Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 11

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  subterranean rodent
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Nutrient uptake and allocation by plants in recent mounds created by subterranean rodent, plateau zokor Eospalax baileyi

100%
Wu R., Wei X., Liu K., Zhong M., Liu Y., Pan D., Shao X.
Polish Journal of Ecology
|
2017
|
tom 65
|
nr 1
To understand the nutrient absorption and adaptability of plant species that initially colonize mounds and the influences of the plateau zokor on the diversity of the plant community after 4 years' period, a series of experiments was conducted in an alpine meadow on the Qinghai-Tibetan Plateau. The contents of C and N and the flow of N in pioneer species were measured and tracked using the ¹⁵N isotope tracer method, and the species diversity on 4-year-old mounds was investigated. The results showed that (1) plateau zokors could influence the plant species on the mounds by creating gaps in the grassland; (2) Elymus nutans and Elsholtzia feddei, with high rates and efficiencies of nutrient absorption and transportation, were more competitive on the newly formed mounds than other species; (3) Elymus nutans played a dominant role in the plant community of the mounds; and (4) plateau zokors did not change the plant diversity after 4 years' period. These findings indicated that species colonizing the mounds experienced a process of competition when gaps were created by the rodents, that species with greater capabilities for resource acquisition and utilization had stronger competitiveness and vice versa, and that after a few years, the plant diversity on the mounds was almost similar to that of the undisturbed grassland.
2

A method for studying social and reproductive behaviour of subterranean rodents in captivity

100%
Zenuto R. R., Vassallo A. I., Busch C.
Acta Theriologica
|
2001
|
tom 46
|
nr 2
A methodology for studying the social and reproductive behaviour of solitary subterranean rodents under laboratory conditions is proposed. A first account of Ctenomys talarum (Thomas, 1898) behaviour is also provided with the aim of evaluating the proposed methodology and to advance presently unknown information on its social behaviour and mating system. The device is a seminatural enclosure, departing from traditional test cages with respect to increased: (1) size, (2) structural complexity, (3) social complexity, and (4) resemblance to natural conditions. It consists of artificial burrows each comprising 3.5 m of tunnel, a resource cage and a nest box, resembling the structural complexity described for C. talarum burrows. Burrows are connected to a common space, which allows social interaction among various individuals. Animals were observed in the seminatural enclosure - 3 females and 2 males, in accordance with sex ratios found in natural populations - for a period of 6 months. We obtained data related to reproductive and social behaviour: marking, aggression, vocalization, courtship and copulation, pregnancy, pup development, and parental care. The proposed system enables the collection of behavioural data as yet unavailable due to the secretive habits and aggressiveness that characterize this group of rodents, coupled with the difficulties associated with simulating subterranean conditions.
3

Geographic variation in vocal signals of Ctenomys pearsoni

100%
Francescoli G.
Acta Theriologica
|
2002
|
tom 47
|
nr 1
The S-type vocalizations of three populations of Ctenomys from Uruguay were compared: two of Ctenomys pearsoni Lessa and Langguth, 1983 from Penino and Relincho and the third from a different karyomorph of the genus (Solis karyomorph). Ten rhythm and 3 frequency variables were used for discriminant analysis. The results showed that a set of nine variables allowed a complete separation of the populations. The two C. pearsoni populations were correctly discriminated from one another using four variables, the differences lying especially in the rhythm domain. Information about the general biology and distribution of the animals suggest that these differences could be explained as a product of chance variations and later fixation of the variants in local populations. The Solis karyomorph was also correctly discriminated from the other populations using four variables, but main frequency seems to play an important role in this case.
4

Strongyloides myopotami in ctenomyid rodents: Transition from semi-aquatic to subterranean life cycle

