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Altitudinal migration and dispersal is an important component of the life history of several temperate and tropical birds but remains poorly understood due to the limited success of mark and recapture techniques. Stable isotopes of hydrogen (δD) in rainfall, and to a lesser extent, carbon (δ13C) in plants are known to change with altitude and hence may(More)
Song divergence among populations can theoretically lead to reproductive divergence and speciation. Despite many studies, this theory is still controversial. Habitat differences have been shown to shape songs, but few studies have looked for a link between ecologically driven acoustic and genetic divergence. We tested whether environmental selection has(More)
Song divergence between closely related taxa may play a critical role in the evolutionary processes of speciation and hybridization. We explored song variation between two Ecuadorian subspecies of the gray-breasted wood-wren (Henicorhina leucophrys) and tested the impact of song divergence on response behaviors. Songs were significantly different between(More)
numbers of Solanum plants found there were no higher than found at random sites (p = 0.48; Figure 1A). However, at established bowers, occupied for longer than one year, we observed more Solanum plants than at random sites (p = 0.036; Figure 1C). Male spotted bowerbirds can occupy the same bower for up to 10 years, separated by about 1 km from their(More)
Serological tests (ELISA) for cysticercosis were performed on groups of schoolchildren from two rural areas of Southern Africa, Ingwavuma in Northern KwaZulu and Isilimela in the Transkei. 22 of 736 Transkeian children were serologically positive while only 8 of 677 KwaZulu children were positive. These results, when corrected for the sensitivity and(More)
A longitudinal study was carried out to identify the spectrum of intestinal parasites present in conventionally maintained BALB/c mice and Mastomys coucha and to determine the effects of concomitant schistosome infections on their parasite status. Six parasites were observed during the course of the study, namely the nematodes Aspiculuris tetraptera and(More)
Morbidity from urinary schistosomiasis was assessed on clinical, radiological, parasitologic and biochemical evidence in 510 schoolchildren living in a Schistosoma haematobium endemic area. The results were viewed against the background of the prevalence and intensity of infection in the subjects. Clinical morbidity correlated well with the intensity of(More)
The use of urinalysis reagent strips (Labstix; Ames) in screening for Schistosoma haematobium infection in various schistosomiasis-endemic areas of the RSA was assessed in 941 children. Sensitivity, specificity, false-positive and false-negative rates and the positive predictive value for haematuria and proteinuria were calculated. Both haematuria and(More)
Birdsong is a sexually selected trait that could play an important evolutionary role when related taxa come into secondary contact. Many songbird species, however, learn their songs through copying one or more tutors, which complicates the evolutionary outcome of such contact. Two subspecies of a presumed vocal learner, the grey-breasted wood-wren(More)
Urbanization poses a challenge to bird communication due to signal masking by ambient noise and reflective surfaces that lead to signal degradation. Bird species (especially oscines) have been shown to alter their singing behaviour to increase signal efficiency in highly urbanized environments. However, few studies on the effects of noise on song structure(More)
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