Where Do Northern ("Baltimore") Orioles Spend the Winter?

Where do Northern {"Baltimore")Orioles spend the winter?

Spencer G. Sealy Department of Zoology University of Manitoba Winnipeg, Manitoba RST 2N2

heforested dune ridge that separates Lake Manitoba Results and Discussion from Delta Marsh, Manitoba, has been the focus since 1974of an ongoinginvestigation into the ecologyof a com- An s¾male 1861-035291, bandedand color marked on munity of denselynesting species of insectivorousbirds the dune-ridge study area on 20 June 1977, was found and one dove species(study area and bird community deadby N. Hansonon 10 July 1977,near Goodridge,Min- describedby Sealy 1980a, b; MacKenzie 1982; MacKen- nesota,about 245 km southeastof the study area. The im- zie et al. 1982). Since this work began, 2,191 Northern plication of this recovery is that SY males leave the Orioles of the "Baltimore" subspecies(Icterus galbula breedinggrounds not long after their prebasicmolt has galbula]have been banded,and in most casesuniquely begun (see Sealy 1979), presumably destined for their color marked. Two of these orioles were encountered off wintering areas.The lack of mist-net captures,repeats, the foresteddune ridge. One recoveryoffers a clue to and sightingsof SY maleson the studyarea after mid-July where individualsof this populationspend the winter. The (Table2) alsosuggests strongly that thesemales leave the otherrecovery, supported by observationsof color-marked study area, whereas it is known that the ASY males and individualsand mist-netcaptures during the late nestling AHY females complete their prebasic molts before andpost-breeding periods on the studyarea, suggests that migrating south in late August (Sealy 1979). It is not SY malesleave the studyarea in mid-summer,presumably known whether the prebasicmolt of SY males is inter- destined for their wintering grounds,up to one month ruptedwhile they migratesouth, and completedafter they before the ASY males and AHY females migrate arrive on the wintering grounds. Why do SY male southward. "Baltimore"Orioles leave the breedinggrounds about one monthor more beforethe adults?As such,the early depar- The recoveriesmentioned above are detailed in the pre- ture of these males from the dune-ridgeforest, and pro- sent paper. In addition, the recordsof the encountersof bably also other areas,occurs before the collapseof the banded "Baltimore" Orioles (Table 1), furnished by the food supply (see Sealy and Biermann 1983). Thus, it is Migratory BirdsBranch, Canadian Wildlife Service,which unlikely that suchearly fall migrationsouthward is direct- date back to 1924, provide additional information on ly relatedto foodavailability on the breedingground (see where "Baltimore" Orioles spend the winter. I have alsoRappole et al. 1979).Sealy (1979) argued that because broken down these encountersas follows: (1) orioles at leastsome SY malesnest successfullyon the studyarea, bandedduring springmigration or the breedingseason with their numbersvarying from year to year (Sealy,un- and recoveredwithin the subspecies'known wintering pub. data), it is possiblethat thosethat move southward range (see Fig. 1) during the following or a subsequent early and while molting did not breed or were failed winter, (2) birds banded in the wintering range and breeders. The continued absence of SY males after mid- recoveredduring the followingor a subsequentbreeding July (Table2) suggeststhat indeedall of thesemales leave season,and (3) birds bandedon the wintering grounds early. Such early departure from the breeding ground which repeated at the same site or returned there in a should mean that these males arrive first on the winter- subsequentwinter. Recoveriesof oriolesfrom the eastern ing ground, but confirmation of this is needed. Sealy United Stateswhere their relatively recent presencein (1979) believedthat the lessexperienced males may be winter apparentlyhas been influenced by the provision- better able to compete for food and spaceon the winter- ing of food at feedingstations (see Erickson 1969) have ing groundsif they arrived beforethe ASY males,as Mor- been ignoredin this analysis. ton (1976)argued for the early-migratingYellow Warbler (Dendroicapetechia]. Age-related differences in the abili- ty to hold territorieson the wintering groundshave been found in Yellow Warblers (Morton 1976) and Dark-eyed Juncos(Junco byemalls] (Ketterson and Nolan 1979) and are probablycommon in many passerinespecies (see also Ewald and Rohwer 1980).

