Search Results - (Author, Cooperation:J. K. Hill)

2011-08-20

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Altitude ; Animals ; *Behavior, Animal ; *Climate Change ; *Ecosystem ; *Environment ; Geography ; Population Dynamics ; Species Specificity ; Time Factors

2012-05-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Butterflies/growth & development/*physiology ; *Cistaceae ; *Climate Change ; *Ecosystem ; Feeding Behavior ; *Geranium ; Great Britain ; Larva/physiology ; Population Dynamics ; Population Growth ; Seasons ; Temperature

2012-01-28

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Animals ; Cell Line ; Cerebellar Diseases/*genetics/metabolism/pathology ; Cilia/metabolism/*ultrastructure ; Conserved Sequence ; DNA, Intergenic ; *Evolution, Molecular ; Eye Abnormalities/*genetics/metabolism/pathology ; Gene Expression Profiling ; *Gene Expression Regulation ; Genetic Heterogeneity ; *Genetic Loci ; Humans ; Kidney Diseases, Cystic/*genetics/metabolism/pathology ; Membrane Proteins/chemistry/*genetics/metabolism ; Molecular Sequence Data ; Multigene Family ; Mutation ; Mutation, Missense ; Phenotype ; Protein Transport ; *Regulatory Sequences, Nucleic Acid ; Retina/abnormalities/metabolism/pathology ; Transport Vesicles/metabolism/ultrastructure

article

1981

Didaktische Grundlageninformation ; Experiment ; Methodik ; Fremdsprachenunterricht ; Englisch ; Lesen ; Leseverstehen ; Hochschule

English language teaching journal, Bd. 35 (1981) H. 3, S. 270-281, 0307-8337

English

Literaturangaben

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Habitat degradation and climate change are thought to be altering the distributions and abundances of animals and plants throughout the world, but their combined impacts have not been assessed for any species assemblage. Here we evaluated changes in the distribution sizes and abundances of 46 ...

Electronic Resource

1570-7458

diapause ; insect-plant interactions ; phenology ; Salix repens

Springer Online Journal Archives 1860-2000

Biology

Abstract Nymphal development of Cacopsylla moscovita (And.) (Homoptera: Psylloidea) takes place only on female catkins of Salix repens L. and close phenological synchrony is crucial because development times of catkins and nymphs are similar. Eggs are laid on catkins as soon as they develop and close synchrony between oviposition and budburst maximizes time available for nymphal development. Sampling adult C. moscovita in the field revealed little synchrony between egg development and budburst, with over 60% of females containing mature eggs four weeks before catkins first appeared. In the laboratory, egg development was influenced by both temperature and photoperiod. At 10°C, egg development occurred approximately one month earlier than at 5°C and two weeks earlier than in the field. Adult survival in the laboratory was substantially reduced at increased temperature, with only 20% of adults surviving longer than two weeks at 10°C, compared with over 95% at 5°C. Body condition (weight corrected for size) of males and females decreased significantly in the field over winter. However, body condition of females levelled off before budburst, coincident with egg development implying that females had resumed feeding. We discuss our results in relation to regulation of phenological synchrony between oviposition and catkin appearance.

Electronic Resource

1432-1939

Key words Dispersal ; Range expansion ; Distribution ; Pararge aegeria

Springer Online Journal Archives 1860-2000

Biology

Abstract Individuals colonizing unoccupied habitats typically possess characters associated with increased dispersal and, in insects, colonization success has been related to flight morphology. The speckled wood butterfly, Pararge aegeria, has undergone recent major expansions in its distribution: in the north of its range, P. aegeria has colonized many areas in north and east England, and in the south, it was first recorded on Madeira in 1976. We examined morphological traits associated with flight and reproduction in the northern subspecies tircis, and in the southern subspecies aegeria, from sites colonized about 20 years ago in northern England and on Madeira, respectively. Investment in flight was measured as relative wing area and thorax mass, and investment in reproduction as relative abdomen mass. All measurements were from individuals reared in a common environment and there were significant family effects in most of the variables measured. Compared with individuals from sites continuously occupied in recent history, colonizing individuals were larger (adult live mass). In the subspecies tircis, colonizing individuals also had relatively larger thoraxes and lower wing aspect ratios indicating that evolutionary changes in flight morphology may be related to colonization. However, sex by site interactions in analyses of thorax mass and abdomen mass suggest different selection pressures on flight morphology between the sexes in relation to colonization. Overall, the subspecies aegeria was smaller (adult live mass) and had a relatively larger thorax and wings, and smaller abdomen than subspecies tircis. Evolutionary changes in flight morphology and dispersal rate may be important determinants of range expansion, and may affect responses to future climate change.

Electronic Resource

1432-1939

Key words Procellariiformes ; Nutrition ; Obesity ; Chick growth ; Life history

Springer Online Journal Archives 1860-2000

Biology

Abstract Procellariiform seabirds such as short-tailed shearwaters Puffinus tenuirostris accumulate large quantities of lipid during the nestling period. The functional significance of this pattern of development remains unclear, but has been related both to temporal variation in feeding conditions around the colony and to stochastic variation in the foraging success of individual parents. This paper examines temporal and age-specific variation in the pattern of food delivery to nestling short-tailed shearwaters, which have one of the lowest provisioning rates of any procellariiforms and are known to experience occasional long intervals between feeds. We assess whether variation in the provisioning rates of chicks was associated primarily with temporal variation in food delivery at the level of the colony or with stochastic variation in food delivery at the level of the individual. We then discuss this variability in the context of nestling obesity. For all but the youngest chick age-classes, individual meals delivered by adults averaged 141 g, which was 25% of adult body mass. The proportion of chicks fed each night was low (49%) and highly variable (coefficient of variation = 82%), which means that occasional long intervals between feeds would be expected to arise simply by chance. In keeping with this, intervals between feeding events for individual chicks followed a negative exponential distribution with a mean of 2 nights and a maximum interval of 13 nights. There was significant temporal variation in food delivery, but deviations from expected values for both feeding frequency and meal size were restricted to a small number of nights, included values both higher and lower than expected and did not persist for more than 2 nights in succession. These data suggest that even among those species with very low feeding frequencies and occasional long intervals between feeds, nestling obesity in Procellariiformes should be regarded as a response to chronic stochastic variability in food delivery at the level of the individual chick rather than as insurance against sporadic temporal variation at the level of the colony.

Electronic Resource