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Oda GA, Valentinuzzi VS. A clock for all seasons in the subterranean. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023:10.1007/s00359-023-01677-z. [PMID: 37815602 DOI: 10.1007/s00359-023-01677-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 09/14/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023]
Abstract
In 1976, Pittendrigh and Daan established a theoretical framework which has coordinated research on circadian clock entrainment and photoperiodism until today. The "wild clocks" approach, which concerns studying wild species in their natural habitats, has served to test their models, add new insights, and open new directions of research. Here, we review an integrated laboratory, field and modeling work conducted with subterranean rodents (Ctenomys sp.) living under an extreme pattern of natural daily light exposure. Tracking animal movement and light exposure with biologgers across seasons and performing laboratory experiments on running-wheel cages, we uncovered the mechanisms of day/night entrainment of the clock and of photoperiodic time measurement in this subterranean organism. We confirmed most of the features of Pittendrigh and Daan's models but highlighted the importance of integrating them with ecophysiological techniques, methodologies, and theories to get a full picture of the clock in the wild. This integration is essential to fully establish the importance of the temporal dimension in ecological studies and tackling relevant questions such as the role of the clock for all seasons in a changing planet.
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Affiliation(s)
- Gisele A Oda
- Laboratório Binacional de Cronobiologia, Universidade de São Paulo, São Paulo, SP, Brazil.
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2
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Cserkész T, Kiss C, Sramkó G. Seasonal and diel activity patterns of small mammal guilds on the Pannonian Steppe: a step towards a better understanding of the ecology of the endangered Hungarian birch mouse (Sicista trizona) (Sminthidae, Rodentia). MAMMAL RES 2022. [DOI: 10.1007/s13364-022-00656-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractTemporal activity differences facilitate species’ coexistence by reducing interspecific competition. Such patterns can be studied via diel activity analysis, but obtaining data in cryptic mammals is difficult. We investigated the annual and diel activity pattern of such a small mammal, the endangered Hungarian birch mouse (Sicista trizona trizona), in its only known habitat. We employ trail cameras for the first time to reveal the diel and annual activity of a sminthid species. Data acquisition included the spring and summer seasons between 2019 and 2022 and was extended to detect the activity overlaps with other common coexisting rodents and shrews. The diel activity results rely on 581 detections of S. trizona over 5670 trap-nights of camera trap deployment characterising also activity pattern of the small mammal community in this Central European grassland ecosystem. S. trizona was not recorded during the day but was active at dawn and night, and in comparison with other coexisting species, its activity level was high. The presumed cold sensitivity was not confirmed as we detected activity at −6 °C. Diel activity peaked in early May in the mating season. Although the diel activity pattern of co-occurring small mammal species was also nocturnal, activity overlaps were relatively high suggesting that temporal niche partitioning is limited within the habitat. Our work provides the first insight into temporal overlaps within a small mammal community in a natural European grassland, moreover, also the first documented research on the activity pattern of a sminthid in its natural habitat.
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3
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Oosthuizen MK, Bennett NC. Clocks Ticking in the Dark: A Review of Biological Rhythms in Subterranean African Mole-Rats. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.878533] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Biological rhythms are rhythmic fluctuations of biological functions that occur in almost all organisms and on several time scales. These rhythms are generated endogenously and entail the coordination of physiological and behavioural processes to predictable, external environmental rhythms. The light-dark cycle is usually the most prominent environmental cue to which animals synchronise their rhythms. Biological rhythms are believed to provide an adaptive advantage to organisms. In the present review, we will examine the occurrence of circadian and seasonal rhythms in African mole-rats (family Bathyergidae). African mole-rats are strictly subterranean, they very rarely emerge aboveground and therefore, do not have regular access to environmental light. A key adaptation to their specialised habitat is a reduction in the visual system. Mole-rats exhibit both daily and seasonal rhythmicity in a range of behaviours and physiological variables, albeit to different degrees and with large variability. We review previous research on the entire circadian system of African mole-rats and discuss output rhythms in detail. Laboratory experiments imply that light remains the strongest zeitgeber for entrainment but in the absence of light, animals can entrain to ambient temperature rhythms. Field studies report that rhythmic daily and seasonal behaviour is displayed in their natural habitat. We suggest that ambient temperature and rainfall play an important role in the timing of rhythmic behaviour in mole-rats, and that they likely respond directly to these zeitgebers in the field rather than exhibit robust endogenous rhythms. In the light of climate change, these subterranean animals are buffered from the direct and immediate effects of changes in temperature and rainfall, partly because they do not have robust circadian rhythms, however, on a longer term they are vulnerable to changes in their food sources and dispersal abilities.
