SHORT COMMUNICATIONS 289 eaters (Meropidae) and cooperative breeding in SAFRIEL,U. N., M. P. HARRIS,M. DE L. BROOKE,AND hot-climate birds. Ibis 114:1-14. C. K. BRITTON. 1984. Survival of breeding oys- GIROUX, J. F. 1985. Nest sites and superclutchesof tercatchersHaematopus ostralegus. J. Anim. Ecol. American Avocetson artificialislands. Can. J. Zool. 53:867-877. 63:1302-1305. SIBLEY,C. G., J. E. AHLQUIST,AND G. L. MONROE, JR. GROVES, S. 1984. Chick growth, sibling rivalry, and 1988. A classification of the living birds of the chick production in American Black Oystercatch- world based on DNA-DNA hybridization studies. ers. Auk 101525-531. Auk 105:408423. LAURO,B., ANDJ. BURGER. 1989. Nest-site selection SMITH,J. N. M. 1990. Summary, p. 593-6 11. In P. of American Oystercatchers(Haematopus pallia- B. Stacey and W. D. Koenig [eds.], Cooperative tus) in salt-marshes.Auk 106:185-192. breedingin birds: long-term studiesof ecologyand MAYR, E. 1939. The sex ratio in wild birds. Am. Nat. behavior. Cambridge Univ. Press,Cambridge, En- 73:156-179. gland. NOL, E. 1985. Sex roles in the American Oystercatch- STACEY,P. B., AND J. D. LIGON. 1987. Territory qual- er. Behaviour 95:232-260. ity and dispersaloptions in the Acorn Woodpeck- NOL, E. 1989. Food supply and reproductive perfor- er, and a challengeto the habitat-saturationmodel mance of the American Oystercatcherin Virginia. of cooperative breeding. Am. Nat. 130:654-676. Condor 91429-435. VAN RHUN, J. G. 1990. Unidirectionality in the phy- NOL, E., A. J. BAKER,AND M. D. CADMAN. 1984. logeny of social organization, with special refer- Clutch initiation dates, clutch size, and egg size ence to birds. Behaviour 115:153-l 73. of the American Oystercatcher in Virginia. Auk WALTERSJ.. AND B. F. WALTERS. 1980. Co-onerative 101:855-867. breedingby SouthernLapwings Vanelluscklensis. RUSSELL,E. M. 1989. Co-operative breeding-a Ibis 122:505-509. Gondwanan perspective. Emu 89:61-62. ZARUDSKY,J. D. 1985. Breeding statusof the Amer- SAFRIEL,U. N. 1981. Social hierarchy among siblings ican Oystercatcher in the town of Hempstead. in broods of the Oystercatcher Haematopus os- Kingbird 35:105-l 13. tralegus.Behav. Ecol. Sociobiol. 9159-63. The Condor 941289-292 0 The CooperOrnithological Society 1992 SCARCITY OF HAEMATOZOA IN BIRDS BREEDING ON THE ARCTIC TUNDRA OF NORTH AMERICA ’ GORDON F. BENNETT International ReferenceCentre for Avian Haematozoa, Memorial Universityof Newfoundland, St. Johns,’ Newfoundland,AIB 3X9, Canada ROBERT MONTG~MERIE AND GILLES SEUTIN* Department of Biology, Queens’ University,Kingston, Ontario, K7L 3N6, Canada Key words: Haematozoa; tundra; arctic:parasites; American arctic-nesting birds. In a review of hae- longspur;ptarmigan; redpoll;plumage color. matozoanprevalence in North American birds, Greiner et al. (1975) indicate that lessthan 3% ofbirds sampled Despite widespreadinterest in documentingthe blood from the “arctic barrens” (their region 6) were para- parasites of birds (e.g. Loye and Zuk 1990) there is sitized, but they provide no further information on the little information available on the haematozoa of spe- sample of birds involved in this analysis. cies occurring in arctic regions. Laird (196 1) reported In this paper, we report on the haematozoa found that none of the 149 individuals of 23 bird specieshe in 276 breeding birds of 10 species samnled in the samuled on Prince of Wales Island (72-74”N. 96- courseof field studiesof their behavior and ecologyat 103”W) during one summer harbored haematozoa,but four very different arctic sites. While some of these no other intensive surveys have been done of North specieshave been sampled for haematozoabefore, our samples allow us to compare haematozoa prevalence between habitat types, both within and between sites. I Received 24 June 199 1. Accepted 27 September We also discuss the implications of our findings for 1991. recent comparative analysesof parasite prevalence in 2Present address: Department of Biology, Univer- relation to plumage brightness in birds (see Moller sity of Pennsylvania, Philadelphia, PA 19104. 1990). 290 SHORT COMMUNICATIONS TABLE 1. Prevalence of Haemoproteus (H), Leucocytozoon (L) and Trypanosoma (T) in tundra-nestingbirds. Total individuals Site Individuals with Species Examined Infected H L T Sarcpa Lake Lagopus mutt.0 39 Eremophila alpestris 3 Calcarius lapponicus 29 Plectrophenax nivalis 8 Churchill Carduelisjlammea 97 63 53 Carduelis hornemanni 19 12 12 Carduelis sp. 6 Calcarius pictus 19 3 Zonotrichia leucophrys 4 4 : St. Paul Island Aethia pusilla 14 0 Fort Simpson Cygnus buccinator 38 25 18 8 0 Total 276 108 26 80 13 Percent 39.1 9.4 29.0 4.1 METHODS We also report on blood samples collected in June Birds were captured opportunistically in a variety of and July 1987 from Least Auklets (Aethiapusilla) nest- ways (mist nets, noose carpets,noose poles and potter ing on St. Paul Island, Pribilof Islands,Alaska (57”08’N, traps), often in conjunction with other researchon their 170”17’W) and in July and