GENERAL NOTES Longevitiesof SomePanamanian Forest Birds, with Note of Low Survivorshipin Old SpottedAntbirds (Hylophylax naevioides).--InJanuary and February 1977 and 1981, I recorded on Barro Colorado Island, Panama,several ant-following birds color-banded duringannual studies from 1960 to 1970 (Willis 1967, Univ. Calif. Publ.Zool. 79:1-1322; 19722,Ornithol. Monogr. 10:1-1622;1972, Wilson Bull. 84:377-4220;1973, Smithson. Contrib. Zool. 144:1-57; Willis and Oniki, 19722, Condor 74:87-101). The oldest such individualsare listedin Table 1. Birdsbanded as adults had probablyfledged the calendar yearprior to bandingor evenearlier, as young of theyear were almost never on territories by the normalbanding months. All wereof the territorialsex (male in all butD. fuliginosa), and ones banded as adults were on or near the territory where banded when last seen. The oldestfemale SpottedAntbirds were 11 y 7 mo and over 122y 7 mo old when last seen;the latter wason the territory wherebanded while the other, bandedas a fledgling, wasrelocated well off my normal studyarea 1 1 yearslater. Ten bandedSpotted Antbirds were locatedin 1981 (the female abovehad not been seenin 1977), while 228other bandedindividuals had been locatedin 1977. All 1977 birds were at least6 yearsold, the actualtime elapsedsince banding being over 13 yearsfor 1 individual,12 y for 2, 11 y for 3, 10 y for 3, 9 y for 5, 8 y for 8, 7 y for 6, and 6 y for 10; 1981 birds were at least 10 y old, the time sincebanding being over 14 y for 1 bird, 13 y for 1, 12 y for 2, 11 y for 3, and 10 y for 3. Specialsearches were made in 1981 for all birds locatedin 1977; and territorial fidelity is strongenough in this speciesthat the missingindividuals were probablydead. At the 81• survivalrate found for birds 1 or more yearsold in 1960-1970 (Willis 1974, Ecol.Monogr. 44:153-169), 16 of the 1977 birds shouldhave been relocated4 y later. This is a significantlyhigher number (X2 = T^Bt_F.1. Longevityrecords on Barro ColoradoIsland, Panama. Species Sexa Banded,age s Last seen Age Ocellated Antbird Phaenomctus mcleannani M 22Aug 1965, ad 16Jan 1977 11 y5mo Bicolored Antbird Gymnopith3's bicolor M 18 Sep 1965, yg 13 Feb 1977 11 y 6 mo Spotted Antbird Hylophylax naevioides M 3Jun 1966, ad 18Jan 1981 14y7mo M 8Jul 1967, ad 13Jan 1981 13 y6mo M 29 Aug 1963,- 11 Feb 1977 13 y 5 mo Chestnut-backed Antbird Myrmecizaexsul M 8Jun 1966, ad 11 Feb 1977 10y8mo M 19Jun 1966, ad 26Jan 1977 10 y 7 mo Plain-brown Woodcreeper Dendrocincla fuliginosa F 24 Aug 1969, ad 12Jan 1981 11 y5mo • M--male; F--female; ad--adult; yg--young. 413 414] GeneralNotes j. FieldOrnithol. Autumn 1983 3.88, df = 1) thanwas actually found, for a survivalrate of only 72% per year is indicated by the 1977-1981 data.Either survivorshipof the speciesdecreased on the island,or very old birds have depressedsurvival rates. Lossof 8 of the 9 oldestbirds (banded1963-1966) is noteworthy,as only 5 should havebeen lost between 1977 and 1981 under a survivalrate of 81% per year. However, 20 of 29 birds banded 1967-1970 (survivorship,75% per year) were also lost between 1977 and 1981. The difference in 1977-1981 survival between birds banded 1963-1966 and onesbanded 1967-1970 is not significant(X 2= 1.7, df = 1). Reanalysisof 1960-1970 data on birds of known age (from Willis 1974) showedno significantannual differencesin survivorshipfor malesknown to be 1-2, 3-4, 5-6, or 7-8 yearsold (213 of 244 individuals,or 87%, survivedto the followingyear), but females 1-2 years old (98 of 126 