The Marsh fritillary (Euphydryas aurinia) (Lepidoptera: Nymphalidae) has declined across Europe, including the Czech Republic. Current conservation strategies rely on prevention of habitat loss and degradation, and increase in habitat quality and connectivity via promoting traditional grassland management. The population structure and adult demography parameters of a single population was investigated for eight years (single system), and of all the known Czech populations (multiple populations) for a single year, using mark-recapture. There was substantial variation in the patterns of adult demography, both among years in the single system and among the multiple populations in a single year. In the single system, the date of the first flight of an adult varied by 18 days over the 8 years and total annual numbers varied with a coefficient of variation of 0.40 (females fluctuating more than males). The average density was ca 80 adults/ha. The population size displayed density-dependence, i.e. decreased following years with high adult numbers, with an equilibrium density of 90 individuals/ha. The average density of the multiple populations was ca 120 individuals/ha. The estimated total population for the Czech Republic was 25,000 individuals (17,000 males / 8,000 females) in 2007, which does not indicate an imminent threat of extinction. The regional persistence of E. aurinia is likely to depend on re-colonisation of temporarily vacant sites by dispersing individuals, facilitated by local shifts in adult flight phenology to that better adapted to local conditions. and Kamil Zimmermann, Pavla Blazkova, Oldrich Cizek, Zdenek Fric, Vladimir Hula, Pavel Kepka, David Novotny, Irena Slamova, Martin Konvicka.
Breeding success and several breeding parameters were studied at 5 feral pigeon colonies. We found that density and the age of breeding pairs affect reproduction, with also the age of the nest significantly influencing reproductive indicators and success. Hatching, fledging and breeding success were higher in colonies with lower breeding pair densities. These indicators were also higher for experienced pairs compared to first time breeders. The number of nests in a pair’s territory had little effect on breeding performance. Among all the breeding parameters studied (timing of breeding, length of the breeding season, number of broods per year) only the latter was positively correlated with the density of birds. Breeding pairs had significantly more broods during a year in highly dense colonies compared with those of low density. The remaining factors studied were similar in all breeding colonies regardless of their density. Breeding parameters were primarily dependent on breeding pair age – experienced pairs began breeding earlier, ended later, conducted a longer breeding season and, as a result, produced more broods per year. The age of a nest also influenced the breeding season. Many factors were found to cause egg and nestling loss. Mechanical damage to eggs, eggs and nestlings falling out of nests, embryo death, jackdaw predation, competition among fledglings, and nestling disease were dependent on the level of pigeons’ reproductive activity, especially in overly dense colonies.