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A costly search for food in subterranean rodents resulted in various adaptations improving their foraging success under given ecological conditions. In Spalax ehrenbergi superspecies, adaptations to local ecological conditions can promote speciation, which was recently supposed to occur even in sympatry at sites where two soil types of contrasting characteristics abut each other. Quantitative description of ecological conditions in such a site has been, nevertheless, missing. We measured characteristics of food supply and soil within 16 home ranges of blind mole rats Spalax galili in an area subdivided into two parts formed by basaltic soil and pale rendzina. We also mapped nine complete mole rat burrow systems to compare burrowing patterns between the soil types. Basaltic soil had a higher food supply and was harder than rendzina even under higher moisture content and lower bulk density. Population density of mole rats was five-times lower in rendzina, possibly due to the lower food supply and higher cover of Sarcopoterium shrubs which seem to be avoided by mole rats. A combination of food supply and soil parameters probably influences burrowing patterns resulting in shorter and more complex burrow systems in basaltic soil.

Eusocial species of African mole-rats live in groups cooperating on multiple tasks and employing division of labour. In captivity, individuals of the same group differ in cooperative contribution as well as in preference for a particular task. Both can be viewed as polyethism. However, little information is available from free-ranging mole-rats, which live in large burrow systems. We made an attempt to detect polyethism in the free-living Ansell’s mole-rat ( Fukomys anselli ) as differences in individuals’ space-use patterns. We radio-tracked 17 adults from five groups. Large individuals, including breeding males, spent more time inside the nest than smaller individuals. Breeding females were more often located <10 m from the nest in comparison to non-breeding females, who were relatively more often located 30–90 m and exclusively >90 m from the nest. One non-breeding female even conducted a brief intrusion into a neighbouring group’s territory via an open tunnel connection. A significant part of the variability in mole-rat space-use patterns was explained by body mass which is probably related to age in this species. This result can therefore be attributed to age polyethism. There was no apparent discontinuity in the space-use patterns of non-breeders that would indicate existence of castes.

Frogs are known to occasionally utilize the burrow systems of subterranean rodents, but this phenomenon has previously attracted little attention. We recorded frogs in burrows and in/under the molehills of three African mole-rat species (Bathyergidae, Rodentia) during burrow system mapping in Malawi and Zambia during the dry season. Eight frog species were detected. The most abundant of them, Kassina senegalensis, was found in large numbers in active Ansell's mole-rat nest areas, obviously tolerated by the hosts. We speculate that in areas with prolonged dry seasons mole-rats may increase anuran abundances and diversity.

The subterranean ecotope, particularly in tropical regions, is almost free of daily fluctuations in environmental factors that may serve as zeitgebers. The question arises as to whether there is circadian periodicity in the activity of its permanent inhabitants and, if so, how it is induced and maintained. We used radiotelemetry to follow the activity of the silvery mole-rat, Heliophobius argenteocinereus (Bathyergidae), in its natural environment in Malawi during the dry season. Silvery mole-rats were found inside their nests during 63% ± 8% SD of radiofixes; the animals were inactive for 72% ± 8% of the within-nest fixes recorded. Activity tended to decrease over the course of the dry season. Although activity was detected at any time of day, most individuals showed a predictable (mostly unimodal, occasionally bimodal) pattern of activity that was associated with slight daily belowground temperature fluctuations (mostly less than 3°C). In the coldest part of the dry season, overall activity rose with daily temperature. At the beginning of the hot and dry season, the period of enhanced daily activity was shifted to earlier (colder) hours. Mole-rats in the field apparently respond to even slight temperature fluctuations and adjusted their activity accordingly. We propose that burrow temperature can work as zeitgeber of circadian activity in this species.

Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia), knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest) 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels). Our results suggest that the breeding individuals (at least males) contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions.

Sympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2 n = 52). The study microsite (0.04 km ²) is sharply subdivided geologically, edaphically, and ecologically into abutting barrier-free ecologies divergent in rock, soil, and vegetation types. The Pleistocene Alma basalt abuts the Cretaceous Senonian Kerem Ben Zimra chalk. Only 28% of 112 plant species were shared between the soils. We examined mitochondrial DNA in the control region and ATP6 in 28 mole rats from basalt and in 14 from chalk habitats. We also sequenced the complete mtDNA (16,423 bp) of four animals, two from each soil type. Remarkably, the frequency of all major haplotype clusters (HC) was highly soil-biased. HCI and HCII are chalk biased. HC-III was abundant in basalt (36%) but absent in chalk; HC-IV was prevalent in basalt (46.5%) but was low (20%) in chalk. Up to 40% of the mtDNA diversity was edaphically dependent, suggesting constrained gene flow. We identified a homologous recombinant mtDNA in the basalt/chalk studied area. Phenotypically significant divergences differentiate the two populations, inhabiting different soils, in adaptive oxygen consumption and in the amount of outside-nest activity. This identification of a possible incipient sympatric adaptive ecological speciation caused by natural selection indirectly refutes the allopatric alternative. Sympatric ecological speciation may be more prevalent in nature because of abundant and sharply abutting divergent ecologies.

A study investigated aesthetic preferences within an integral taxonomic group, boid snakes, in several distant cultures: Bolivia, Philippines, India Rajasthan and Delhi, Malawi and Morocco, and compare them to previous results from the Czech Republic and Papua New Guinea (Mareov et al. 2009a and new data). People across cultures seem to infer values from external features, often applying the rule what is beautiful is good.

The taxonomy and distribution of rodents in Zambia was comprehensively summarized in 1978 by W.F.H. Ansell in his excellent book Mammals of Zambia. Despite the fact that during the last three decades many new taxonomic revisions of African rodents were published and extensive new material collected, not much work has been done on Zambian rodents since the book publication. Here we summarize the current knowledge of one of the most speciose group of African rodents, the tribe Praomyini, in Zambia. We review available historical records and revise our recently collected material by sequencing the mitochondrial DNA gene of cytochrome b. The presence of eight species of Praomyini in Zambia is documented and the pattern of their geographical distribution is described and discussed. Two species, Praomys minor and Mastomys coucha, are reported for the first time from Zambia and Praomys cf. jacksoni probably represents a new undescribed species. On the other hand, the actual occurrence of Colomys goslingi, known in Zambia only from one historical record, is questionable. The results document the usefulness of the DNA barcoding approach for description of species diversity of taxonomically complicated groups with many cryptic species.

The African mole rats (Bathyergidae) is a rodent family unique for subterranean life and diverse social systems. Solitary species are thought to be confined to areas with abundant, evenly distributed food resources and easily workable soils, which favors early natal dispersal and independent reproduction. However, there is a paucity of empirical data confirming this assumption. We examined ecological conditions of a typical natural habitat of the solitary silvery mole-rat ( Heliophobius argenteocinereus ), which is the Miombo woodland, and we identified behavioral and other adaptations which potentially improve its foraging success. We also tested food selectivity of captive mole-rats. In the Miombo, mole-rat food resources were clumped, but relatively ample. This, along with a predictable and relatively short period of year with dry and difficult-to-work soil, creates relatively moderate ecological conditions. Analysis of food stores showed that food storing alone probably does not secure enough food to overcome the advanced dry season in this species. In light of this, several other adaptations, such as food generalism and area-restricted search can assist silvery mole-rats retaining positive energy balance during these times. Food-preference tests showed that silvery mole-rats prefer tubers with high sugar content, followed by those with high water content.

We analysed seismic signals in two spalacid rodents, the giant root-rat (Tachyoryctes macrocephalus) and Gansu zokor (Eospalax cansus), displaying a different degree of fossoriality. Both produced seismic signals during the peak of activity, probably as territorial advertisement. Comparison with other spalacids did not reveal a relationship between inter-pulse distance and body mass; although this relationship appeared after the giant root-rat, the largest and most fossorial species, was excluded. All hitherto studied spalacids produce seismic signals by head-thumping, which probably evolved as a ritualization of soil tampering, an interesting case of convergent evolution of communication in rodents.