are a pictureof miseryas they huddletogether on a perch,their heads drawn in among their damp, bedraggledfeathers. Although they dislikewetness, they must often seek their foodamid water-laden grass and foliage. Then to dry themselvesthey perchatop a fencepost, a stakeor a bare limb and patientlyhold their wingsspread to the rays of the sun, lookingvery much (if they will forgivethe comparison) like miniaturevultures. This habit of restingin the sunlightwith outstretchedwings seems best developed in birdswith blackor blackish plumage. In Central America the species! have most often seen sunningtheir wingsin thismanner are the Turkey Vulture (Cathartes aura), the Black Vulture (Coragypsatratus), the Anhinga (Anhin.ffa anhinga)and the anis. Becausenot only in plumagebut alsoin this mannerism the ani resembles a vulture, in Costa Rica it is sometimes calledzopilotillo, the diminutiveof zopilote(vulture). Habitat.--The varietyof habitatsacceptable to the anisis greatand their chief restrictionseems to be that they do not toleratethe forest. Birds of open country,they seemnearly indifferentto its type. In F Auk 284 SKUTC•,Life Historyof Groove-billed.4ni LVol.76 the cultivatedparts of the humid coastalregions oœ Central America they are one of the mostconspicuous species, although certainly not more numerousthan the tiny seedeaters(Sporophila spp.), which are legion but much lessnoticeable because of their smallness.Their favoritehabitats are bushypastures, orchards, light open woods,lawns with shrubbery,and the clearedareas about the huts of squatters. Marshlandis almostas acceptableto them as a well-drainedhillside; and I found them numerous in such extensivestands of sawgrassas that surroundingthe Toloa Lagoon in Honduras, although it is probablethat in theseareas they do not venture far from someout- standinghummock or ridge which supportsa few low treesor bushes in which they can roostand nest. In the semi-desertregions of the interior, where their associatesof the coastallands, if present at all, are as a rule rare and confined to moist thickets along the rivers, the anis are abundant, living among thorny cacti and acaciasas success- fully as amid the rankestvegetation of the districtswatered by twelve feet of rainfall in the year. In altitude they range upward to about 5000 feet above sea level in Guatemala and 7500 feet in Costa Rica, but they are not nearly so abundantin the highlandsas in the low- lands. Food and foraging.--Thefood of the anisconsists largely of insects, which they obtain both from the ground and amid the foliage of bushes,and to a much smallerextent of berriesand other fruits. They vary their diet with an occasionalsmall lizard. Often they hunt grasshoppersand other creaturesamid long grassor tall weeds,where they are completelyhidden from view exceptwhen from time to time they