6—
OPTIONS FOR MANAGEMENT OF THE 'ALALA

Success in endangered-species preservation is possible only when the right combination of people and techniques are allowed to operate with adequate financial support and minimal institutional and political interference. The key ingredients for successful recovery programs are imaginative planning, effective administrative organization and commitment, funding continuity, creative and dedicated staffing, and effective communication and cooperation among interested and affected parties. Most of those programmatic ingredients are obvious, but the critical importance of coordination and cooperation needs to be emphasized. Recovery programs are never conducted in a vacuum, and they typically affect, directly or indirectly, diverse interest groups represented by government agencies, academic institutions, conservation organizations, and private land-holders. Without the support and cooperation all of the parties, decisions will usually be made in the political rather than biological arena, and recovery actions will be thwarted or delayed.

As noted in Chapter 5, decisions about what to do to save critically endangered species involve complex considerations of biology, societal concerns, and government regulation. In selecting a course of action, it is often helpful to lay out all the basic options and to consider the positive and negative ramifications of each. Indeed, the techniques and processes of "risk analysis" or "decision analysis" are receiving increased attention from conservation biologists (Maguire, 1991; Starfield and Herr, 1991). Table 6.1 summarizes eight options for joint management of the two subpopulations of 'Alala and presents their main pros and cons. By comparing the advantages and disadvantages of these options, we might be able to clarify the tradeoffs among alternative courses of action and thereby reach a consensus (or at least maximize agreement) on how to save the 'Alala and its habitat.

Option 1. Passive Management (Protection) of Wild Population

This is essentially the only action that has been followed for the last decade to aid the wild crows. The relict population on the McCandless Ranch appears to have remained relatively stable during this period. Passive management could continue to maintain the status quo as long as natality balances mortality, or it could result in a slow increase in local numbers if natality exceeds mortality, as in the population model developed in Chapter 2. Passive management will not result in a rapid increase in the number of crows or in a major expansion of their geographic



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Scientific Bases for the Preservation of the Hawaiian Crow 6— OPTIONS FOR MANAGEMENT OF THE 'ALALA Success in endangered-species preservation is possible only when the right combination of people and techniques are allowed to operate with adequate financial support and minimal institutional and political interference. The key ingredients for successful recovery programs are imaginative planning, effective administrative organization and commitment, funding continuity, creative and dedicated staffing, and effective communication and cooperation among interested and affected parties. Most of those programmatic ingredients are obvious, but the critical importance of coordination and cooperation needs to be emphasized. Recovery programs are never conducted in a vacuum, and they typically affect, directly or indirectly, diverse interest groups represented by government agencies, academic institutions, conservation organizations, and private land-holders. Without the support and cooperation all of the parties, decisions will usually be made in the political rather than biological arena, and recovery actions will be thwarted or delayed. As noted in Chapter 5, decisions about what to do to save critically endangered species involve complex considerations of biology, societal concerns, and government regulation. In selecting a course of action, it is often helpful to lay out all the basic options and to consider the positive and negative ramifications of each. Indeed, the techniques and processes of "risk analysis" or "decision analysis" are receiving increased attention from conservation biologists (Maguire, 1991; Starfield and Herr, 1991). Table 6.1 summarizes eight options for joint management of the two subpopulations of 'Alala and presents their main pros and cons. By comparing the advantages and disadvantages of these options, we might be able to clarify the tradeoffs among alternative courses of action and thereby reach a consensus (or at least maximize agreement) on how to save the 'Alala and its habitat. Option 1. Passive Management (Protection) of Wild Population This is essentially the only action that has been followed for the last decade to aid the wild crows. The relict population on the McCandless Ranch appears to have remained relatively stable during this period. Passive management could continue to maintain the status quo as long as natality balances mortality, or it could result in a slow increase in local numbers if natality exceeds mortality, as in the population model developed in Chapter 2. Passive management will not result in a rapid increase in the number of crows or in a major expansion of their geographic