individualssurvived, or 78%) were significantlyless likely to survive(X 2 = 4.25, df = 1) than were females3-6 yearsold (55 of 61 were alive the next year, or 90%; 3 of 4 females7-8 yearsold survived,too smalla samplefor tests).Females sit on nestsat night, and may be unusuallysubject to predation when inexperiencedat nesting;or there maybe other causesof high mortalityin femalesbreeding for their first or second seasons. I alsoanalysed 1960-1970 data on birdsbanded as adults. Known-age males survived aboutlike malesbanded as adults if the latter were banded6 or fewer yearsbefore (238 of 286 survived,or 83%),but malesof unknownage that hadcarried bands 7-10 y survived significantlyless well (22 of 32 survivedto a followingyear, or 69%; X2 = 4.13, df = 1). The low survivalof this group of very old malescorresponds to the low survivalof old malesa decadelater, and suggeststhat low survivorshipof old birdswas one causeof the high lossesbetween 1977 and 1981. However, femalesbanded as adults of unknownage in 1960-1970 showedlittle changein survivorshipwith increasingtime sincebanding, except that only 6 of 8 femalesthat had been adults 9-10 yearsearlier survivedto the next year; the survivorshipof femalesbanded 1-6 y previously(193 of 245 surviving,or 79%)is not significantlydifferent from that of femalesbanded 7-10 y earlier(20 of 25 survived,or 80%). If adult birds are bandedat unknownages, and old birds surviveless well than do younger ones,old birds will die too early in a studyand will lower average survivorshipat that time to levelswhere small samplesmight fail to detect differences. Possiblehigh mortality of females1-2 y old wouldbe maskedby includingbetter-surviving females3-6 y old with them, also. In two cases,very old malessang little and wanderedwithout mates when lastseen, while their former mateswere with younger birds. Such unmated malesare not known to helprelatives, and extended postreproductive life isprobably not normalfor the species. Barro Coloradohas lost many species of predators(Willis 1974), someof whichmust have removedadult antbirds.Return of 1-2 individualsof one suchpredator to the islandfrom 1970 on (the forest-falconMicrastur semitorquatus; see Willis and Eisenmann1979, Smith- son. Contrib. Zool. 291:1-31) may partly explain high lossrates of SpottedAntbirds in 1977-1981, althoughdepressed survivorship of old birds is even more likely. I appreciatethe supportof the SmithsonianTropical ResearchInstitute for studies in 1977 and 1981, and of the Universityof Miami for a grant for air travel. Nick Brokaw providedobservations of bandedantbirds, and YoshikaOniki helpedat severalstages.-- EDWIN O. WILLIS, Departamentode Zoologia,Universidade Estadual Paulista, Caixa Postal 178, 13500 Rio Claro, SP, Brazil. Received 19 Aug. 1982; accepted9 Aug. 1983. Chickadee, Thrasher, and other Cowbird Hosts from Northwest Iowa.--I recorded 2 unexpectedhosts of the Brown-headedCowbird (Molothrus ater)--Black-capped Chick- adee (Parusatricapillus) and Brown Thrasher (Toxostomarufum)--while at Iowa Lakeside Laboratory,Dickinson Co., Iowa. I give detailsof theseobservations below as well asmy observationsof other cowbird hostsduring 1982 and 1983 at Iowa LakesideLaboratory and nearbyCayler Prairie and the Freda Haftnet KettleholePreserve. Black-cappedChickadee.--From 21 June to 29 June 1982, I monitoreda pair of Black- cappedChickadees which apparentlyhad reared 3 cowbirdsand 1 of their own young. I first heard the callsof a youngcowbird the morningof 21 June. I searchedfor and found .