Dana Rymešová

Differences in mortality rates, dispersal distances and breeding success of commercially reared and wild grey partridges in the Czech agricultural landscape

The aim of this study was to evaluate the efficiency of releasing commercially reared individuals of the grey partridge (Perdix perdix) as a method for species recovery. This study compares the mortality risk of grey partridges depending on origin, sex and body condition, controlling for age, infection risk and release method. In total, 110 locally caught wild individuals and 75 commercially reared game-farm partridges were released and radio tracked within the same study area in the Czech Republic between 2009 and 2011. To exclude a possible effect of age on survival, only individuals in the second calendar year of life were chosen for the analysis. Commercially reared partridges had significantly higher mortality risk than wild ones. None of the commercially reared birds survived in the wild until the end of the nesting period, and none produced a fledged brood. Females from game farms showed significantly better survival than males and preferred to mate with wild males, whereas wild females avoided mating with commercially reared males. Predation was the main cause of mortality, and proportion of birds killed by raptors and mammals did not differ between wild and commercially reared birds. These results highlight the uselessness of releasing adult commercially reared partridges in an effort to establish viable populations of this species in the wild and stress the need for a change from intensive rearing methods aimed predominantly at quantity towards a more conservation breeding-oriented approach aimed at quality.

Mate choice for major histocompatibility complex complementarity in a strictly monogamous bird, the grey partridge (Perdix perdix)

BackgroundSexual selection has been hypothesised as favouring mate choice resulting in production of viable offspring with genotypes providing high pathogen resistance. Specific pathogen recognition is mediated by genes of the major histocompatibility complex (MHC) encoding proteins fundamental for adaptive immune response in jawed vertebrates. MHC genes may also play a role in odour-based individual recognition and mate choice, aimed at avoiding inbreeding. MHC genes are known to be involved in mate choice in a number of species, with ‘good genes’ (absolute criteria) and ‘complementary genes’ (self-referential criteria) being used to explain MHC-based mating. Here, we focus on the effect of morphological traits and variation and genetic similarity between individuals in MHC class IIB (MHCIIB) exon 2 on mating in a free-living population of a monogamous bird, the grey partridge.ResultsWe found no evidence for absolute mate choice criteria as regards grey partridge MHCIIB genotypes, i.e., number and occurrence of amino acid variants, though red chroma of the spot behind eyes was positively associated with male pairing success. On the other hand, mate choice at MHCIIB was based on relative criteria as females preferentially paired with more dissimilar males having a lower number of shared amino acid variants. This observation supports the ‘inbreeding avoidance’ and ‘complementary genes’ hypotheses.ConclusionsOur study provides one of the first pieces of evidence for MHC-based mate choice for genetic complementarity in a strictly monogamous bird. The statistical approach employed can be recommended for testing mating preferences in cases where availability of potential mates (recorded with an appropriate method such as radio-tracking) shows considerable temporal variation. Additional genetic analyses using neutral markers may detect whether MHC-based mate choice for complementarity emerges as a by-product of general inbreeding avoidance in grey partridges.

Microsatellite analysis detects low rate of extra-pair paternity in Tengmalm's owl, Aegolius funereus

Abstract. Genetic methods enable to reveal cryptic parental contributions in reproduction, especially in socially monogamous species. The rate of extra-pair paternity is generally low in raptors and owls and its presence in some species is tightly associated with sequential polyandry which can rarely occur in years with high food availability. In this study we investigated the mating system of the Tengmalms owl (Aegolius funereus) in the Ore Mountains (Czech Republic). In this area, the species usually nests in high breeding densities which could increase an opportunity for extra-pair copulations. In total, 297 individuals (54 females, 47 males and 196 juveniles) from 46 nest boxes were genotyped at seven microsatellite loci. We present results of a five-year study and four extra-pair nestlings (2.3 %) were detected which did not result from sequential polyandry.