MI(• r•.•rlON AND r, •"1 r.I.iBu Jackdaws reach the New World The first specimenrecord for North America with notesconcerning the birds' probable origin P. William Smith OMETIME IN EARLY March or April, I984, ChristopherBlane, a young residentof Block Island, Rhode Island, realized that while he was huntingcrows on local agriculturalland he had shot a small corvid with a gray nape.He wasintrigued with the bird and took it to the island's formidable orni- thologist,Merrill Slate. Slate, after con- sultingvarious bird books, felt that the bird was most certainly a [Eurasian] Jackdaw, Corvus monedula. He froze the specimen awaiting corroboration,but withoutnoting the date.On May 5, 1984, EliseLapham, a birderand bird bander of longexperience, arrived on BlockIsland and was shownthe specimensoon there- after. Shewas told thatthe specimenwas about a month old. She, too, was of the opinionthat the bird wasa Jackdaw.The bird wastaken from the islandby Richard Bowenand the specimenwas eventually acquiredby Duncan Evered and P. W. Smith (the author), both of whom con- firmed it as Corvus monedula. The specimenwas prepared as a study skinby M. McClellanthrough the courte- sy of the MassachusettsAudubon Soci- ety. After thawing, this male Jackdaw (testes approximately 3 x 5 mm), weighed250.5 g. Its wing chord mea- sured 235 min. It did have some subcuta- neousfat. The studyskin measured336 mm (tail 140 mm, flattenedwing 228 mm); the tarsallength was 44 mm, and the culmen24.3 min. from nostrilto tip. The specimenis now in the bird collec- tionof theMuseum of ComparativeZoo- logy at Harvard University as Number 331,728. When compared with an extensive Therelative size of threecorvids is readilyapparent in thisdrawing. Top to bottom:Carrion Crow studyskin seriesat the AmericanMuse- (Corvuscorone), Rook (Corvus frugilegus), and Jackdaw (Corvus monedula). More agile and um of NaturalHistory in New York City, lesscautious than the Rook or CarrionCrow, the Jackdaw is oftenthe more successful scavenger. the Block Island Jackdaw's dark tone, Drawing/Keith Hansen. Volume 39, Number 3 255 lackingany hint of white on the feathers of the sides of the lower neck, indicated that this individual was of the West Euro- pean race, Corvus monedulaspermolo- gus. Its mainlydull browngreater wing coverts and secondaries,only a few BLOCK ISLAND, R.I. feathersof whichshowed metallic green or purple, indicatedthat this bird was in its firstalternate plumage while retaining somejuvenal feathers(based on Svens- son, 1984). In thespring and summer of 1984there wererecords of nineJackdaws occurring on coastal islands in northeastern North America(Table 1, Fig. 1). The first indi- vidualreported was present on Nantucket Island, Massachusetts,from December 31, 1983 on, and was probablypresent from at least November 28, 1982 (S. Per- kins and R. Stymeist, pers. comm.). None of the othereight sightings, includ- ing the BlockIsland specimen discussed here, was found beforelate March, 1984. One of thosefound on MiquelonIsland, France(overseas) on March23, appeared exhausted,suggesting a recent long-dis- tanceflight (A. Desbrosseand R. Etche- berry,ms). Additional evidence support- ing the longdistance theory was the fact thatthat bird waspicked up andhandled by a child. •œRo¾^l• MEXEOROI•OaiC^L Soci- ety WeatherLog for March, 1984, showedthat an intenselow pressuresys- tem formednear lceland aboutMarch 18, andsubsequently blanketed the NorthAt- lantic for severaldays (in Weather39:5 [1984]). Elkins (1983), discussedhow easterlywinds between low pressuresys- A CommonCrow, Corvusbrachyrhynchos (top), and a Jackdawfly over BlockIsland. The asteriskin the upper-right-handcorner of the map indicateswhere the first North American tems (suchas these)and high pressure Jackdaw specimento reach our shoreswas collected. areas extendingsouth from the North Drawing/Keith Hansen. Pole are directedfrom northernEurope toward Iceland, southern Greenland, Movementsthrough Germany peak dur- In recent years, migratingJackdaws eastern Canada, and the northeastern ing a shortperiod in mid-to-lateOctober have been noted after being displaced UnitedStates. This occurs most frequent- and flocks often include other corvids, over the North Atlantic. October 18, ly betweenlate autumnand early spring. i.e., Rooks, Corvusfrugilegus (Water- 1975, a flock of 20 reached the British Bagg (1967) explainedhow thesecondi- house, 1949). Flocks of Jackdawsarrive weathershipon Ocean Station Lima at tions can cause east-west trans-Atlantic in Britainin lateOctober and disperse to 57øN, 20øW, approximately400 miles displacementwhen they occur in con- winter in agriculturalareas (Bannerman south of Iceland (Sea Swallow 26:18 junction with birds' normal movements & Lodge, 1953). In autumn 1983, there [1977]). In late Octoberand early No- in