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Finn KT, Janse van Vuuren AK, Hart DW, Süess T, Zöttl M, Bennett NC. Seasonal Changes in Locomotor Activity Patterns of Wild Social Natal Mole-Rats (Cryptomys hottentotus natalensis). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.819393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Differences in individual locomotor activity patterns may be linked to a number of ecological factors, such as changes in ambient temperature or photoperiod. Observations on subterranean mammals suggest that they exhibit diel rhythms despite the lack of visual cues in their underground burrows, but it is unknown how seasonality and individual characteristics affect their activity. In this study we use RFID technology to monitor daily activity patterns of wild, social Natal mole-rats (Cryptomys hottentotus natalensis) during the summer and winter to investigate how their activity varies with season and whether their activity depends on individual characteristics such as body mass, sex and reproductive status. We found that in winter, individuals were more active during the time with the highest soil temperatures, whereas in summer, they showed a bimodal activity pattern during early morning and late afternoon coinciding with cooler soil temperatures. Individual characteristics, including reproductive status, did not affect general activity indicating that reproductive and non-reproductive individuals contribute equally to cooperative behaviors. We suggest that the activity patterns may be a behavioral adaptation to avoid extreme burrow temperatures and a mechanism to maintain a stable core body temperature. We highlight the advantages of RFID technology to study wild small mammal movements.
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Oosthuizen M, Robb G, Harrison A, Froneman A, Joubert K, Bennett N. Flexibility in body temperature rhythms of free-living natal mole-rats (Cryptomys hottentotus natalensis). J Therm Biol 2021; 99:102973. [DOI: 10.1016/j.jtherbio.2021.102973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 10/25/2022]
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Vejmělka F, Okrouhlík J, Lövy M, Šaffa G, Nevo E, Bennett NC, Šumbera R. Heat dissipation in subterranean rodents: the role of body region and social organisation. Sci Rep 2021; 11:2029. [PMID: 33479351 PMCID: PMC7820455 DOI: 10.1038/s41598-021-81404-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 12/30/2020] [Indexed: 01/29/2023] Open
Abstract
The relatively warm and very humid environment of burrows presents a challenge for thermoregulation of its mammalian inhabitants. It was found that African mole-rats dissipate body heat mainly through their venter, and social mole-rats dissipate more body heat compared to solitary species at lower temperatures. In addition, the pattern of the ventral surface temperature was suggested to be homogeneous in social mole-rats compared to a heterogeneous pattern in solitary mole-rats. To investigate this for subterranean rodents generally, we measured the surface temperatures of seven species with different degrees of sociality, phylogeny, and climate using infrared thermography. In all species, heat dissipation occurred mainly through the venter and the feet. Whereas the feet dissipated body heat at higher ambient temperatures and conserved it at lower ambient temperatures, the ventral surface temperature was relatively high in all temperatures indicating that heat dissipation to the environment through this body region is regulated mainly by behavioural means. Solitary species dissipated less heat through their dorsum than social species, and a tendency for this pattern was observed for the venter. The pattern of heterogeneity of surface temperature through the venter was not related to sociality of the various species. Our results demonstrate a general pattern of body heat exchange through the three studied body regions in subterranean rodents. Besides, isolated individuals of social species are less able to defend themselves against low ambient temperatures, which may handicap them if staying alone for a longer period, such as during and after dispersal events.
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Affiliation(s)
- František Vejmělka
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Jan Okrouhlík
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Gabriel Šaffa
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic
| | - Eviatar Nevo
- Institute of Evolution, University of Haifa, 3498838, Haifa, Israel
| | - Nigel Charles Bennett
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0002, South Africa
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, 370 05, České Budějovice, Czech Republic.
