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Many birds in breeding seasons engage in vigorous dawn singing that often turns to a prominent chorus. We examined dawn chorus variation of avian assemblages in a tropical montane forest in Taiwan and tested the hypothesis that onset sequence is affected by eye sizes, foraging heights, and diet of birds. Chorus onset and duration varied between sampling months, but generally peaked in the prime breeding season. Overall dawn chorus length increased with, but mean duration per species was negatively correlated with, species richness. The inter-correlation among trait variables in phylogenetic independent contrasts was calculated and examined. Both foraging height and relative eye size were selected as positively explanatory factors, but no dietary effects were detected, for chorus onsets. Dawn singing onsets also tended to delay as decreasing log (eye sizes) that, however, was not selected with enough explanatory power. The positive relationship of chorus onsets versus relative eye sizes contradicts our prediction, yet the negative correlation of relative eye sizes with log (eye sizes) indicates an allometric constraint on eye sizes along with increasing body sizes. Lowerlayer species initiated singing earlier than upper-layer species, which complies with the positive correlation of onsets with foraging heights and supports our prediction. This pattern may be condition-specific and more likely occurs in forests lacking a sufficient canopy height and layering and a distinct light difference among forest layers. Foraging heights were additionally found negatively correlated with canopy coverage and slightly positively correlated with ground coverage of perches. Our results concord that foraging height is a relevant factor as eye size in determining the onset and sequence of dawn chorus, yet, suggest that forest settings and vegetation structure may likely complicate the prediction.

Silicon carbide reinforced copper matrix composites containing 50–80 vol.-%SiCp were fabricated by hot pressing copper coated SiCp powder. The results show that the densification, thermal expansion coefficients, flexural strength, and thermal conductivity of Cu/SiCp composites reinforced by electroless copper plating and their corrosion resistance in 5%NaCl solution are better than those without electroless plating. Physical properties and flexural strength of the composites decrease with an increase in SiCp content, whereas the corrosion resistance increases with an increase in SiCp volume fraction. By observing the fracture surface after a flexural test, it can be seen there are two types of fracture model: the cracking of Cu/SiCp interface and the pulling out of SiCp particles. The experiment also proved that the bonding strength of the Cu/SiCp interface and the pressure of the hot pressing operation are the two main factors which influence the fracture of these composites.

The nocturnal distribution and resource use by Ryukyu flying foxes was studied along 28 transects, covering five types of habitats, on Iriomote Island, Japan, from early June to late September, 2005. Bats were mostly encountered solitarily (66.8%) or in pairs (16.8%), with a mean linear density of 2.5 ± 0.6 bats/km of transect/night. Across the island, however, bat densities were distributed non-randomly among transect-nights, not correlated with transect length, and showed a slightly clumped distribution (variance/mean = 3.3). Outskirt trails contributed higher values to the relative importance of bat abundance, but the highest mean abundances occurred mostly at village sites on the west coast, which on average devoted only a quarter of their land area to agriculture/husbandry compared to those on the east coast. This supports our prediction that higher bat abundances are found in areas with less anthropogenic interference and more forest. Among habitats, the mean total abundance and density were lower in cultivated areas than in villages and inland forests. Bat perches in cultivated areas were also lower, and were in correspondence with lower shrub and canopy heights, and less canopy coverage. Flying fox abundance was correlated moderately with the heterogeneity of the tree composition, and strongly with the density of major fruiting trees. Thirty-nine species of plants and some animal items were used by Ryukyu flying foxes, including at least 31 species of fruits, 13 species of flowers, and leaves of seven species, with 14 species new to the record. Ficus septica and F. variegata were the most frequently encountered and dominant items in both fecal and rejecta/dropped samples, followed mostly by other figs and mulberries in the former, but by larger-seed non-Moraceae plants in dropped samples. Our results suggest that for conservation of flying foxes undisturbed forests providing an adequate resource basis are of major importance.