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Scientific Bases for the Preservation of the Hawaiian Crow Table 6.1 Potential management options for Hawaiian Crow Advantages Disadvantages 1. PASSIVE MANAGEMENT (PROTECTION) OF WILD POPULATION a. Prevents harmful influences and mortality related to human activity b. Provides compelling reason to maintain suitable habitat c. Affords opportunity to obtain some biological information a. Ignores conservation methods successful with other avian species b. Precludes veterinary support or monitoring of disease c. Prevents collection of data necessary for managing wild and captive populations d. Does not protect small population from chance extinction 2. REMOVAL OF ALL BIRDS TO CAPTIVITY a. Might increase genetic diversity in captive population b. Diminishes responsibility to protect the habitat c. Protects last remaining birds from natural mortality in the wild d. Increases potential for research studies of captive birds e. Provides a source of birds for reintroduction a. Increases risk of losing species as a result of a local catastrophe b. Increases size of captive population c. Eliminates habitat use and social traditions necessary for successful reintroduction d. Adult wild-caught birds are less likely to breed in captivity than in wild e. Might increase risk of transmitting diseases between wild and captive birds f. Eliminates acquisition of essential information on wild birds

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Scientific Bases for the Preservation of the Hawaiian Crow Advantages Disadvantages 3. TRANSLOCATE ALL WILD BIRDS TO ANOTHER LOCATION IN THE WILD a. Could allow research and management under more favorable sociopolitical conditions b. Theoretically, birds could be moved to a more favorable environment a. Creates a potentially harmful effect of trapping and handling b. Birds might fail to acclimate to new situation and survive c. Provides no benefits unachievable in other ways d. Removes incentives to maintain existing habitat e. Factors responsible for the decline of species in areas of former distribution would not be identified or addressed 4. REMOVAL OF EGGS FROM WILD POPULATION FOR ARTIFICIAL INCUBATION a. Should increase hatchability and survivability of eggs and chicks and therefore increase reproductive output b. Should increase the size of the annual cohort of young because Crows are capable of renesting and laying more than one clutch c. Allows determination of fertility and causes of embryo death d. Provides method to increase number and genetic diversity of captive birds e. Provides birds for enhancing or establishing wild or captive population f. Provides opportunities to conduct field research on released birds (e.g., with radiotelemetry) a. Optimum techniques for artificial incubation are not yet established for the crow b. Hatching and rearing chicks close to nesting birds will require new staffing and facilities c. Some nesting pairs might not lay another clutch of eggs when first clutch is taken

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Scientific Bases for the Preservation of the Hawaiian Crow Advantages Disadvantages 5. REMOVAL OF NESTLINGS FROM WILD POPULATION a. Circumvents uncertainties and facilities required for artificial incubation b. Increases the number and genetic diversity of captive population c. Increases number of birds available for release in unoccupied territory d. Might increase survival rate of young raised in the wild (fewer mouths to feed) a. Does not increase the gross reproductive output of the overall population b. Greatly decreases the possibility of renesting and producing more eggs 6. FOSTERING AS A METHOD OF RELEASE a. Is the simplest and least expensive way to release captive-reared b. Allows young to interact naturally with adult, parent crows a. Nestling mortality in the wild decreases effectiveness of fostering birds (e.g., caused by predation, disease, sibling competition) b. Opportunities with small number of wild pairs are few 7. HACKING AND OTHER "SOFT" METHODS OF RELEASE a. Allows release in vacant range where species is not already present (creates new populations) b. Circumvents early-nestling mortality and in some cases first-year mortality, depending on when birds are release c. Allows release of large numbers of birds independently of wild birds d. Allows for adequate prerelease quarantine and screening for parasites and disease e. Provides opportunity for establishing new behavior patterns and social organizations more adaptive to changed environments a. Is labor-intensive and expensive b. Naive birds held too long in captivity might lose capacity to adjust to wild conditions c. Captive birds might not learn essential social traditions and survival skills needed in the wild

