Social organisation and mating system of the fosa (Cryptoprocta ferox)
Soziale Organisation und Paarungssystem der Fossa (Cryptoprocta ferox)
by Mia-Lana Lührs
Date of Examination:2012-07-16
Date of issue:2012-09-24
Advisor:Prof. Dr. Peter M. Kappeler
Referee:Prof. Dr. Peter M. Kappeler
Referee:Prof. Dr. Eckhard W. Heymann
Files in this item
Name:luehrs.pdf
Size:3.90Mb
Format:PDF
Abstract
English
Mammalian mating systems are closely related to the social organisation of a species, which in turn is determined by sex-specific selection pressures with respect to access to limited resources. In previous studies of solitary carnivores, mating systems have often been described based on social organisation or molecular evidence alone, due to difficulties of observing mating behaviour in far-ranging species with low population densities. In the present study, I combined spatial data collected via GPS technology with detailed behavioural and genetic data on the fosa (Cryptoprocta ferox: Eupleridae), a medium-size solitary carnivore with a mating system characterised by prolonged polyandrous mating on traditional mating trees. The main aim of this thesis was to illuminate determinants of this unusual system with a specific focus on the underlying sex-specific reproductive strategies; thereby contributing new insights into our general understanding of the incentives of female polyandry, the operation of pre-copulatory female choice and male competitive tactics. A further focus of this thesis was to investigate the occurrence, patterns and consequences of male associations in this otherwise solitary species. From 2007 to 2010, I trapped, anaesthetised, sampled and took measurements of 33 fosas (24 males, 9 females) in Kirindy Forest/CNFEREF, Madagascar. Nine males and four females could be partially tracked simultaneously by means of GPS tags, which provided data on movement patterns, ranging area and degree of sociality. To investigate correlates and consequences of male association, I combined body acceleration data with spatial information of simultaneous tracking and stable isotope analyses of hair samples. Furthermore, I used genetic analyses based on 16 variable microsatellite markers to determine relatedness patterns in the population and specifically the degree of relatedness among associated males. During the seasonal mating periods of four successive years, I followed six oestrous females during their complete mating activity, collecting 540 hours of continuous observation including information on 316 copulations on four different mating trees. These data allowed elucidating determinants of male mating success, the degree of polyandry and patterns of female pre-copulatory choice. This combination of multiple methodological approaches yielded several major results. First, females ranged solitarily and showed indications of territoriality. Males had three times larger ranges (
Keywords: social system; mating system; reproductive strategies; carnivore; Cryptoprocta; Madagascar; GPS-tracking; animal movement; sexual selection; polyandry; cooperative hunting; stable isotopes; microsatellite
Schlagwörter: Sozialsystem; Paarungssystem; Fortpflanzungsstrategien; Raubtiere; Cryptoprocta; Madagaskar; GPS-tracking; Raumnutzung; sexuelle Selektion; Polyandrie; kooperative Jagd; stabile Isotope; Mikrosatelliten; Verhalten