Biological Control of Aleutian Island Arctic Fox: a Preliminary Strategy

WellBeing International WBI Studies Repository

1983

Biological Control of Aleutian Island Arctic Fox: A Preliminary Strategy

Edward W. West University of California - Davis

Robert L. Rudd University of California - Davis

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Recommended Citation West, E.W., & Rudd, R.L. (1983). Biological control of Aleutian Island Arctic fox: A preliminary strategy. International Journal for the Study of Animal Problems, 4(4), 305-311.

This material is brought to you for free and open access by WellBeing International. It has been accepted for inclusion by an authorized administrator of the WBI Studies Repository. For more information, please contact [email protected]. }.K. Blackshaw-lnduced Nest-building in Sows Original Article

tration may be responsible for the differ Hanson, R.P. and Karstad, L. (1959) Feral ences in nest building intensity over the swine in the southeastern United States. oestrous cycle. j Wild/ Mgmt 23:64-73. The acute effects of PG F2cr on the Hughes, P.E. and Varley, M.A. (1980) Re Biological Control sow also raises the question of its suita production in the pig. Butterworth & bility as a drug to induce farrowing. It is Co. Ltd., pp. 50-51,138-141. of Aleutian Island Arctic Fox: easy to ignore these effects if the end re Jones, J. E. T. (1966) Observations on par sult is achieved. If the welfare of the ani turition in the sow. Part 1: The pre-par A Preliminary Strategy mal is considered seriously it is impor tum phase. Brit Vet j 122:420-426. tant to look at all aspects of drug therapy. Kurz, J.C. and Marchinton, R.L. (1972) Ra diotelemetry studies of feral hogs in References South Carolina. j Wild/ Mgmt 36:1240 Edward W. West and Robert L. Rudd Blackshaw, J .K. and Blackshaw, A.W. -1248. (1982) The effects of prostaglandin Pullar, E.M. (1950) The wild (feral) pigs of Drs. West and Rudd are with the Department of Zoology, University of California, Davis, California. (PGF2cr) on the behavior of the Australia and their role in the spread domestic non-pregnant sow and boar. of infectious diseases. Aust Vet j 26: Proc Aust Soc Anim Prod 14th Bien 99-110. Intentional introduction of exotic animals can normally be expected to yield un nial Conf Brisbane 14:550-552. Riddel, 0., Bates, R.W. and Lahr, E.L. (1935) anticipated biological consequences. Single-purpose introductions frequently result Blackshaw, J .K. and Smith, I .D. (1982) Maternal behavior induced in virgin in ecological catastrophe. Islands are particularly vulnerable to such assault. Behavioral effects of PGF2cr in the rats by prolactin. Proc Soc Exper Bioi Arctic foxes [A/apex /agopus), released for the purpose of fur farming on the Aleu non-pregnant sow. App/ Anim Etho/ & Med 32:730-734. tian Islands formerly devoid of land predators, have significantly altered nesting avi 8:581-583. Signoret, J.P., Baldwin, B.A., Fraser, D. and fauna/ diversity, abundance and productivity. A program for restoring the historic dis Diehl, J.R. and Day, B.N. (1974) Effect of Hafez, E.S.E. (1975). The behavior of tribution and abundance of critically affected bird species is described. In a long-term prostaglandin F2cr on luteal function swine. In E.S.E. Hafez (Ed.), Behavior study biological control methods are proposed to test the hypothesis that introduced in swine. j Anim Sci 39:392-396. of domestic animals. London: Bailliere sterile red foxes [Vulpes fulva), apparently a competitively superior species, will markedly Fradrich, H. (1974) A comparison of be Tindall. reduce or extirpate resident Arctic foxes. havior in the Suidae. Vol. 1. The behav Taverne, M., Willemse, H.H., Dielman, S.J. ior of ungulates and its relation to and Bevers, M. (1978/79) Plasma pro management. International Symposium lactin, progesterone and oestradiol- Introduction held at the University of Calgary, Alber 17{3 concentrations around partu ri Attitudes toward population con tion reduction (Rudd, 1964). The present ta, Canada, in November 2-5, 1971, tion in the pig. Anim Reprod Sci 1: trol of introduced mammals range from article describes an example of attempts 133-143. 257-263. regarding them equal or superior to na at eradication of a predatory mammal tive forms to irrational hostility toward population in the Aleutian Islands by an introduced species. Most introductions specific biological means. can be viewed as detrimental in some as The target species is the Arctic fox, pect (Roots, 1976). Although population re A/apex lagopus. Displacement by biologi Animals Bights-Animal Souls? ductions (and the extreme form- eradica cal and behavioral means subsumes our Veterinarian L.T. Keenan of Pomona, New York, writing in the tion) may be generally regarded as benefi methods and purposes. The specific method Journal of the American Veterinary :Medical Association (Vol. 183, cial, controversy inevitably accompanies is generally known as the sterile male July 1, 1983, p. 10) states that he is "tired of being an 'animal doc the methodologies by which reductions technique. Detailed ecological informa tor.' I want to become a 'real doctor.' This can only be achieved if are attemped (Hutchins eta/., 1982). Trap tion is vital to biological control of this animals are believed to have souls and the same basic rights as our ping, shooting, exclusion, and poisoning sensitive character. Especially impor fellow human beings. Only then can I justify to clients large money are the traditional methods used in mam tant is the fact that fox populations to malian population control. Novel, often be controlled are only those on small outlays for reconstructions, repairs, or treatment modalities. It species-specific, methods such as bio is I ands (West et a/., 1982). Throughout would help my professional status if an Animal Bill of Rights were logical control have been introduced in all our work is the background attitude to be proposed and eventually made into the law of the land .... The to insect and weed control practices but that humane and scientific considera sooner this is accomplished, the better it will be for me, my fellow have been rarely attempted in mammal tions can be effectively combined, as veterinarians, and our fellow animals." control. One of us has extensively re well described by Kellert (1982). viewed the many aspects of pest popula- The delicate balance of natural

