SHORT COMMUNICATIONS 145 includingone inside a nestcavity. Six other islandsshowed penetrated in the present study, however, suggeststhat no indication of abnormally low nestingsuccess, and were ermine are quite capable of reaching coastal islands in probably not visited by ermine. years when their populations are high, and that such in- The major effects of ermine on guillemot breeding ap- vasionsmay be more frequent than the paucity of records pearedto be discouragementof egg-layingand a reduction suggests. of hatching successdue to nest abandonment. Many cav- ities on Black, Yellow, and Green islands which were oc- I thank W. Cairns, V. Friesen and H. Kaiser for field cupied in previous years were not used in 1983. Eggslaid assistance,and A. J. Gaston, M. B. Fenton and P. Ewins on islands where ermine presencewas confirmed or sug- for commenting on the manuscript. This study was sup- gestedwere often displacedfrom the nest cup and lacked ported by the Canadian Department of Supply and Ser- the shiny appearancewhich is normal for regularly incu- vices and the Canadian Wildlife Service. bated eggs(pers. observ.). Guillemots may have been re- LITERATURE CITED luctant to enter their nests if they had seen an ermine in the colony, which would explain the reductionin both egg- BANFIELD,A. W. F. 1974. The mammals of Canada. laying and hatching. Univ. of Toronto Press. Ermine visited islands as far as 1.6 km from the main- BIANIU,V. V. 1967. Gulls, shorebirdsand alcids of Kan- land (Pitsulak City), and may have reached Kingituayu dalaksha Bay. Israel Program for Scientific Transla- Island as well (2.2 km). This latter island is the highest of tions, Jerusalem. the 12 examined (22 m above sea level), which suggests FINERTY,J. P. 1980. The population ecology of cycles that conspicuousnessfrom the mainland may increase in small mammals. Yale Univ. Press, New Haven, likelihood of visitation. CT. Ermine must have reachedthese islandseither by cross- GASTON, A. J., D. K. CAIRNS,R. D. ELLIOT,AND D. G. ing the ice or by swimming. If they came over the ice, they NOBLE. In press. A natural history of DiggesSound. must have arrived at least two weeks before laying, since Can. Wildl. Serv. Rep. Ser. heavy ice disappearedfrom the area in early June. If er- KARTASCHEW,N. N. 1960. Die Alkenvogel des Nordat- mine were on islands during the pre-laying period, they lantiks. Die Neue Brehm-Btlcherei 257. Wittenberg, might have subsistedon eggsabandoned the previousyear. West Germany. Such food, however, would not have been available on LACK, D. 1967. Interrelationships in breeding adapta- PitsulakCity, becauseall unhatchedeggs were clearedfrom tions as shown by marine birds. Proc. XIV Int. Or- the island the previous fall. Ermine may instead have nithol. Congr. (1966):3-42. reached the islands by swimming. A local Inuit told me SETON,E. T. 1929. Lives of game animals. Doubleday of seeing an ermine swimming in salt water, and Seton Doran, New York. (1929) reported anecdotalaccounts of the species’ ability STORER,R. W. 1952. A comparison of variation, be- to swim. havior and evolution in the sea bird genera Uria and Ermine numbers are known to vary with those of lem- Cepphus.Univ. Calif. Publ. Zool. 52:121-222. mings (Finerty 1980), and the 1983 boom in ermine pop- ulations that led to the invasion of coastal islands in the BiologyDepartment, Carleton University, Ottawa KlS 5B6, study area may have been related to the lemming cycle. Canada. Presentaddress: Newfoundland Institute for Cold Although ermine and guillemots(Cepphus spp.) are broad- OceanScience, % BiologyDepartment, Memorial Univer- ly sympatric (Storer 1952, Banfield 1974), reports of pre- sity OfNewfoundland,St. Johns,’ NewfoundlandAlB 3X9, dation by small weaselson guillemots are rare (e.g., Kar- Canada. Received 7 December 1983. Final acceptance12 taschew 1960, Bianki 1967). The number of colonies September 1984. The Condor 87:145-147 0 The Cooper Ornithological Society 1985 and derive a major portion of their diet as ectoparasites taken from the skins of these animals (Ma&worth-Praed and Grant 1955). OBSERVATIONS OF SCRUB JAYS In North America, examples of such protocooperation CLEANING ECTOPARASITES are rare. Although Cattle Egrets(Bubulcus ibis). cowbirds (Molothrus spp.); and occasionallyother blackbirds often FROM BLACK-TAILED DEER perch on the backs of cattle or other large grazers, they are thought to use the cattle only as “beaters” to stir up insectfood from the grass(Heatwole 1965,Dinsmore 1973). FRANK R. ISENHART It is not clear that cowbirds or Cattle Egrets ever pick AND insectsoff the animals themselves.This behavior is, there- fore, better consideredan example of commensalismrath- DAVID F. DESANTE er than protocooperation. In contrast, Black-billed Mag- pies (Pica pica) pick and eat ticks from the backs of elk (Cervurcanadensis) and mule deer (Odocoileushemionus), Instances of protocooperation between birds and other an example of true protocooperation(Linsdale 1946). large animals are relatively uncommon, although certain Here we report a seriesof observationsof an apparently examplesare quite