Seasonal pattern of abundance of honeyeaters and their resources in heathland areas near Sydney

THE EVOLUTION OF FLORAL COLOR CHANGE: POLLINATOR ATTRACTION VERSUS PHYSIOLOGICAL CONSTRAINTS IN FUCHSIA EXCORTICATA

Field experiments showed that the green-to-red color change in the flowers of Fuchsia excorticata is age-dependent, rather than pollination-induced. Nectar is produced only in green and, to a lesser extent, intermediate-phase flowers; red flowers are postreproductive and are avoided by pollinators (bellbirds). Additional experiments suggested that the red flowers are retained because pollen tubes require at least three days to reach the ovaries, and abscission of the floral tube and accompanying style requires at least another 1.5 days. The change in color directs pollinators away from the postreproductive flowers while these physiological processes are occurring, thereby increasing foraging efficiency and visitation to flowers that are still capable of receiving and donating pollen. No evidence was found to suggest that red-phase flowers function to attract pollinators. Finally, we suggest that the color change evolved through neotenous retention of the green coloration of buds and is a derived trait reflecting an interaction between natural selection and physiological constraints.

Shifts in composition of monthly invertebrate assemblages in Moorland differed between lowland and montane locations but not fire-ages

Understanding seasonal changes in invertebrate populations is important for understanding ecosystem processes and for conservation of invertebrate communities. Few studies have investigated variation in seasonal responses of multiorder and multispecies invertebrate assemblages. To determine whether temporal patterns in invertebrate assemblages and taxa vary between locations and vegetation age since burning, patterns of invertebrate occurrence were investigated monthly for 12 mo in cool temperate buttongrass moorlands at two locations (lowland and montane) containing paired plots with different fire history (young and old regrowth). For both locations and fire-ages, invertebrate taxon richness and abundance were generally higher during the warmer months than during the winter months. At the lowland location, foliage dwelling invertebrates were caught in greater numbers during winter than during summer owing to large numbers of Collembola. Each season had a distinct invertebrate assemblage. The invertebrate assemblages did not differ between young and old regrowth. The shifts in composition of monthly invertebrate assemblages between winter and summer differed between locations with assemblages in cooler months more dissimilar from warmer months at the montane location than the lowland location. Most taxa common to both locations had similar patterns of monthly occurrence but some taxa showed markedly different patterns. Mid- to late summer is the optimum time to conduct short-term surveys in buttongrass moorland to maximize species richness and abundance but short-term studies will miss significant components of the invertebrate community.