304 /NT j STUD ANIM PROB 4(4) 1983 /NT j STUD ANIM PROB 4(4) 1983 305 E. W. West and R.L. Rudd- Aleutian Island Fox Original Article E. W. West and R.L. Rudd- Aleutian Island Fox Original Article

174° 177° lBO' 177' 174' 171° 168' 165' The full impact of fox introductions cula) are still heavily preyed upon by fox was first assessed in 1936. Murie (1959) on St. Lawrence Island. Horned puffins ALEUTIAN ISLANDS NATIONAL WILDLIFE REFUGE ALASKA conducted a two-year faunal survey of (Fratercula corniculata) and tufted puf 22 islands along the chain. His findings fins (Lunda cirrhata) are also taken in r------, : G real S1fkln I : showed significant reductions in bird high numbers. On Big Koniuji Island, Moe species diversity, distribution and pro (1977) determined that 6 adult and 7 1 AVakI Lillie 1 1 Tanag~~a Unimak~ ductivity. These changes, he concluded, juvenile fox killed 763 crested auklets i;ilanaqal .~: 54' were primarily due to fox predation. Large and 95 horned puffins over a three-month :I I :I 54° colonies of ancient murrelets (Synthlibo period. On a recent survey of the Alaska : Kagaloska I: I I L ______j rampus antiquus) and Cassin's auklets (Pty Peninsula, which have, or have had foxes, A flu I choramphys aleuticus) vanished from Sa no nocturnal seabirds were found (Bailey, ~ BERING SEA 52° nak Islands. Storm petrels (Oceanodroma 1978). The most significant, and current e::]Agattui Kanagal sp) were entirely eliminated from Salt ly most pressing, ecological concern is ',c 0 Klska~ Tanaqo/7~~~~;. ~-=:- 0 25 50 100 150 200 0 and llak islands. Cassin's auklets went the near total extinction of the Aleutian "- ~- ~~>\~''-xaqalaska I STATUTE MILES PACIFIC OCEAN .. Adak! 0 50 100 150 200 extinct on Keegaloo and Adugak Islands . Canada goose (Branta canadensis leuco KILOMETERS Whiskered auklets (Aethia pygmaea) were pareia). It has vanished from its former LNEARJ L____ RAT___j L__ANDREANOF__j '------FOX----___j also eliminated from the Near Islands. extensive nesting range in the Aleutians ISLANDS ISLANDS ISLANDS ISLANDS Recent bird surveys of other Alas except for a small population on Buldir kan Islands document a continued and Island (Jones and Byrd, 1979).