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Okrouhlík J, Šumbera R, Gardner B, Schoemann K, Lövy M, Bennett NC. Are southern African solitary mole-rats homeothermic or heterothermic under natural field conditions? J Therm Biol 2020; 95:102810. [PMID: 33454040 DOI: 10.1016/j.jtherbio.2020.102810] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 10/22/2022]
Abstract
Abandoning of a stable body temperature (Tb), a phenomenon known as heterothermy, is an adaptation to cope mainly with a lack of food and water, especially in species inhabiting daily or seasonally variable environments. There is increasing evidence that African mammals avoid adverse conditions by heterothermy and eventually by entering torpor. Members of subterranean rodent family, the African mole-rats (Bathyergidae), are suitable candidates to study both phenomena, because of the diversity of their strategies in respect of maintaining stable Tb ranging from homeothermic species to a mammal with the most labile Tb, the naked mole-rat. Currently, there are field data on daily and seasonal Tb in one social species only and such information are lacking for any solitary mole-rat. In our study, we recorded yearly Tb in two solitary bathyergids, the Cape mole-rat Georychus capensis and the Cape dune mole-rat Bathyergus suillus from South Africa using intraperitoneally implanted dataloggers. Since this region is characterised by changing ecological characteristics, we expected either decreases of Tb within 24 h indicating daily torpor and/or longer-term decreases of Tb, which would indicate multiday torpor. Although we found seasonally phase shifted low amplitude daily Tb cycles, we did not find any remarkable and regular daily and/or seasonal Tb deviations, likely showing an absence of torpor in both species. Due to absence of this energy saving mechanism, we may speculate that both species could be vulnerable to ongoing global climatic change.
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Affiliation(s)
- Jan Okrouhlík
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa; Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
| | - Brett Gardner
- Werribee Open Range Zoo, Veterinary Hospital, Zoos Victoria, K Road, Werribee, Victoria, 3029, Australia
| | - Keegan Schoemann
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
| | - Nigel Charles Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
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Šumbera R, Lövy M, Marino J, Šimek M, Šklíba J. Gas composition and its daily changes within burrows and nests of an Afroalpine fossorial rodent, the giant root-rat Tachyoryctes macrocephalus. ZOOLOGY 2020; 142:125819. [PMID: 32750648 DOI: 10.1016/j.zool.2020.125819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 06/27/2020] [Accepted: 07/02/2020] [Indexed: 01/12/2023]
Abstract
Fossorial mammals are supposed to face hypoxic and hypercapnic conditions, but such conditions have been rarely encountered in their natural burrow systems. Gas composition in burrows after heavy rains, deeper burrows and especially nest chambers, where animals usually spend most of the day, could be even more challenging than in shallow burrows. Such situations, however, have been rarely surveyed in the wild. In our study, we determined concentrations of O2, CO2 and CH4 in active burrows and nests of the giant root-rat Tachyoryctes macrocephalus, a large fossorial rodent endemic to the Afroalpine zone of the Bale Mountains in Ethiopia. We were able to determine the precise location of nests by tracking individuals equipped with radio-collars. To the best of our knowledge, this is the first study that analyses air samples taken directly from the nests of actually occupied burrow systems in any free-living fossorial mammal. We found no evidence for environmental hypoxia in the examined burrows and nests (range 19.7-21.6% O2). Concentrations of CO2 in the burrows increased after the burrows were plugged in the evening, but did not reach physiologically problematic levels. The highest CO2 concentrations in burrows were detected in the evening during a wet period (up to 0.44%). In root-rat nest chambers, the highest (but still harmless) CO2 concentrations (up to 1.31%) were detected in the morning (measured in the late dry season only) together with an elevated concentration (up to 13.5ppm) of CH4. Regular surface activity of giant root-rats, combined with the relatively large dimensions of their nest chambers and tunnels, and the absence of heavy soils, may contribute to harmless atmospheres within their burrow systems.
