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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. . Wiley and Nordic Society Oikos are collaborating with JSTOR to digitize, preserve and extend access to Ornis Scandinavica. . 1992. Energy budgets of wintering Barnacle Geese: the effects of declining food resources. -Ornis Scand. 23: 451-458.This paper documents the daily activities and feeding rates of Barnacle Geese Branta leucopsis through the autumn and winter in relation to changes in biomass of their food supply. Energy intake and expenditure were estimated and energy surplus or deficit for each month calculated. A net surplus was achieved in the months of October (+ 235 kJ d-1) and November (+ 247 kJ d-1) when most food was available.Geese suffered a net deficit in December (-225 kJ d-1) and January (-113 kJ d-1) when biomass and food quality were lowest. In February, when grass began to grow again, the birds achieved a surplus once again (+ 167 kJ d-'). Body mass changes through the winter were modelled using observed intake rates and estimated energy expenditure. Body mass predictions were consistent with observed mass and body condition changes. It is argued that mass loss in midwinter in this species is enforced by the limited feeding opportunity and declining food supply rather than an adaptive response to reduce predation risk. Geese gain substantial body reserves in autumn prior to this predictable mass loss. As soon as daylength and food biomass allow, lost reserves are replaced and mass increases rapidly in preparation for migration and breeding.

The new compounds [H2GaE(SiMe3)2]3 (E = P (1), As (2)), the first authenticated examples of a phosphinogallane and an arsinogallane containing the GaH2 moiety, are prepared via efficient dehydrosilylation from the respective combinations of H3Ga·NMe3 and E(SiMe3)3 in diethyl ether or toluene. Compounds 1 and 2 are characterized by elemental analysis, NMR, IR, and mass spectrometry. Single-crystal X-ray structural studies show that the molecular structures of 1 and 2 feature a flattened six-member ring of alternating Ga and E centers. Both compounds are reasonably stable at −30 °C but spontaneously decompose at ambient temperatures, 2 noticeably faster than 1, with the evolution of HSiMe3, H2, and E(SiMe3)3. The pyrolysis of 1 yields nanocrystalline GaP while the pyrolysis of solids from decayed 2 results in nanocrystalline GaAs as determined from XRD studies. Under applied pyrolysis conditions, the thermally accelerated dehydrosilylation of the precursors is accompanied by a side-evolution of CH4 and retention of small quantities of amorphous Si/C phases.