Page 12 North American Bird Bander Vol. 10, No. 1 Figure 1. Breedingand wintering distributionsof the "Baltimore" Oriole. Distributional data upon which this map is basedare from: A.O.U. Check-list{1983}, Bond {1960},Dickey and van Rossera{1938}, Paynter {1955},Godfrey {1966},Johnsgard {1979}, Land {1970},Meyer de Schauensee{1970}, Monroe {1968},Edwards {1972}, Ridgely {1976}, Rising {1970, 1983}, Salt and Salt {1976},and Slud {1964}. This subspeciesis a rare transient through the western portion of the West Indies {Bond1960} and apparentlyan occasionalwinter resident{Lack 1976}. Inset: Major portion of the wintering range of the "Baltimore" Oriole showingwhere and how many recoveries{numbers in circles}have been obtainedof individualsof this subspeciesbanded on their breedinggrounds {see also Table 3}. One of the two Mexican recoverieswas obtained in the south central part of the country, where this subspeciesis known to occurin winter. The exactlocation in Mexico of the the other recoveryis not known.

Fig. 1

BREEDING RANGE

WINTERING RANGE

MEXICO

BELIZE

HONDURAS /

NICARAGUA

GUATEMALA/ COSTA RICA EL SALVADOR

PANAMA

Jan.-Mar. 1985 North AmericanBird Bander Page 13 Table 1. Encounters with banded Northern Orioles, An SY male (861-03511),banded and color marked on 18 1924-1979. June 1977, was reported by Alfredo Garcia at Desconocido,Guatemala, in January,1981. This male was Encounters*** about 5V2 years old when reported and had not been Number**number Withinsame 10'grid number outside 10'grid of recapturedduring the interveningyears on the Manitoba Number of oflatitude and longitude of latitude and longitude Subspecies*banded encounters where banded (% of tota) wherebanded (% of total) study area. I did not ascertainwhether it nested in 1977, althoughmany $Y males did that year on the study area Baltimore45,981 700 627(89.6) 73 (10.4) (Sealy 1980a). This is the only Manitoba-banded Bullock's 4,434 199 197(99.0) 2 (1.0) "Baltimore" Oriole that has been recovered in winter Totals ,50,415 899 824(91.7) 7,5 (8.3) (Table 3). *"Baltimore"Oriole (Icterus galbula galbula); "Bullock's" Oriole (I. g. bullockii). Rogerset al. (1982)presented three criteriafor designating **An encounter is defined in North American Bird Banding Tech- niques, Vol. 1, 1977, appendix A-4, as an observationof a a speciesas a winter resident: (1) frequencyof repeats previouslybanded bird. Encountersoccur through hunting (recapturesduring the samewintering season), (2) the time or finding birds dead (recoveries),trapping (repeats, returns, lapse between repeats,and (3) recapturesof individuals retraps),or sightings by observers(not included in the pre- sent analysis). during subsequentyears, implying that an individual is ***Encounter rate: Baltimore, 1.52%; Bullock's, 4.49%; both more likely to be a return if it is a winter residentthan subspecies, 1.78%. if it is a transient. These authors considered 3 weeks to be an adequateinterval betweenrepeats for designating an individual a winter resident. The recovery in Guatemala of the Manitoba-banded oriole therefore does not constitute,by the criteria of Rogerset al. (1982), a record of a resident wintering bird. On the other hand, this individual probably was resident when and where it was recovered, although it is not known whether the wet and dry seasonsinfluence the areas this species choosesover the wintering period (e.g., Karr 1971, Mor- Table 2. Mist-net captures, repeats and returns, and ton 1980). The return of migrant passerinebirds to the sightingsof color-marked AHY "Baltimore" same locality in winter has been reported from Central Orioles during the late nestling and post- and South America (e.g., Schwartz 1963, Loftin 1977, breeding periods on the forested dune- Thurber and Villeda 1980, McNeil 1982, Rogers et al. ridge, Delta Marsh, Manitoba, 1976-1983. 1982) and the West Indies (Diamond and Smith 1973). Rogerset al. (1982) banded 8 Northern Orioles (of the MALES FEMALES "Baltimore"subspecies, D.T. Rogers,in litt. 4 January 1984) 7.DAY PERIODS SY ASY in Guatemala in March and April, 1979, but only one

