Barn owl release in lowland southern England—a twenty-one year study

Twenty-one years of carefully documented barn owl (Tyto alba) study and release in England by the South Midlands Barn Owl Conservation Group (SMBOCG) have necessitated a re-examination of some of the premises on which such release schemes are judged. Fifteen years after the first releases, the number of independently breeding owls (i.e. breeding ‘wild’ or ‘as though wild’) in a 1200 km² study area is still increasing sharply and now far exceeds the number released in any one year, with the rate of increase outstripping the cumulative number of release events. Ringing returns indicate that fledged young dispersed further than adults, and that released adults which immediately deserted their release sites were less likely to survive their first 30 days than those staying in the vicinity of their release, where they could take advantage of supplementary feeding. Artificial feeding at release sites led to pellets containing lower liveweight equivalent of wild-caught prey but higher numbers of fledged young. Otherwise, and importantly, no significant difference in survival, mortality, dispersal, foraging success or breeding success was found between wild/independent owls and various categories of released bird. Availability of field vole habitat was not as important for barn owl breeding success as was found in previous studies, with owls able to replace this species in their diet with the less habitat-specific wood mouse. Evidence is provided that starvation was not as important a cause of mortality as has been proved elsewhere. Although barn owl nests often occurred in extreme close proximity, breeding density had no effect on either foraging or breeding success. The possible genetic consequences of barn owl release in Britain are briefly discussed. Very few barn owl release schemes have attempted to prove that their work is worthwhile, so long-term, well-documented studies such as that presented here are vital in establishing some of the principles involved in releasing barn owls into the wild.     

Captive-reared burrowing owls show higher site-affinity, survival, and reproductive performance when reintroduced using a soft-release

A remaining challenge for animal reintroductions is how best to aid individuals transitioning from captivity into the wild. We tested two techniques – ‘soft’ vs. ‘hard’ release – in a 7-year study on endangered Western burrowing owls (Athene cunicularia hypugaea) in British Columbia, Canada. Traditionally, captive-reared yearling adults were released into the wild, as pairs, directly from artificial burrows (hard-release). Only 46% of 201 owls released in this way (2001–2004) stayed at release sites. To test for improved success, soft-releases were performed in the same manner as concurrent hard-releases (2005–2007), except above-ground enclosures confined each soft-release pair to the vicinity of their burrow for 2 weeks before complete release. Of 140 soft-released owls, 86% stayed at release sites; whereas, 66% of 100 hard-released owls stayed. Breeding-season survival was 70% for soft-released owls vs. 50% for hard-released owls. On average, soft-released owls produced 50% more fledglings than concurrently hard-released owls. Post-fledging survival was 69% and first-year return rate was 7.0% for fledglings from soft-released parents, compared to 50% and 4.0% for fledglings from hard-release parents. Ultimately, 0.17 offspring were recruited into the local wild breeding population per soft-released pair, compared to 0.05 local recruits per hard-released pair. We recommend that enclosure-based soft-releases be used for reintroduction of burrowing owls in British Columbia and elsewhere in North America. We encourage other tests for improved release success with soft-releases, particularly for species with a high tendency for dispersal or those likely to experience significant predation pressure.     

The success of a soft-release reintroduction of the flightless Aldabra rail (Dryolimnas [cuvieri] aldabranus) on Aldabra Atoll, Seychelles

Humans and introduced mammalian predators have caused local extinctions and range reductions in the rallid genus Dryolimnas (endemic to western Indian Ocean islands); today two subspecies survive, one on Madagascar and one on three islands (ca. 8000 birds) of Aldabra Atoll. Domestic cats (Felis catus) still occur on Aldabra and their presence poses a significant potential threat to the rails. Reintroduction to cat-free islands would significantly improve their conservation status. In 1999, 20 rails were captured and brought to now cat-free Picard Island (the third largest island of Aldabra Atoll). Two rails died in captivity but all 18 remaining birds were released and survived beyond the first breeding season. Eight pairs had bonded and bred successfully within 2 months of release, producing a minimum of 13 chicks. Eleven monitored pairs produced 20 chicks in 2000/2001, with 1-year-old birds breeding successfully. Average chick production was significantly higher in the reintroduced population than in the source population in both breeding seasons. The reintroduced population at the end of the 2001 breeding season was at least 51, an increase of 283% in 18 months. Around 20 pairs are expected to attempt breeding on Picard in the third season after reintroduction, with excellent prospects for continued, exponential population growth in the medium-term. The soft-release reintroduction protocol allowed monitoring of individual birds' health before release into the wild. This is believed to have played a crucial role in the success of the reintroduction by allowing individuals to acclimatise and providing additional energetic reserves for the period between release and self-sufficiency. A soft-release is recommended as the conservative and precautionary method of choice for avian reintroductions and translocations.     

