© Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ G. Peters 246 Peters, G. (1978a): Vergleichende Untersuchung zur Lautgebung einiger Fehden — (Mammaha, Feh- dae). Spixiana, Suppl. 1, 1-206. (1978b): Einige Beobachtungen zur Lautgebung der Bären: Bioakustische Untersuchungen im Zoologischen Garten. Z. Kölner Zoo 21, 45-51. Roberts, M. S. (1981): Reproductive biology of the red panda, Ailurus fulgens, in captivity. M. S. Thesis, Univ. Maryland, College Park (unpubl.). Roberts, M. S.; Kessler, D. S. (1979): Reproduction in Red pandas, Ailurus fulgens (Carnivora: Ailuropodidae). J. Zool. 188, 235-249. Schäfer, E. (1938): Der Bambusbär (Ailuropus melanoleucus). Zool. Garten N. F. 10, 21-31. Schaller, G. B. (1981): Pandas in the wild. Nat. geogr. Mag. 160, 735-749. Schneider, K. M. (1939): Einiges vom Großen und Kleinen Panda. I. Vom Großen Panda. Zool. Garten N. F. 11, 203-232. Sheldon, W. G. (1937): Notes on the giant panda. J. Mammalogy 18, 13-19. (1975): The Wilderness Home of the Giant Panda. Amherst: Univ. Massachusetts Press. Stirling, I.; Warneke, R. M. (1971): Implications of a comparison of the airborne vocalizations and some aspects of behaviour of the two Australian für seals, Arctocephalus spp., on the evolution and present taxonomy of the genus. Aust. J. Zool. 19, 227-241. Thenius, E. (1979): Zur systematischen und phylogenetischen Stellung des Bambusbären: Ailuropoda melanoleuca David (Carnivora, Mammalia). Z. Säugetierkunde 44, 286-305. Thielcke, G. (1964): Lautäußerungen der Vögel in ihrer Bedeutung für die Taxonomie. J. Orn. 105, — 78-84. Thorpe, W. H. (1961): Bird Song: The Biology of Vocal Communication and Expression in Birds. Cambridge Monographs in Experimental Biology. No. 12. London: Cambridge Univ. Press. Trillmich, f.; Majluf, P. (1981): First observations on colony structure, behavior, and vocal repertoire of the South American Für Seal {Arctocephalus australis TÄmmermznn, 1783) in Peru. Z. Säugetierkunde 46, 310-322. B.; Richards, R. E. (1981): Vocalizations of the ringtail (Bassariscus astutus). SWest. Nat. 26, 23-30. WiLLEY, R. Author's address: Dr. Gustav Peters, Zoologisches Forschungsinstitut und Koenig, Adenauerallee 150-164, D-5300 Bonn 1 Trichinelh spiralis in walruses from the Thüle North Greenland, and E. W. Born, B. Museum Alexander district, possible routes of transmission Clausen and Sv. Aa. Henriksen Receipt of Ms. 5. 2. 1982 Abstract from 126 Atlantic walruses, Odobenus rosmarus rosmarus (L.), collected in the Thüle district. North Greenland (1975, 77 and 78), for Trichinella spiralis. Two adult males were found to be infected with Trichinella spiralis (prevalence of 1.6%). It is suggested that the walrus in the Thüle district contracts trichinosis from scavenging on Examined samples of muscle tissue carcasses of polar bears or/and sied dogs. Introduction The parasite Trichinella, spiralis in the walrus ( Odobenus rosmarus Linnaeus) is a potential An epidemic disease in 1947 among the Inuit of central West Greenland was caused by the eating of trichinous walrus meat (Thorborg et al. 1948; Roth 1949). Since then, trichinous walruses have been reported from different arctic areas threat to the Inuit health. U.S. Copyright Clearance Center Code Statement: Z. Säugetierkunde 47 (1982) 246-251 © 1982 Verlag Paul Parey, Hamburg und Berlin ISSN 0044-3468 / InterCode: ZSAEA 7 0044-3468/82/4704-0246 $ 02.50/0 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ 247 Trichinella spiralis in the Atlantic walrus (e. g. Roth and Madsen 1953; Rausch et al. 1956; Brown et al. 1949; Kuitunen Thorshaug and Rosted 1956; Fay 1960; Madsen 1961 Kozlov 1971 Thing et al. ; Margolis ; 1954; 1976; et al. 1979). North Greenland, the walrus is a cornerstone in the subsistence do occasionally cause trichinosis in humans. In the fall 1977 a woman and two children were severely sick of trichinosis after having eaten raw walrus meat which was insufficiently frozen. The Inuit of Grise Fjord at Ellesmere Island, Canada, take a limited number of walruses from the same population (Bowler 1976, fide Reeves 1978). In the Thüle district, catch and trichinous walruses Materials and methods Samples of diaphragma, the masseter and the intercostal muscles from 126 walruses (64 males, 59 females and 3 with no sex