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Scientific Bases for the Preservation of the Hawaiian Crow Advantages Disadvantages 8. EXCHANGE OF CAPTIVE AND WILD CROWS a. Might increase genetic diversity of wild and captive populations b. Allows captive and wild birds to be managed as one population c. Could aid in formation of viable wild pairs a. Increases the risk of disease transmission between populations b. Captive birds might not survive and reproduce well in the wild c. Wild adult birds are less likely to breed in captivity than in the wild d. Captive-raised birds might show serious behavior deficits (e.g., in foraging, predator recognition, and interactions with conspecifics) e. Does not increase the gross reproductive output of the overall population f. Requires close synchrony in breeding of wild and captive pairs range. The expansion of their range, through the establishment of additional, separate populations (''metapopulation") (Levins, 1970; Soulé, 1987; Simberloff, 1988), is one of the main strategies needed for long-term survival of the species. Moreover, for the foreseeable future, an unmanaged crow population will remain so small that it will continue to be subject to a high probability of extinction from chance events related to genetics, demography, or local environmental catastrophes. It is true that passive management provides a compelling reason to maintain the crows' existing habitat and affords some opportunity to obtain needed biological information unobtrusively (e.g., determination of incubation time, nestling period, social structure, and seasonal movements and their biological functions), but those benefits are not precluded by some other options that emphasize active management. The possible prevention, by passive management, of harmful disturbances or deaths resulting from human actions must be weighed against the benefits of manipulation. Although there is some evidence that research-related disturbances during past breeding seasons caused pairs to abandon their nests, such disturbances can be minimized by the use of proper research techniques and by progressive conditioning of

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Scientific Bases for the Preservation of the Hawaiian Crow birds (cf. Grier and Fyfe, 1987). The benefits to species survival of active management far outweigh the occasional losses of individual birds associated with accidents that result from research or management. When its advantages and disadvantages are compared, Option 1, passive management, evinces no compelling benefits as the exclusive mode for conserving the 'Alala. It is time to replace passive management with intelligently considered, and carefully executed, active management. Option 2. Removal of All Birds to Captivity Translocation of all individuals of a species from the wild to captivity is an extreme measure that has been carried out on only a few endangered species—the California Condor (Snyder and Snyder, 1989), the black-footed ferret (Mustela nigripes) (Thorne and Williams, 1988; Clark, 1990), the Guam Rail (Rallus owstoni), and the Micronesian Kingfisher (Halcyon c. cinnamomina) (Witteman et al., 1990). In those cases, the surviving populations were so small (10–30 birds remaining in the wild) and the adult mortality so abnormally high that extinction within a few years could be confidently predicted. It should be noted that the captive populations of the condor, ferret and rail have thrived with high reproductive success; and the first exploratory releases of captive-produced animals have been initiated in the last 2 years. It remains problematical, however, whether any of these species can be re-established in the wild in the absence of social organization or a tradition of habitat use into which animals released from captivity could fit, although Andean Condors might function as guides for the released California birds. For some species with relatively simple social systems and largely innate (instinctive) responses to environmental factors—such as food, nest sites, and predators—re-establishment of naive animals into vacant habitat is relatively easy; the Peregrine Falcon (Falco peregrinus) is an example. For other species, with highly developed social organizations and a dependence on learning to cope adaptively with environmental factors, reintroduction is much more complicated and has a lower probability of success (Lyles and May, 1987; Snyder and Wallace, 1987; Scott et al., 1988; Snyder and Johnson, 1988; Griffith et al., 1989, 1990; Derrickson and Snyder, 1992). Removal of all 'Alala to captivity has been seriously discussed. Certainly the number of surviving crows is critically low, and high adult mortality has been implicated in this report as a more important factor than poor reproduction in the decline of previous decades (Chapter 2). It is hard, therefore, to argue against any of the advantages listed in Table 7.1. However, the amount of genetic diversity that would be introduced into the captive population by Option 2 would depend on how distantly related the wild birds were to the captive birds, and those relationships are unknown. (It is likely that all surviving 'Alalas are inbred to some degree—see Chapter 3.) Protecting all birds from high mortality in the wild is the only benefit that could not be accomplished by other options, but adult survivorship in the single remaining wild population appears to be high (see Chapter 2).

