This study was undertaken for two reasons. The first was that the New Zealand Falcon was largely unstudied, and research on its basic biology would provide a base-line for further work. The second was that the topic covered a number of disciplines which meant that, as an academic exercise, the scope was broad rather than narrowly specialised. The easiest projects to write up are those in which there are so many data that the figures almost speak for themselves or those in which there are so few data that one is free to speculate. Unfortunately most of the chapters in this study fall into a middle category in which the samples are small and statistical probabilities are marginal. Also, in trying to maintain a broad approach I have been compelled to sacrifice depth and so each chapter tends to reveal more questions than it answers. While writing, I have been acutely aware of the differences between potential readers. Overseas raptor specialists on the one hand may know little about New Zealand's avifauna and ecology, and New Zealand biologists, familiar with New Zealand, may know little about the ways of raptors. Therefore a short glossary of terms has been included. Briefly, the study has set out to answer a few straightforward questions such as 'Is the Falcon monotypic?', 'What is it related to?', 'Why are the females larger?', 'What do they eat?', 'How do they hunt?', 'How big is their range?', 'What is their breeding biology?', 'Will they breed in captivity?', 'What do they die of?', 'Where are they?', 'How many are there?'. Some of these questions, such as the diet, can be answered with some precision; others, such as the problem of sexual dimorphism, can only be answered in a general way. Because I was strongly advised at the start of this project that a study of the New Zealand Falcon was not feasible, I started a subsidiary project on the Australasian Harrier (Circus approximans). This was soon abandoned and although the results have been published (Fox 1977b) they have not been included in this thesis. Certain portions of this thesis, such as 'Rangle' (Chapter 5.15 -5.19), 'Diet values and food consumption' (5.8-5.11) and 'The shape of nesting territories' (8.9) have already been published or are in press, but for the sake of continuity have been kept as an integral part of the thesis. To a certain extent I have been handicapped by lack of raptor specialists in New Zealand with whom I could discuss my work. Another aspect of New Zealand's isolation is the difficulty in obtaining certain literature. Thus Chapter Four has suffered from my not having access to Noel Snyder's and James Wiley's recent monograph on Sexual Dimorphism. The compensation for this isolation has been the' privilege of working on such a magnificent, and unstudied, raptor.

This study was undertaken for two reasons. The first was that the New Zealand Falcon was largely unstudied, and research on its basic biology would provide a base-line for further work. The second was that the topic covered a number of disciplines which meant that, as an academic exercise, the scope was broad rather than narrowly specialised. The easiest projects to write up are those in which there are so many data that the figures almost speak for themselves or those in which there are so few data that one is free to speculate. Unfortunately most of the chapters in this study fall into a middle category in which the samples are small and statistical probabilities are marginal. Also, in trying to maintain a broad approach I have been compelled to sacrifice depth and so each chapter tends to reveal more questions than it answers. While writing, I have been acutely aware of the differences between potential readers. Overseas raptor specialists on the one hand may know little about New Zealand's avifauna and ecology, and New Zealand biologists, familiar with New Zealand, may know little about the ways of raptors. Therefore a short glossary of terms has been included. Briefly, the study has set out to answer a few straightforward questions such as 'Is the Falcon monotypic?', 'What is it related to?', 'Why are the females larger?', 'What do they eat?', 'How do they hunt?', 'How big is their range?', 'What is their breeding biology?', 'Will they breed in captivity?', 'What do they die of?', 'Where are they?', 'How many are there?'. Some of these questions, such as the diet, can be answered with some precision; others, such as the problem of sexual dimorphism, can only be answered in a general way. Because I was strongly advised at the start of this project that a study of the New Zealand Falcon was not feasible, I started a subsidiary project on the Australasian Harrier (Circus approximans). This was soon abandoned and although the results have been published (Fox 1977b) they have not been included in this thesis. Certain portions of this thesis, such as 'Rangle' (Chapter 5.15 -5.19), 'Diet values and food consumption' (5.8-5.11) and 'The shape of nesting territories' (8.9) have already been published or are in press, but for the sake of continuity have been kept as an integral part of the thesis. To a certain extent I have been handicapped by lack of raptor specialists in New Zealand with whom I could discuss my work. Another aspect of New Zealand's isolation is the difficulty in obtaining certain literature. Thus Chapter Four has suffered from my not having access to Noel Snyder's and James Wiley's recent monograph on Sexual Dimorphism. The compensation for this isolation has been the' privilege of working on such a magnificent, and unstudied, raptor.

Commercial pine plantations made up of exotic tree species are increasingly recognised as habitats that can contribute significantly to the conservation of indigenous biodiversity in New Zealand. Encouraging this biodiversity by employing sympathetic forestry management techniques not only offers benefits for indigenous flora and fauna but can also be economically advantageous for the forestry industry. The New Zealand falcon (Falco novaeseelandiae) or Karearea, is a threatened species, endemic to the islands of New Zealand, that has recently been discovered breeding in pine plantations. This research determines the ecological requirements of New Zealand falcons in this habitat, enabling recommendations for sympathetic forestry management to be made. Plantation forests that create a mosaic of pine stand ages across a plantation, offer suitable habitat for breeding New Zealand falcons by providing abundant nest sites, promoting high abundances of avian prey and creating favourable conditions for hunting. The diet of falcons within pine forests consisted primarily of birds, of which the majority were exotic passerines. Prey abundances were highest along pine stand edges. Both sexes preferentially hunted along pine stand edges between stands less than four years old and stands more than 20 years old. Pairs also preferentially nested along these borders, particularly within and along the edges of pine stands less than two years old. Within pine stands, nest sites were always located on the ground. Introduced predators and some forestry operations negatively affected breeding success. Nevertheless, productivity was higher than recorded for other habitats and female falcons were recorded successfully breeding in their first year for the first time. High prey densities and availabilities are suggested as the primary explanation for this. The extent of juvenile dispersal strongly suggests that pine plantations supplement populations in surrounding areas where falcons are in decline. This research demonstrates that changes to the existing forestry operational practices can influence the success of the breeding population. This research establishes that if commercial pine plantations are suitably managed, they can support extremely high falcon densities. Plantation forests therefore have a significant role to play in the future conservation of this species.