Schotborgh, Huibertje M. E.2010-10-142005https://hdl.handle.net/10182/2681Aspects of kereru (Hemiphaga novaeseelandiae) ecology were studied on Banks Peninsula, New Zealand, from February 2004 until March 2005 (13 months). Telemetry equipment was used to locate 15 radio-tagged kereru. Characteristic of the human-modified landscape where this study took place is a mosaic of farmland, peri-urban areas, townships, native forest patches, and conifer plantations. Main study sites were at Church Bay and Orton Bradley Park. This study is part of the Kaupapa Kereru Programme which aims to enhance the kereru population on Banks Peninsula, and also contributes to national efforts to enhance kereru populations in human-modified landscapes. Before this study, little was known of kereru ecology in landscapes such as on Banks Peninsula. The breeding season extended from mid-July 2004 to at least March 2005. Sixty-seven percent of tagged kereru bred and seven chicks fledged from 20 nesting attempts (35% success rate). Breeding success was higher compared with kereru populations on mainland New Zealand, but not as successful as a relatively predator-free population or for populations in areas where predators were controlled. Kereru nested in native forest patches and in areas frequently occupied by humans. Kereru ate 11 native and 12 introduced plant species. Two to eight species were eaten each field week. Introduced species were eaten solely during parts of summer and autumn, and made up at least 50% of the diet during these periods. Native species were eaten during winter but made up less than 50% of diet. During mid to late summer, kereru ate solely native species. Native species provided leaves, flowers, and fruit. Introduced species provided leaves and flowers, except plum trees (Prunus spp.) which also provided fruit. Before and during the first part of the breeding season, kereru were recorded eating leaves and flowers, mostly of introduced deciduous species and kowhai. The crop content of one brooding female found dead suggested that a chick was at least partly raised on plum tree and willow (Salix spp.) leaves. The kereru population did not appear to be limited by food. However, planting of additional food sources could enhance food variety and ensure availability of sufficient foods for an increased population. Home ranges, estimated using cluster analysis, were significantly smaller during the breeding season than during the non-breeding season. Home ranges (1.8-22.2 ha) and core areas (0.01-0.28 ha) were significantly smaller than those found in the Whirinaki Forest Park (13.9-704.2 ha, and 1.1-26.7 ha respectively). Home range overlap was less at Orton Bradley Park than at Church Bay. Home range overlap was generally less during the breeding season than during the non-breeding season at both study sites. During the non-breeding season, six of 10 kereru moved away from Orton Bradley Park for about two months perhaps as a result of insufficient food. Daily movements were mostly less than 500 m at both study sites. Presence of kereru was regulated by food availability, except during the breeding season when kereru also required suitable nesting sites. The Church Bay and Orton Bradley Park study sites appeared to contain all required resources as home ranges were within these sites. However, more predation events occurred at Orton Bradley Park reducing its quality. Increased food availability across Banks Peninsula should allow kereru to colonise new areas. Additional (native) fruiting food species should improve carrying capacity of areas, diet choice of kereru, and indirectly improve species composition in forest patches through improved seed dispersal by kereru. Seed dispersal of native plant species occurred only during mid to late summer and mostly within 500m from foraging locations. Management efforts to enhance the kereru population on Banks Peninsula should first focus on predator control. Adult survival should be prioritised above reproductive output. Adult kereru were especially vulnerable to predation during summer and the breeding season when foraging on low scrub and while incubating or brooding. Five of 20 nests were preyed upon; four eggs and one chick were preyed upon. Kereru in human-modified landscapes elsewhere in New Zealand could be exposed to similar threats. Secondly, management should focus on providing suitable nesting sites and increasing the food availability before and during the breeding season for future, increased populations (i.e., following predator control). Suggestions for future research of kereru in human-modified landscapes are made.enkereruHemiphaga novaeseelandiaeNew Zealand pigeonBanks PeninsulaecologyThesisQ112867441