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Scientific Bases for the Preservation of the Hawaiian Crow Some of the disadvantages of Option 2 could be partly mitigated. Protection from catastrophic events in captivity could be increased by housing the crows in multiple facilities. Legally binding agreements could be reached about protecting the vacated habitat for future reintroduction. Improved veterinary services could greatly reduce the risks of diseases in captivity. The option would, however, absolutely preclude acquisition of further information about crows in the wild and would destroy existing social traditions and learned habitat uses specifically related to the McCandless Ranch, the only environment that is certainly still suitable for crows. For several reasons, Option 2 should be viewed as a last resort, to be undertaken only if it becomes certain that adult mortality exceeds recruitment and that the number of breeders is clearly in decline. First, the available data (Chapter 2) indicate that the relict population of crows on the McCandless Ranch has been relatively stable in number for the last decade and might even be increasing slightly and producing a surplus of nonbreeders for potential dispersal or new territory establishment. Second, there is a great need to obtain information on the biology of crows in the wild that is critical for management. Third, like other corvids, the 'Alala appears to have a relatively complicated social system and is probably a species that depends on transferring adaptive information and habits from parents to offspring. Although leaving the remnant population in the wild constitutes a risk whose magnitude depends on the uncertainties inherent in the demographics of small populations and on unpredictable environmental catastrophes, it appears that the disadvantages of Option 2 outweigh the advantages, especially because most of the advantages can be achieved through other options that depend on retaining a viable population of wild crows. Option 3. Translocation of All Wild Birds to Another Location in the Wild This extreme measure has been used successfully to rescue the Chatham Island Black Robin from probable extinction in New Zealand (Reed and Merton, 1991). It has also been proposed for the 'Alala, primarily to circumvent sociopolitical problems that have hampered state and federal efforts to manage the wild crows, most or all of which now live on private land. From a regulatory and institutional standpoint, there could be advantages to having the crows on public land, rather than private land. If the new location were biologically more suitable than the current range, that would be an added incentive for such a translocation. However, there is no certainty that the crows would adapt to a new location; more important, translocation of all crows provides no biological or managerial benefits that could not be achieved in other ways. Option 3 is not recommended, although once numbers are increasing, the translocation of some birds to a new areas could be a reasonable future option, as a method of establishing additional populations. Cooperation of private landowners would need to be an integral part of the recovery plan.

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Scientific Bases for the Preservation of the Hawaiian Crow Option 4. Removal of Eggs from Wild Population for Artificial Incubation Egg removal ("egg-pulling," "double clutching," or "multiple clutching") is an increasingly common method for augmenting the natural reproductive output of wild birds (Carpenter and Derrickson, 1981; Derrickson and Carpenter, 1987; Cade et al., 1988; Kuehler, 1989; Snyder and Snyder, 1989; Wallace, 1990; Jones et al., 1991; Reed and Merton, 1991; Derrickson and Snyder, 1992). It relies on the capability of most female birds to renest and lay a second or third set of eggs after removal of the previous clutch or to continue laying eggs beyond the normal clutch size if eggs are removed in sequence as laid. Because eggs have a much higher rate of hatch in laboratory incubators if they have received several days of natural incubation, taking full clutches after 5–7 days is the best procedure. The great advantage of Option 4 is that it provides a way to take substantial numbers of eggs from the wild for hatching and rearing of young without depriving the wild birds of all their reproductive output. There are two slight disadvantages for the wild birds: a higher percentage of late-laid eggs than early eggs are likely to be infertile or otherwise unhatchable, and late-hatching young might not survive as well as earlier ones, because of seasonal changes in food supply (although this can be alleviated by supplemental feeding) or because of other changing factors, such as weather (e.g., higher temperatures and more rain). The important point, however, is that the combination of natural and artificial hatching and rearing yields many more young than could be produced by the unaided wild population. The young reared in captivity can be used in several ways: they can be released back into the wild, they can be retained in captivity to augment the captive breeding stock, and they can be used to learn more about the biology of the species. Like other corvids, the 'Alala has been documented to renest after loss of a first clutch (for reports on 'Alala see Temple and Jenkins, 1981; for recent reports on other species see Butler et al., 1984; Stiehl, 1985; Kilham, 1986a; Buitron, 1988; Goodburn, 1991). Efficiency and success would be increased by placing the incubation and rearing facilities near the wild population. Even collected eggs that are infertile or that die during incubation can provide important information on the effects of inbreeding on reproduction and on the role of nutritional influences in hatchability and embryonic development. Although it is true that optimum conditions for artificial incubation have not yet been worked out for the 'Alala, this problem can be partly offset by making sure that the wild eggs receive some natural incubation before they are removed. Modifications of the current method of incubation at Olinda suggested in Chapter 4 should also improve the hatchability of both wild- and captive-produced eggs. It is unlikely, on the basis of what is known about other corvids and birds generally, that failure to renest will be more than an infrequent occurrence or a rare peculiarity of particular females.

