Action: Translocate parrots
- Three studies of two translocation programmes from the Pacific and New Zealand found that populations of parrots were successfully established on islands following translocations, including the colonisation of other islands in the New Zealand study.
- Survival of translocated birds was monitored in five studies of four programmes from across the world and ranged from 41% over 60 days for red-fronted parakeets Cyanoramphus novaezelandiae in New Zealand to 98% for kakapos Strigops habroptila in New Zealand.
- Survival for translocated thick-billed parrots Rhynchopsitta pachyrhyncha in the USA was higher than for captive-bred birds.
- Despite very high survival, kakapos that were translocated had very low reproductive output in New Zealand.
Kakapos Strigops habroptila are large, flightless parrots that used to be found across New Zealand, but declined catastrophically after the introduction of mammalian predators. The entire population has now been transferred to predator-free islands off the mainland in an attempt to save the species.
Supporting evidence from individual studies
A replicated 1994 study on four off-shore islands in New Zealand (Lloyd & Powlesland 1994) found that survival of translocated kakapos Strigops habroptila was high (63-85% until 1992, see Clout & Merton 1995 for details). However, reproduction was extremely low, with only two young reared to independence and a third hand-reared in captivity. Between 1974 and 1992, 65 kakapo were translocated from Stewart Island (1,746 km2, South Island) to Maud Island (300 ha, South Island; 1974-81: nine birds; 1989-91; six birds), Little Barrier Island (3,055 ha; 1982: 22 birds), Codfish Island (1,480 ha; 1987-92: 30 birds) and Mana Island (217 ha; 1992: two males). Translocations occurred because kakapos were suffering extremely high mortality rates due to predation by introduced mammalian predators (particularly cats Felis catus and stoats Mustela erminea) on Stewart Island. Such predators were removed from target islands prior to translocations.
A replicated study in southeastern Arizona, USA (Snyder et al. 1994), reintroduced 88 thick-billed parrots Rhynchopsitta pachyrhyncha into the Chiricahua Mountains between September 1986 and September 1993. Survival two months after release was significantly higher for wild birds caught as adults, compared to parrots caught as juveniles or captive-bred birds, either parent- or hand-reared (6.3% survival for 16 captive-bred, parent-reared birds vs. 0% for four hand-reared birds, 0% for four wild birds caught at juveniles and 43% for 65 wild birds caught as adults). Translocated birds were known to fly more than 110 km away from the release site, with small groups returning each autumn to the Chiricahua Mountains, where at least one pair producing two fledglings. This study is also discussed in ‘Release captive-bred individuals’ and ‘Use holding pens at release sites’.
A before-and-after study in 1992-4 on Hiva, Marquesas Islands, French Polynesia (Kuehler et al. 1997), found 14 ultramarine lorikeets Vini ultramarina on the island following the translocation of 13 birds from Ua Huka between August 1992 and November 1993. There were also anecdotal reports of juvenile lorikeets being present. This translocation programme is discussed in more detail below.
A second before-and-after study in January 1997 (Lieberman et al. 1997) assessed the same population of ultramarine lorikeets Vini ultramarina on Fatu Hiva, Marquesas Islands, French Polynesia as discussed in Kuehler et al. 1997, after the translocation of 29 individuals from Ua Huka Island between 1992 and 1994. The introduced population on Fatu Hiva was estimated at 51 individuals. The initial 29 translocated individuals were captured with mist nests, ringed, weighed, and measured before being kept up to seven days in captivity, while further captures took place. The authors identify the absence of black rats Rattus rattus and the location of Fatu Hiva within the lorikeet’s former range as key considerations in its selection as a release site.
A 1998 review (Clout & Merton 1998) of the kakapo Strigops habroptilus translocation programme described in Lloyd & Powlesland 1994 stated that yearly survival rates of 61 kakapo was around 98% following their translocation from Stewart Island to four other offshore islands. In 1997, at least 48 translocated birds (78%) were known to be alive. Productivity of translocated kakapo has been low, with high rates of egg infertility (approximately 40%) and nestling mortality. The population in February 1998 was 57 individuals, approximately 10% fewer than in 1982, when translocations began in earnest.
A small study (Oehler et al. 2001) following the translocation of 14 blue-and-gold macaws Ara ararauna from Guyana to their former range in Trinidad found that 11 macaws were observed within 51 km of the release site between three and eight months after release, with several travelling in pairs. One individual did not leave the release site and was recaptured. Translocated macaws were tested for papillomavirus, psittacosis, Newcastle’s disease, and avian influenza before transport and provided with supplementary food immediately after release.
A before-and-after study of a 2008-9 translocation programme for red-fronted parakeet Cyanoramphus novaezelandiae in North Island, New Zealand (Ortiz-Catedral & Brunton 2010), found that at least 41% of 32 parakeets translocated to Motuihe Island from Little Barrier Island in 2008 survived at least 60 days after release, with at least two family groups and four juveniles being identified eight months after release. In addition, birds have dispersed to other nearby islands and have bred on them. A further 18 birds were released in 2009, but were not monitored. One bird translocated in 2008 died before release due to trauma and disease, and one female caught in 2009 was very weak and was therefore returned to Little Barrier Island without being released. It is not clear how the other birds died (or if they were just not seen during surveys). Parakeets were caught using mist nets and held in aviaries on Little Barrier Island for up to six days before transport to Motuihe Island by helicopter. Birds were supplied with fruit, water and grains in excess and released immediately upon arrival at a forest fragment on Motuihe.
- Lloyd B.D. & Powlesland R.G. (1994) The decline of kakapo Strigops habroptilus and attempts at conservation by translocation. Biological Conservation, 69, 75-85
- Snyder N.F.R., Koenig S.E., Koschmann J., Snyder H.A. & Johnson T.B. (1994) Thick-billed parrot releases in Arizona. The Condor, 96, 845-862
- Kuehler C., Lieberman A., Varney A., Unitt P., Sulpice R.M., Azua J. & Tehevini B. (1997) Translocation of ultramarine lories Vini ultramarina in the Marquesas Islands: Ua Huka to Fatu Hiva. Bird Conservation International, 7, 69-79
- Lieberman A., Kuehler C., Varney A., Sulpice R.M. & Tehevini B. (1997) A note on the 1997 survey of the translocated Ultramarine Lory Vini ultramarina population on Fatu Hiva, Marquesas Islands, French Polynesia. Bird COnservation International, 7, 291-292
- Clout M.N. & Merton D.V. (1998) Saving the kakapo: the conservation of the world's most peculiar parrot. Bird Conservation International, 8, 281-296
- Oehler D.A., Boodoo D., Plair B., Kuchinski K., Campbell M., Lutchmedial G., Ramsubage S., Maruska E.J. & Malowski S. (2001) Translocation of blue and gold macaw Ara ararauna into its historical range on Trinidad. Bird Conservation International, 11, 129-141
- Ortiz-Catedral L. & Brunton D.H. (2010) Success of translocations of red-fronted parakeets Cyanoramphus novaezelandiae novaezelandiae from Little Barrier Island (Hauturu) to Motuihe Island, Auckland, New Zealand. Conservation Evidence, 7, 21-26