Survival, dispersal and early migration movements of captive-bred juvenile eastern loggerhead shrikes (Lanius ludovicianus migrans)

Avian captive breeding programs pose a particular challenge with migratory birds due to natal dispersal and high mortality during migration. In Canada a captive breeding program for the eastern loggerhead shrike (Lanius ludovicianus migrans) has released over 400 juveniles since 2001, but the fate of almost all these birds is unknown. In 2007 and 2008, we used radio-telemetry of captive-reared juveniles to determine pre-migration survival and dispersal movements away from the release site. Overall, 76% (29 of 38) of shrikes survived from release to the initiation of migration and the daily survival rate was 0.987. Most deaths (78%) occurred in females, suggesting a possible sex-biased pre-migration mortality. Shrikes typically dispersed independently, there was little overlap between dispersal sites, and the average pre-migration dispersal distance from the release site was 4.2 km (SD 2.4). Release date was negatively correlated with time spent at the release site prior to dispersal, but did not have a significant effect on survival, time spent at dispersal sites or distance of dispersal. Migration initiation date ranged over 6 weeks and early-hatched juveniles were the first to begin migration. Using aerial telemetry, we located five of 29 birds that had begun migration at distances up to 180 km from the release site; no birds were found dead after initiating migration despite the extensive search area. High juvenile survival to migration for captive-reared juveniles suggests that the captive breeding and release program has high potential to augment wild populations of the eastern loggerhead shrike.     

Maximizing re-introduction success: Assessing the immediate cost of release in a threatened waterfowl

Translocations have become one of the most commonly used tools for biodiversity restoration worldwide, however one out of three re-introduction plans fails to create a viable population or to successfully reinforce the existing one. We used results from the analysis of individual-based information on the re-introduction of a threatened waterfowl species, the crested coots Fulica cristata, to provide guidelines to maximise re-introduction success. We found that about a third of the post-release mortality took place within the first month after release. This immediate ‘cost of release’ in terms of local survival or ‘release risk factor’ seems to be a common feature of re-introduction projects, and it is likely due to the inexperience of captive-born individuals to face the new environment. This hypothesis was supported by the positive association between survival and time spent in the wild Results suggested that coots released between February and May have a slightly higher survival. A joint measure of survival and breeding probabilities indicated that birds released in late winter (February-March) had a higher chance to survive and reproduce compared to birds released later in the year. From an applied perspective our results can be used within an adaptive management framework to determine the optimum period of release, providing substantial support for future decision-making in the management of waterfowl, and other long-term projects of re-introduction of threatened vertebrate species.     

Covey-oriented partridge management in France

For centuries winter-feeding of pheasants has been a common and successful management practice; winter-feeding of partridges has met with less success largely due to the covey-confined behaviour and inter-covey hostility of the monogamous and territorial partridge. Successful French experiments have recently been carried out with the construction and even distribution of special ‘partridge cafeterias’, providing food, shelter, sand-bath and water. These bird-oases in the modern, cover-deficient farm landscapes should preferably correspond in number and distribution to the covey territories during autumn-winter and thus provide easy access to food and cover for all partridges without territorial friction between coveys.     

Ecologically enhanced areas - a key habitat structure for re-introduced grey partridges Perdix perdix

We analysed the spatial distribution of home-ranges and the habitat use of re-introduced grey partridges Perdix perdix in relation to newly established ecologically enhanced areas, i.e. wild-flower strips and hedges, within an intensively cultivated area in Switzerland from which the species had become extinct. All birds settled within the ca. 30% of the study area where the proportion of enhanced areas was highest (5.8%). At the level of the individual family group, we found a significant over-proportional use of enhanced areas throughout the year. Furthermore, when the birds used the agricultural fields, the use densities strongly declined with distance from the nearest enhanced area. Thus, the availability and spatial distribution of ecologically enhanced areas were the main determinants of the partridges’ range use. These results indicate that a framework of ecologically enhanced areas is a key habitat structure for grey partridges, and that these enhancements, even if small in proportion, were the crucial first measure to restore the research area to an appropriate grey partridge habitat and, thus, the basis for successful re-introduction in this intensively cultivated area.     