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Affiliation(s)
- Radim Šumbera
- Faculty of Science, University of South Bohemia, Czech Republic.
| | - Matěj Lövy
- Faculty of Science, University of South Bohemia, Czech Republic
| | - Jorgelina Marino
- Wildlife Conservation Research Unit, Zoology Department, University of Oxford, Oxford, UK
| | - Miloslav Šimek
- Biology Centre CAS, Institute of Soil Biology, České Budějovice, Czech Republic
| | - Jan Šklíba
- Faculty of Science, University of South Bohemia, Czech Republic
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9
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Evaporative water loss in seven species of fossorial rodents: Does effect of degree of fossoriality and sociality exist? J Therm Biol 2020; 89:102564. [DOI: 10.1016/j.jtherbio.2020.102564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/09/2023]
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Jannetti MG, Buck CL, Valentinuzzi VS, Oda GA. Day and night in the subterranean: measuring daily activity patterns of subterranean rodents ( Ctenomys aff. knighti) using bio-logging. CONSERVATION PHYSIOLOGY 2019; 7:coz044. [PMID: 31341624 PMCID: PMC6640163 DOI: 10.1093/conphys/coz044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 06/11/2019] [Accepted: 06/17/2019] [Indexed: 06/10/2023]
Abstract
While most studies of the impacts of climate change have investigated shifts in the spatial distribution of organisms, temporal shifts in the time of activity is another important adjustment made by animals in a changing world. Due to the importance of light and temperature cycles in shaping activity patterns, studies of activity patterns of organisms that inhabit extreme environments with respect to the 24-hour cyclicity of Earth have the potential to provide important insights into the interrelationships among abiotic variables, behaviour and physiology. Our previous laboratory studies with Argentinean tuco-tucos from the Monte desert (Ctenomys aff. knighti) show that these subterranean rodents display circadian activity/rest rhythms that can be synchronized by artificial light/dark cycles. Direct observations indicate that tuco-tucos emerge mainly for foraging and for removal of soil from their burrows. Here we used bio-logging devices for individual, long-term recording of daily activity/rest (accelerometry) and time on surface (light-loggers) of six tuco-tucos maintained in outdoor semi-natural enclosures. Environmental variables were measured simultaneously. Activity bouts were detected both during day and night but 77% of the highest values happened during the daytime and 47% of them coincided with time on surface. Statistical analyses indicate time of day and temperature as the main environmental factors modulating time on surface. In this context, the total duration that these subterranean animals spent on surface was high during the winter, averaging 3 h per day and time on surface occurred when underground temperature was lowest. Finally, transport of these animals to the indoor laboratory and subsequent assessment of their activity rhythms under constant darkness revealed a switch in the timing of activity. Plasticity of activity timing is not uncommon among desert rodents and may be adaptive in changing environments, such as the desert where this species lives.
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Affiliation(s)
- Milene G Jannetti
- Laboratorio Binacional Argentina-Brasil de Cronobiologia, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA
| | - Veronica S Valentinuzzi
- Laboratorio Binacional Argentina-Brasil de Cronobiologia, Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica (CRILAR), Entre Ríos y Mendoza, s/n, Anillaco, La Rioja, Argentina
| | - Gisele A Oda
- Laboratorio Binacional Argentina-Brasil de Cronobiologia, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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Šumbera R. Thermal biology of a strictly subterranean mammalian family, the African mole-rats (Bathyergidae, Rodentia) - a review. J Therm Biol 2019; 79:166-189. [DOI: 10.1016/j.jtherbio.2018.11.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/09/2018] [Accepted: 11/09/2018] [Indexed: 12/12/2022]
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Katandukila JV, Ngalameno MK, Mgode GF, Bastos AD, Bennett NC. Pattern of ovulation in an ancient, solitary mole-rat lineage: Heliophobius argenteocinereus emini from Tanzania. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The genus Heliophobius Peters, 1846 is an ancient subterranean rodent lineage within the family Bathyergidae that displays seasonal breeding over a broad geographical range. In East Africa, reproduction in these solitary mole-rats has been shown to coincide with the long rains, but it is not clear whether the silvery mole-rat subspecies Heliophobius argenteocinereus emini Noack, 1894 from Tanzania is an induced or spontaneous ovulator. To address this, urinary progesterone was measured every second day over a period of 132 days in six wild-caught females subjected to three sequential experimental treatments. In the first, control (C) treatment, females were housed singly for a period of 44 days, following which nonphysical contact (NPC) with a vasectomised male and then physical contact (PC) with the same vasectomised male occurred in each of the subsequent 44-day treatments. Noninvasive monitoring of ovarian cyclicity confirmed that mean urinary progesterone concentration was higher during PC than during either NPC or C, despite the fact that the males were vasectomised and incapable of fertilising the females. Examination of penile morphology revealed that males possess epidermal projections on the glans penis, which probably bring about cervical stimulation during coitus. These findings together with the female progesterone profiles imply the species is an induced ovulator stimulated by penile intromission.