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Scientific Bases for the Preservation of the Hawaiian Crow Option 4 should receive a high priority, because it provides a way to achieve most of the management objectives through the simultaneous buildup of a captive-breeding colony or colonies, and the manipulative establishment of captive birds in the wild, without necessitating the removal of any juveniles or adults from the wild population or otherwise seriously interfering with the social organization and productivity of the wild crows. Removal of eggs with the later option of reintroduction obviously constitutes a long-term strategy, and a working recovery team should evaluate the results annually and make recommendations about what to do with the crows that are produced in captivity on the basis of careful consideration of the demographic and genetic requirements of both the wild and captive populations. Option 5. Removal of Nestlings from Wild Population This option provides essentially the same products as removal of wild eggs, but without the labor and cost of maintaining facilities for artificial incubation of eggs. Its chief drawback is that it does not increase the gross reproductive output (number of fertile eggs) of the combined populations and can exert little influence on net reproductive output by increasing the survival rate of nestlings. It should be considered in addition to egg removal, especially for wild pairs that have a history of poor nestling survival—e.g., a pair that usually hatches two or three young, but consistently raises zero or one to fledgling age. Obviously, the relevant data on reproductive history have to be in hand in order to use Option 5 intelligently. Option 6. Fostering as a Method of Release Fostering young into the nests of wild "parents" is the simplest, least expensive, and most natural way to reintroduce captive-reared birds into the wild and it has been used with great success for several altricial (helpless at hatching) and semialtricial species, especially raptors (Cade et al., 1988; Garcelon and Roemer, 1988). At least initially, it would have little applicability to the 'Alala because the breeding pairs are few (currently estimated to be four or five) and because pairs of crows appear able to fledge only one or two young. Supplemental feeding might improve that number to the point where three or four young could be reared per nest, but this possibility should be tested first on unaugmented, natural broods of two or three. If wild pairs or groups of crows can be induced to adopt fledglings instead of nestlings, then additional opportunities for efficient augmentation will be possible. Cross-fostering into the nest of a different, surrogate species is a variant of fostering that can be used when a suitable surrogate species is available in a suitable environment. However, there is not now a suitable surrogate—native or exotic—for the 'Alala. If the 'Alala requires the transfer of complicated social traditions or survival techniques from parents to offspring, or if social and sexual imprinting are critical to the development of normal functions, then cross-fostering would be precluded as a management technique.

