Mate choice in kaki (black stilts) : Does this highly managed and endangered species avoid inbreeding? : A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Science with Honours at Lincoln University

• Main Author: Tansell, A. J. S.
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Lincoln University 2001
• Subjects: New Zealand birds; endangered species; kaki; Himantopus novaezelandiae; breeding programmes; ANZSRC::050202 Conservation and Biodiversity; ANZSRC::050211 Wildlife and Habitat Management; New Zealand; Mackenzie Basin
• Online Access: https://hdl.handle.net/10182/13003

In order to maximise individual fitness, animals would be expected to pair with a mate of the highest possible quality. One measure of mate quality is relatedness, or genetic similarity. Choosing an unrelated, genetically dissimilar mate enriches the genetic resources of the offspring and reduces the chances that detrimental recessive alleles will be brought into homozygosity, causing inbreeding depression. In order to avoid mating with close kin, it is necessary for animals to be able to recognise kin. The mechanisms suggested for kin recognition include learning the characteristics of kin by association with them, or learning a kin template, which other individuals are judged against. In small populations of endangered species, animals may be left with little choice of mates and as a result may be forced to breed with close relatives. One of the threats faced by small populations of endangered New Zealand birds, such as the kaki (Himantopus novaezelandiae), is that inbreeding will be detrimental to the population, reducing reproductive success or survival, or the ability of the population to adapt to environmental challenges. Kaki are a critically endangered endemic wader reduced to one population in the Mackenzie Basin. The population has been actively managed for the past 20 years, using a variety of management techniques. Since 1993 multiple clutching has been combined with captive rearing and pulse releases of kaki and dark hybrids. The practise of multiple clutching means that not all siblings from a season are raised together, a situation that does not occur naturally as kaki usually only lay a second clutch if the first fails. In addition, some clutches are intermingled in captivity, so that some kaki are raised with unrelated birds. If kaki learn to recognise close siblings by association with them, the practise of multiple clutching presents kaki with siblings that they will assume to be unrelated and clutch intermingling presents kaki with unrelated birds they will assume are related. Management ...