The use of hand-raised psittacines for reintroduction: a case study of scarlet macaws (Ara macao) in Peru and Costa Rica

This study reports on three scarlet macaw (Ara macao) reintroduction projects using hand-raised birds in Peru and Costa Rica. The habitats at the release sites ranged from pristine tropical forest to forest fragments in an agricultural matrix. The combined first-year survival was 74% and the annual post first-year survival was 96%. Survival rates were very high despite a wide range in predator communities. Number of birds released explained 70% of the variation in survival with birds from larger releases having higher survival rates. Behavioral evidence suggests that birds established at the site facilitated survival of later releases. Breeding attempts were recorded at all three sites and hand-raised birds with wild mates successfully fledged young in Peru. Supplemental feeding post-release played an important role in keeping the birds near the release site and facilitating social interactions. This work shows that properly socialized hand-raised macaws can survive and breed in the wild but that ex-pets are not good release candidates.     

Lessons from a failed translocation program with a seabird species: Determinants of success and conservation value

Conservation diagnosis of ex situ techniques (e.g. releasing chicks by hacking) cannot be evaluated without quantitative assessment of the fate of individuals, mainly their survival and recruitment. Here we use a long-term monitoring at a large spatial scale of a hacking programme (i.e. chick translocations) for Audouin’s gulls in an uninhabited site so as to establish a new breeding patch and reinforce the metapopulation. The success of the programme relied on the assumption that birds tend to recruit to the site where they fledge (i.e. they were philopatric). Multi-state capture-recapture models applied to a large dataset (more than 43,500 resights at 30 colonies during 1999–2010) were used to evaluate the survival of released chicks and the probability of being philopatric. Adult survival was high, but juvenile survival was lower than that of wild gulls, suggesting that there was a cost associated with hacking only during their first year of life. As expected, most released birds returned to the hacking site, but very few (including immigrants from abroad) attempted to breed here. Dispersal was inversely correlated with distance from the hacking site and positively associated with the population size of the patch (i.e. conspecific attraction). Even though most hacking procedures met the ecological conditions to succeed, results clearly showed that the program failed to establish a new breeding site. The ability of prospecting and the attraction made by conspecifics at established sites may be a constraint for the success of hacking programs, particularly for social and nomadic species.     

The influence of food availability on breeding success of African penguins Spheniscus demersus at Robben Island, South Africa

From 1989 to 2004, the breeding success of African penguins Spheniscus demersus at Robben Island, South Africa was significantly related to estimates of the abundance of both their main prey species, anchovy Engraulis encrasicolus and sardine Sardinops sagax, and to the combined biomass of these species. When the combined spawner biomass of fish prey was less than 2 million ton, pairs fledged an average of 0.46 chicks annually. When it was above 2 million ton, annual breeding success had a mean value of 0.73 chicks per pair. Given previously estimated values of survival and age at first breeding, these levels of breeding success are inadequate to sustain the African penguin population. With the higher level of breeding success, an equilibrium situation might be attained if adult survival could be increased by 6-7% per annum. Attempts to reduce mortality of penguins have included the collection, cleaning and return to the wild of oiled birds, culling of Cape fur seals Arctocephalus pusillus pusillus seen preying on penguins around breeding localities and control of the spread of disease. Management of the purse-seine fishery should ensure adequate escapement of fish to maintain the combined biomass of anchovy and sardine above 2 million ton. The maintenance of suitable breeding habitat and removal of feral predators from breeding localities will also be important in improving breeding success.     