recorded) in the Thüle district were collected in 1975, 1977 and 1978 (Fig. 1). of the Inuit annual subsistence catch of walrus on the Stretch, The total sample represents about 60 Saunders Island (Agpat, 76°30'N) to Cape Inglefield (Anoritooq, 78°30'N) in the period 24 April until 28 July. The samples were kept frozen at minus 12 °C until examination in the laboratory where 15-20 g muscle from each individual were examined in a trichinoscope and by digestion (Henriksen % 1978). The ages of 106 walruses caught in 1977 and 1978 were determined from growth layers in the cement of the lower cheek teeth as described in Mansfield (1958) and Krylov (1965). No teeth for age determination were obtained from 20 walruses in 1975 (reported in Thing et al. 1976). However, an approximate age has been determined for these specimens by comparison of: 1. nosetail length and 2. tusk length and circumference, with age-dependent growth curves established on measurement results of walruses of known age collected in 1977 and 1978. Results ^zs detected in two adult males. One was killed 28 May 1975 off Neqe Murchison Sound. According to tusk and body dimensions this male was about 12 years old and in good condition. No larvae were detected in the trichinoscope, but 1-2 larvae per gram muscle tissue were found after digestion, this indicating a low infection level. The other infected walrus was a 20-year-old, apparently healthy, male killed 6 June 1978 off the northeastern point of Northumberland Island (Kiataq). This animal was infected with about 50 Trichinella larvae per gram muscle tissue, indicating a moderate infection level. Trichinella spiralis in The results of the present study are shown in the Table together with the results of other studies for comparative purposes. In this study the overall infection prevalence in the walrus from the Thüle district is 1.6%. Including the 74 walruses recorded (1961) the infection prevalence in the Thüle area is 1.0 in Madsen %. Although there is no criterion for determining whether a walrus is trichinous or not, from physical appearance alone, it should be mentioned that the infected male taken in 1978 had an abnormal hump on its Shoulders. By a superficial inspection this hump consisted of normal-looking somatic muscle tissue and blubber. In the fall 1977 three persons in the Thüle district became severely sick of trichinosis after having eaten infected meat from an old bull which had been caught at Northumberland Island. Judged from the skull of this walrus it was estimated to be at least 20 years old. Discussion Trichinella spiralis in the walrus and other marine mammals is puzzling. The an inshore bottom-feeder whose main diet consists primarily of bivalve molluscs. The finding of walrus is Occasionally an insignificant number of fish and decapod crustaceans are also found in the © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ 248 E. W. Born, N Clausen und Sv. Aa. Henriksen B. 126 = Age composition of the com- bined sample of walruses analyzed for Trichinella spiralis (1975, 1977 and 1977), Thüle North Greenland. district Black columns = males; White columns = females; Gross hatched columns = animals with age determined from tusk and Body measures 0 5 Table Prevalence of Trichinella spiralis Area among walruses (Odobenus rosmarus) in different arctic areas No. No. % examined infected infected 104' 1 1.0 401' 17 7 4.2 0 0 0.0 18' 271' 5 1.8 10' 0 0.0 (1961) 74' 0 0.0 1975 1977 1978 242 1 4.2 492 0 0.0 532 1 1.9 Alaska Eastern Canada The Svalbard Area 74' 9.5 Source Rausch Fay (1960) Kuitunen (1954) Thorshaug and Rosted (1956) Brown et al. (1956); et al. (1949); Greenland East Greenland Upernavik (NW. Greenl.) Egedesminde (W. Greenl.) Frederikshab (W. Greenl.) Thüle ' district 1' 0.0 Madsen (1961) 1 (N. Greenl.) Trichinoscopical detection. - 2 Madsen (1961) Thing et al. (1976); this study This study This study Trichinoscop ical detection and digestion. stomach (Dunbar 1949; Vibe 1950; Mansfield 1958; Fay and Lowry 1981). Because Trichinella is absent from these food items different alternative routes of infection in the walrus have been proposed. Vibe (1950), Rausch et ah (1956) and Fay (1967) suggested that Trichinella is transferred from carcasses of polar bears and sied dogs to marine