largely forested ridges on either side to the east and west. Generally, this gully is a swampy area but it also represents an ephemeral watercourse and during and following heavy rain a small creek flows down it. A 1942 map shows a small dam across the creek. Environmental restoration The Royal Forest and Bird Protection Society of New Zealand (Forest & Bird) has been revegetating the island since 1984 and successfully eradicated rats and mice between 1988 and 1989. Red-crowned kākāriki (parakeets) from Kapiti Island were re-introduced in 2003 and 2004. North Island robins sourced from Kapiti Island were released in April 2006; they bred for the first time in late September that year and this was viewed as encouraging by DOC staff as it appeared to indicate that the island ecosystem represents a suitable habitat for this species. The island is a stronghold for the little blue penguin, the spotted shag and black shag, the red-billed gull, and several rare and endangered species of plants. Between 2012 and 2014, 237 fluttering shearwater chicks were translocated from the Marlborough Sounds to Matiu / Somes Island and hand-fed until they fledged. Some of the now-adult birds have since returned to the island and begun to breed. A solar-powered speaker system was also installed to transmit fluttering shearwater calls each night, and has attracted wild birds to Matiu / Somes Island. This species is common in Wellington Harbour but there has been no local breeding population since pre-European times. They were once an important food source for local iwi. There are more than 500 species of invertebrates on the island including three species of wētā. Wellington tree wētā were transferred to Matiu / Somes Island in 1996 and 1997, and 67 Cook Strait giant wētā were successfully transferred from Mana Island in 1996. A species of small ground wētā had survived on Matiu / Somes Island after deforestation. The island is now home to several species of native reptiles, including the common skink (Oligosoma nigriplantare), spotted skink (Oligosoma lineoocellatum), copper skink (Cyclodina aenea) and common gecko (Hoplodactylus maculatus). Twenty-five forest geckos (Mokopirirakau granulatus) were transferred to the island in April 2005, and more than 90 Wellington green geckos (Naultinus punctatus) were released in several transfers between 2006 and 2013. Two of these geckos were fitted with transmitters so that they could be monitored after release. In 2015 the green geckos were confirmed