Search results for " Systematics"
showing 10 items of 6576 documents
Life in varying environments: experimental evidence for delayed effects of juvenile environment on adult life history
2011
Summary 1. The effects of environment experienced during early development on phenotype as an adult has started to gain vast amounts of interest in various taxa. Some evidence on long-term effects of juvenile environment is available, but replicated experimental studies in wild animals are still lacking. 2. Here we report the first replicated experiment in wild mammals which examines the long-term effects of juvenile and adult environments on individual fitness (reproduction, survival and health). The early development of bank vole (Myodes glareolus) individuals took place in either foodsupplemented or un-supplemented outdoor enclosures. After the summer, adult individuals were reciprocally…
Within territory abundance of red wood ants Formica rufa is associated with the body condition of nestlings in the Eurasian treecreeper Certhia famil…
2007
Studies on individual reproductive success in relation to interspecific competition between distantly related taxa are scarce. We studied whether the abundance of red wood ants Formica rufa -group is related to the breeding habitat selection, fecundity and offspring quality in the Eurasian treecreeper Certhia familiaris, an old-growth forest passerine. The nest-box occupancy data were gathered over a five-year study period, whereas the breeding performance analyses were based on a two-year data set. The abundance of wood ants, measured within 50 m around the nest-boxes, was not related to nest-box occupancy rate, fecundity or the physiological stress of nestlings. In contrast, the abundance…
Different demography of friends and strangers: an experiment on the impact of kinship and familiarity in Clethrionomys glareolus.
1989
We examined demographic effects of familiarity and relatedness in the bank vole Clethrionomys glareolus (Schreber) in four 0.5-ha enclosures in Central Finland. In two enclosures were mature voles which had overwintered together and some of their mature off-spring (hereafter referred to as “Friends”), and in the other two individuals of the same species captured from different localities near the study area (“Strangers”). The experiment lasted from June to September. The populations of Friends reached densities twice as high as those of Strangers with a significantly higher rate of recruitment and survival of the young. This may have been due to mutual familiarity decreasing antagonism towa…
Taxonomy and evolution of the Convolvulus sabatius complex (Convolvulaceae)
2010
A revision of the Convolvulus sabatius complex is presented and five taxa are now recognised. Convolvulus valentinus is re-circumscribed to comprise only blue-flowered individuals. Yellow-flowered plants previously referred to this species are transferred to C. supinus where they are recognised as a distinct variety: C. supinus var. melliflorus, comb nov. Variation in intensity of flower colour, pubescence and leaf shape among blue-flowered C. valentinus is highly variable within populations and in contrast to earlier treatments, no infraspecific taxa based on these traits are recognised. Despite suggestions to the contrary, the delimitation of the cultivated ornamental C. sabatius and its …
Accumulation of plerocercoids of Triaenophorus crassus in the second intermediate host Coregonus lavaretus and their effect on growth of the host
1999
Patterns of accumulation of Triaenophorus crassus in its second intermediate host whitefish Coregonus lavaretus s.l. were studied between 1991 and 1996 from two host populations in two separate areas of Lake Saimaa, Finland. Whitefish were infected commonly with several T. crassus plerocercoids and the parasites were aggregated into the oldest hosts. In one host population the annual parasite accumulation was 0·9 parasites in all host age groups between 3 and 8 years. In the other host population the annual accumulation was 1·6 parasites in 3–5-year-old fish, but increased up to 3 to 4 parasites per year in fish over 5 years old. The increase did not coincide with the period of maturation o…
Predation by signal crayfishPacifastacus leniusculuson fish eggs and its consequences for coregonid recruitment
2015
The character and magnitude of predation by the invasive, ectothermic Pacifastacus leniusculus, a crayfish widely introduced to Europe and Japan from North America, on the eggs of coregonid fishes, vendace Coregonus albula and whitefish Coregonus lavaretus were examined by experimentation, modelling and field data. The present results showed that P. leniusculus has the potential to be very efficient predator of fish eggs under winter conditions, but the predation by P. leniusculus did not significantly decrease production of coregonid larvae during the years with a high P. leniusculus population in the study lake. Hence, the mortality caused by the novel invertebrate predator appeared to co…
Color-assortative mating in a color-polymorphic lacertid lizard
2013
Color polymorphisms are common in lizards, which provide an excellent model system to study their evolution and adaptive function. The lacertid genus Podarcis is particularly interesting because it comprises several polymorphic species. Previous studies with lacertid lizards have tried to explain the maintenance of color polymorphisms by correlational selection between color morphs and several phenotypic traits. Particular attention has been paid to their putative role as signals reflecting alternative reproductive strategies under frequency-dependent selection, but the relationship between mating patterns and color polymorphism has not been previously considered. In this study, we use long…
Preliminary health screening and possible pathogen determination in aBufo bufo(Linnaeus, 1758) (Amphibia: Bufonidae) population
2010
The population of the common toad, Bufo bufo, on Jersey (Channel Islands, UK) has undergone a marked decline over recent years. Hypothesized causes for this decline include land use change, pollution, climate change and predation. We examined the carcasses of 97 wild adult common toads for gastrointestinal and pulmonary helminths. In addition, 31 adult toad carcasses were examined for the presence of ranavirus infection, and 212 wild common toads were examined for the presence of infection with the fungus Batrachochytrium dendrobatidis. Three nematode species Rhabdias bufonis, Aplectana macintoshii and Oswaldocruzia filiformis, and one species of cestode, Nematotaenia dispar, were identifie…
The joint emergence of group competition and within-group cooperation
2015
Abstract Between-group conflict and within-group cooperation can be seen as two sides of the same coin, coevolving in a group-structured population. There is strong support for between-group competition facilitating the evolution of human cooperative tendencies, yet our understanding of how competition arises is less clear. We show that groups of randomly assembled individuals spontaneously engage in costly group competition, and that decisions promoting between-group conflict are associated with high levels of within-group cooperation. Remarkably, when groups were given the possibility to compete against other groups, net earnings for individuals were higher than when groups were not allow…
Taxonomic clarification in W-Mediterranean Androcymbium (Colchicaceae): A. wyssianum sunk in the synonymy of A.gramineum and A.europaeum restored
2010
Abstract Hoyo A. del & Pedrola-Monfort J.: Taxonomic clarification in W Mediterranean Androcymbium (Colchicaceae): A. wyssianum sunk in the synonymy of A. gramineum and A. europaeum restored. — Willdenowia 40: 47–53. — Online ISSN 1868-6397. — © 2010 BGBM Berlin-Dahlem. doi:10.3372/wi.40.40103 (available via http://dx.doi.org/) Capsule dehiscence has been used as a diagnostic character for W Mediterranean species of Androcymbium. Depending on the state of capsule maturity, the character, however, can be ambiguous in herbarium material. Based on morphological, phenological and cpDNA characters it is shown that misinterpretation of the capsule as indehiscent in the type material of A. gramine…