mammals, with amphipods serving as „intermediate hosts". The transfer of Trichinella Viz amphipods (Fay 1967) and via fish (Kozlov 1971) has been experimentally demonstrated. Although the ringed seal {Phoca hispida Schreber) feeds extensively on amphipods and (one of 1775 examined) Trichinella other crustaceans (e.g. McLaren 1958), only 0.06 (two of 300 infected ringed seals have been found in Greenland (Madsen 1961) and 0,7 % % examined) in Alaska (Fay 1960). These findings indicate that transfer of Trichinella via amphipods to marine mammals is very unusual and may be even more unlikely in the case of the walrus, which does not feed on crustaceans to any extent. Fay (1960), underlining the occasional carnivorous habits of the walrus, suggested that walruses might be infected © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ 249 Trichinella spiralis in the Atlantic walrus from bearded {Erignathus harhatus Erxleben) and ringed seals seals. The walrus kills seals during periods of famine, and there are several reports of walruses with remnants of seals in the stomach (e.g. Johansen Fay Manning 1959; 1960). 1910; 1935; Vibe 1950; Loughrey low frequency of seals infected Degerb0L and Freuchen (1960) drew attention to the with Trichinella and suggested that a polar bear-walrus-polar bear cycle could not be ruled out. It is most likely that the walrus is infected when scavenging on polar bear carcasses, as suggested by Manning (1960) or on polar bear and sied dog carcasses (Vibe 1950). In the Thüle 20 and 91 district Trichinella KoZLOV % of the polar bears (3 of 15 examined) was found to be infected with % (38 of 42 examined) of the sied dogs was also infected (Madsen 1961). main source of Trichinella infection in mammals. In the Thüle district the Inuit kill diseased and old sied dogs and leave them on the ice in the tidal zone before ice break-up in June-July (Vibe 1950 and own information). This activity is designed to eliminate the necessity of feeding surplus dogs during the open water period. About 200-300 dogs of a total of about 1500-1600 sied dogs in the Thüle district are disposed in this manner every year. If the walrus contracts trichinosis when scavenging on polar bear and dog carcasses this route of infection could also explain why trichinous bearded seals have been found, as reported by Madsen (1961). The bearded seal is also a bottomfeeder (Vibe 1950) which has never been reported to prey on other seals, to our (1971) was pinnipeds and whales is also of the opinion that the carcasses of terrestrial and marine knowledge. The average annual catch of walruses in the Thüle district is about 200 animals of which are males (own information). Thus, probably three to four trichinous walruses about 53 are taken in the district annually. The yield of the annual walrus catch is about 80 tons of meat, blubber and hide. While most of the yield is used for dog food an unknown Proportion is eaten by humans. In the case of the walrus the epidemiological risk to humans is theoretically large because walrus meat is distributed to many households in the communities in contrast to the meat of other pinnipeds and of the polar bear. About 77 of the annual catch of walrus is taken in the period from May until October (own information) where temperatures in the Thüle district are often about or above freezing % % point which increases the risk of walrus meat being infectious. household freezers are not low enough to reduce infectivity of arctic 1981). For example, portions of infected meat of the Alaskan black bear {Ursus americanus Pallas) held at minus 15 °C for up to 35 days showed no loss of Temperatures Trichinella ssp. in (Anon. infectivity for laboratory animals (Anon. 1979, fide Anon. 1981). Thus, walrus meat must be cooked thoroughly, which according to Ransom and ScHWARTS (1919) means that all parts of the meat must be raised to 58 °C (137 F) in order to kill the encysted Trichinella larvae. In the Thüle district the walrus meat is boiled on kerozene burners, and at least when on hunting trips the Inuit often eat the meat while parts of it are only half done. Furthermore, raw walrus meat which previously has been frozen for a variable period is also eaten. Acknowledgements We wish to thank the Inuit of the Thüle