We have developed a new approach to create microsatellite primer sets that have high utility across a wide range of species. The success of this method was demonstrated using birds. We selected 35 avian EST microsatellite loci that had a high degree of sequence homology between the zebra finch Taeniopygia guttata and the chicken Gallus gallus and designed primer sets in which the primer bind sites were identical in both species. For 33 conserved primer sets, on average, 100% of loci amplified in each of 17 passerine species and 99% of loci in five non-passerine species. The genotyping of four individuals per species revealed that 24-76% (mean 48%) of loci were polymorphic in the passerines and 18-26% (mean 21%) in the non-passerines. When at least 17 individuals were genotyped per species for four Fringillidae finch species, 71-85% of loci were polymorphic, observed heterozygosity was above 0.50 for most loci and no locus deviated significantly from Hardy-Weinberg proportions. This new set of microsatellite markers is of higher cross-species utility than any set previously designed. The loci described are suitable for a range of applications that require polymorphic avian markers, including paternity and population studies. They will facilitate comparisons of bird genome organization, including genome mapping and studies of recombination, and allow comparisons of genetic variability between species whilst avoiding ascertainment bias. The costs and time to develop new loci can now be avoided for many applications in numerous species. Furthermore, our method can be readily used to develop microsatellite markers of high utility across other taxa.

SummaryNest-site reduction has played a significant role in the decline of Barn Owl Tyto alba populations throughout Europe and North America. Techniques of nest-site augmentation, involving the provision of nest-boxes, have been widely used in a range of species of conservation concern, including falcons, eagles, parrots, owls and cavity-nesting ducks. A common method of Barn Owl conservation is the placement of nest-boxes on church towers. Despite the usefulness of nestboxes, several studies have shown that there may be associated disadvantages and that nestboxes may even act as 'ecological traps'. The purpose of this research was to compare the survival rate of owlets hatched in nest-boxes with those hatched in the more ''natural'' environment of church towers. Survival time analysis elucidated that owlets developing in nest-boxes had significantly lower survival than those hatched in church towers. This difference was most obvious after the parent-dependent period of the life history. Surprisingly, the length of time from hatching to the onset of winter had no effect on the survival of the owlets, even though the accumulation of sufficient body reserves and acquisition of hunting experience are thought to be important in determining survival during the critical first winter of life. We propose possible causes for the negative effects of nest-boxes and recommend some modifications to the priorities of Barn Owl Action Plans, e.g. partial reopening of buildings instead of nest-box installation. This paper emphasizes the importance of considering revision of Species Action Plans in the case of other endangered species where conservation is based on nest-site supplement (e

We have identified 15 polymorphic microsatellite loci for the barn owl (Tyto alba), five from testing published owl loci and 10 from testing non-owl loci, including loci known to be of high utility in passerines and shorebirds. All 15 loci were sequenced in barn owl, and new primer sets were designed for eight loci. The 15 polymorphic loci displayed two to 26 alleles in 56-58 barn owls. When tested in 10 other owl species (n = 1-6 individuals), between four and nine loci were polymorphic per species. These loci are suitable for studies of population structure and parentage in owls.

We report 21 new polymorphic microsatellite markers in the European barn owl (Tyto alba). The polymorphism of the reported markers was evaluated in a population situated in western Switzerland and in another from Tenerife, Canary Islands. The number of alleles per locus varies between two and 31, and expected heterozygosity per population ranges from 0.16 to 0.95. All loci are in Hardy-Weinberg equilibrium and no linkage disequilibrium was detected. Two loci exhibit a null allele in the Tenerife population.