Jun 28-4 30* 64 143 repeated,3 daysafter it wasbanded, and nonewas recap- Jul 5-11 6 41 62 tured at the samelocality during the sameperiod in 1980. 12-18 3 10 17 Evidencefrom Honduras(Table 3) suggests,however, that 19-25 1 4 27 "Baltimore" Orioles do indeed return to the same locali- 26-1 0 14 13 ty in winter (see also Nickell 1968). One male banded Aug 2-8 0 15 11'* there in May, 1964, was recoveredin December of the 9-15 0 12 9 same year; 1 of 3 males banded between 13 and 20 16-22 0 5 3 December 1964 returnedthere the followingMarch, the 23-29 0 2 2 other two one year and about 18 monthslater, respective- 30-5 0 I 0 ly; one male banded in early December, 1966, repeated Sep 6-12 0 0 1'** the following March, and a male bandedin late March, * Includessingle SY males collected on 30 June and 5 July 1978. 1965, was recoveredthere about 6 years later. Observa- **Includes three mist-net mortalities. tions of "Baltimore" Orioles in Costa Rica and Panama ***AHY female (74-180909),banded on the dune-ridge study area suggestthat they are not only residenton their wintering on 16 July 1974, was recaptured on 9 September 1975 still on study area. When recaptured,its ninth primarywas about 90% groundsbut alsoterritorial (e.g.,Timken 1970, Leck 1974, grown. Schemske1975).

Page14 NorthAmerican Bird Bander Vol. 10,No. 1 The singlerecovery of a Manitoba-bandedoriole on its Three orioles, banded during spring migration or the presumedwintering grounds obviously does not tell us breedingseason in Connecticut,Illinois and Ontario,also where the dune-ridgepopulation overwinters. It is not have beenrecovered in Guatemalain winter (7hble3). The known whether individuals that nest and show year-to- remainingrecoveries during winter are from Mexico,Hon- yearfidelity to the sametract of habitatwinter together, duras and E1 Salvador{Table 3). Interestingly,none has in fact, availableevidence suggests otherwise IRamos and been recovered from the southern portion of this Warner1980 I. Also,the two Ontario-bandedorioles ITable subspecies'winter range {Fig. 1), that is, in Nicaragua, 31,banded during the breedingseason at the samelocali- CostaRica, Panama,Colombia, or Venezuela.This may ty, wererecovered in Guatemalaand Honduras Ireported supportthe pattern that is emergingwhich suggeststhat by Nickell 1968}. most long-distancemigrants winter in the northern regionsof Central America and the West Indies with the numberof winteringspecies and individualsdecreasing progressivelyfrom Mexico toward the equator{Terborgh 1980}.

Table 3. Recoveries of Northern ("Baltimore") Orioles banded: (1) during spring migration or the breeding season and recovered within the subspecies' known wintering range, (2) within the wintering range and recovered during the breeding season, and (3) on the wintering grounds and repeated at the same site later the same winter or returned there in a subsequent winter.

