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Selected AbstractsBlunt egg pole holds cues for alien egg discrimination: experimental evidenceJOURNAL OF AVIAN BIOLOGY, Issue 2 2010L. Pola, iková Eggshell colour patterns play a crucial role in avian host,parasite coevolution. In contrast to many experiments investigating general host egg discrimination abilities, studies testing where specific recognition cues are located on the eggshells (on blunt, sharp or both egg poles) are lacking. Previous studies suggested that discrimination cues might be located at the blunt egg pole, where the shell patterning is typically concentrated. We tested this hypothesis experimentally in species subject to interspecific (great reed warblers Acrocephalus arundinaceus, reed warblers A. scirpaceus), and also intraspecific parasitism (song thrushes Turdus philomelos, blackbirds T. merula). We examined host responses towards two types of intraspecific eggs painted non-mimetic immaculate blue either at blunt or sharp poles. All four species rejected eggs manipulated at the blunt pole at significantly higher rates, indicating that they perceive the critical recognition cues in the same egg part. Thus, the presence of egg recognition cues at the blunt egg pole may be a general phenomenon in birds parasitized by both intraspecific and interspecific parasites. [source] Habitat fragmentation and adaptation: a reciprocal replant,transplant experiment among 15 populations of Lychnis flos-cuculiJOURNAL OF ECOLOGY, Issue 5 2008Gillianne Bowman Summary 1Habitat fragmentation and variation in habitat quality can both affect plant performance, but their effects have rarely been studied in combination. We thus examined plant performance in response to differences in habitat quality for a species subject to habitat fragmentation, the common but declining perennial herb Lychnis flos-cuculi. 2We reciprocally transplanted plants between 15 fen grasslands in north-east Switzerland and recorded plant performance for 4 years. 3Variation between the 15 target sites was the most important factor and affected all measures of plant performance in all years. This demonstrates the importance of plastic responses to habitat quality for plant performance. 4Plants from smaller populations produced fewer rosettes than plants from larger populations in the first year of the replant,transplant experiment. 5Plant performance decreased with increasing ecological difference between grassland of origin and target grassland, indicating adaptation to ecological conditions. In contrast, plant performance was not influenced by microsatellite distance and hardly by geographic distance between grassland of origin and target grassland. 6Plants originating from larger populations were better able to cope with larger ecological differences between transplantation site and site of origin. 7Synthesis: In addition to the direct effects of target grasslands, both habitat fragmentation, through reduced population size, and adaptation to habitats of different quality, contributed to the performance of L. flos-cuculi. This underlines that habitat fragmentation also affects species that are still common. Moreover, it suggests that restoration projects involving L. flos-cuculi should use plant material from large populations living in habitats similar to the restoration site. Finally, our results bring into question whether plants in small habitat remnants will be able to cope with future environmental change. [source] Polymorphic microsatellite DNA markers for the Patagonian squid, Loligo gahi (Cephalopoda)MOLECULAR ECOLOGY RESOURCES, Issue 3 2002P. W. Shaw Abstract Squid populations are being put under rapidly increasing commercial fishing pressure worldwide. The same species are known to be susceptible to extreme population fluctuations, so detailed knowledge of population substructuring and genetic diversity is essential for rational management. We present a set of microsatellite DNA loci suitable for population genetic analysis of Loligo gahi, the squid species subject to the most detailed monitoring and fishery control (around the Falkland Islands), with the future aim of generating management-related information to aid conservation of this valuable natural resource. [source] Are dingoes a trophic regulator in arid Australia?AUSTRAL ECOLOGY, Issue 2 2010A comparison of mammal communities on either side of the dingo fence Abstract The direct and indirect interactions that large mammalian carnivores have with other species can have far-reaching effects on ecosystems. In recent years there has been growing interest in the role that Australia's largest terrestrial predator, the dingo, may have in structuring ecosystems. In this study we investigate the effect of dingo exclusion on mammal communities, by comparing mammal assemblages where dingoes were present and absent. The study was replicated at three locations spanning 300 km in the Strzelecki Desert. We hypothesized that larger species of mammal subject to direct interactions with dingoes should increase in abundance in the absence of dingoes while smaller species subject to predation by mesopredators should decrease in abundance because of increased mesopredator impact. There were stark differences in mammal assemblages on either side of the dingo fence and the effect of dingoes appeared to scale with body size. Kangaroos and red foxes were more abundant in the absence of dingoes while Rabbits and the Dusky Hopping-mouse Notomys fuscus were less abundant where dingoes were absent, suggesting that they may benefit from lower red fox numbers in the presence of dingoes. Feral cats and dunnarts (Sminthopsis spp.) did not respond to dingo exclusion. Our study provides evidence that dingoes do structure mammal communities in arid Australia; however, dingo exclusion is also associated with a suite of land use factors, including sheep grazing and kangaroo harvesting that may also be expected to influence kangaroo and red fox populations. Maintaining or restoring populations of dingoes may be useful strategies to mitigate the impacts of mesopredators and overgrazing by herbivores. [source] |