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<br />"\T1t3:U~l,~~ation as a SpeciesCo~seryarion T:ool:
<br />Status and'Strategy
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<br />BRAD GRIFFITH, J. MICHAEL Scon, JAMES W. CARPENTER, CHRISTINE REED
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<br />At least 93 species of native birds and manunals were translocated
<br />between 1973, the yeartheEndangeraLSpeciesActbccame law,
<br />and 1986. Most (90%) transloeations were of game species; threat-,
<br />ened, endangered, or sensirivespecies accounted for 7%. Ungulates
<br />(39%), gallinaceous birds (43%), andwaterfowl (12%) dominated
<br />translocations of game species;raptors (28%) and marsupials (22% )
<br />dominated threatened, endangered, or sensitive species transloca-
<br />tions.
<br />, . ":," ", , _, . .: A.typical n:anslocation ~onsjs~ed C?f ~ix ~c1~s '!ver the course of
<br />ATRANSWCATION IS THE INTENTI folAL REL~E OF ANI- '3 years"Many(46%) released 30 or fewer anJn13ls'and most (72%)
<br />mOlls to the wild in an attempt to tablish., reestablish, ~r rcleased75 or f~er :l;flimals.
<br />augment a population (1) and may onsist of more thartone' ' The 'average numbCr of translocations per reporting organization
<br />release. To date, translocations have been sed to establish popula- doubled from 1974 (5.5) to 1981 (10.6) suggesting contemporary
<br />tions of nonnative species and restore na ve species extirpated by totals of 700 translocations per year. Most (98%) of these were
<br />hunting. An increasing perception of the v lue of biological diversi-' conducted in the United States and Canada'; Effort was not uniform-
<br />lY has focused attention on translocation of rare: native species. ly distributed; 21% of North American agencies conducted 71% of
<br />These latter translocations are expensive ( , 3) and are subject to North American translocations. Only 27% of reporting organiza-
<br />intense public scrutiny (4). They have vari d goals (3) that include tions had protocols that specified the types of information to be
<br />bolstering gen,e,ticheterogencity 'of small, pulations (5-7), atab- 'rccordedduring'translocation' programs. - . . '
<br />lishing satellite populations to reduce the r sk of species loss due to '
<br />cat3Srrophes(8, 9). and speeding rccove of species after their
<br />habitats have been restored or recovered fr m the negative effects of Theoretical Considerations
<br />environmental toxicants (2) or other limid g factors.
<br />In the face of increasing species extin ion rates (10-12) and
<br />impending reduction in overall biological, iversity (12). transloca-
<br />tion of rare: species J1l3Y become an' increasi gly important conserva- '
<br />tion technique. If current patterns of h:ibi t loss continue. natural
<br />communities may become restricted to disjunct habitat fragments
<br />. and intervening development may disrupt dispersal and interchange
<br />mechanisms (2). Increased rates of extinction may be expected in
<br />small fragmented habitats (13) and translocation may be required to
<br />maintain community composition, especially for species with limit-
<br />, ed dispersal abilities. .
<br />The immediacy of reduction in biodiversity (14) demands a
<br />rigorous analysis of translocation methodology, results. and strate-
<br />gy. We need to know how well it works. what factors are associated
<br />with success, and ~hat strategies, suggest greatest potential success.
<br />We conducted threc:.survq.s of contemporary ,( 1973 ,to, 1986)
<br />tranSlocatioDs of native birds and mammals in Australia, Canada,
<br />Hawaii. New Zealand, and the United States (15). In the first
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<br />Surveys Df recent (1973 to 1986) intentional releases of
<br />native birds and mammals to the wild in Australia,
<br />Canada, Hawaii;'New Zealand, anll the United States
<br />were, conducted to document current ac:tivities, identify
<br />factors associ~ted with success, and suggest guidelines for
<br />enhancing future work. Nearly 700 translocations were
<br />conducted each year. Native game species constituted 90
<br />percent of translocations and were more successful (86
<br />perCent) than' were translocations of threatened, endan-
<br />ger~ or sensitive species (46 percent). Knowledge_of
<br />habitat quality, location of release area within the species
<br />range, number of animals released, rogram length, and
<br />reproductive traits allowed correct classification of 81
<br />percent ofobscrved translocations a successful or not.
<br />
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<br />+ AUGUST 1989
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<br />survey, we obtained general information on the numl>cr of pro-
<br />gramS completed by various organizations; In the later surveys, we
<br />sought detailed information 'on' translocations of (i) threatened,
<br />endangered, or sensitive species .arid' (ii) , native game birds and
<br />mammals. '
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<br />Current Status
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<br />A, translocation is' a success if it results in a self-sustaining
<br />population; conversely, the founder group may become extinct.
<br />Theoretical "considerations predict" that population <pcrsistcoce ,-is
<br />more likely when the number of founders is large, the rate of
<br />population increase is high, and the effect of competition is low (13).
<br />Low variance in rate of increase (16), presence of refugia (9).
<br />reduced environmental variation (16), herbivorous food habits (17),
<br />and high genetic diversity among founders (18) may also mhar.ce
<br />persistence., Suitable. protected, and maintained habitat, control, of
<br />limiting factors, and proper care' and training of captive reared
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<br />B. Grillith was in the IXpanmcnr of Fisheries and \YJIdlifc Resources, Unh'Cl'sil)' of
<br />Idaho, Moscow, ID 83843, and is cprrcn~ ~",lqdcr,U.S. !fISh and ~ldl!fc,
<br />Service (USfWS),CoopcrativcF~ ,and Wtkllifc Itcsc2tchUnit (CFWRU),~n~'l)'
<br />of Maine.'Ol'OllO.;:MEM469. J. M; -Scott isld~,:USFWS,':C~Ui, Unn'CQll)'qf'i;' .
<br />.,Idaho, M~;ID 83843. JrW,~ra 1S2,I'UC;1fl:h .~~~,;l,I$~~
<br />"l'2rmcnrWildlifc Rcsarch ~cr, l,:iurcl, MI>~07!J8. C. Rtcd IS a ConscMtiOrI
<br />Olliccr, Dcpartmcnr ofConscrvarion;TwiZcI<NcwZa1and. . .
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<br />ARTICLES +77
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