BANDING RECOVERY BAND NUMBER (age/sex) LOCATION BANDING DATE LOCATION RECOVERY DATE 501-28253 (ASY-M) Minnesota 16 May 1955 Honduras 10 Oct 1957 651-50426 (AHY-F) Ontario 9 May 1965 Guatemala 17 Feb 1966 1041-63412 (ASY-M) Connecticut 19 May 1967 Guatemala 3 Mar 1972 691-62221 (AHY-F) Michigan 16 May 1969 El Salvador 8 May1972 761-91661 (ASY-M) Massachusetts 22 May 1971 Mexico 17 May1971 761-85227 (ASY-M) Illinois 11 Jun 1971 Guatemala 21 Feb 1972 761-36245 (ASY-M) Ontario 13 May 1972 Honduras 26 Jan 1973 731-17315 (AHY-F) Connecticut 15 May 1972 Mexico 9 Sep 1973 861-03511 (SY-M) Manitoba 18 Jun 1977 Guatemala Jan 1981

641-26200 (ASY-M) Honduras 8 Dec 1963 Ontario 25 Jun 1964 641-26233 Honduras 14 Jan 1964 Michigan May 1965 681-11734 (AHY-F) Honduras 22 Nov 1964 Wisconsin May 1965 751-56268 (AHY-F) Mexico 10 Nov 1970 Pennsylvania 8 Jun 1973

651-93413 (ASY-M) Honduras* 12 May 1964 Honduras* 16 Dec 1964 681-36612 (ASY-M) Honduras 20 Dec 1964 Honduras 21 Mar 1965 681-11793 (ASY-M) Honduras 13 Dec 1964 Honduras 12 Dec 1966 651-92503 (ASY-M) Honduras 20 Dec 1964 Honduras Jun 1966 681-49268 (ASY-M) Honduras 23 Mar 1965 Honduras 14 Feb 1971 681-36718 (ASY-M) Honduras 2 Dec 1965 Honduras 24 Mar 1966

*Banding and recovery sites in Honduras are the same (15.2-087.5).

