Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Tags: Bufo (X)

12 results (86ms)   

View Results as: JSON ATOM CSV
Male calling effort and mitochondrial DNA (mtDNA) variation were examined in a breeding chorus of toads from a hybrid zone between Bufo microscaphus and B. woodhousii in central Arizona. The chorus comprised 50 B. microscaphus and 17 hybrids, identified on the basis of morphology and advertisement calls; no pure B. woodhousii were observed. Males produced advertisement calls throughout the early evening, even when relatively large numbers of males (>50) were present at the chorus; active searching and satellite tactics were not observed. Calling efforts (call duration X call rate) of hybrids (23.9%, n= 8) and B. microscaphus (24.9%, n= 19) were similar and comparable to call efforts of B. woodhousii (21.9%, n= 10)...
1. 1.|The temperature preference of Bufo marinus in a linear thermal gradient over a 24 h period was measured in the spring using uniform light (UL) over the length of the gradient and in the spring and fall using a point source of light over the hot end of the gradient only (LH). 2. 2.|The temperature preference of Bufo cognatus in a linear thermal gradient was measured over a 24 h period during the fall with the LH regime. 3. 3.|Light regime and season had no effect on the mean body temperature (Tb) selected over a 24 h period in B. marinus. The pattern of temperature selection over time was influenced by season. 4. 4.|Temperate B. cognatus selected significantly higher mean Tbs that the tropical B. marinus and...
thumbnail
In a survey of anuran amphibian mating patterns, intraspecific variation was found in 13 of 15 species, including the present study of the western toad. Intrapopulation variation in mating patterns among breeding years has been observed in 5 of 8 anurans, whereas within-site, within-year mating pattern variation has only been reported for the western toad. These results strongly suggest that anuran mating patterns are frequently neither species-specific nor population-specific attributes. Variable mating patterns were most commonly observed in explosively-breeding anurans. Explosive breeders may be susceptible to variable mating patterns because they may be more sensitive to fluctuations in environmental conditions,...
The Anaxyrus boreas species group currently comprises four species in western North America including the broadly distributed A. boreas, and three localized species, Anaxyrus nelsoni, Anaxyrus exsul and Anaxyrus canorus. Phylogenetic analyses of the mtDNA 12S rDNA, cytochrome oxidase I, control region, and restriction sites data, identified three major haplotype clades. The Northwest clade (NW) includes both subspecies of A. boreas and divergent minor clades in the middle Rocky Mountains, coastal, and central regions of the west and Pacific Northwest. The Southwest (SW) clade includes A. exsul, A. nelsoni, and minor clades in southern California. Anaxyrus canorus, previously identified as paraphyletic, has populations...


    map background search result map search result map Mating pattern variability among western toad (Bufo boreas) populations Mating pattern variability among western toad (Bufo boreas) populations