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Pleštilová L, Hrouzková E, Burda H, Meheretu Y, Šumbera R. Ear morphology in two root-rat species (genus Tachyoryctes) differing in the degree of fossoriality. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 207:469-478. [PMID: 33956210 DOI: 10.1007/s00359-021-01489-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/20/2021] [Accepted: 04/24/2021] [Indexed: 11/30/2022]
Abstract
It is supposed that the subterranean lifestyle in mammals is reflected in ear morphology and tuning of hearing to low frequencies. We studied two root-rat species to see if their ear morphology reflects the difference in the amount of their surface activity. Whereas the more subterranean Tachyoryctes splendens possesses shorter pinnae as expected, it has smaller bullae compared to the more epigeic Tachyoryctes macrocephalus. The ratio between the eardrum and the stapedial footplate area and the ratio between the mallear and the incudal lever were lower in T. splendens (19.3 ± 0.3 and 1.9 ± 0.0, respectively) than in T. macrocephalus (21.8 ± 0.6 and 2.1 ± 0.1), probably reflecting the latter's higher surface activity. The cochlea in both species has 3.5 coils, yet the basilar membrane is longer in the smaller T. splendens (13.0 ± 0.5 versus 11.4 ± 0.7 mm), which indicates its wider hearing range and/or higher sensitivity (to some frequencies). In both root-rat species, the highest density of outer hair cells (OHC) was in the apical part of the cochlea, while the highest density of inner hair cells (IHC) was in its middle part. This OHC density pattern corresponds with good low-frequency hearing, whereas the IHC pattern suggests sensitivity to higher frequencies.
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Affiliation(s)
- Lucie Pleštilová
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská, 1760, 37005, České Budějovice, Czech Republic.
| | - Ema Hrouzková
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská, 1760, 37005, České Budějovice, Czech Republic
| | - Hynek Burda
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 16521, Praha, Czech Republic
| | - Yonas Meheretu
- Department of Biology, College of Natural and Computational Sciences, University of Mekelle, Mekelle, Ethiopia
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská, 1760, 37005, České Budějovice, Czech Republic
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Hrouzková E, Bernasová E, Šklíba J. Eavesdropping on a heterospecific alarm call in the giant root-rat (Tachyorytes macrocephalus), an important prey of the Ethiopian wolf (Canis simensis). J ETHOL 2019. [DOI: 10.1007/s10164-019-00618-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Šklíba J, Vlasatá T, Lövy M, Hrouzková E, Meheretu Y, Sillero‐Zubiri C, Šumbera R. The giant that makes do with little: small and easy‐to‐leave home ranges found in the giant root‐rat. J Zool (1987) 2019. [DOI: 10.1111/jzo.12729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. Šklíba
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - T. Vlasatá
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - M. Lövy
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - E. Hrouzková
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
| | - Y. Meheretu
- Department of Biology College of Natural and Computational Sciences University of Mekelle Mekelle Ethiopia
| | - C. Sillero‐Zubiri
- Wildlife Conservation Research Unit Zoology Department University of Oxford Oxford UK
- Born Free Foundation Horsham UK
| | - R. Šumbera
- Faculty of Science University of South Bohemia Ceske Budejovice Czech Republic
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Šklíba J, Vlasatá T, Lövy M, Hrouzková E, Meheretu Y, Sillero-Zubiri C, Šumbera R. Ecological role of the giant root-rat (Tachyoryctes macrocephalus) in the Afroalpine ecosystem. Integr Zool 2016; 12:333-344. [PMID: 27734606 DOI: 10.1111/1749-4877.12241] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Rodents with prevailing subterranean activity usually play an important role in the ecosystems of which they are a part due to the combined effect of herbivory and soil perturbation. This is the case for the giant root-rat Tachyoryctes macrocephalus endemic to the Afroalpine ecosystem of the Bale Mountains, Ethiopia. We studied the impact of root-rats on various ecosystem features within a 3.5-ha study locality dominated by Alchemilla pasture, which represents an optimal habitat for this species, in 2 periods of a year. The root-rats altered plant species composition, reducing the dominant forb, Alchemilla abyssinica, while enhancing Salvia merjame and a few other species, and reduced vegetation cover, but not the fresh plant biomass. Where burrows were abandoned by root-rats, other rodents took them over and A. abyssinica increased again. Root-rat burrowing created small-scale heterogeneity in soil compactness due to the backfilling of some unused burrow segments. Less compacted soil tended to be rich in nutrients, including carbon, nitrogen and phosphorus, which likely affected the plant growth on sites where the vegetation has been reduced as a result of root-rat foraging and burrowing.