August 1989 from Trum- behavior and ecology. All individuals were banded to peter Swans (Cygnus buccinator) nesting on the Mac- facilitate later identification. Blood smearswere made kenzie River near Fort Simpson, NWT (62”N, 122”W). following the protocols of Bennett (1970). All smears These two samplespermit comparisonwith those from were air-dried in the field and fixed in 100% ethanol related speciesreported elsewhere.St. Paul Island is a within 24 hr. At the International ReferenceCentre for small oceanic island in the Bering Sea, well beyond the Avian Haematozoa, smears were stained with Giem- arctic limit of trees and tall shrubs,whereas Fort Simp- sa’s stain and examined for Leucocytozoon, Trypano- son is at the southern edge of the forest-tundra/open soma and microfilaria at 250 x and for Haemoproteus forest vegetationzone (seeDanks 198l), about 500 km and Plasmodium at 400x magnification. Each slide southwestof the arctic treeline. was examined until approximately 100,000 erythro- At Sarcpa Lake, Churchill and on St. Paul Island, cytes had been scanned.In this paper we mainly report all blood smearswere taken from adult breeding birds; parasiteprevalence, i.e., whether or not each individual at Fort Simpson, they were taken from 25 adult breed- was infected with eachof thesetaxa. Parasiteintensities ers and 13 goslings.Adults of both sexes were repre- (i.e., infestation levels per individual bird) tend to vary sented in all samples except Horned Larks (females seasonallyand among age and sex cohorts (Weather- only). head and Bennett 1991) and are thus not very useful in interspecificcomparisons unless these factors can be RESULTS AND DISCUSSION statistically or experimentally controlled. Sarcpa Lake, Northwest Territories. No haematozoa Most of our samples were collected at Sarcpa Lake, were found in the 79 individual birds of four species Melville Peninsula, Northwest Territories (68”33’N, sampled at Sarcpa Lake (Table 1). Both Rock Ptar- 83”19’W) during June and July 1987-1989 and at migan (Lagopus mutus) and Lapland Longspurs(Cal- Churchill, Manitoba (58”45’N, 94”05’W) during June car&s lapponicus) were sampled during the breeding and July 1989. The habitat at Sarcpa Lake is upland seasonin three different years; nine individual Rock high arctic tundra (see Montgomerie et al. 1983 for Ptarmigan and two individual Lapland Longspurswere details), more than 1,000 km north of the northern sampled in more than one year. Thus, the absenceof limit of treesat this loneitude (Danks 1981). Churchill. haematozoa in breeding birds at this site appearsto be on the other hand, is onthe arctic treeline at the north: a general phenomenon. ern edge of the forest-tundra/open boreal forest vege- Forty-three individuals of the same four speciesalso tation zone (see Fig. 3 in Danks 1981). All birds cap- were sampled by Laird (1961) in a single season on tured at Churchill were breeding within 5 km of the Prince of Wales Island and no haematozoawere found Hudson Bay coast, either on relatively open tundra there either. Horned Larks (Eremophila alpestris) and with scatteredclumps of black spruce (Picea mariana Rock Ptarmigan also nest south of the northern limit (Mill.) BSP) or within the spruce stands themselves of trees where haematozoa have been found in their (see Jehl and Smith 1970 for habitat details). blood - 36% of 50 Rock Ptarmigan from insular New- SHORT COMMUNICATIONS 291 foundland harbored haematozoa (Bennett and Inder exposureto biting flies compared to sympatric species 1972) and 13% of 23 Homed Larks from St. Bride’s occupyingmore shelteredhabitats. A similar argument Newfoundland and False River, Ungava Bay, Quebec was made by Laird (196 1) to explain the low prevalence had either Leucocytozoon or Haemoproteus (unpub- of parasites in several Charadriiforme species when lished data, see Greiner et al. 1975). Thus, the absence compared to sympatrically breeding speciesof other of haematozoain thesespecies on the high arctic tundra avian orders at Lac Kohlmeister, Quebec. However, it is not a species-specificphenomenon, but rather seems should be noted that the Charadriidae in general are to be site-related. seldom infected with blood parasites-only 1.2% of The complete absence of avian haematozoa from individuals in this family, sampled in North America, birds nesting in high arctic regions is almost certainly had haematozoa (Greiner et al. 1975) and it is not due to the absenceof suitable vectors (see also Laird known whether this is due to microhabitat or some 1961, Greiner et al. 1975) especiallythe various spe- parasite resistancein this taxon. cies of omithophilic black flies (Simuliidae; see Danks Fort Simpson, Northwest Territories. Twentv-live 1981). The fact that haematozoa have been found in adult Trumpeter Swans(Cygnus buccinator) were-Sam- both Homed Larks and Rock Ptarmigan nesting south nled near Fort Simoson. of which 19 (76%) were in- of the arctic treeline supportsthis argument. The four fected with haematozoa:’L.