Untersuchung zur Brutbiologie und Populationsgenetik der Wiesenweihe (Circus pygargus Linnaeus, 1758) mittels Mikrosatelliten-Analyse

Montagu’s harrier (Circus pygargus) breeds on the ground and is endangered due to intensifi-cation of agricultural activities. Therefore, in most European countries the species is in high demand of intensive conservation efforts. The aim of this work was to identify novel microsa-tellite loci for Montagu’s harrier that can be used for breeding biological and population genetic analyses by means of paternity tests. These data could be used for conservation manage-ment. The work concentrated on the largest population in Germany: Mainfranken, Bavaria. Between 2000 2012 from chicks and between 2009 2012 from adult females blood samples were collected from this population. By means of 454-pyrosequencing 14 STR loci could be identified for use in parentage analyses. Another two loci from related species were found and three multiplex-PCR sets were developed for the microsatellite analysis. Genotyping of Mon-tagu’s harrier samples was performed by capillary-array electrophoresis using fluorescently labelled primers. Altogether 204 families containing 1276 samples from chicks and 123 samp-les from adult females were analysed via paternity tests. Investigation on age of first breeding revealed an age of three years for males and of two years for females. Nests of first-breeding males were located 15 km away from the hat-ching site, whereas those of females were 22 km. 41.2% of males and 29.4% of females can be considered to be philopatric, since distances between nests of first breeding and hatching site were ≤10 km. Recruitment rates of males were 4.9% and for females 2.9%. Sex ratio of chicks was biased towards males (53.1%). Altogether, only 4% of the studied chicks returned to the breeding colony. Adult males seem to be the more philopatric sex because nesting dis-tances between two consecutive years were found to be 1.7 2.9 km (6.4 km for females). Concerning results on partner fidelity, the breeding system of the species can be considered to be seasonally monogamous. Rates of bigamy (1.5%, three of 204 families) and extrapair youngs (0.5 1% of broods and 0.3% of all chicks) seem to be very low. Only 25.5% of fema-les bred with the same partner in more than one year. A significant higher breeding success could be detected when females remained with the same partner compared to females that changed their partner every year. Moreover, nests of faithful females were located closer to the nest of the previous year, than those of non-faithful females. Mean age of males obser-ved during the study period time was 3.8 years and 3.6 years for females. Individual birds reached much higher ages of 7-10 years. Furthermore, yearly survival rates of 60 82% could be determined for females. With regard to conservation efforts and management strategies, eight European populations were investigated for genetic exchange. Result indicate pro-nounced mixing of these populations, since they were found to be genetically homogenous. More detailed analyses on population genetics is needed to derive consequences for conser-vation. All findings are discussed regarding to biological and methodological aspects

Development of New Microsatellite (STR) Markers for Montagu’s Harrier (Circus pygargus) via 454 Shot-Gun Pyrosequencing

During the last decades the ground-breeding Montagu’s harrier ( Circus pygargus , Linnaeus, 1758) has changed its breeding habitats in Europe to agricultural areas in which many local populations would be close to extinction without a special nest protection regime. Although Montagu’s harrier is a well-studied species in terms of ecology and breeding biology, its genetic structure and population genetics are almost unknown. As there is a lack of good genetic markers we developed a set of 19 microsatellite markers comprising 16 new STR markers which were identified by next-generation sequencing (NGS) using 454 shot-gun pyrosequencing of genomic DNA. The STR markers were arranged into three multiplex PCR sets for high throughput genotyping and characterised. The marker set provides a powerful tool for kinship analysis. The combined non-exclusion probability for parent pairs was 1.13* 10-11. Only three loci showed PIC values < 0.50. In total, 121 known family relationships were compared with genetically calculated ones to test the markers suitability for parentage analysis. In 97.5% of all cases full-sibships were accurately determined and 97.6% of all mothers were assigned correctly to their chicks. The present multiplex PCR panels can be used to investigate several hypotheses concerning breeding behaviour, kinship, exchange rates between populations and phylogeography

New Microsatellite Markers for the Common Tern (Sterna hirundo) Developed with 454 Shot-Gun Pyrosequencing

Long term studies, focusing on population- and socio-biology research, require the unequivocal identification of individuals. DNA studies with Short Tandem Repeats (STR loci) became a widespread tool in population genetics. We used the next-generation sequencing (NGS) approach with 454 shot-gun pyrosequencing to identify 13 new polymorphic STR loci for the Common Tern, Sterna hirundo. To enlarge the marker set we added two more loci originally developed for Black-legged Kittiwake (Rissa tridactyla) and Red-billed Gull (Chroicocephalus scopulinus) and arranged these 15 loci into three multiplex PCR panels for high throughput genotyping. Loci characterization demonstrated that our marker set is of high quality. A PIC value of about 0.67 and a power of exclusion value of 0.99 were reached. Deviation from Hardy-Weinberg expectations of some loci and low frequencies for null alleles are interpreted as a result of inbreeding and founder effect in the investigated tern colony. We used a test data set of this well-studied breeding colony of Common Tern at Banter Lake, Wilhelmshaven, Germany, to perform a parentage test. Parent-chick relationships, known from the social pedigree of that colony, were compared with genetically calculated ones. In order to test our markers and the used parentage program COLONY, we conducted six competing data sets with varying completeness of included parental genotypes. By including fully sampled parent pairs of known family assignment, results were correct for nest mates, single parents and parent pairs. Our marker set provides a powerful tool to investigate life-time reproductive success and other issues of population and socio-biology for Common Terns, e.g. in the aforementioned colony monitored for decades