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Affiliation(s)
- Jestina V. Katandukila
- South African Research Chair for Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, Republic of South Africa
- Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
| | - Mungo K. Ngalameno
- South African Research Chair for Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, Republic of South Africa
| | - Georgies F. Mgode
- Pest Management Centre, Sokoine University, P.O. Box 3110, Morogoro, Tanzania
| | - Armanda D.S. Bastos
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, Republic of South Africa
| | - Nigel C. Bennett
- South African Research Chair for Mammal Behavioural Ecology and Physiology, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, Republic of South Africa
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Vlasatá T, Šklíba J, Lövy M, Meheretu Y, Sillero-Zubiri C, Šumbera R. Daily activity patterns in the giant root rat (Tachyoryctes macrocephalus
), a fossorial rodent from the Afro-alpine zone of the Bale Mountains, Ethiopia. J Zool (1987) 2017. [DOI: 10.1111/jzo.12441] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T. Vlasatá
- Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - J. Šklíba
- Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
- Institute of Entomology; Biology Centre CAS; České Budějovice Czech Republic
| | - M. Lövy
- Faculty of Science; University of South Bohemia; České Budějovice 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
| | - R. Šumbera
- Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
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Ngalameno M, Bastos A, Mgode G, Bennett N. The pattern of reproduction in the mole-rat Heliophobius from Tanzania: do not refrain during the long rains! CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The genus Heliophobius Peters, 1846 comprises at least six cryptic, topotypical species in the Heliophobius argenteocinereus Peters, 1846 species complex. The current study investigated the breeding patterns of a wild-caught population from Tanzania where the putative species Heliophobius argenteocinereus emini Noack, 1894 resides. Individuals were collected on a monthly basis for an entire calendar year. Assessment of fœtus presence, gonadal histology, reproductive-tract morphometrics in combination with gonadal steroid (plasma progesterone and œstradiol-17β in females and testosterone in males) measurements and field observations revealed that rainfall is important for the onset of breeding. The results further confirmed that breeding is limited to a single, yearly reproductive event synchronised to the long rainfall pattern. The distinct breeding peak in July is associated with an elevation in gonadal mass, increase in concentrations of reproductive hormones, and presence of Graafian follicles and corpora lutea in the ovaries of females. These reproductive parameters coincided with the end of the long rainfall period, whereas presence of young in the maternal burrow system corresponded with the start of the short rainfall of East Africa. These findings confirm Heliophobius has a single breeding opportunity each year, and this species is therefore vulnerable to any changes that may impact their climatically attuned breeding patterns.
