The Southern Oscillation and variations in waterfowl abundance in southeastern Australia

Mean sizes of duck hunters’ bags on the opening days of annual waterfowl seasons at selected wetlands in southeastern Australia, between 1972 and 1990, are correlated with an index of the Southern Oscillation (SOI). Simple correlations exist between bag sizes at the various sites, and the mean bag size in Victoria shows a positive relationship with that obtained at Barrenbox Swamp, New South Wales. Bag sizes are most significantly correlated with monthly SOI some 25–28 months before the eventual start of an open season. Interannual variations in rainfall in eastern Australia are generated by the El Niño–Southern Oscillation, which is monitored by the SOI, and the waterfowl populations respond to changing water and wetland availability. Accepting that annual bag sizes represent an index of waterfowl abundance, the regional population size may be related to climatic events associated with changes in SOI values. Further consideration of the SOI and indices of waterfowl abundance may allow variations in legislative or management options well in advance of individual open seasons.     

Historical ozone concentrations and flavonoid levels in herbarium specimens of the Antarctic moss Bryum argenteum

Depletion of stratospheric ozone since the mid 1970s has led to significant increases in ultraviolet B (UVB) irradiation over Antarctica. The detrimental effects of UVB on plants are many, but plants produce photoprotective flavonoids that reduce cellular damage. We used herbarium samples of the moss Bryum argenteum collected in Antarctica to compare the levels of flavone aglycones in plants collected before and after the formation of the ozone hole. The interpretation of historical data is difficult, because environmental conditions immediately before sample collection are unknown. Factors such as cloud cover can have a significant influence on UVB dose at ground level, modifying the flavonoid content of the specimen and adding considerable variability to the results. Nevertheless, our results revealed significant relationships between total flavone concentration and pooled year classes ( P = 0.001). Furthermore, regression analysis showed a significant negative relationship of total flavone concentration and the level of ozone immediately before the time of collection ( P = 0.016). In addition, the ratio of luteolin (an ortho -dihydroxylated flavone) to apigenin (a monohydroxylated flavone) increased significantly with several environmental parameters. These included (a) increasing modelled midday UVB radiation ( P = 0.002), (b) increasing modelled midday UVB/PAR ratio ( P < 0.001), and (c) decreasing ozone concentration ( P < 0.001). We emphasise the utility of this ratio in interpreting the historical ozone trends rather than relying on changes in total flavone concentrations alone. These results illustrate that herbarium specimens may reveal historical levels of UVB radiation.     

Characteristics of woods used recently and historically by Lesser Spotted Woodpeckers Dendrocopos minor in England

Lesser Spotted Woodpecker Dendrocopos minor numbers have declined greatly in England since the early 1980s for reasons that are not yet fully understood. It has been suggested that the species’ decline may be linked to the increase in Great Spotted Woodpeckers Dendrocopos major, changes in woodland habitat quality (such as deadwood abundance) and landscape‐scale changes in tree abundance. We tested some of these hypotheses by comparing the characteristics of woods in southern England where the species is still relatively numerous with those of woods used in the 1980s before the major decline. In each time period, habitat, predator and landscape information from woods known to be occupied by Lesser Spotted Woodpeckers was compared with those found to be unoccupied during surveys. Before the main period of decline, Lesser Spotted Woodpeckers used oak‐dominated, mature, open woods with a large amount of standing deadwood. Habitat use assessed from recent data was very similar, the species being present in mature, open, oak‐dominated woodlands. There was a strong relationship between wood use probability and the extent of woodland within a 3‐km radius, suggesting selection for more heavily wooded landscapes. In recent surveys, there was no difference in deadwood abundance or potential predator densities between occupied and unoccupied woods. Habitat management should focus on creating and maintaining networks of connected woodlands in areas of mature, open woods. Finer‐scale habitat selection by Lesser Spotted Woodpecker within woodlands should be assessed to aid development of beneficial management actions.     

