In 2015 seven captive-bred red-and-green macaws Ara chloropterus were experimentally released into the Iberá National Park, Corrientes, Argentina. After a month in a pre-release cage, they were hard released. Two birds were preyed upon, three flew beyond our detection range, one transmitter was recovered underwater, and one bird was recaptured. We identify ways in which future releases of captive-bred macaws could be improved.

https://conservationevidencejournal.com/reference/pdf/5988

Remove vegetation to create nesting areas

A study in 2008 on Denis Island, Seychelles (Feare et al. 2015) reported that sooty terns Onychoprion fuscatus did not land in plots cleared of vegetation but without decoys and/or playback of vocalizations. In contrast, 23 terns landed in nearby cleared plots with decoys and/or vocalizations. Terns were observed in 120 hour-long periods, across day and night in June and July 2008. In early 2008, trees and bushes had been cleared from most of a 50 x 160 m area, about 40 m from a beach. Some tall trees were left standing on one half of the area. A herbaceous layer developed. Herbs other than pourpier Portulaca oleracea, and woody seedlings, were weeded before and during the breeding season. Sixteen 5 x 5 m treatment plots were established within the cleared area: four with no additional treatment, four with 2D decoys, four with 3D decoys, four with 3D decoys and vocalizations.

A study in 2009–2012 on Denis Island, Seychelles (Feare et al. 2015) reported that sooty terns Onychoprion fuscatus interacted with an area where vegetation was controlled, decoys were installed and vocalizations were played. In 2009 and 2010, terns flew high over the study area 20–53 times/h, flew low and circled the study area 12–61 times/h, and landed in the study area 3–12 times/h. Nest territory acquisition and courtship behaviours were recorded during 27–122 hours of observation/year. In 2011 and 2012, terns were also observed circling and landing in the study area, although no systematic observations were made. For these four years, the study does not distinguish between the effects of three interventions: removing vegetation (large trees and bushes in early 2008, then weeding undesirable herbs and seedlings afterwards), installing decoys (3D models in place during the breeding season) and playing vocalizations (collected from a nearby sooty tern colony). The cleared area was 50 x 160 m and about 40 m from a beach.

Use vocalisations to attract birds to safe areas

A replicated, randomized, paired, controlled study in 2008 in a patch cleared of vegetation on Denis Island, Seychelles (Feare et al. 2015) found that sooty terns Onychoprion fuscatus interacted more with plots with vocalization playback than plots without vocalization playback. Over 120 hours of observation, terns were more likely to land in plots with three-dimensional decoys and vocalizations (21 landings) than plots with three-dimensional decoys only (one landing). There were also some inadvertent breaks in playback in the plots with vocalizations. All landings occurred during periods with continuous playback. There were more flights over plots during periods with continuous playback (4.8 high and 1.1 low flights/hour) than in flights with no or interrupted playback (1.5 high and 0 low flights/hour). Most woody vegetation was cleared from a 50 x 160 m area, about 40 m from a beach. Within this area, sixteen 5 x 5 m treatment plots were established (four sets of four). In each set, one random plot received each treatment: 3D decoys with vocalizations; 3D decoys only; 2D decoys only; neither vocalizations nor decoys. Vocalizations were locally recorded daytime and night-time calls. They were played from loudspeakers facing into the four vocalization plots and away from the others. Terns were observed day and night in June and July.

A study in 2009–2012 on Denis Island, Seychelles (Feare et al. 2015) reported that sooty terns Onychoprion fuscatus interacted with an area where vegetation was controlled, decoys were installed and vocalizations were played. In 2009 and 2010, terns flew high over the study area 20–53 times/h, flew low and circled the study area 12–61 times/h, and landed in the study area 3–12 times/h. Nest territory acquisition and courtship behaviours were recorded during 27–122 hours of observation/year. In 2011 and 2012, terns were also observed circling and landing in the study area, although no systematic observations were made. For these four years, the study does not distinguish between the effects of three interventions: removing vegetation (large trees and bushes in early 2008, then weeding undesirable herbs and seedlings afterwards), installing decoys (3D models in place during the breeding season) and playing vocalizations (collected from a nearby sooty tern colony). The cleared area was 50 x 160 m and about 40 m from a beach.