Water depth influences nest predation for a wetland-dependent bird in fragmented bottomland forests

The alteration and fragmentation of natural habitats has resulted in increased rates of nest predation and poor reproductive success for many bird species. The development of effective conservation strategies to reduce elevated rates of nest predation has been hindered by difficulties in fully understanding mechanisms underlying patterns and rates of nest predation in particular habitats. I recorded the outcome for 2726 nesting attempts of prothonotary warblers (Protonotaria citrea) breeding in fragmented bottomland forests and quantified the effect of nest predation on annual fecundity, determined the influence of different nest predators on rates of nest predation, and identified the factor driving rates of nest predation. There was a highly significant negative correlation between rates of nest predation and the actual annual reproductive output of prothonotary warblers. Of 1156 nest predation events, 73% were attributed to raccoons (Procyon lotor), 15% to snakes and 7% to southern flying squirrels (Glaucomys volans). Rates of nest predation decreased with increasing water depth as a result of nest predation by raccoons. Nests that were over water deeper than 60 cm were particularly successful. Habitat fragmentation, the draining of wetlands, and stream channelization may act synergistically to elevate rates of nest predation for those birds breeding in forested wetlands. Conservation actions designed to stop or reverse these processes will be especially beneficial to birds breeding in bottomland forest ecosystems.     

Psittacine reintroductions: Common denominators of success

With 28% of the 350 species of parrots considered threatened, numerous conservation efforts have been initiated for these species. Among these, the restoration or establishment of new populations has increasingly relied on reintroductions as a conservation strategy, often with mixed or uncertain results. We reviewed the results and methodologies of 47 distinct releases and reintroductions of psittacines in nine different countries worldwide over the past 25 years to identify common denominators of successful efforts. To do so, we established a uniform and objective definition of reintroduction success (first-year survival >0.50 and released birds breeding with conspecifics, either captive-reared or wild), and applied generalized linear models and information-theoretic model selection to multiple datasets to identify important predictor variables. We identified several likely predictors of successful psittacine reintroductions, relating to predation mitigation, habitat quality, and post-release supplementation that may provide guidance for future efforts. We also advocate SWOT analysis for objectively evaluating the suitability of potential reintroduction sites.     

Can small, isolated primate populations be effectively reinforced through the release of individuals from a captive population?

Since November 1997 the Madagascar Fauna Group (MFG) has released 13 captive-bred black and white ruffed lemurs (Varecia variegata variegata) into the Betampona reserve in eastern Madagascar. Five of the thirteen are currently surviving, including one male who has integrated into a wild group. Five of the released lemurs fell victim to predation by fossa (Cryptoprocta ferox), one died of malnutrition, one disappeared from the reserve and one was withdrawn from the release programme. Ten of the released lemurs survived for more than one year post release, although all required varying levels of supplementary feeding. One pair bred twice—the first time the infants did not survive, but on the second occasion triplets were successfully raised beyond weaning. One of the triplets (male) is still surviving. One male has integrated into a wild group and sired a single infant in 2002 and a female released in 2001 gave birth to twins sired by a wild male also in 2002. The release programme has thus achieved a major objective of reinforcing the existing wild population. To date there is no significant difference in survival rates between animals born and raised in free-ranging environments and those raised in cages, between animals greater than or less than 5 years old at time of release, or between males and females.     

Can an introduced predator trigger an evolutionary trap in a colonial seabird?

Animals use environmental cues, social information and behavioural decision-making rules moulded by natural selection to decide where to breed. We assessed whether the presence of an alien nest predator, the Black Rat (Rattus rattus) is used by a colonial seabird, the Cory’s shearwater (Calonectris diomedea), as an environmental cue in the selection of breeding sites. We compared potential habitat preference using quality of breeders and nest fidelity as response to nest predation between two sub-colonies with different habitat characteristics, breeding success and predation pressure. Quality of individuals was better in the predated habitat and birds did not perceive the presence of predators signalling differences in predation risk and in turn of breeding success. This failure of perception could be at two levels: in the selection of habitat for first breeding and in the breeding dispersal following a reproductive failure. Preference for the sub-colony with higher predation risk suggests the presence of an evolutionary trap. In fact, the introduction of alien predators probably transformed the behaviour of shearwaters in a maladaptive response due to a mismatch between the new environmental factors and their behavioural and evolutionary algorithms. This can be a common pattern in other species with little behavioural plasticity, evolved in stable environments free of predators.     