FIGURE 1 Aleutian Islands in Alaska more widespread reduction in bird pop ulations by the foxes (Stephenson, 1970; Early Management Programs island ecosystems can be easily upset by ies on ecology and population dynamics Bailey, 1978; Bailey and Faust, 1980, 1981). Former attempts by the United States the introduction of foreign organisms. of interactions between the two species Crested auklets (Aethia cristatel/a) and Fish and Wildlife Service to reduce the Island species, isolated from complex will provide an empirical test of the po parakeet auklets (Cyclorrhynchos psitta- impact of fox predation on the Aleutians mainland ecosystems, evolve to form rela tential for complete competitive exclu tively simple communities. These systems sion of the arctic fox by red foxes. generally lack sufficient natural con trols to respond effectively to competi History tion or predation by introduced species. Foxes were first introduced to the Without strong checks on their growth, Aleutian Islands in 1886 by the Russian non-island species increase rapidly. This American Company for the purpose of population growth invariably occurs at the establishing fur "ranches" (Ashbrook expense of many forms of endemic fauna. and Walker, 1925). Pairs of foxes were On the Aleutian Islands in Alaska transported to many islands and left to (Fig. 1) Arctic foxes (Aiopex lagopus, Fig. 2), breed and multiply. After several years introduced for purposes of fur farming, the surplus was trapped off. Islands were have eliminated many breeding popula frequently selected on the basis of bird tions of marine bird species and threaten abundance, a natural food source. By the total extinction of a race of Canada 1925, foxes had been introduced to 77 is Goose (Branta canadensis leucopareia). lands. By 1936 over 25,600 pelts had In an effort to restore island ecosystems been taken from the Archipelago (Jones to their natural state, research has been and Byrd, 1979). The economic depres conducted in cooperation with the U.S. sion after 1929, destroyed the market for Fish and Wildlife Service to develop an wild furs (Chesemore, 1975). With the arctic fox management program using onset of World War II, fur farming was biological control techniques. Sterile red virtually eliminated in Alaska. The foxes foxes, (Vulpes fulva, Fig. 3), a competi remained and without frequent harvest tively superior species in sympatric main their numbers increased. Many endemic land habitats, will be ultimately intro bird populations were markedly reduced duced on a target island (Kagalaska). Stud- or eliminated. FIGURE 2 Arctic fox (A/apex /agopus)

/NT I STUD ANIM PROB 4(4) 1983 307 306 /NT j STUD ANIM PROB 4(4) 1983 E. W. West and R.L. Rudd- Aleutian Island Fox Original Article E. W. West and R.L. Rudd- Aleutian Island Fox Original Article

tional to the degree to which resource the red fox as a control agent would be requirements overlap. If the overlap is successful. It would also be compara complete, coexistence is not possible and tively rapid, economical and environmen over time the less fit species will die out tally safe. or be excluded from the range of sympa try. This ecological relationship is com Field Research monly referred to as the competitive ex Validation of the hypothesis that clusion principle (Hardin, 1960). red fox are effectively displacing the arc Research on the dynamics of sym tic will be obtained if, after introduction, patric populations of arctic and red fox there is a marked displacement of arctic suggest that both types of competition fox from prime denning and foraging sites occur. In Russia, Skrobov (1960) and and a sharp decline in arctic fox numbers. Chirkova (1968) noted that red fox re Baseline data on arctic fox density, place arctic fox wherever their ranges home range, dennings and foraging pat overlap. On Hardangervidda, Norway, Oes terns have been gathered on Kagalaska tybe et a/. (1978) found that the red fox Island (Fig. 1) and are presented elsewhere occupied 50% of the dens originally dug (West eta/., 1982). Foxes have been trapped by arctic foxes. Similar exclusions have in large box traps, ear-tagged and fitted been recorded by Marsh (1938) in Mani with collars bearing radio transmitters. toba, Canada. Tracking results show that resident foxes Recent comparative analysis of the den and forage almost exclusively along social dynamics, territoriality and pop the coast. Analysis of scat composition ulation structure of arctic and red fox by shows that fox diet is comprised largely use of radiotelemetry in Great Britain FIGURE 3 Alaskan red fox (Vulpes fulva) of beach amphipods and birds, although and Iceland also showed marked similar fish are taken during salmon runs. Recap ities between the two species (Hersteins ture data provide an index to density. followed the standard control method tions suggest that the red fox naturally son & MacDonald, 1982). These similari In the future sterilized red fox, col of broadcasting lethal baits on selected controls the numbers of arctic fox locally ties suggest that complete direct com lected in the eastern Aleutian Islands, islands (Springer et a/., 1978). This tech by competitive exclusion and predation. petition between the two species under will be introduced to the island. Groups nique freed only one island (Amchitka) Competition occurs when two spe lies present allopatric distribution. of pairs will be released in selected bays of foxes. In 1972, an executive ban on cies vie for the same resource in limited Red fox are also known to prey upon and coves. From an analysis of similari chemical control agents (primarily com supply. Interaction between species re arctic fox. Alaska trappers consider red ties in food and density requirements pound 1080) limited control activities to duces the fitness and the population foxes to be one of the primary predators (West et a/., 1982) it is estimated that trapping, shooting and the use of M-44's size of the weaker species. This process of arctic fox (Chesemore, 1975). Marsh these introductions will minimally require "coyote getters" (gas-propelled cyanide can occur in one or both of two ways (Pi (1938) found that red foxes often attacked an approximate 1 :2 red to arctic fox guns). These techniques were compara anka, 1974). The first, termed inter and killed trapped arctic foxes. Fur farm ratio and noticeably increase the fox tively slow, expensive and extremely dif ference competition, occurs by direct ers noted that if arctic and red fox were population of the island. Available food ficult to support logistically. Clearly, a physical interaction, such as aggressive placed on the same island the arctic fox and den sites will then be subject to in more expedient, more humane, and tar encounters. In this instance an excessive was soon exterminated. Recent behavioral tense interspecific competition. get-specific program is required to amount of time and energy is required observations of interactions between achieve the management objective of re for competition or its avoidance, so that captive arctic and red foxes showed that Discussion moving foxes. the amount remaining for self-mainte red fox pairs dominated the use of en nance and reproduction drops below sur closures and forced arctic foxes to use The success of a biological control Biological Control vival level. The second process, termed less preferred denning and feeding areas program of this nature depends greatly exploitation competition, occurs when (Rudzinski eta/., 1982). upon the intensity of competition im Biological control is a management one species monopolizes a limiting and Available biological evidence strong mediately following introduction of the program that uses natural controls to reg essential resource (e.g., food or denning ly suggests the hypothesis that red foxes red fox. lsl<:.nd habitats provide optimal ulate the population density of a pest sites) thereby making its use unavailable will eliminate arctic fox when introduced conditions for maximizing the factors in species. Zoogeographic patterns and field to its competitor). The extent to which on the same island. It is therefore very several ways. Islands are confined areas; observations of arctic-red fox interac- competition will occur will be propor- likely that a management program using emigration to escape competitive inter-

