Изучены типовые серии tibetanus и B. tuberculatus, описанных Царевским (1926) из восточного Тибета. B. tibetanus характеризуется 1) темной пятнистостью, на спине, особенно вокруг крупных бородавок, 2) широкой светлой полосой вдоль середины спины и 3) вздутыми canthus rostralis. Первый и второй признаки указывают на сходство с североамериканскими жабами из групп B. americanus и B. boreas. Западный Китай, по-видимому, является одним из важных центров видообразования в группе серых жаби обладает наибольшим числом (4) форм этой группы. Предполагается, что B. tuberculatus - это реликтовая форма, близкая к предковой форме всей группы серых жаб, проникшей в Азию через Берингийскую сушу. B. tuberculatus отличатся от B. tibetanus и, судя по результатам дискриминантного анализа 24 морфометрических признаков, напоминает B. andrewsi Shmidt, 1827, описанную на год позже. Встречаемость этой формы на высоких плато Тибета, в таком случае, проливает новый свет на распространение серых жаб в Восточной Азии. Выделены лектотипы и обозначены типовые местонахождения обоих номинальных видов Царевского. уточнены коллекционные данные (места и даты сбора, коллектор и др.) для типовых серий этих и двух других видов Царевского, 1926 (B. brevipes и Aelurophryne gigas)

Several recent studies have demonstrated the occurrence of multiple paternity in anuran amphibians, implying that it is more common than previously thought. However, an adaptive explanation for polyandry in anurans is still lacking. The common toad Bufo bufo is an explosively breeding species that releases its eggs in strings. The operational sex ratio (OSR) is male biased, causing strong scramble competition among males; females can even drown through harassment during multiple amplexi. We used microsatellite markers to determine patterns of paternity in natural B. bufo populations and experimentally mated individuals (females exposed to either two or six males). Thirty per cent of field-collected and 22% of experimentally produced egg strings were sired by at least two males; all others were sired by a single father. Multiple paternities arose only from multiple amplexi, and we found no indication of fertilization from non-amplexing males, for example through free-swimming sperm. Our results suggest that polyandry in B. bufo is likely to occur most often at high population densities, and under the most male-biased OSRs. Moreover, polyandry might be interpreted as being the consequence of females spawning when amplexed by a few males, to avoid the risk of drowning by amplexus with multiple males.

Knowledge of factors that affect population demographic and genetic characteristics is of importance to the development of conservation strategies. Using field and remote sensing of microgeographic and landscape-level features of the aquatic and terrestrial environment, we examined the degree to which habitat characteristics were correlated with population demographic and genetic characteristics in the common toad (Bufo bufo). Measures of genetic diversity and departures from random mating are described for 20 semi-isolated breeding populations of B. bufo from Leicestershire, Great Britain, based on three species-specific single locus variable number of tandem repeat minisatellite loci. Spatial autocorrelation of allele frequencies revealed significant population structuring or lack of independence in allele frequencies over inter-breeding pond intervals of 2 km. Such estimates of “patch size” which are inferred from correlograms, may be useful in defining the extent of effective gene flow and spatial scales over which landscape-level features could plausibly be used to characterize ecological attributes of importance to individuals from specific local breeding populations. Toad presence or absence at amphibian breeding ponds, population size, and population estimates of observed heterozygosity, allelic richness, and Wright's inbreeding coefficient (F) were individually used as dependent variables in analyses with aquatic and terrestrial habitat characteristics. Inter-population variation in inbreeding coefficients was significantly related to presence of additional ponds near each breeding site. Allelic richness, population size, and toad presence/absence were primarily associated with terrestrial habitat variables, including pond density and vegetative characteristics reflecting surrounding land use (e.g. presence of woodlands, hedgerows, extent of area in livestock [sheep] pasture, and anthropogenic development). In the absence of definitive population demographic data, specific habitat characteristics may offer predictive potential for inferring population characteristics and future viability. However, the choice of ecologically and evolutionarily relevant habitat characteristics should be made with care.

Estimates of the effective number of breeding adults were derived for three semi-isolated populations of the common toad Bufo bufo based on temporal (i.e. adult-progeny) variance in allele frequency for three highly polymorphic minisatellite loci. Estimates of spatial variance in allele frequency among populations and of age-specific measures of genetic variability are also described. Each population was characterized by a low effective adult breeding number (Nb) based on a large age-specific variance in minisatellite allele frequency. Estimates of Nb (range 21-46 for population means across three loci) were approximately 55-230-fold lower than estimates of total adult census size. The implications of low effective breeding numbers for long-term maintenance of genetic variability and population viability are discussed relative to the species' reproductive ecology, current land-use practices, and present and historical habitat modification and loss. The utility of indirect measures of population parameters such as Nb and Ne based on time-series data of minisatellite allele frequencies is discussed relative to similar measures estimated from commonly used genetic markers such as protein allozymes.