Jam-Mar. 1985 North AmericanBird Bander Page 15 Acknowledgements Ketterson,E.D., and V. Nolan,Jr. 1979.Seasonal, annual, and geographicvariation in sex ratio of wintering Theresearch onthe forested dune ridge has been fund- populationsof Dark-eyedJuncos [Junco hyemalisJ. Auk ed by the CanadianNational Sportsmen'sFund, Frank M. 96:532-536. Chapman Memorial Fund of the American Museum of Lack,D. 1976.Island biology: illustrated by the landbirds Natural History, Manitoba Naturalists Society, Natural of Jamaica.Univ. CaliforniaPress, Berkeley. 445 pp. Sciencesand EngineeringResearch Council of Canada, Land,H. C. 1970.Birds of Guatemala.Livingston Pub. Co., and the ResearchBoard of the University of Manitoba. Wynnewood, PA. 381 pp. G. C. Biermann, D. G. Busby, H. E. den Haan, J.P. Leck,C. 1974.Further observations of nectarfeeding by Goossen, D. M. Guinan, J. L. Morgan, and G. D. orioles. Auk 91:162-163. Sutherlandhave contributedimportantly to the banding Loftin, H. 1977. Returns and recoveries of banded North effort. Kathleen L. Newell, Canadian Wildlife Service, Americanbirds in Panamaand the tropics. Bird-Banding kindly provided printouts of banding and encountersof 48:253-258. Northern Orioles. Thanks are due the many banderson MacKenzie,D.I. 1982.The dune-ridgeforest, Delta Marsh, whoseefforts I have relied in this analysis.I thank R. B. Manitoba: overstoryvegetation and soilpatterns. Can. Payne for critically reading the manuscript.The staff of Field-Nat. 96:61-68. the University of Manitoba Field Station IDelta Marshi , S.G. Sealy, and G.D. Sutherland. 1982. Nest-site has continouslysupported our work through the provi- characteristicsof the avian community in thedune-ridge sion of facilitiesand assistance.I owe a specialdebt of forest,Delta Marsh, Manitoba: a multivariateanalysis. gratitudeto the officersof the PortageCountry Club who Can. J. Zool. 60:2212-2223. have permitted us to band birds on their property. This McNeil, R. 1982.Winter residentrepeats and returnsof publicationis contributionnumber 89 of the University austral and boreal migrant birds banded in Venezuela. of Manitoba Field Station IDelta MarshI. J. Field Ornithol. 53:125-132. Meyer de Schauensee,R. 1970. A guide to the birds of Literature Cited SouthAmerica. Livingston Pub. Co.,Wynnewood, PA. 470 pp. AmericanOrnithologists' Unionß 1983. Check-list of North Monroe,B.L., Jr. 1968.A distributionalsurvey of the birds Americanbirds. Sixth edition. American Ornithologists' of Honduras.Ornithol. Monogr. 7:1-458. Union, Lawrence, Kansas.877 pp. Morton, E.S. 1976. The adaptive significanceof dull Bond,J. 1960. Birds of the West Indies. Collins, London. coloration in Yellow Warblers. Condor 78:423. 256 pp. ß 1980. Adaptationsto seasonalchanges in migrant Diamond, A.W., and R.W. Smith. 1973. Returns and sur- landbirds in the PanamaCanal Zone. Pp.437-453. In A. vival of banded warblers wintering in Jamaica. Bird- Keast and E.S. Morton (eds.} Migrant birds in the Banding 44:221-224. Neotropics:ecology, behavior, distribution, and conser- Dickey, D.R. and A.J. van Rossem.1938. The birds of E1 vation. SmithsonianInst. Press, Washington,D.C. Salvador. Publ. Field Mus. Nat. Hist., Zool. Ser., Vol. 23. 576 pp. Edwards,E.E 1972. A field guide to the birds of Mexico. Nickell,W.P. 1968. Return of northernmigrants to tropical E.P. Edwards, Sweet Briar, VA. 300 pp. winter quarters and banded birds recovered in the Ewald, P.W.,and S. Rohwer. 1980. Age, coloration, and United States.Bird-Banding 39:107-116. dominancein nonbreedinghummingbirds: a test of the Paynter, R.A., Jr. 1955. The ornithogeographyof the asymmetry hypothesis. Behav. Ecol. Sociobiol. Yucatan Peninsula. Bull. Peabody Mus. Nat. Hist. 7:273-279. 9:1-347. Erickson, J.E. 1969. Banding studies of wintering Ramos,M.A., and D.W.Warner. 1980.Analysis of North Baltimore Orioles in North Carolina, 1963-1966. Bird- Americansubspecies of migrantbirds wintering in Los Banding 40:181-198. Tuxtalas,southern Veracruz, Mexico. Pp. 173-180. In A. Faaborg,J., andJ.E. Winters. 1979. Winter residentreturns Keast and E.S. Morton (eds.} Migrant birds in the and longevityand weightsof Puerto Rican birds. Bird- Neotropics: ecology,behavior, distribution, and conser- Banding 50:216-223. vation. Smithsonian Inst. Press, Washington, D.C. Godfrey,W.E. 1966. The birds of Canada.Nat. Mus. Can. 576 pp. Bull., No. 203. Rappole,J.H., M.A. Ramos,RJ. Oehlenschlager,D.W. Johnsgard,P.A. 1979. Birdsof the Great Plains: breeding Warner,and C.P.Barkan. 1979. Timing of migrationand species and their distribution. Univ. Nebraska Press, route selection in North American songbirds. Lincoln. 539 pp. Pp.199-214. In L. Drawe (ed.}Proceedings of the First Karr,J.R. 1971.Structure of avian communitiesin selected Welder Wildlife Foundation Symposium. Welder Panamaand Illinois habitats.Ecol. Monogr. 41:207-233. Wildlife Foundation, Sinton, Texas.