district for their great help during our work in the area. Furthermore, we wish to express our gratitude to Dr. Therese Kristensen, Zoological Museum of Copenhagen, for collecting some of the samples, and Dr. Holger Madsen, Zoology Laboratory University of Copenhagen, for offering useful criticism during the preparation of this paper. This study was supported by grants from the Danish Natural Science Research Council and from the Commission for Scientific Research in Greenland. © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ 250 E. W. Born, B. Clausen und Sv. Aa. Henriksen Zusammenfassung Trichinella spiralis in Walrossen aus dem Thule-Gebiet, Nordgrönland, und mögliche Wege der Übertragung Fleischproben von 126 Atlantischen Walrossen, Odobenus rosmarus rosmarus (L.) aus dem ThuleGebiet, Nordgrönland (1975, 1977 und 1978), sind auf Befall durch den Parasiten Trichinella spiralis analysiert geworden. Zwei erwachsene Bullen waren mit Trichinella spiralis infiziert (Häufigkeit 1,6 %). Es wird angenommen, daß das Walroß aus dem Thule-Gebiet durch Fressen von Eisbären- und/ oder Hundekadavern infiziert wird. References Anonymous (1979): Trichinosis surveillance annual summary 1978. Center for Disease Control, Sept., 1979. Anonymous (1981): Trichinois Associated with Meat from a Grizzly Bear. Morbidity and Mortality Weekly Report, Center for Disease Control, March 20, Vol. 30, 15-21 Brown, M.; Cronk, B.; de Sinner, F.; Green, J. E.; Gibbons, J. E.; Kuitunen-Ekbaum (1949): A Note on Trichinosis in Animals of the Northwest Territories. Can. Public Health 40, 20-21. Degerbol, M; Freuchen, P. (1935): Mammals. Report of the Fifth Thüle Expedition 1921-1924, (4-5): 278 pp. Copenhagen: Gyldendalske Boghandel. Nordisk Forlag. DowLER, D. H. (1976): Average marine mammal harvest 1973 to 1975. Northwest Territories. (Unpubl. tables received from H. R. Trudeau. Fish, and Marine Service, Yellowknife, N. W. T.). Dunbar, M. J. (1949): The pinnipedia of the arctic and subarctic. Fisheries Research Board of Canada. Bulletin 85, 1-22. Fay, f. H. (1960): Carnivorous walrus and some arctic zoonoses. Arctic 13, 111-122. Fay, f. H. (1967): Experimental transmission of Trichinalla spiralis via marine amphipods. Can. J. Zool. 46, 597-599. Fay, f. H.; Lowry, L. F. (1981): Seasonal use and feeding habits of walruses in the proposed Bristol Blay dam fishery area. Final Report to North Pacific Management Council P.O. Box 3136 DT, Anchorage, Alaska 99510, U.S.A. Contract No. 80-3. Henriksen, Sv. Aa. (1978): A new teqnique for demonstration of Trichinella spiralis larvae in suspensions of digested muscle tissue. Acta vet. scand. 19, 466-68. Johansen, f. (1910): Observations on Seals (Pinnipedia) and Whales (Cetacea) on the Denmark Expedition, 1906-1908. Meddelelser om Grönland 45, 203-224. KozLOV, D. P. (1971): K voprosu o putyakh zarazheniya lastonogikh trikhinellezom. Trudy Gel' mintologicheskoi Laboratorii Akademii Nauk SSSR 21, 36-40. (Sources of Trichinella spiralis infection in pinnipeds. Fisheries Research Board of Canada 1974, Translation Series No. 3010). Krylov, V. I. (1965): Opredelenie vozrasta, temp rosta i analiz vozrastnoi struktury poboek tikhookeanskogo morzha. Morskie mlekopitayushchie. Akademiya Nauk SSSR. Izdatel'stvo Nauko, Moskva: 201-210. Determination of age, rate of growth and analysis of the age structure of the Pacific walrus catch. Fisheries Research Board of Canada 1968. Translation Series No. 1004). Kuitunen, E. (1954): Walrus meat as a source of trichinosis in Eskimos. Can. J. Public Health 45, 30. LouGHREY, A. G. (1959): Preliminary Investigation of the Atlantic Walrus Odobenus rosmarus rosmarus (Linnaeus). Can. Wildl. Serv., Wildlife Management Series 1, No. 14. Madsen, H. (1961): The distribution of Trichinella spiralis in sledge dogs and wild mammals in Greenland under a global aspect. Meddelelser om Grönland 159. Manning, T. H. (1960): Gommerns on "Carnivorous Walrus and Some Arctic Zoonoses". Arctic 14, 76-77. Mansfield, A. W. (1958): The Biology of the Atlantic Walrus {Odobenus rosmarus rosmarus L.) in Eastern Canadien Arctic. Journal of Fisheries Research Board of Canada. Manuscript Report Ser. Biol. 653. Margolis, H. S.; Middaugh, J. P; Burgess, R. D. (1979): Arctic Trichinosis: Two Alaskan Outbreaks from