Sky Lark (Alauda arvensis) Science Article 1 abstract The seasonal variation in Skylark Alauda arvensis occurrence, in terms of both presence and abundance, was examined in relation to crop type on a number of survey sites in English lowland farmland in two periods, 1965-70 and 1990-95 . These two periods were selected to coincide with […]
Do habitat association models have any generality? Predictingskylark Alauda arensis abundance in different regions of southernEngland
Sky Lark (Alauda arvensis) Science Article 3 abstract Much of conservation science is based upon determining the use by organisms ofdifferent resources. However, the field data used to construct habitat associationmodels generally come from a small number of sites covering a fraction of the areaof interest. It is important therefore to assess the generality of […]
The impact of grazing animals on nesting success of grassland passerines in farmland and natural habitats: a field experiment
Sky Lark (Alauda arvensis) Science Article 4 abstract A study was made of the influence of trampling by grazing animals on the nesting success of real nests (meadow pipit, Anthus pratensis; water pipit, Anthus spinoletta; and skylark, Alauda arvensis) and simulated nests (caps from jam-jars filled by green plasticine) on pasture in the Orlicke Mountains […]
Population fluctuations of Siskins Carduelis spinus,Common Crossbills Loxia curvirostra, and Citril FinchesCarduelis citrinella in relationship to flowering intensityof spruce Picea abies
Siskin (Carduelis spinus) Science Article 1 abstract Annual population abundances from 1992 to 2002 of Siskins Carduelis spinus, CommonCrossbills Loxia curvirostra and Citril Finches Carduelis citrinella were studied in relationto flowering intensity of spruce Picea abies.We used point countmethod to study thechanges in abundance of the three species in the Northern Black Forest (southwest Germany).Our […]
BEHAVIOR, MORPHOLOGY, AND SYSTEMATICS OF SIRYSTES SIBILATOR (TYRANNIDae)
Sirystes (Sirystes sibilator) Science Article 1 abstract Field and laboratory studies support recent hypotheses that Sirystes sibilator is closely allied with the myiarchine flycatchers rather than with Tyrannus or with the cotingids. The first confirmed nest of this tyrant (located in a natural tree cavity), its foraging behavior, and the derived character states of the […]
THE NESTING OF SOME VENEZUELAN BIRDS
Silver-beaked Tanager (Ramphocelus carbo) Science Article 1 abstract I passed the interval from 15 March to 24 July 1966 at ‘La Araguata,’ a large cattle farmsituated among the hills near Pirapira, some 20 miles south of Valencia in the state ofCarabobo, Venezuela. Although most of my time was devoted to the study of the RufousfrontedThornbird […]
THE NESTING OF CHaeTURA ANDREI MERIDIONALIS
Sicks Swift (Chaetura meridionalis) Science Article 1 abstract On the middle Rio das Mortes (15 o S., 52 o 15′ W. Greenwich), Mato Grosso, Brazil, I frequently observed a swift that inhabited principally the extensive groves of ‘buritf’ palms. On October 15, 1946, I located two nests of the species. One was torn from its […]
Behaviour and life-history responses to chick provisioning under risk of nest predation.
Siberian Jay (Perisoreus infaustus) Science Article 2 abstract This thesis examines risk management in breeding Siberian jays (Perisoreusinfaustus), which is indigenous to the northern taiga. Parent behaviour and the nestare cryptic. A new nest is built each year. It is placed on spruce or pine branches closeto the trunk and well insulated with lichens, feathers […]
Parental nepotism enhances survival of retained offspring in the Siberian jay
Siberian Jay (Perisoreus infaustus) Science Article 1 abstract The evolutionary payoff accruing to parents from breeding offspring could be an incentive for prolonged investments in the offspring. Enhanced survival for offspring as a result of such a prolonged parental investment would increase the value of remaining in the natal territory for the offspring. Here we […]
Nest spacing and breeding performance in Shorttoed Eagle Circaetus gallicus in northeast Greece
Short-toed Snake Eagle (Circaetus gallicus) Science Article 2 abstract Capsule There is some evidence of susceptibility to stochastic or human factors. Aims To describe the phenology and breeding success of one of the densest populations of Short-toed Eagle in Europe. Methods All nests in the Dadia-Lefkimi-Soufli forest in northeast Greece were located and visited regularly […]