Detection of recombinant haplotypes in wild mice (Mus musculus) provides new insights into the origin of Japanese mice

Japanese house mice (Mus musculus molossinus) are thought to be a hybrid lineage derived from two prehistoric immigrants, the subspecies M. m. musculus of northern Eurasia and M. m. castaneus of South Asia. Mice of the western European subspecies M. m. domesticus have been detected in Japanese ports and airports only. We examined haplotype structuring of a 200 kb stretch on chromosome 8 for 59 mice from throughout Eurasia, determining short segments (≈ 370–600 bp) of eight nuclear genes (Fanca, Spire2, Tcf25, Mc1r, Tubb3, Def8, Afg3l1 and Dbndd1) which are intermittently arranged in this order. Where possible we identified the subspecies origin for individual gene alleles and then designated haplotypes for concatenated alleles. We recovered 11 haplotypes among 19 Japanese mice examined, identified either as ‘intact’ haplotypes derived from the subspecies musculus (57.9%), domesticus (7.9%), and castaneus (2.6%), or as ‘recombinant’ haplotypes (31.6%). We also detected recombinant haplotypes unique to Sakhalin. The complex nature of the recombinant haplotypes suggests ancient introduction of all three subspecies components into the peripheral part of Eurasia or complicated genomic admixture before the movement from source areas. ‘Intact’domesticus and castaneus haplotypes in other Japanese wild mice imply ongoing stowaway introductions. The method has general utility for assessing the history of genetic admixture and for disclosing ongoing genetic contamination.     

Use of remote sensing to measure change in the extent of habitat for the critically endangered Jerdon's Courser Rhinoptilus bitorquatus in India

Jerdon's Courser Rhinoptilus bitorquatus is one of the most endangered and least understood birds in the world. It is endemic to scrub habitats in southeast India which have been lost and degraded because of human land use. We used satellite images from 1991 and 2000 and two methods for classifying land cover to quantify loss of Jerdon's Courser habitat. The scrub habitats on which this species depends decreased in area by 11–15% during this short period (9.6 years), predominantly as a result of scrub clearance and conversion to agriculture. The remaining scrub patches were smaller and further from human settlements in 2000 than in 1991, implying that much of the scrub loss had occurred close to human population centres. We discuss the implications of our results for the conservation of Jerdon's Courser and the use of remote sensing methods in conservation.     

A RANKL-Inducible Gene Znf216 in Osteoclast Differentiation

Osteoclasts possess catabolic activity in mineralized tissues and are involved in bone remodeling coordinating with osteoblasts. Although the pathway using receptor and activator of NF-κ B (RANK) and its ligand, RANKL, is known to be essential for osteoclast differentiation, their precise mechanisms are not fully understood. Using DNA microarray technology, we searched for genes that were up-regulated after RANKL stimulation in the macrophage cell line, RAW264.7 cells. A gene, Znf216, which encodes a zinc-finger protein, was detected among those genes up-regulated after RANKL stimulation. Expression of Znf216 was also induced by other cytokines such as TNFα and IL-1β. Although ectopic expression of full-length ZNF216 abrogated osteoclast differentiation, its truncated forms accelerated it. No significant inhibitory effect on the NF-κ B pathway was observed, however. These results suggest that ZNF216 is a potent inhibitory factor for osteoclast differentiation and that the mechanism is unlikely due to direct attenuation of the NF-κ B pathway.     

The development of activity ranges in juvenile Brown Boobies Sula leucogaster

The post‐fledging dependence period is extremely important because it allows young birds the opportunity to develop behavioural skills required for later life. We raised 12 hatchling Brown Boobies Sula leucogaster and attached a miniaturized GPS logger to each bird to examine how flight improves after fledging. The Boobies made daily trips and increased the maximum distance, total distance travelled each day, trip duration and flight speed. Young Boobies seemed to gradually acquire flight skills towards independence.     

Metabolic rate affects adult life span independently of developmental rate in parasitoid wasps

Developmental time and body size correlate with lifespan in a wide range of taxa, although not in insect parasitoids. When the rate of development is independent of adult metabolic rate, adult lifespan is free to adapt to the adult environment. We suggest that interspecific variation in intrinsic adult metabolic rates, differences in allocation of lipids to longevity, and reproduction and differences in the ability to use carbohydrates as an adult should all result in variation of adult lifespan, independent of development time. To test these ideas, we measured metabolic rate, lipid content and egg load at eclosion, developmental time, and lifespan of females with and without carbohydrate food in five species of Asobara, which represent parasitoids of Drosophila. No relationship between development time and adult longevity was found. As predicted, metabolic rates varied between species and appeared to trade off with adult longevity. We found no clear link between initial egg load and the longevity of a species, suggesting that lipid allocation may be less important in determining adult lifespan. The results obtained indicate that differences in metabolic rate have an important effect on adult lifespan, without affecting developmental rate in parasitoids. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 45–56.