Use decoys to attract birds to safe areas

A replicated, randomized, paired, controlled study in 2008 in a patch cleared of vegetation on Denis Island, Seychelles (Feare et al. 2015) reported that sooty terns Onychoprion fuscatus only landed in plots containing decoys. Over 120 hours of observation, two sooty terns landed in plots with decoys: one in a plot with two-dimensional decoys and one in a plot with three-dimensional decoys. No terns landed in plots without decoys. Statistical significance of these comparisons was not assessed. Twenty-one sooty terns landed in plots with three-dimensional models and vocalizations, but note that this treatment does not demonstrate the effect of decoys alone. All woody vegetation was cleared from a 50 x 80 m area, about 40 m from a beach. Eight 5 x 5 m plots (two sets of four) were established within this area. In each set, one random plot received each treatment: none, 2D decoys, 3D decoys, or 3D decoys plus vocalizations. Terns were observed day and night in June and July (the normal months of arrival to breeding sites).

A study in 2009–2012 on Denis Island, Seychelles (Feare et al. 2015) reported that sooty terns Onychoprion fuscatus interacted with an area where vegetation was controlled, decoys were installed and vocalizations were played. In 2009 and 2010, terns flew high over the study area 20–53 times/h, flew low and circled the study area 12–61 times/h, and landed in the study area 3–12 times/h. Nest territory acquisition and courtship behaviours were recorded during 27–122 hours of observation/year. In 2011 and 2012, terns were also observed circling and landing in the study area, although no systematic observations were made. For these four years, the study does not distinguish between the effects of three interventions: removing vegetation (large trees and bushes in early 2008, then weeding undesirable herbs and seedlings afterwards), installing decoys (3D models in place during the breeding season) and playing vocalizations (collected from a nearby sooty tern colony). The cleared area was 50 x 160 m and about 40 m from a beach.

Fifty-three captive-bred, sub-adult red-billed curassow Crax blumenbachii were reintroduced to the Guapiaçu Ecological Reserve, Brazil, from 2006 to 2008.  Post-reintroduction movements were monitored for 25 months, but little information on breeding was collected during this period as few of the birds had reached sexual maturity. However, in the period 2009-2014, six observations of probable breeding were made. This positive outcome will help inform the feasibility of further reintroductions.

https://conservationevidencejournal.com/reference/pdf/5477

In December 2011, 59 adult Seychelles warblers Acrocephalus sechellensis were translocated between two islands in the Seychelles. Birds were captured on Cousin Island and translocated to Frégate Island using a hard release method, with minimum time in captivity. Frégate had been previously identified as a suitable host for a substantial population of Seychelles warblers, although the presence of the species had never been confirmed on this island. It was estimated that Frégate currently has the potential to support about 500 Seychelles warblers, rising to over 2,000 after habitat regeneration. All birds survived the translocation and were released unharmed at the new site within 24 hours of capture. Close monitoring of both the new and source population was undertaken over a period of 18 months. By June 2013, the Frégate population had increased to 80 individuals, which included 38 of the original translocated birds and 42 birds which had hatched on Frégate. There was also evidence that multiple generations had already hatched on the island. This shows that the Seychelles warbler responded well to a hard release translocation, with observed population growth on Frégate comparable to previous warbler translocations. The source population on Cousin recovered to carrying capacity within a single breeding season. This is the fourth translocation of this species, fulfilling the species action plan requirement of five populations of this endemic island passerine.