84%
Rossin M. A., Varela G., Timi J. T.
Acta Parasitologica
|
2009
|
tom 54
|
nr 3
257-262
Strongyloides myopotami, a parasite of Myocastor coypus (nutria or coypu), was found during an extensive parasitological survey carried out on parasitic helminths of 5 species of subterranean rodents (tuco-tucos) belonging to the genus Ctenomys from Argentina and Uruguay. Strongyloides myopotami became known by causing “marsh itch” (also called “nutria itch” or “swimmer’s itch”), a severe rash caused by larvae that enter the skin in humans, and it is recognised as a zoonosis for people handling nutria fur. In the present study S. myopotami was found in 2 of the 5 examined species of Ctenomys (C. talarum from Argentina and C. pearsoni from Uruguay), both inhabiting the vicinity of water courses. Population descriptors of S. myopotami in C. talarum showed that a population of this parasite is well established in this rodent. The development of infective filariform larvae from eggs in the faeces of C. talarum and the prevalence of gravid parasitic females in this host can be considered as evidence of the establishment of a population of S. myopotami independent of the source population parasitizing M. coypus. Therefore, the presence of S. myopotami in these species of tuco-tucos indicates a change from a semi-aquatic to subterranean life cycle. Evidence that tuco-tucos are reservoirs for these nematodes and therefore may be a risk to human health in the areas studied is provided.
5

Parasitism underground: lice (Insecta: Phthiraptera) from Ctenomys talarum (Rodentia: Ctenomyidae) along its coastal distribution in Argentina

84%
Martino N. S., Romero M. D., Malizia A. I.
Acta Parasitologica
|
2015
|
tom 60
|
nr 1
6

What determines the way of deposition of excavated soil in a subterranean rodent?

84%
Skliba J., Sumbera R., Chitaukali W. N.
Acta Theriologica
|
2010
|
tom 55
|
nr 3
271-277
Subterranean rodents continuously extend their burrow systems primarily in search of food, which has an important impact on the ecosystem in which they live. Excavated soil may be pushed either into aboveground mounds or into tunnels underground. Factors affecting the amount of burrowing and the preference of aboveground or underground soil deposition are, nevertheless, little known. We investigated the influence of food supply, soil hardness, and the animal’s body mass on the mode of soil deposition in ten burrow systems of free ranging silvery mole-rats Heliophobius argenteocinereus Peters, 1846. In each burrow system, we estimated the volume of backfilled tunnels and the volume of soil deposited aboveground. The highest amount of variation in these parameters was explained by the interaction of food supply and soil hardness. The ratio of the volume of backfilled tunnels to the volume of mounds was not significantly dependent on any of the explanatory variables. The proportion of backfilled tunnels decreased with the increasing volume of the complete burrow system. We propose that both low food supply and soft soil lead to an increased amount of burrowing, which results in a larger volume of soil deposited both above ground and under ground over a given period of time.
7

Foraging strategy of plateau zokors (Eospalax baileyi Thomas) when collecting food for winter caches

84%
Xie J.-X., Lin G.-H., Zhang T.-Z., Su J. P.
Polish Journal of Ecology
|
2014
|
tom 62
|
nr 1
Subterranean life style is characterized by limited food resource and energy consuming burrow behavior. Subterranean rodents are usually recognized as dietary generalists. In the current study, we investigated the species composition of winter caches of plateau zokors (Eospalax baileyi), and the dissimilarity of species composition in caches and in the vicinity of the burrows. We have made our research in Kobresia dominated vegetation at the altitude 3200 m a.s.l. We used the non-parametric method to test the similarities between the relative dry mass of the plant species within caches and their closed vicinity. This method was based on measures of distance between pairs of individual multivariate observations. Our results revealed that although plateau zokors cached most (60) of the plant species found in the vicinity of their burrow systems (66), the cached dry mass was dominated by a few species. Nine plant species accounted for 80% dry mass of plants present in zokors’ caches, Polygonum viviparum (50%) and other perennial poisonous forbs constitute 70% dry mass of the caches. Results showed that the dissimilarity between the relative dry mass of plant species within caches and in their vicinity was extremely significant (for Bray-Curtis distance measure, R = 0.355, P = 0.000; for Euclidean distance measure R =0.319, P =0.000). These results showed that plateau zokors don’t forage randomly when collecting food for winter caches. We suppose that rather than using a non-selective foraging strategy by dealing with high fiber-content plants, plateau zokors have forged another dietary strategy to meet the energy demands in the evolutionary process: to deal with poisonous forbs.
8