Walrus Meat. J. Infect. Diseases 139, 102-105. McLaren, I. A. (1958): The Biology of the Ringed Seal {Phoca hispida Schreber) in the Eastern Canadian Arctic. Journal of Fisheries Research Board of Canada. Bulletin 118. Ransom, B. H.; Schwartz, B. (1919): Effect on heat on trichinae. J. Agricult. Res. 17, 201-221. Rausch, R.; Babero, B. B.; Rausch, R. V.; Schiller, E. L.; (1956): Studies on the helminth fauna of Alaska. XXVII. The occurrence of larvae of Trichinella spiralis in Alskan mammals. Parasitology 42, 259-271. Reeves, R. R. (1978): Atlantic walrus {Odobenus rosmarus rosmarus): A literature survey and Status report. Unites Staates Department of the Interior. Fish and Wildlife Service. Wildlife Res. Report 10. Roth, H. (1949): Trichinosis in arctic animals. Nature 163, 805-806. © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/ 251 Trichinella spiralis in the Atlantic walrus Roth, H.; Madsen, H. (1953): Die Trichinose in Grönland, abschließender Bericht der Jahre 1948-1953. Proc. 14th Int. Congr. Zoology. Section X, Copenhagen, 340-341. Thing, H.; Clausen, B.; Henriksen, Sv. Aa. (1976): Finding of Trichinella spiralis in a walrus {Odobenus rosmarus L.) in the Thüle district, Northwest Greenland. Nordisk Vet. Med. 28, 59. Thorborg, N. B.; Tulinius, S.; Roth, H. (1948): Trichinosis in Greenland. Acta Pathologica 25, 778-794. Thorshaug, K.; Rosted, A. F. (1956): Researches on the prevalence of trichinosis in animals in Arctic and Antarctic waters. Nordisk Vet. Med. 8, 115-129. Vibe, C. (1950): The marine mammals and the marine fauna in the Thüle district (Northwest Greenland) with observations on ice conditions in 1939 in 1939-1941. Meddelelser om Grönland 150. W. Born, Greenland Fisheries Investigations, Tagensvej 135, DK-2200 Copenhagen N; B. Clausen and Sv. Aa. Henriksen, State Veterinary Serum Laboratory, 27 Bülowsvej, DK-1870 Copenhagen V Authors' addresses: E. WISSENSCHAFTLICHE KURZMITTEILUNGEN Der Einfluß der Domestikation auf der die Riechleistung Hausmaus (Mus musculus) Von Christel Schmidt und U. Schmidt Zoologisches Institut der Universität Bonn Eingang des Ms. 6. 1. 1982 Domestizierte Tiere unterscheiden sich von ihren freilebenden Wildformen nicht nur durch Veränderungen im äußeren Erscheinungsbild (Größe, Fellfärbung, Schädelform etc.), sondern auch durch die Kapazität ihrer Hirnschädel. Darwin (1859) wies erstmals auf dieses Phänomen hin; inzwischen wird die Abnahme der Hirngröße als ein Charakteristikum der Domestikation angesehen (Herre und Röhrs 1973). Nieder evoluierte (Laborratte: 8,3 %; Kruska Gehirne, wie die der Nager, weisen dabei mit bis zu 9 1975b) jedoch weit geringere Gewichtsverluste auf als in der Evolution höher stehende (Hausschwein: 33 %; Kruska 1970). Eine Ausnahme macht die Labormaus, bei der sich im Vergleich mit der westHchen Hausmaus keinerlei Hirngrößenunterschiede ergaben % (Nord 1963). Veränderungen des Hirngewichtes sagen jedoch nicht unbedingt etwas über die Leistungsfähigkeit einzelner Funktionsbereiche aus, da Teilstrukturen wesentlich stärkere Umwandlungen aufweisen können als das Gesamtsystem, So besitzt z. B. die Laborratte, größeren Bulbus Gesamthirngewichtsabnahme von 8,3 %, einen um 4,5 olfactorius und ein um 11,2 vergrößertes Tuberculum olfactorium als die Wanderratte % trotz einer % (Kruska 1975a). am olfaktorischen System der wilden Hausmaus und der Labormaus sollten klären, ob bei dieser Art, die als einzige keinerlei Abweichungen im Hirngewicht aufweist, Divergenzen in der Leistungsfähigkeit des Elektrophysiologische Untersuchungen olfaktorischen Systems auftreten. Männchen der wilden Hausmaus (Wildfänge und Fl), Elektroden (Methode: Schmidt 1978) wurden neurale olfakto- Als Versuchstiere dienten adulte Mit Hilfe fest implantierter U.S. Copyright Clearance Center Code Statement: 2. Säugetierkunde 47 (1982) 251-252 © 1982 Verlag Paul Parey, Hamburg und Berlin ISSN 0044-3468 / InterCode: ZSAEA 7 0044-3468/82/4704-0251 $ 02.50/0 ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Mammalian Biology (früher Zeitschrift für Säugetierkunde) Jahr/Year: 1981 Band/Volume: 47 Autor(en)/Author(s): Born E.W., Clausen B., Henriksen S.A. Artikel/Article: Trichinelh spiralis in walruses from the Thüle district, North Greenland, and possible routes of transmission 246-251