RECOMENDACIONES FINALES

The tūī is a protected endemic honeyeater (males, 120 g, females 85 g, average mass) (Higgins et al., 1990). The IUCN Red List category for tūī is ‘Least concern’ as it does not approach the threshold for ‘Vulnerable’ within the range size or population trend criterions (BirdLife International, 2012). Tūī are common throughout mainland New Zealand, but are sparse in large deforested regions, especially east of the central Southern Alps in the South Island, and Manawatu, south Taranaki and central Waikato in the North Island (Robertson, 2007).

Although tūī are commonly found in urban areas, they have suffered serious declines in some areas, including cities. Tūī abundance in Christchurch declined rapidly in the 1990s (Day, 1995), and tūī were recorded as absent from Hamilton in 1993 (Innes et al., 2005). Cities or towns with large adjoining forest patches are considered capable of supporting tūī year round, whereas cities lacking forest remnants were only utilized by tūī during winter and spring, and breeding occurred in outlying forest patches (Innes et al., 2004). A recent study found that

forests (Innes et al., 2015). These results suggest that recolonisation of urban habitats by tūī is possible providing adequate food is available and effective pest control is implemented (Innes et al., 2015). Tūī became locally extinct from Banks Peninsula in the mid 1990s due to habitat loss and predation (Schmechel, 2002) and a translocation was conducted in 2009 along with revegetation and pest control programmes (Banks Peninsula Conservation Trust, 2014). Post- translocation monitoring has indicated that the project has been successful in the short-term (Banks Peninsula Conservation Trust, 2014). A subspecies of the tūī, the Chatham Island tūī (Prosthemadera novaeseelandiae chathamensis), is classified as Endangered by the IUCN Red List Category, and is in decline due to ongoing habitat destruction and the effects of introduced predators (Dilks, 2004). The abundance of both of the two endemic New Zealand honeyeaters (family Meliphagidae), tūī and bellbirds (Anthornis melanura), has decreased rapidly since human colonisation, due mainly to a combination of mammalian predators, habitat loss, reduction in food sources and disease (Diamond and Veitch, 1981). Of the two honeyeaters, tūī are the larger and more dominant species (Bergquist, 1989) and are more abundant and widespread on the mainland (Gill et al., 2010). Tūī is an iconic New Zealand species with a distinctive song and it plays an important ecological role as one of the key pollinators (Anderson, 2003) and seed dispersers (Kelly et al., 2010) of many native plant species (Castro and Robertson, 1997).

Tūī are opportunistic foragers and feed on flower nectar, fruits, insects and honeydew in different proportions according to their availability but nectar being the most important food (Bergquist, 1989; Castro and Robertson, 1997). The uneven spatial and temporal distribution of nectar leads to competition between new individuals and residents in areas with high nectar resources (Craig, 1985) and aggressive behavior is used by males to displace conspecifics and other species when defending a nectar resource (Craig, 1984). Residents usually

dominate both conspecifics and other species in defense of resources (Craig, 1984).

New Zealand native birds vary in their adaptability to urbanisation (Robertson, 2007) and less specialised, opportunistic species such as tūī regularly exploit native and exotic nectar resources provided in urban habitats (van Heezik et al., 2008b). Tūī were listed as the fifth most common New Zealand garden bird in surveys from 2007-2013, (Spurr, 2012) and are a common feature of urban parks and gardens. However, the percentage of gardens in which tūī occurred varied regionally, with tūī occurring in only 2% of gardens in Canterbury compared with 52% of gardens nationally (Spurr, 2012). Tūī are considered more pest-resistant compared with most natives (Innes et al., 2010) and are highly mobile, often travelling long distances to secure nectar (Schmechel, 2002). Outside the breeding season, tūī will travel up to 30 kilometres to gain access to winter food resources such as winter flowering Eucalyptus species, puriri (Vitex lucens), kowhai

(Sophora microphylla) and kahikatea (Dacrycarpus dacrydiodes) fruit

(Schmechel, 2002; Stevens, 2006).

During the breeding season, a pair of tūī will select a nest site near a patch of continuous vegetative cover and an adequate nectar supply, with the male using long-range songs to defend the nest (Bergquist, 1989). Tūī have a long breeding season (September through to the end of February) and a relatively short nesting period. Tūī can produce at least two broods in a year, and can therefore more easily withstand losses due to predation and disease than many other native birds (Bergquist, 1989).

The presence of private gardens and native bush fragments can potentially support a wider diversity and abundance of native birds in urban areas and tūī were found in greater numbers in residential areas with larger and more structurally complex gardens (van Heezik et al., 2008b). Urban forest fragments, such as scenic reserves, have the potential to act as a population source area for some bird species that then disperse into surrounding suburbs (Parsons et al., 2006; van Heezik et al., 2008b).

Tūī utilise many exotic nectar and fruit producing species in the urban landscape at different times of year, whereas non-urban, agricultural landscapes may offer less year-round supplies of native and exotic food resources such as flowering cherry (Prunus campanulata), flame tree (Erythrina spp), Protea species, bottlebrush (Callistemon sp.) and Moreton Bay fig (Ficus macrophylla). Urban environments may provide more food abundance than other areas. However how tūī adapt their songs and singing behaviour to successfully survive in the urban habitat has not been investigated.