https://conservationevidencejournal.com/reference/pdf/5482

The global range of the Aldabra white-throated rail Dryolimnas cuvieri aldabranus, the last surviving flightless bird in the Indian Ocean, was restricted to only three islands of Aldabra Atoll in 1998. It was extirpated on the islands of Grand Terre (before the late 1800s) and Picard (soon after 1910), mainly due to the introduction of feral cats by early settlers. In 1999, following the eradication of cats from Picard, 18 Aldabra rails were successfully reintroduced. After the reintroduction, population growth of the Aldabra rail on Picard was predicted to continue to approximately 1,000 pairs by 2010. In this paper, we report on the long-term effectiveness of the reintroduction by updating the Aldabra rail population estimate on Picard 12 years after the translocation and one year after the predicted maximum was expected to be reached. We confirm the predicted carrying capacity on Picard has been reached and probably exceeded; report a reliable survey method for the Aldabra rail, which can be applied to other terrestrial bird species; and recommend subsequent monitoring and conservation management strategies for the Aldabra rail and potentially other species of rail.

https://conservationevidencejournal.com/reference/pdf/5374

In March 2009, 79 hihi (stitchbird) Notiomystis cincta were translocated from Tiritiri Matangi and Little Barrier (Hauturu) Islands to Maungatautari, a 3,255 ha New Zealand mainland reserve with a predator (exotic mammals) exclusion fence. Genetic management, by mixing founders from both a reintroduced and highly productive site (Tiritiri Matangi) and the only naturally occurring extant population (Little Barrier), appears successful with at least one mixed pairing producing fledglings in the first breeding season after release. Monitoring this population is challenging due to the large area and rugged terrain of the reserve.  However, closed mark-recapture analysis based on a 15-day survey about 1 year after release indicated that between 15 and 41 (19 - 52%) of the translocated hihi had survived.  Unringed hihi were also observed during this survey (25 observations but it is unknown how many of these were the same individuals), indicating successful breeding in the first year. If they persist and thrive in the longer term, this translocation will provide an important hihi population at a large mainland site and will contribute to the ongoing ecological restoration of Maungatautari.

https://conservationevidencejournal.com/reference/pdf/2348

A translocation of South Island saddlebacks Philesturnus carunculatus from Ulva Island to Orokonui Ecosanctuary near Dunedin, New Zealand was conducted by a community group and university scientists in April 2009. In this paper we describe and assess methods used during this complicated five day translocation, which involved birds being held over-night in transfer boxes. Post-release surveys determined a minimum of 79% of individuals survived the critical initial 48 h after release. The survival rate did not appear to be affected by the presence or absence of perches in each transfer box, although the lack of perches does not follow best-practice for most passerine translocations. Experienced advisors should be involved during every phase of the translocation process.

https://conservationevidencejournal.com/reference/pdf/2319

The red-fronted parakeet Cyanoramphus novaezelandiae is a vulnerable New Zealand endemic with a fragmented distribution, mostly inhabiting offshore islands free of introduced mammalian predators. Four populations have been established since the 1970s using captive-bred or wild-sourced individuals translocated to islands undergoing ecological restoration. To establish a new population in the Hauraki Gulf, North Island, a total of 31 parakeets were transferred from Little Barrier Island (Hauturu) to Motuihe Island in May 2008 and a further 18 in March 2009. Overall 55% and 42% of individuals from the first translocation were confirmed alive at 30 and 60 days post-release, respectively. Evidence of nesting and unassisted dispersal to a neighbouring island was observed within a year of release. These are outcomes are promising and indicate that translocation from a remnant wild population to an island free of introduced predators is a useful conservation tool to expand the geographic range of red-fronted parakeets.