Page16 North AmericanBird Bander Vol. 10, No. 1 Ridgely, R.S. 1976. A guide to the birds of Panama. to a changingfood supply.Can. J. Zool. 58:221-227. Princeton Univ. Press, Princeton, N.J. 394 pp. 1980b. Breedingbiology of Orchard Orioles in a Rising,J.D. 1970. Morphologicalvariation and evolution new population in Manitoba. Can. Field-Nat. in someNorth Americanorioles. Syst. Zool. 19:315-351. 94:154-158. 1983. The Great Plains hybrid zones. Pp.131-157. __, and G.C. Biermann. 1983. Timing of breedingand In R.E Johnston {ed.} Current Ornithology, Vol. 1. migrations in a population of Least Flycatchersin Plenum Press, New York. 425 pp. Manitoba. J. Field Ornithol. 54:113-122. Rogers,D.T., Jr., D.L. Hicks, E.W. Wischausen,and J.R. Slud, P. 1964. The birds of Costa Rica: distribution and Parrish. 1982. Repeats,returns, and estimated flight ecology.Bull. Amer. Mus. Nat. Hist., Vol. 128. 430 pp. rangesof someNorth Americanmigrants in Guatemala. Terborgh, J.W. 1980. The conservationstatus of neo- J. Field Ornithol. 53:133-138. tropicalmigrants: presentand future. Pp.21-30.In A. Salt, W.R., and J.R. Salt. 1976. The birds of Alberta with Keast and E.S. Morton {eds.} Migrant birds in the their rangesin Saskatchewanand Manitoba.Hurtig, Ed- Neotropics: ecology,behavior, distribution,and con- monton. 498 pp. servation. SmithsonianInst. Press, Washington, D.C. Schemske,D.W. 1975. Territoriality in a nectar feeding 576 pp. Northern Oriole in Costa Pdca. Auk 92:594-595. Timken, R.L. 1970. Food habits and feedingbehavior of Schwartz,P. 1963.Orientation experiments with Northern the Baltimore Oriole in Costa Rica. Wilson Bull. Waterthrusheswintering in Venezuela.Proc. XIII Int. 82:184-188. Ornithol. Congr.:481-484. Thurber, W.A., and A. Viileda. 1980. Wintering site Sealy, S.G. 1979. Prebasicmolt of the Northern Oriole. fidelity of migrant passerinesin E1 Salvador, Central Can. J. Zool. 57:1473-1478. America. N. Amer. Bird Bander 5:131-135. ß1980a. Reproductive responses of Northern Orioles

Tree Swallows as Foster Parents to Barn Swallows

Peter and Timothy Dring The next day they were placed in the nest of a Tree P.O. Box 92 Swallow {IridoprocnebicolorJ that containedyoung of the Willow Springs, IL 60480 same approximateage and size. This nest was chosen becauseof the size similarity of the young though there heRed Schoolhouse Nature Center located inNorth was someconcern as this nesthad five young,in it already. eastern Illinois in Cook County has had a wildlife The nestwas checkedevery two daysuntil July 20 when rehabilitationprogram as part of its ongoingnatural all of the Tree Swallowyoung fledged along with two of historyactivities. Many youngwild creaturesare brought the Barn Swallows.Three of the Barn Swallowyoung were in eachyear by the generalpublic and we do our bestto found dead in the nest, one on July 14 and two on July try and help with their survival.On July 11, 1979 five 16, thesewere apparentlyto weak to survive.All of the young Barn Swallows {Hirundo rustica erythrogaster}, young were banded with U.S. Fish and Wildlife Service whosenest was destroyed,were broughtinto the center Bands.Since the original nest site of the Barn Swallows as orphans.These young swallowswere in goodcondi- was destroyedit cannot be checkedfor the return of the tion and were thoughtto be aboutnine to elevendays old. young birds raised by the Tree Swallowsand they have We fed them and placedthem in a warm cageovernight. not been heard from since.

Jam-Mar. 1985 North AmericanBird Bander Page 17