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actions is not possible. In addition, be cert will provide a system of natural con 131. (Translated from Russian by Trans and red fox (Vu/pes vu/pes) on Hardan cause of the relatively small size of the trol that is species-specific and avoids the lation Sec., Nat/ Res Council, Ottawa, gervidda, Norway; den ecology, distri islands, the carrying capacity and equi often haphazard methods of trapping, Canada.) bution and population status. Medd librium density for foxes is rapidly at shooting and poisoning. The management Fox, M.W. (ed.) (1975) The Wild Canids: Nor Viltfprsk 3:1-66. tained. Arctic fox numbers are assumed to system proposed exploits naturally oc Their Systematics, Behavioral Ecology Pianka, E.A. (1974) Evolutionary Ecology. be at saturation density. Fluctuations in curring processes that are precise and and Evolution. Van Nostrand Reinhold Harper and Row, New York. 356 pp. population density are primarily density enduring. They easily and logically ap Co., New York. 508 pp. Roots, C. (1976) Anima/Invaders. Universe dependent. Increasing the density of ply to islands in the Aleutian chain and Hersteinsson, P. and MacDonald, D.W. Books, New York. foxes will immediately maximize com may also be modified for other species (1982) Some comparisons between red Rudd, R.L. (1964) Pesticides and the Living petitive pressure. The highly seasonal of insular introduced mammals (cf., Bar and arctic foxes, Vulpes vulpes and Landscape. Univ. of Wisconsin Press, nature of the Aleutian Island environ nett and Rudd, 1983). A/apex /agopus, as revealed by radio Madison. ment also favors concentration and fo tracking. In: C.L. Cheeseman and R.B. Rudzinski, D.R., Graves, H.B., Sargeant, cusing of competitive impact. Breeding Acknowledgments Mitson (eds.). Telemetric Studies of Ver A.B. and Storm, G.L. (1982) Behavioral birds provide ample food for the foxes tebrates. Symp No. 49, Zoo/ Soc Lon interactions of penned red and arctic Financial support under cooperative during the spring and summer. During don, Academic Press. p. 259-289. foxes. j Wild/ Mgmt 46(4):877-884. agreement with the U.S. Fish and Wildlife the winter, however, most birds migrate. Hutchins, M., Stevens, V. and Atkins, N. Skrobov, V.D. (1960) Interrelations of the Service, Alaskan Region, is gratefully ac The foxes are then forced to subsist on (1982). Introduced species and the is polar bear and fox in the tundras of knowledged. We extend our thanks to beach amphipods and carrion (Murie, 1959; sue of animal welfare. tnt J Stud Anim the Nenatsk National Okrug. Zool. many individuals, particularly in the Aleu this study). These food items have lim Prob 4:318-336. Zhur. 39:469-471. tian Islands, but most especially note ited food value and the foxes are nutri Jones, R.D. and Byrd, G.V. (1979) Interre Springer, P.F., Byrd, B. and Woolington, with warmest thanks the sustained high tionally stressed. lations between seabirds and introduced D.W. (1978) Reestablishing Aleutian interest of Dr. Ronald L. Garrett of An Optimally, red fox introductions animals. In: Conservation of Marine Canada geese. In: S.A. Temple (ed.). chorage and Bethel, Alaska. should be made during midsummer to Birds of Northern North America (Pa Endangered Birds, Univ. of Wisconsin minimize the predatory impact on nest per from the International Symp. at Press, Madison. ing birds, and to allow sufficient time for References Seattle, WA, May 1975). Wild/ Res Rep Stephenson, R.O. (1970) A study of the sum the foxes to acclimate to the island be Ashbrook, F.G. and Walker, E.P. (1925) 11. U.S. Fish and Wildlife Serv.. Wash mer food habits of the arctic fox on fore winter sets in. Introduction of foxes Blue fox farming in Alaska. U.S. Dept ington, D.C. St. Lawrence Island, Alaska. Unpubl. from the eastern Aleutian Islands would Agri Bull No. 1350. Kellert, S.R. (1982) Striving for common M.S. Thesis, Univ. of Alaska, College, minimize the acclimation period. To Bailey, E.P. (1978) Breeding seabird dis ground: Humane and scientific consid Alaska. minimize intraspecific competition be tribution and abundance in the Suma erations in contemporary wildlife man West, E.W., West, K.L. and Rudd, R.L. (1982) tween the red foxes, introductions should gin Islands, Alaska. Murrelet 59:82-91. agement. tnt j Stud Anim Prob 3:137- Biological control of Aleutian Island be made at several localities around the Bailey, E.P. and Faust, N.H. (1980) Summer 140. arctic fox. Summary report, Research island, or at periodic intervals to allow distribution and abundance of marine MacPherson, A.H. (1969) The dynamics contract (14-16-0007-80-5519) be adequate time for dispersal. All intro birds and mammals between Mitrofa of Canadian arctic fox populations. tween University of California, Davis, ductions should be made within one sea nia and Sutwick Islands south of the Canadian Wild/ Serv, Rep Ser, 8:1-52. and U.S. Fish and Wildlife Service, son to maximize interspecific competition. Alaska Peninsula. Murrelet 61:6-19. Queens Printer, Ottawa. Anchorage, Alaska. 162 p. Red fox displacement of arctic Barnett, B.D. and Rudd, R.L. (1983) Feral Marsh, D.B. (1938) The influx of the red foxes away from prime feeding areas dogs of the Galapagos Islands: Im fox and its color phases into the Barren will cause a multifaceted reduction in pact and control. tnt J Stud Anim Prob Lands. Canadian Field Nat 52:47-59. arctic fox numbers. As arctic fox are 4:44-58. Moe, RA (1977) The summer diets of three forced into already saturated areas, star Chesemore, D.L. (1975) Ecology of the Arc predator species on Big Koniujii Is vation will occur in addition to secondary tic fox (A/apex /agopus) in North land, Alaska. Unpubl. report, Office causes of mortality induced by physiologi America- a review. In: Fox, M.W. of Bioi. Serv.-Coastal Ecosystems, cal stress. Fecundity could be expected (ed.) 1975. The Wild Canids. Their Sys U.S. Fish and Wildl. Serv., Anchorage, to drop due to reabsorption of embryos tematics, Behavioral Ecology and Evo Alaska. and poorer kit survival. Under condi lution. Van Nostrand Reinhold Co., Murie, O.H. (1959) Fauna of the Aleutian tions of stress foxes are also known to New York. Islands and Alaska Peninsula. North cannibalize mates, young and I ittermates Chirkova, A.F. (1968) The relationship be American Fauna 61:1-104. (MacPherson, 1969; Chesemore, 1975; tween arctic fox and red fox in the far Ostybe, E., Skar, H.J., Svalastog, D. and Fox, 1975). These factors acting in con- north. Problems of the North 11: 129- Westby, K. (1978) Arctic fox (A/apex)

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