Morphological characteristics of Cape sugarbirds (Promerops cafer) from Helderberg Nature Reserve

Cape sugarbirds (Promerops cafer) are the largest nectarivores in the Western Cape and feed almost exclusively on protea nectar and associated arthropods. Helderberg Nature Reserve, Western Cape, South Africa, has a large diversity of Protea and supports breeding sugarbirds. As part of a larger study, we captured sugarbirds using mist-nets during the breeding and non-breeding season at several sites in the Helderberg Nature Reserve, Western Cape, South Africa, from 1996 to 2000. From these data (n=283 males, 272 females), we found that in both sexes, individuals with longer tails have longer wings. Males were significantly larger in mass, culmen, head, tarsus, wing and tail length than females. Males with larger mass were larger in all morphometric  measurements than those with smaller mass. Mate choice and territory defence may be based on wing and tail ornament displays of male sugarbirds, thus larger males with larger ornaments could benefit through greater breeding success than smaller males.Key words: sexual size dimorphism, ornament, passerine

Geographic changes in the Aegean Sea since the Last Glacial Maximum : Postulating biogeographic effects of sea-level rise on islands

In order to assess how the last sea level rise affected the Aegean archipelago, we quantified the magnitude andrate of geographic change for the Aegean islands during the last sea-level-rise episode (21 kyr BP–present)with a spatially explicit geophysical model. An island-specific Area-Distance-Change (ADC) typology was constructed,with higher ADC values representing a higher degree of change. The highest fragmentation rates ofthe Aegean archipelago occurred in tandem with the largest rates of sea-level-rise occurring between 17 kyrand 7 kyr ago. Sea-level rise resulted in an area loss for the Aegean archipelago of approximately 70%. Spatiotemporaldifferences in sea-level changes across the Aegean Sea and irregular bathymetry produced a variety of islandsurface-area loss responses, with area losses ranging from 20% to N90% per island. In addition, sea-levelrise led to increased island isolation, increasing distances of islands to continents to N200% for some islands.Wediscuss howrates of area contractions and distance increasesmay have affected biotas, their evolutionary historyand genetics. Five testable hypotheses are proposed to guide future research. We hypothesize that islandswith higher ADC-values will exhibit higher degrees of community hyper-saturation, more local extinctions, largergenetic bottlenecks, higher genetic diversity within species pools, more endemics and shared species on continentalfragments and higher z-values of the power-law species-area relationship. The developed typology andthe quantified geographic response to sea-level rise of continental islands, as in the Aegean Sea, present an idealresearch framework to test biogeographic and evolutionary hypotheses assessing the role of rates of area and distancechange affecting biota