Vocal signals from Ctenomys pearsoni pups

84%
Francescoli G.
Acta Theriologica
|
2001
|
tom 46
|
nr 3
Calls emitted by newborn pups of Ctenomys pearsoni Lessa and Langguth, 1983 away from the nest were frequency modulated succesive notes. The notes were charac­terized by mean maximum frequency under 5165 Hz, with mean main frequency under 2155 Hz, and mean note duration under 0.165 s. Their possible function as contact or distress calls, resulting in recovering to the nest by the mother, is discussed.
9

Redescription and new host record of Paraspidodera uncinata [Rudolphi, 1819] [Nematoda, Aspidoderidae] from the South American subterranean rodent Ctenomys talarum [Rodentia, Octodontidae]

84%
Rossin M. A., Timi J. T., Malizia A. I.
Acta Parasitologica
|
2004
|
tom 49
|
nr 4
Paraspidodera uncinata (Rudolphi, 1819) (Nematoda, Aspidoderidae), a parasite of Neotropical caviids and octodontids, is redescribed based on specimens from the caecum and large intestine of the subterranean rodent Ctenomys talarum Thomas, 1898 (Octodontidae). During 2002, a total of 3,899 nematodes was recovered from eighty one specimens of C. talarum (prevalence 93.8%, mean abundance 51.3) from Mar de Cobo, Buenos Aires Province, Argentina (37°58'S, 57°34'W). In spite of the long list of records of P. uncinata published since its original description in 1819, descriptions available in the literature are scattered and incomplete. Therefore, a number of diagnostic morphological and morphometric features that were omitted in previous descriptions of this species, are given. These are: variability in number and position of caudal papillae in males, presence of caudal papillae in females, as well as descriptions and measurements of corpus, bulb, pharynx, lateral alae, deirids, nerve ring, vagina and uterus. Location of labial papillae and the vulva as well as the length of the left and right spicules are also provided.
10

Use of olfaction for sexual recognition in the subterranean rodent Ctenomys talarum

84%
Fanjul M. S., Zenuto R.R. Busch C.
Acta Theriologica
|
2003
|
tom 48
|
nr 1
The ability of the tuco-tuco Ctenomys talarum Thomas, 1898 to recognize sex by olfactory cues contained in urine, faeces and soiled shavings was tested by using preference tests. Nonbreeding tuco-tucos selected odours from opposite-sex rather than same-sex conspecifics. This pattern differed between sexes: females spent more time sniffing male than female odours for all scent sources whereas males did not show any difference in the time they spent investigating odours of each sex for each tested odour sources. Dissimilarities in odour selections between sexes may be attributed to a different combination of factors involved in olfactory interest for each sex. The function of gender cues recognition is discussed.
11

Female reproductive responses to photoperiod and male odours in the subterranean rodent Ctenomys talarum

67%
Fanjul M. S., Zenuto R. R.
Acta Theriologica
|
2008
|
tom 53
|
nr 1
The tuco-tucoCtenomys talarum Thomas, 1898 is a solitary subterranean rodent that breeds seasonally in coastal sand-dune grasslands from Argentina. We assessed whether short-day photoperiod determines the onset of reproduction by an increase in female’s receptivity and whether male odour interacts with photoperiod as a cue by producing a greater response in receptivity. Receptivity was measured by an increase in the percentage of vaginal epithelial cells, particularly cornified cells. Females were trapped during their non-reproductive season (summer-long days) and randomly assigned to different day-length experimental groups: constant summer (CS), early winter (EW), and natural (NA) photoperiod. We examined the vaginal epithelium using vaginal smears during the first experimental phase (120 days) to test the effect of photoperiod. In the second experimental phase (15 days), we presented the females with male-soiled shavings to test the effect of photoperiod and male odor.Ctenomys talarum females showed some evidence of reproductive responsiveness to photoperiodic cuing. The proportion of epithelial cells peaked earlier in females when winter day-length was advanced than in females under natural photoperiod. Contrary to that expected, male odours did not stimulate female receptivity. These results suggest that, while photoperiod may participate in regulating reproduction, the integration of other environmental and social factors, as well as the identification of bodily conditions that lead to differences in individual response needs further consideration.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.