Intercolonial encounters and xenophobia in the common mole rat, <i>Cryptomys hottentotus hottentotus</i> (Bathyergidae): the effects of aridity, sex, and reproductive status

Spinks, A. C.; O’Riain, M. Justin; Polakow, Daniel

doi:10.1093/beheco/9.4.354

Cited by 22 publications

(17 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They furthermore suggest that larger groups may form more social sub-units which may in turn counter any densitydependent parasite propagation (Chapman et al 2009). In the common mole-rat the heightened xenophobia in arid populations (Spinks et al 1998) is a social mechanism likely to be responsible for maintaining group integrity and decreasing transmission rates (Freeland 1976;Loehle 1995).…”

Section: Discussionmentioning

confidence: 99%

“…On South Africa's west coast dispersal patterns differ along a latitudinal gradient with increasing annual rainfall from north to south and dispersal being greater in mesic areas (Spinks et al 2000b;Bishop et al 2004). The resulting differences in colony integrity coincides with a markedly increased xenophobia in arid compared to mesic sites (Spinks et al 1998). At the same time, the population densities of common mole-rats at the rainfall extremes differ by an order of magnitude and can reach densities of 18.7 ±1.2 individuals/ha in mesic compared to 1.8 ±0.2 individuals/ha in arid sites while mean colony size (5.1 ±0.2 individuals) is comparable (Spinks et al 2000b;Bishop et al 2004).…”

Section: Introductionmentioning

confidence: 88%

“…Traps were checked every two to three hours from first light until just after dark. A colony was considered complete when no activity was recorded at a trap site for 36h after the last animal capture (Spinks et al 1998). Once captured, individuals of the same colony were housed together in plastic crates provided with at least a 3cm layer of soil and air holes in the lid.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal

2015

View full text Add to dashboard Cite

Due to the density-dependent nature of parasite transmission parasites are generally assumed to constrain the evolution of sociality. However, evidence for a correlation between group size and parasite burden is equivocal, particularly for mammals. Host contact rates may be modified by mobility of the host and parasite as well as social barriers. In the current study, we used the common mole-rat (Cryptomys hottentotus hottentotus), a social subterranean rodent, as a model system to investigate the effect of host density and frequency of contact rates on ectoparasite burdens. To address these factors we used a study species that naturally varies in population densities and intergroup contact rates across its geographic range. We found that ectoparasite prevalence, abundance and species richness decreased with increasing host density at a regional scale. At the same time, measures of parasite burden increased with intergroup contact rates. Ectoparasite burdens decreased with colony size at the group level possibly as a result of increased grooming rates. Equating group size with population density might be too simplistic an approach when assessing parasite distributions in social mammals. Our data suggest that frequencydependent mechanisms may play a much greater role at a population level than density-dependent mechanisms in determining parasite distributions in social species. We suggest that future studies should explicitly consider behavioural mechanisms that may affect parasite distribution.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal

2015

View full text Add to dashboard Cite

show abstract

“…Mole rats tend to prune the buds and sprouting shoots from corms and tubers (Bennett & Faulkes, 2000), whereas the Mediterranean blind mole rat Spalax ehrenbergi does the same with Oxalis bulbs but eats the shoots (Galil, 1967). It has also been observed that mole rats ‘farm’ geophytes (Jarvis & Sale, 1971; Bennett, 1988; Spinks, 1998; Bennett & Faulkes, 2000) by partially consuming the geophytes and then replugging the consumed section with soil so that it will regenerate.…”

Section: Introductionmentioning

confidence: 99%

“…Geophytes have a high water content of 77–80% by weight (Bennett & Jarvis, 1995) and the humidity in the burrow systems of the mole rats is high (>95%); therefore water loss is low (Buffenstein & Yahav, 1991). The size of the geophytes is also important and, in arid areas where there is a decrease in geophyte density, there tends to be an increase in the average size of food items (Bennett, 1988; Spinks, 1998).…”

Section: Introductionmentioning

confidence: 99%

Burrow architecture and burrowing dynamics of the endangered Namaqua dune mole rat (Bathyergus janetta) (Rodentia: Bathyergidae)

Herbst

Bennett

2006

Journal of Zoology

View full text Add to dashboard Cite

The Namaqua dune mole rat Bathyergus janetta is a solitary subterranean rodent that occurs in the arid and sandy regions of Namaqualand. The predictable winter rainfall and high diversity of geophytes, the predominant food resource, enables the mole rat to survive in this extreme environment. Burrowing and burrow system configuration were measured by observing mound production and the excavation of six mole rat burrow systems. A typical burrow system comprises nest chambers, food stores, defecation sites and bolt holes, which serve as a place of retreat when the animal is alarmed or threatened. Males tend to have linear-shaped burrow systems, whereas the burrow systems of females are more reticulate. The linear nature of the male burrow system probably increases the home range used to search for potential mates. Burrow systems undergo constant excavation and reexcavation within the home range. The average burrow length ranges from 71.2 to 165 m with a mean home range of 805.8 AE 375.5 m 2 .

show abstract

New insights into morphological adaptation in common mole‐rats (Cryptomys hottentotus hottentotus) along an aridity gradient

Merchant,

Portugal,

Bennett

et al. 2024

Ecology and Evolution

View full text Add to dashboard Cite

Morphological adaptation is the change in the form of an organism that benefits the individual in its current habitat. Mole‐rats (family Bathyergidae), despite being subterranean, are impacted by both local and broad‐scale environmental conditions that occur above ground. Common mole‐rats (Cryptomys hottentotus hottentotus) present an ideal mammalian model system for the study of morphological variation in response to ecology, as this species is found along an aridity gradient and thus can be sampled from geographically non‐overlapping populations of the same species along an environmental longitudinal cline. Using the mass of five internal organs, ten skeletal measurements and 3D morphometric analyses of skulls, we assessed the morphology of wild non‐breeding individuals from five common mole‐rat populations in South Africa. We found that the body mass and mean relative mass of the spleen and kidneys in arid populations was larger, and individuals from arid regions possessed shorter legs and larger inter‐shoulder widths compared to individuals from mesic regions. Additionally, arid populations demonstrated greater skull depth, and shape change of features such as angular processes of the lower jaw than mesic individuals, indicating that these distinct geographic populations show differences corresponding to the aridity gradient, potentially in response to environmental factors such as the variation in food sources found between different habitats, in addition to different soil compositions found in the different regions. Arid populations potentially require a stronger jaw and neck musculature associated with mastication to chew xeric‐adapted plants and to dig through hard soil types, whereas mesic populations excavate through soft, looser soil and may make use of their front limbs to aid the movement of soils when digging. Aridity influences the morphology of this species and could indicate the impact of environmental changes on speciation and mammalian skull morphology.

show abstract

Intercolonial encounters and xenophobia in the common mole rat, Cryptomys hottentotus hottentotus (Bathyergidae): the effects of aridity, sex, and reproductive status

Cited by 22 publications

References 15 publications

Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal

Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal

Burrow architecture and burrowing dynamics of the endangered Namaqua dune mole rat (Bathyergus janetta) (Rodentia: Bathyergidae)

New insights into morphological adaptation in common mole‐rats (Cryptomys hottentotus hottentotus) along an aridity gradient

Contact Info

Product

Resources

About