https://conservationevidencejournal.com/reference/pdf/2312

The Mauritius fody Foudia rubra is threatened by habitat loss and nest predation from introduced mammalian predators. The establishment of populations on predator-free smaller islands around 'mainland' Mauritius is one of the main conservation strategies for endangered Mauritian birds. Ninety-three Mauritius fodies were released on Ile aux Aigrettes in three breeding seasons between November 2003 and March 2006. The first fledglings were produced on the island during the 2004-05 breeding season, and by the following season sufficient numbers of juveniles were being produced on the island to render further releases unnecessary. The population has since increased to 47 breeding pairs and 142 individuals as of December 2008.

https://conservationevidencejournal.com/reference/pdf/2289

The Kermadec red-crowned parakeet Cyanoramphus novaezelandiae was driven to extinction on Raoul Island over 150 years ago by introduced cats Felis catus and rats (Rattus norvegicus and R.exulans). These predators were eradicated from the island (2,938 ha) between 2002-04 during the world's largest multi-species eradication project. In 2008 we documented a unique recolonisation event when parakeets were observed to have returned to Raoul, presumably from a nearby island group, The Herald Islets (51 ha). We captured and aged 100 parakeets, of which 44% were born in 2008, and breeding was observed on Raoul Island. This represents the first evidence of nesting of this species on Raoul Island since 1836. Our findings highlight the global conservation potential for island avifaunas by prioritising eradication areas through consideration of proximity of remnant populations to target management locations, instead of the classical translocation approach alone. The natural recolonization of parakeets on Raoul Island from a satellite source population is to our knowledge, a first for parrot conservation and the first documented population expansion and island recolonization of a parrot species after removal of invasive predators.

https://conservationevidencejournal.com/reference/pdf/2293

We report on the translocation of Seychelles magpie-robins Copsychus sechellarum, from the island of Frégate to the island of Cousin between 1994 and 1995. Prior to this translocation, the world population consisted of 47 individuals confined to Frégate . Five magpie-robins were translocated to Cousin and subsequently a new self-sustaining breeding population was established; this population increased almost 10-fold in less than 12 years to a high of 46 individuals in May 2006. It is now currently experiencing signs of regulation with a slight decrease in numbers with 31 birds recorded in June 2007. It is hoped that ongoing studies will identify the reasons for this decline, which at present are unclear.

https://conservationevidencejournal.com/reference/pdf/2276

In August 2005, 20 North Island saddleback Philesturnus rufusater were translocated from Tiritiri Matangi Island to Motuihe Island in the Hauraki Gulf, New Zealand. Post release survival over the first year was high (70%). A minimum of 11 juveniles successfully fledged in the 2005/2006 breeding season bringing the population to a minimum of 25 birds one year after release. Assuming long term success this translocation brings the total number of island populations of North Island saddleback to 13 and contributes to the ongoing ecological restoration of Motuihe Island.

https://conservationevidencejournal.com/reference/pdf/2279

In May-June 2004, 58 adult Seychelles warblers Acrocephalus sechellensis were translocated to Denis Island. The first pairs started nest-building within three days of release. By August 2005, their numbers had increased to 75. Of the 35 breeding territory vacancies created by the translocation on the source island of Cousin, all but three were occupied within an average of 5.4 days, by sub-ordinate birds.

https://conservationevidencejournal.com/reference/pdf/2221

A total of 105 (44 wild, 61 captive-bred) Campbell Island teal Anas nesiotis were transferred to Campbell Island in 2004 and 2005. They were kept in pens and released once above normal weight. At least 78% of the 2004 cohort survived five months after release and a minimum of 41 out of 55 survived a similar period in 2005. Successful breeding was proven when two nests and four immature teal were found in 2006.

https://conservationevidencejournal.com/reference/pdf/2223

To restore brown teal Anas chlorotis populations, a captive breeding and release programme has been developed. At the Moehau Kiwi Sanctuary, a first release of 60 teal had a survival rate of 45%, and the second release of 40 birds an 85% survival rate. As the survival rate of the second release was so high, the same methods will be used in the next planned release, in combination with ongoing predator control.

https://conservationevidencejournal.com/reference/pdf/2164