The Galápagos giant tortoises (Geochelone elephantopus) Part II: Conservation methods

Eight of the 11 surviving races of Galápagos tortoises are threatened due to decreased population sizes and predation and/or competition by introduced mammals. Systematic hunting has been effective for controlling and even eliminating goats on the less elevated, more sparsely vegetated, smaller islands and for controlling pigs, even on some of the larger islands. However, the method has been ineffective against dogs and cats and it is doubtful that it could be used to eliminate goats or pigs on the more elevated, larger islands which have a diversity of vegetation zones. Alternative control or extermination methods are being sought and tested for these feral mammals and black rats. In an attempt to increase yearly recruitment of hatchlings, lava corrals have been constructed around nests, resulting in almost 100 per cent success in preventing nest destruction by pigs; but the method was ineffective against dogs. While other control methods are being sought, young of the endangered races are being hatched and raised in captivity for restocking of endemic populations. During the past seven years, improved and highly successful techniques have been found for (1) establishment of breeding colonies and construction of artificial nesting sites, (2) transport of eggs from wild nests, (3) incubation of eggs, and (4) raising of young in captivity. By August 1972, 231 young of six races were being raised, and 71 4·5–6·5 year old captive raised tortoises released on Pinzón in 1970 and 1971 were in good condition and growing rapidly. The advantages of conducting the breeding/raising programme in the Galápagos rather than foreign locations are discussed.     

From both sides: Dire demographic consequences of carnivorous mice and longlining for the Critically Endangered Tristan albatrosses on Gough Island

The IUCN recently uplisted the Tristan albatross (Diomedea dabbenena) to Critically Endangered. Here we present new data indicating negative population trends on Gough Island arising from low adult survival (∼91%, ascribed to accidental mortality on fishing gear) and low breeding success (averaging 32%, due to mouse predation). Fledgling production from 1979 to 2007 and numbers of incubating adults from 1956 to 2007 have both decreased by ∼1% p.a. Consecutive annual counts of incubating adults and a population model permit the first reliable estimates of the Tristan albatross population, presently 5400 breeding adults and 11,300 birds in all age- and stage-classes. Population models explore scenarios of likely demographic trends using combinations of hypothetical best-case estimates vs. observed estimates for two key parameters: adult survival and breeding success. These scenarios highlight the relative benefits to the species of eradicating mice or mitigating bycatch. The model scenario using observed estimates predicts annual growth rate at −2.85%. Adult survival rates have probably decreased in recent years, concomitant with increased longline fishing effort, which might explain the discrepancy between counts and modelled trends. Negative trends cannot be reversed by improving breeding success alone, and adult survival must exceed an improbable 97% to balance the current chick production. A worst-case scenario including a fixed number of adult deaths annually predicted a catastrophic 4.2% p.a. decrease and extinction in ∼30 years. Population growth was most sensitive to adult survival, but even using an adult survival estimate without fishery mortality, current breeding success is insufficient to maintain the population. These findings do not support the ‘compensatory mitigation of bycatch’ model (offsetting bycatch impacts by eradicating invasive species), and the impacts of both fishery mortality and mouse predation must be addressed to improve the conservation status of the Critically Endangered Tristan albatross.     

What do artificial nests tells us about nest predation?

Artificial nests are commonly used to evaluate predation, but the assumption that this method mimics predation on natural nests has seldom been tested. Natural and artificial nests of eastern yellow robins (Eopsaltria australis) were monitored in four, 55-ha plots over two breeding seasons. Overall, daily survival rates were higher (P<0.001) for natural (95%/day) than for artificial nests (88%/day). Among plots, daily survival rates for the two types of nests were not correlated with one another (P=0.72) indicating that the spatial pattern of predation on artificial nests did not mimic that for natural nests. Seasonal variation was evident for natural nests in one year, when they were more successful at the beginning and end of the breeding season. No seasonal patterns were observed for artificial nests in either year. Neither natural nor artificial nests showed annual variation in predation. Previous researchers concluded that large birds were important predators on robin nests. In this study, predation by large birds on artificial nests was positively correlated with the numbers of large birds counted on the plots (P=0.04). However, large birds depredated only 16% of artificial nests. Daily survival rates for artificial nests were recalculated using predation by large birds only. These rates were compared with natural nests, but there was still no correspondence in the spatial and temporal patterns of predation for the two types of nests. These results suggest that inferences about predation on natural nests based on artificial nest studies should be avoided.     

Introduced house mice Mus musculus: a significant predator of threatened and endemic birds on Gough Island, South Atlantic Ocean?