Europe.Bagg used east-west displace- was an especiallylarge and out-of-place vember, 1976, 42 Jackdaws, three ment of Nothem Lapwings, Vanellus assemblageof thousandson the Isles of Rooks, and three Carrion Crows, Corvus vanellus,as a typical example. Scilly, off the southwestcoast of Britain, corone,were reported from two commer- Jackdawsin Europehave becomein- on October 23-24 (Brit. Birds 77:40 cial ships140 to 200 miles southwestof creasinglynumerous in modem times. [1984]). ContinentalJackdaws begin to Ireland (Sea Swallow 27:26 [1978]). In They have spreadnorthwest into Scot- form migratoryflocks in late February the sameautumns there were major in- land,first breeding there during this cen- andhave mostly departed Britain by late fluxes of Jackdawsinto Iceland(Nielsen tury (Parslow, 1967). Many from the April (Bannerman& Lodge, 1953).Wa- 1979). At least 58 were recordedthere in Eurasian interior and Scandinavia mi- terhouse(1949) found that the peak of the thoseyears; the only previousincursion gratewest in order to winter in the milder returnflight through central Germany oc- of any magnitudehad involvedabout 20 climateof coastalEurope (Busse, 1969). curs in late March. individualsin autumn 1952. European 256 AmericanBirds, Fall 1985 86' 80' weathersystems in October, 1975, were particularly conducive to east-to-west bird movement and resulted in the dis- placementof many other species(Baker 1977). Between 1950 and 1979, Jackdawsar- rived in Icelandin aboutas manysprings asautumns (30%), primarilyfrom March to early May (Nielsen 1979). The great- est numberin a singlespring appeared in 1972, when six individuals were found Quebec.. •= One of those(Icelandic Museum of Natu- 46' ral History Number RM 5957), shot in March, was an adult female of the race spermologus.Individuals from the 1975 and 1976 autumn incursions remained in Iceland over the summer of 1977, built .:. two nests,but did not lay eggs.As of the early 1980s,the specieshad not success- fully colonizedIceland. New Brunswic, imSXAXUS OFxlm Jackdaw inNorth America was uncertain before the 1984 appearances.There is a published account of one photographedat Ft 40' Myers, Florida, in the winter of 1962- 1963, which was thoughtto havebeen an escaped cagebird (Aud. Field Notes 17:322[1963]). The originof onewidely observed on Nantucket Island in the win- ter of 1982-1983 was also questioned (Bird Obs. East. Mass. 11:49 [1983]), and its habits and movements were not B systematicallyfollowed (Table 1). How- ever its discovery in late November, 1982, did in fact coincide with the ap- pearanceof four individualsin Iceland NorthAmerican locations of Jackdawsreported during 1984 through October 1: (A) BlockIsland, duringthat month (Bliki 3:41-42 [1984]) RhodeIsland: 41o10 ' N, 71o35' W (B)Nantucket Island, Massachusetts: 41ø15 ' N, 70o00' W (C) It was the first influx of Jackdaws in Ice- BrlerIsland, Nova Scotia: 44o15 ' N, 66o20' W (D) BonPortage Island, Nova Scotia: 43030 ' N, land in autumn since 1976, other than a 65o45' W (E) MiquelonIsland, France (overseas): 47005 ' N, 56o25' W. singleindividual in 1978.There is also an anecdotalreport of this speciesappear- Table 1. JackdawsReported in North AmericaDuring 1984Through 1 October. ance earlier in Nova Scotia, probablyin spring1983 (I. McLaren, in litt.). B•rd# Map Location Dates Authorityand Notes Accordingto T. P. Inskippof theBrit- 1 Siasconset, From December Bird Obs. East. Mass. 12:102 (1984). ish Wildlife Trade Management Unit Nantucket I., 31, 1983 Probablythe sameindividual present in (pers.comm.), countries in WesternEu- MA (B) samelocation November 28, 1982-April 4, ropehave not allowed commercial trade 1983. in their native wild avifauna for many A. Desbrosseand R. Etcheberry(ms). MiquelonI., Mamh 23-April 6 years.Because of variouswildlife laws, FrenchOverseas and from July 18, Birdsfound July 18 werepresumed to be Dept. (E) 1984 thesame as those seen earlier. cf. Am. Birds e.g. the Conventionon International 38:886 [1984]. Trade in EndangeredSpecies (CITES), 5 Block I., RI (A) Early April, 1984 Specimento MCZ (this paper). signedby boththe United States and Can- 6 BrierI., May 6, 1984 Nova ScotiaBirds 2613]:16(1984). adain 1975, bird importationinto North Nova Scotia (C) Publishedphoto. America is now closelymonitored and 7 BonPortage I., May 20-24, 1984 McLaren, I. A. (1985). Nova ScotiaBirds regulatedand penaltiesfor non-compli- Nova Scotia (D) 2711]:56. ance are severe (Fuller, 1983). While 8 Siasconset, From July 9, 1984 Bird Obs. East. Mass. 12:294 (1984). Nantucket I., Another individual seen with No. 1 above; personally-ownedor captive-bredJack- MA (B) possiblypresent earlier. daws,or onesobtained for bonafide sci- 9 MiquelonI., FromJuly 18,
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages4 Page
-
File Size-