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Despite major differences between human and avian colour vision, previous studies of cuckoo egg mimicry have used human colour vision (or standards based thereon) to assess colour matching. Using ultraviolet-visible reflectance spectrophotometry (300-700 nm), we measured museum collections of eggs of the red-chested cuckoo and its hosts. The first three(More)
Several hypotheses have been proposed to explain the direction and extent of sexual size dimorphism in anurans (in which males are usually smaller than females) as a result of sexual selection. Here, we present an analysis to test the hypothesis that sexual dimorphism in anurans is largely a function of differences between the sexes in life-history(More)
Prevailing theory assumes cuckoos lay at random among host nests within a population, although it has been suggested that cuckoos could choose large nests and relatively active pairs within host populations. We tested the hypothesis that egg matching could be improved by cuckoos choosing nests in which host eggs more closely match their own, by assessing(More)
One of the most important measures of offspring performance is growth rate, which is often traded off against another important survival trait, immune function. A particular feature of ostrich chicks maintained in farmed environments is that cohorts of chicks vary widely in size. As parents can have a profound effect on the phenotype and fitness of their(More)
Sequence data derived from four markers (the nuclear RP1 and Aldolase and the mitochondrial 16S rRNA and cytochrome b genes) were used to determine the phylogenetic relationships among 32 species belonging to the genus Hippocampus. There were marked differences in the rate of evolution among these gene fragments, with Aldolase evolving the slowest and the(More)
Prevailing theory predicts that lower levels of intra-clutch variation in host eggs facilitate the detection of brood parasitism. We assessed egg matching using both human vision and UV-VIS spectrophotometry and then followed the nest fate of great reed warblers naturally parasitised by European cuckoos. Rejection was predicted by the following three(More)
We describe the vocal repertoire of a facultatively social carnivore, the yellow mongoose, Cynictis penicillata. Using a combination of close-range observations, recordings and experiments with simulated predators, we were able to obtain clear descriptions of call structure and function for a wide range of calls used by this herpestid. The vocal repertoire(More)
The evolutionary history of the endangered Knysna seahorse, Hippocampus capensis, and the extent of gene flow among its three known populations, were investigated using 138 mitochondrial DNA control region sequences. Similarly high levels of genetic diversity were found in two of the populations (Knysna and Keurbooms Estuaries), whereas diversity in the(More)
It has been suggested that secondary sexual ornamentation signals male ability to resist infections, as only high-quality individuals are able to invest both in high immune defence and elaborate ornament expression. Such ornaments could thus serve as indicators of male quality and could be used by females in choosing mates. Ostriches are sexually dimorphic(More)
OBJECTIVE We evaluated the value of all 3 common biochemical serum markers, maternal serum alpha-fetoprotein, beta-human chorionic gonadotropin, and unconjugated estriol, and combinations thereof as predictors of pregnancy outcome. STUDY DESIGN A total of 60,040 patients underwent maternal serum screening. All patients had maternal serum alpha-fetoprotein(More)