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Affiliation(s)
- M.K. Ngalameno
- Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
- Sokoine University of Agriculture, P.O. Box 3000, Morogoro, Tanzania
| | - A.D.S. Bastos
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
| | - G. Mgode
- Sokoine University of Agriculture, P.O. Box 3000, Morogoro, Tanzania
| | - N.C. Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa
- SARChI Chair of Mammal Behavioural Ecology and Physiology, Department of Zoology, University of Pretoria, Pretoria 0002, South Africa
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Ackermann S, Bennett NC, Katandukila JV, Oosthuizen MK. Circadian rhythms of locomotor activity in captive Emin’s mole-rats,Heliophobius emini(Rodentia: Bathyergidae). J Mammal 2016. [DOI: 10.1093/jmammal/gyw166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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16
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Kott O, Němec P, Fremlová A, Mazoch V, Šumbera R. Behavioural Tests Reveal Severe Visual Deficits in the Strictly Subterranean African Mole-Rats (Bathyergidae) but Efficient Vision in the Fossorial Rodent Coruro (Spalacopus cyanus, Octodontidae). Ethology 2016. [DOI: 10.1111/eth.12515] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ondřej Kott
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - Pavel Němec
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague Czech Republic
| | - Aneta Fremlová
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - Vladimír Mazoch
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
| | - Radim Šumbera
- Department of Zoology; Faculty of Science; University of South Bohemia; České Budějovice Czech Republic
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Šklíba J, Lövy M, Koeppen SCW, Pleštilová L, Vitámvás M, Nevo E, Šumbera R. Activity of free-living subterranean blind mole ratsSpalax galili(Rodentia: Spalacidae) in an area of supposed sympatric speciation. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12741] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jan Šklíba
- Department of Zoology; Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic
| | - Matěj Lövy
- Department of Zoology; Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic
| | - Stephan C. W. Koeppen
- Department of General Zoology; Faculty of Biology; University of Duisburg-Essen; Universitätsstr. 5 45141 Essen Germany
| | - Lucie Pleštilová
- Department of Zoology; Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic
| | - Miloš Vitámvás
- Department of Zoology; Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic
| | - Eviatar Nevo
- Institute of Evolution; University of Haifa; Haifa 31905 Israel
| | - Radim Šumbera
- Department of Zoology; Faculty of Science; University of South Bohemia; Branišovská 31 37005 České Budějovice Czech Republic
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Tucker CR, Strickland JT, Edmond BS, Delaney DK, Ligon DB. Activity Patterns of Ornate Box Turtles (Terrapene ornata) in Northwestern Illinois. COPEIA 2015. [DOI: 10.1643/ch-15-249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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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] [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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Katandukila JV, Bennett NC, Chimimba CT, Faulkes CG, Oosthuizen MK. Locomotor activity patterns of captive East African root rats,Tachyoryctes splendens(Rodentia: Spalacidae), from Tanzania, East Africa. J Mammal 2013. [DOI: 10.1644/13-mamm-a-095.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Bloch G, Barnes BM, Gerkema MP, Helm B. Animal activity around the clock with no overt circadian rhythms: patterns, mechanisms and adaptive value. Proc Biol Sci 2013; 280:20130019. [PMID: 23825202 DOI: 10.1098/rspb.2013.0019] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Circadian rhythms are ubiquitous in many organisms. Animals that are forced to be active around the clock typically show reduced performance, health and survival. Nevertheless, we review evidence of animals showing prolonged intervals of activity with attenuated or nil overt circadian rhythms and no apparent ill effects. We show that around-the-clock and ultradian activity patterns are more common than is generally appreciated, particularly in herbivores, in animals inhabiting polar regions and habitats with constant physical environments, in animals during specific life-history stages (such as migration or reproduction), and in highly social animals. The underlying mechanisms are diverse, but studies suggest that some circadian pacemakers continue to measure time in animals active around the clock. The prevalence of around-the-clock activity in diverse animals and habitats, and an apparent diversity of underlying mechanisms, are consistent with convergent evolution. We suggest that the basic organizational principles of the circadian system and its complexity encompass the potential for chronobiological plasticity. There may be trade-offs between benefits of persistent daily rhythms versus plasticity, which for reasons still poorly understood make overt daily arrhythmicity functionally adaptive only in selected habitats and for selected lifestyles.
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Affiliation(s)
- Guy Bloch
- Department of Ecology, Evolution and Behavior, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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Lövy M, Sklíba J, Sumbera R. Spatial and temporal activity patterns of the free-living giant mole-rat (Fukomys mechowii), the largest social bathyergid. PLoS One 2013; 8:e55357. [PMID: 23383166 PMCID: PMC3559640 DOI: 10.1371/journal.pone.0055357] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 12/27/2012] [Indexed: 11/29/2022] Open
Abstract
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.
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Affiliation(s)
- Matěj Lövy
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
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Possible incipient sympatric ecological speciation in blind mole rats (Spalax). Proc Natl Acad Sci U S A 2013; 110:2587-92. [PMID: 23359700 DOI: 10.1073/pnas.1222588110] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
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 (2n = 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.