House mice Mus musculus have successfully colonized many temperate and sub-Antarctic islands that are the location for breeding colonies of millions of seabirds. Unlike other introduced mammals, the impact of house mice on seabirds and endemic birds is believed to have been negligible. The breeding ecology of seabirds breeding on Gough Island, central South Atlantic Ocean, was studied for the first time during September 2000 to September 2001. Breeding success of the endangered Tristan albatross Diomedea (exulans) dabbenena and endangered Atlantic Petrel Pterodroma incerta were 27.3 and 19.9% respectively. Mortality of large Tristan albatross and Atlantic petrel chicks was observed, and the pattern of wounds and observations of feeding indicate that introduced mice were responsible for this predation. Breeding numbers of the endemic Gough bunting Rowettia goughensis are mostly found in upland areas of Gough Island where mice are scarce and are restricted to inaccessible cliffs in the lowlands where mice are abundant. This pattern, together with the high predation rates of artificial-eggs in lowland habitats in comparison to the uplands, strongly suggests that mice constrain the distribution of Gough buntings. The results of this study provide the first evidence for the role of house mice as a significant predator of endangered and endemic birds. Further research is required to determine if the observed levels of mice predation are a regular occurrence.     

Reintroducing endangered Vancouver Island marmots: Survival and cause-specific mortality rates of captive-born versus wild-born individuals

Recovery of the endangered Vancouver Island marmot (Marmota vancouverensis) is contingent upon releases of captive-born marmots into natural habitats. Success of such re-introduction programs largely depends on the ability of released animals to survive in the wild. However, whether and to what extent survival and cause-specific mortality rates of captive-born marmots differ from those of their wild-born counterparts remains unknown. We used radio-telemetry (1992–2007) and mark-resighting (1987–2007) data to estimate seasonal and annual survival rates of the Vancouver Island marmot, to compare survival and cause-specific mortality rates of captive-born marmots that have been released into the natural habitat with those of wild-born marmots, and to test for the effect of age-at-release on survival of the released marmots. Analysis of radio-telemetry data suggested no difference in survival of males versus females. However, annual survival of captive-born marmots released into the wild was low (S = 0.605; 95% CI = 0.507–0.696) compared to wild-born marmots (S = 0.854; 95% CI = 0.760–0.915). Marmots released as 2-year-old or older survived more successfully than those released as yearlings. Additional forensic evidence reinforced the idea that predation was the most important cause of mortality. Causes of death differed significantly between captive-born and wild-born marmots. Predation by golden eagles (Aquila chrysaetus) was the most important cause of mortality for captive-born marmots, whereas predation by wolves (Canis lupus) and cougars (Felis concolor) was more important for wild-born marmots. Age-specific apparent annual survival rate, estimated using the combined mark-resighting and radio-telemetry data, was lowest for pups (S = 0.500; 95% CI = 0.375–0.616) and highest for yearlings and adults (S = 0.656; 95% CI = 0.604–0.705); and apparent survival of 2-year-old was similar to that of yearlings and adults (S = 0.649; 95% CI = 0.527–0.754). Our results, based on the analysis of radio-telemetry data, suggest that delaying release of captive-born marmots until 2 years of age may enhance their probability of survival in the wild, and will likely improve the success of the release program.     

Behavior and mortality of caught-and-released bonefish (Albula spp.) in Bahamian waters with implications for a sustainable recreational fishery

Bonefish (Albula spp.) are a widely distributed group of morphologically indistinguishable marine fish species, that provide a recreational sport fishery, that is important for many local economies. Although the majority of angled bonefish are released following capture, little is known about their behavior or post-release survival. Using ultrasonic transmitters and small visual floats, we assessed behavior and mortality of bonefish following catch-and-release angling at spring water temperatures (25.5-27.3 °C) in two regions of the Bahamas with differing shark abundances. All observed mortality occurred within 30 min of release and was a direct result of predation by sharks. In the low shark abundance areas, all released bonefish survived, whereas in the high shark abundance areas, some mortality (39%) was observed. Exhaustively angled fish exposed to air had problems maintaining equilibrium following release. These fish typically spent substantial periods of the first 30 min post-release remaining stationary, then moved in rapid bursts. The results of this study, highlight the benefits of angling and releasing bonefish quickly, minimizing handling and particularly air exposure. Furthermore, when shark predation threat is high, anglers should avoid releasing bonefish in the immediate area. The conservation of exploited recreational bonefish fisheries will depend upon the development and dissemination of science-based catch-and-release strategies.