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Affiliation(s)
- Jan Šklíba
- Faculty of Science, University of South Bohemia, Czech Republic.,Institute of Entomology, Biology Centre CAS, Czech Republic
| | - Tereza Vlasatá
- Faculty of Science, University of South Bohemia, Czech Republic
| | - Matěj Lövy
- Faculty of Science, University of South Bohemia, Czech Republic
| | - Ema Hrouzková
- Faculty of Science, University of South Bohemia, Czech Republic
| | - Yonas Meheretu
- Department of Biology, College of Natural and Cmputational Sciences, Mekelle University, Ethiopia
| | | | - Radim Šumbera
- Faculty of Science, University of South Bohemia, Czech Republic
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Affiliation(s)
- Veronika Dvořáková
- Faculty of Sciences, University of South Bohemia, České Budějovice, Czech Republic
| | - Ema Hrouzková
- Faculty of Sciences, University of South Bohemia, České Budějovice, Czech Republic
| | - Radim Šumbera
- Faculty of Sciences, University of South Bohemia, České Budějovice, Czech Republic
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Pleštilová L, Hrouzková E, Burda H, Šumbera R. Does the morphology of the ear of the Chinese bamboo rat (Rhizomys sinensis) show "Subterranean" characteristics? J Morphol 2016; 277:575-84. [PMID: 26880690 DOI: 10.1002/jmor.20519] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 01/21/2016] [Accepted: 01/24/2016] [Indexed: 11/08/2022]
Abstract
In spite of the growing interest in rodents with subterranean activity in general and the spalacids (Spalacidae) in particular, little is known about the biology of most members of this clade, such as the Chinese bamboo rat (Rhizomys sinensis). Here, we analyzed the ear morphology of R. sinensis with respect to hearing specialization for subterranean or aboveground modes of communication. It is well-known that ecology and style of life of a particular species can be reflected in morphology of its ear, its hearing and vocalization, so we expect that such information could provide us insight into its style of life and its sensory environment. The ratio between the eardrum and stapedial footplate areas, which influences the efficiency of middle ear sound transmission, suggests low hearing sensitivity, as is typical for subterranean species. The cochlea had 3.25 coils and resembled species with good low frequency hearing typical for subterranean mammals. The length of the basilar membrane was 18.9 ± 0.8 mm and its width slowly increased towards the cochlear apex from 60 to 85 μm. The mean density of outer hair cells was 344 ± 22 and of inner hair cells 114 ± 7.3 per 1 mm length of the organ of Corti, and increased apically. These values (except for relatively low hair cell density) usually characterize ears specialized for low frequency hearing. There was no evidence for an acoustic fovea. Apart of low hair cell density which is common in aboveground animals, this species has also relatively large auricles, suggesting the importance of sound localization during surface activity. The ear of the Chinese bamboo rat thus contains features typical for both aboveground and subterranean mammals and suggests that this spalacid has fossorial habits combined with regular aboveground activity.
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Affiliation(s)
- Lucie Pleštilová
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, 37005, Czech Republic
| | - Ema Hrouzková
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, 37005, Czech Republic
| | - Hynek Burda
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, 37005, Czech Republic.,Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, D-45117 Essen, Germany
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, 37005, Czech Republic
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Lövy M, Šklíba J, Hrouzková E, Dvořáková V, Nevo E, Šumbera R. Habitat and Burrow System Characteristics of the Blind Mole Rat Spalax galili in an Area of Supposed Sympatric Speciation. PLoS One 2015; 10:e0133157. [PMID: 26192762 PMCID: PMC4508111 DOI: 10.1371/journal.pone.0133157] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 06/23/2015] [Indexed: 11/18/2022] Open
Abstract
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.
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Affiliation(s)
- Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- * E-mail:
| | - Jan Šklíba
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Ema Hrouzková
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Veronika Dvořáková
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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Šklíba J, Lövy M, Hrouzková E, Kott O, Okrouhlík J, Šumbera R. Social and Environmental Influences on Daily Activity Pattern in Free-Living Subterranean Rodents. J Biol Rhythms 2014; 29:203-214. [DOI: 10.1177/0748730414526358] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Predictable daily activity patterns have been detected repeatedly even in mammals living in stable environments, as is the case for subterranean rodents. Whereas studies on activity of these rodents under laboratory conditions almost exclusively have concerned themselves with the influence of light, many field studies have revealed signs of an association between the activity pattern and daily fluctuations of temperature under the ground. This would assume that behavioral thermoregulation is probably involved. The only exceptions to the relationship between temperature and activity are 2 eusocial mole-rats of the genus Fukomys (Bathyergidae, Rodentia), which indicates that activity patterns could be affected also by social cues. To better understand how social and environmental factors influence the activity pattern in a eusocial mole-rat, we monitored the outside-nest activity in another species of this genus, the Ansell’s mole-rat ( Fukomys anselli), which has a relatively small body mass, high conductance, and more superficially situated burrows. Its daily activity had 1 prominent peak (around 1400 h), and it was tightly correlated with the temperature measured at depth of foraging burrows. Since F. anselli has high thermoregulatory requirements to maintain stable body temperature below the lower critical temperature, we conclude that the observed pattern is probably the result of minimizing the cost of thermoregulation. There were no significant differences in the daily activity patterns of breeding males and females and nonbreeders. Members of the same family group tended to have more similar activity patterns, but consistent activity synchronization between individuals was not proven. From the comparison of available data on all subterranean rodents, we assume that social cues in communally nesting mole-rats may disrupt (mask) temperature-related daily activity rhythms but probably only if the additional cost of thermoregulation is not too high, as it likely is in the Ansell’s mole-rat.
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Affiliation(s)
- Jan Šklíba
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
| | - Ema Hrouzková
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
| | - Ondřej Kott
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
| | - Jan Okrouhlík
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, Cˇeské Budeˇjovice, Czech Republic
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Šklíba J, Mazoch V, Patzenhauerová H, Hrouzková E, Lövy M, Kott O, Šumbera R. A maze-lover's dream: Burrow architecture, natural history and habitat characteristics of Ansell's mole-rat (Fukomys anselli). Mamm Biol 2012. [DOI: 10.1016/j.mambio.2012.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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