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Schielke CK, Begall S, Burda H. Reproductive state does not influence activity budgets of eusocial Ansell's mole-rats, Fukomys anselli (Rodentia, Bathyergidae): A study of locomotor activity by means of RFID. Mamm Biol 2012. [DOI: 10.1016/j.mambio.2011.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Meek PD, Zewe F, Falzon G. Temporal activity patterns of the swamp rat (Rattus lutreolus) and other rodents in north-eastern New South Wales, Australia. AUSTRALIAN MAMMALOGY 2012. [DOI: 10.1071/am11032] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The activity patterns and partitioning of time by four small mammal species, with a focus on the swamp rat (Rattus lutreolus) in north-eastern New South Wales, was investigated using camera trap data from two studies. Analysis was carried out on 1079 camera trap events over 1530 camera trap–nights or 36 720 h of camera trap deployment in the field. The activity patterns of Rattus lutreolus were distinctly diurnal with crepuscular peaks of activity but this differed between sites and when in the presence of competitors. The Hastings River mouse (Pseudomys oralis) and the bush rat (Rattus fuscipes) displayed typical bimodal patterns of nocturnal activity. Antechinus were mostly nocturnal but were occasionally active during the day. These data indicate that where species of Muridae co-occur, diurnal time partitioning by R. lutreolus may reduce competition for food resources. It also confirms the speculation that R. lutreolus displays diurnal behaviour, albeit dependent on the presence of other murids.
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Resource characteristics and foraging adaptations in the silvery mole-rat (Heliophobius argenteocinereus), a solitary Afrotropical bathyergid. Ecol Res 2011. [DOI: 10.1007/s11284-011-0860-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Zelová J, Šumbera R, Okrouhlík J, Šklíba J, Lövy M, Burda H. A seasonal difference of daily energy expenditure in a free-living subterranean rodent, the silvery mole-rat (Heliophobius argenteocinereus; Bathyergidae). Comp Biochem Physiol A Mol Integr Physiol 2011; 158:17-21. [DOI: 10.1016/j.cbpa.2010.07.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 06/29/2010] [Accepted: 07/02/2010] [Indexed: 10/19/2022]
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Šklíba J, Šumbera R, Chitaukali WN. What determines the way of deposition of excavated soil. ACTA ACUST UNITED AC 2010. [DOI: 10.4098/j.at.0001-7051.099.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Kott O, Šumbera R, Němec P. Light perception in two strictly subterranean rodents: life in the dark or blue? PLoS One 2010; 5:e11810. [PMID: 20676369 PMCID: PMC2911378 DOI: 10.1371/journal.pone.0011810] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 06/23/2010] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The African mole-rats (Bathyergidae, Rodentia) are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. Because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. However, recent anatomical studies have suggested retention of basic visual capabilities. In this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they are able to discriminate colours and, finally, if the presence of light in burrows provokes plugging behaviour, which is assumed to have a primarily anti-predatory function. METHODOLOGY/PRINCIPAL FINDING We used a binary choice test to show that the silvery mole-rat Heliophobius argenteocinereus and the giant mole-rat Fukomys mechowii exhibit a clear photoavoidance response to full-spectrum ("white"), blue and green-yellow light, but no significant reaction to ultraviolet or red light during nest building. The mole-rats thus retain dark/light discrimination capabilities and a capacity to perceive short to medium-wavelength light in the photopic range of intensities. These findings further suggest that the mole-rat S opsin has its absorption maximum in the violet/blue part of the spectrum. The assay did not yield conclusive evidence regarding colour discrimination. To test the putative role of vision in bathyergid anti-predatory behaviour, we examined the reaction of mole-rats to the incidence of light in an artificial burrow system. The presence of light in the burrow effectively induced plugging of the illuminated tunnel. CONCLUSION/SIGNIFICANCE Our findings suggest that the photopic vision is conserved and that low acuity residual vision plays an important role in predator avoidance and tunnel maintenance in the African mole-rats.
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Affiliation(s)
- Ondřej Kott
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Radim Šumbera
- Department of Zoology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Pavel Němec
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
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Reactions to disturbances in the context of antipredatory behaviour in a solitary subterranean rodent. J ETHOL 2007. [DOI: 10.1007/s10164-007-0056-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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