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Scientific Bases for the Preservation of the Hawaiian Crow Option 7. Hacking and Other "Soft" Methods of Release It is highly unlikely that a "hard release" (turning birds loose in a new environment) would work for captive-reared crows. Some form of slow, controlled release over a period of days or weeks (hacking) will probably be needed to allow captive-reared crows time to acclimate to wild conditions and to learn the necessary survival techniques—which foods to eat, how to avoid predators, where to roost, and so on. These "soft" techniques range from the traditional "hacking" used for raptors (Sherrod et al., 1981) to more elaborate systems involving the holding of birds for extended periods in outdoor flight cages in the habitat where they are to be released (Broo, 1978; Bloesch, 1980; Zwank and Derrickson, 1981; von Frankenburg et al., 1984; Blackwell, 1990). Depending on the species and the particular demands of the environment, the birds can be released at any age from fledgling to sexually mature adult. They might be released as individuals, as "sibling" groups, as integrated flocks, or as paired adults. In the case of the 'Alala, it is likely that results will be best with the release of social groups—perhaps as juvenile flocks with one or more wild or captive-produced adults as flock "guides." They might be released as paired nonbreeders, or even as breeders that are first allowed to nest in a holding enclosure before being set free. Several different approaches will need to be tried to discover which works best. The main advantage of soft procedures is that they provide a way to establish released birds in vacated habitat where no wild population exists. Thus, new populations can be created, the range of the species becomes expanded, and the species becomes reorganized into a metapopulation (linked through dispersal) and with a higher probability of long-term survival. Soft releases can sometimes also avoid the high mortality associated with fostering eggs or young birds. Moreover, they provide opportunities to acclimate and condition birds to survive and function adaptively in degraded or partially exotic habitats that unconditioned, wild birds would find difficult or impossible to live in (Cade, 1986a; Cade and Jones, in press). The main drawback of Option 7 is that soft releases require a cadre of dedicated and informed workers and much money over a long period. In addition, naive, captive-reared crows can present special problems related to socialization and learning, as noted in Thick-Billed Parrots (Rhynchopsitta pachyrhyncha) (Snyder and Wallace, 1987), Hispaniolan Parrots (Amazona vittata) (Wiley et al., 1992), and Mississippi Sandhill Cranes (Zwank et al., 1988). Captivity can also result in genetic, anatomical, or behavioral changes that can compromise survival in the wild (Derrickson and Snyder, 1992). Even so, some variation of Option 7 will be the only likely way to expand the species into now-unoccupied range and to increase substantially (say, by a factor of 10) the number of crows in the wild. Once field studies have clarified the social organization of the 'Alala and the role that learning plays in the acquisition of social behavior and survival skills, it should be possible to design a soft-release procedure that works effectively.

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Scientific Bases for the Preservation of the Hawaiian Crow Option 8. Exchange of Captive and Wild Crows The main advantage of Option 8 is that it allows the small wild and captive populations to be managed as one population, so that gene flow can be maintained between the two subpopulations while increase in numbers is under way (recovery). A demographic advantage accrues to the wild population primarily through the exchange of wild eggs or nestlings (possibly some yearling and adult birds) for later captive-produced young, yearling, or adult birds that can be released (Options 4, 5, 6 and 7). Another demographic advantage would be to fill in existing "gaps" or vacancies in the wild population, as when a mate lost from a pair is not replaced by a wild bird. A case in point is the single female that might still survive in Hualalai. If a suitable captive male were available, he could be released in the new home range and be carefully monitored. Alternatively, she might be trapped and brought into captivity. In either situation, her genes could make an important contribution to the genetic diversity of the overall population, because she is likely to be more distantly related to the crows on the McCandless Ranch than any of them are to each other. The main disadvantage to Option 8 is the potential for disease transmission. The adoption of strict quarantine and veterinary screening procedures should reduce that risk to a minimum, and such a precaution tips the balance in favor of this option. Conclusions It appears that a combination of several options would yield the highest probability of a successful recovery of the 'Alala. In general, the wild and captive populations should be managed as one population, with human intervention to direct gene flow and the exchange of birds between the two subpopulations on the basis of the best available information on genetics and pedigrees and on demographics of the two subpopulations. Unless an unexpected emergency arises, the wild population on the McCandless Ranch should be left essentially intact, i.e. no removal of adult or postnestling birds until numbers have increased substantially—at least a doubling of the effective population size. Manipulation of the reproductive output of the wild crows should begin in the 1993 breeding season with the removal of first sets of eggs from all nests that can be located. If possible, the eggs should be incubated and the young should be hatched at a facility near the wild population. Some of the young hatched and reared in captivity should be retained as captive-breeding stock; others should be experimentally released according to one or more of the methods outlined above. The released birds should be color-banded and radio-tagged so that the maximum amount of biological information about them can be obtained. As the wild population increases over the next few years, additional manipulative procedures can be introduced—supplemental feeding of wild pairs; translocation of nestlings, subadults, and nonbreeding adults to new territories; development of optimum "soft-release" methods for establishing crows in a vacated range; perfection of methods to prevent disease in the wild and captive birds; and conditioning of crows to acclimate and adjust to human-modified habitats.