well-known. These include the Greater protocooperative associationbetween Scrub Jays (Aphe- Honeyguide(Indicator indicator)leading the honey badger locoma coerulescens)and Columbian black-tailed deer (Mellivora capensis)to a beehive (Skead 195l), the Egyp- (Odocoileushemionus columbianus) in which jays regu- tian Plover (Pluvianusaegyptius) picking leeches and small larly picked ticks and perhapsother ectoparasitesfrom the bits of food from the open mouths of crocodiles (Howell skin of deer. Dixon (1944) first reported such behavior 1979), and the Small Ground Finch (Geospizafuliginosa) between a Scrub Jay and a California mule deer (0. h. grooming ticks from the skin of the marine iguana (Am- cahfornicus)in SequoiaNational Park, California. Schulz blyrynchuscristatus; Amadon 1967). Uniquely among and Budwiser (1970) reported another Scrub Jay presum- birds, the two African speciesof oxpeckers(Buphagus spp.) ably taking ectoparasitesfrom the back of a black-tailed habitually associatewith herds of large grazing animals deer 4 km northeast of Alpine Lake in Marin County, 146 SHORT COMMUNICATIONS California. For both cases, single observations were re- deer entered the raised open area; one bird immediately ported of individual ScrubJays alighting on a deer’s back, flew onto its back, while the other remained on its perch. picking at the deer’s skin, and flying off. We have tallied The deer remained motionless even though it faced an eight additional cases,five of them involving singlejays observer, 150 m away. Cleaning followed in the sequence and three involving pairs of jays. These observationsin- describedabove, after which the jay returned to its partner clude the interaction of at least five different Scrub Jays and the deer departed. After 3 min, two additional deer (two of which were individually color-banded)and 17 deer, appearedon the outcroppingand were cleanedin the same althoughwe do not know exactly how many different deer manner as the first. We do not know whether or not the were involved becausethey were not marked. jay that performed this cleaning was the same individual The first observation was made in spring 1982 by Jack that cleaned the first solitary deer. When this jay was fin- Swenson on the undisturbed, mature part of the 36-ha ished with both deer, it returned to its partner and both coastalscrub study plot of the Palomarin Field Station of deer re-entered the thick vegetation beside the tree. This the Point Reyes Bird Observatory(PRBO), at the southern interaction lasted 20 min and occurred in full view of a end of the Point Reyes National Seashore(PRNS), Marin human observer. The observer’s presencedid not seem to County, California. The remainingobservations were made affect the deer’s or the jays’ behavior, as we confirmed between January and May 1983-by Isenhart, David Sie- subsequentlyby using more inconspicuousobservation mens, and David Forma. Five of theseincidents occurred points and even a blind, the same behavior was seen as near the location of the 1982 sightingand three occurred before. about 2 km northwest on a recently burned coastal scrub Corvids are widely accepted as highly intelligent birds study plot. Both areas were situated on variously gentle (Linsdale 1937) with well-developed learning capabilities to steep south-southwest-facingslopes that are immedi- (Brower et al. 1970). At Palomarin, young color-banded ately adjacent to the Pacific Ocean. The vegetation there ScrubJays remain with their parentsfor up to five months consistedprimarily of extensiveareas of successionalstage after fledgingand could well learn to clean deer during this coastal scrub (recovering from grazing and limited culti- time. Young Scrub Jays disperseduring their first fall or vation prior to 1965), interspersedwith smaller patches winter and may go surprisingly far. One Scrub Jay that of mature undisturbed coastal scrub. Coyote bush (Bac- was color-banded at Palomarin during its first winter was charispilularis, var. consanguinea)was the predominant recapturedfour years later as a resident of Carson Ridge, shrubin both areas,but substantialnumbers of other coastal 11 km east-northeastof Palomarin. This location is ap- scrub speciesalso occurred, especiallyin the undisturbed proximately 3 km northeast of Alpine Lake. and must be areas. One plant associate,blueblossom (Ceunothus thry- closeto the location where, in 1965, a ScrubJay was seen siflorus),is known to be an especiallyfavored waiting place atop a deer bv Schulz and Budwiser (1970). Thus. it is for the Pacific Coast tick (Dermacentor occidentalis),a possible that young jays could learn ‘cleaning behavior common parasite of both humans and deer at Palomarin from their parents and spread it among other jays when (Robert S. Lane, pers. comm.). The open coastalhills are they disperse from their natal territories. Several other borderedto the eastand north by douglas-fir(Pseudotsuga pairs of color-banded Scrub Jays at Palomarin, however, menziesir) forest and, in the arroyos and canyons, by occupy territories adjacent to the territory of a “learned” broadleaf evergreenwoodland.