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1

Species richness relative abundances and habitat use in local assemblages of Sorex shrews in Eurasian boreal forests

100%
Sheftel B. I., Hanski I.
Acta Theriologica. Supplement
|
2002
|
tom 47
|
nr 1
Using a large body of observational data on the occurrence of Sorex shrews in boreal forests, we test two models that predict the structure of small mammal com­munities along a gradient of increasing habitat productivity. Tilman's (1982) model predicts a humped curve of species richness along productivity gradients. In contrast, we found a linear increase in species richness with increasing logarithm of the pooled density of shrews, which we use as a measure of habitat productivity for shrews. The model of Hanski and Kaikusalo (1989) assumes a trade-off between exploitative and interference competitive abilities, and it predicts that the size structure of small mammal communities should shift from the dominance of small species (superior in exploitative competition) in unproductive habitats to the dominance of large species (superior in interference competition) in productive habitats. Shrew assemblages show such a shift. Though it is not possible to draw definite conclusions about the role of interspecific competition from our observational data, the changing size structure of local shrew assemblages with increasing habitat productivity is a predictable feature of their community structure.
2

Why are shrews so small? The costs and benefits of small size in Northern temperate Sorex species in the context of foraging habits and prey supply

100%
Churchfield S.
Acta Theriologica. Supplement
|
2002
|
tom 47
|
nr 1
This paper reviews the ecological advantages and disadvantages of very small body size in Sorex Linnaeus, 1758 shrews living at high latitudes with cold winters. It examines the feeding and foraging habits of small and large shrews in the context of prey supply, location of winter prey sources, territory requirements, habitat exploitation and inter-specific competition. Data on feeding habits and prey availability show that the major costs of small size are a reduction in food niche breadth and prey biomass resulting from restrictions on the type and size of prey eaten, and large territory requirements. Major benefits of small size are the ability to subsist on small, numerous and accessible arthropods with high encounter rates, enabling coexistence with larger congeners and exploitation of low-productivity habitats less suitable for larger earthworm-eating species. Small size, coupled with low per capita food intake, is shown to be of special adaptive value in cold winters when food supply is restricted mostly to small arthropods, and earthworms are few.
3

Habitat preferences of four sympatric species of shrews

100%
Rychlik L.
Acta Theriologica. Supplement
|
2000
|
tom 45
|
nr 1
4

Home ranges of sympatric soricine shrews in Hokkaido, Japan

100%
Ohdachi S.
Acta Theriologica
|
1992
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tom 37
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nr 1-2
Home ranges of sympatric shrews, Sorex unguiculatus Dobson, 1890 S. gracillimus Thomas, 1907 and S. caecutiens Thomas, 1907 were studied by a mark-recepture method during the non-snow covered seasons in northern Hokkaido, 1988 and 1989. Home range size of S. unguiculatus, the largest species (15.1 g for adult males), was not significantly different from that of S. gracillimus, the smallest species (4.4 g for adult males). Both S. unguiculatus and S. gracillimus had more exclusive home ranges within species than between species. Tolerance of home range overlap may be related to the reduction of dietary overlap. No reliable information of home range for S. caecutiens was obtained in this study.
5

Developmental stability and population dynamics of shrews Sorex in Central Siberia

84%
Zakharov V. M., Demin D. V., Baranov A. S., Borisov V. I., Valetsky A. V., Sheftel B. I.
Acta Theriologica. Supplement
|
1997
|
nr 04
We examined temporal variation in developmental stability measured by fluctuating asymmetry of 10 skull characters in sympatric populations of three shrew species: Sorex araneus Linnaeus, 1758, S. caecutiens Laxmann, 1788 and S. tundrensis Merriam, 1900 from one locality in central Siberia with a high four-year-cycle of small mammals. Simultaneous significant changes in developmental stability have been revealed during a population cycle 1986-1989 for all three, most abundant shrew species in the locality. The highest asymmetry for all these species occurred in the year of maximal density. Similar high asymmetry was found for the separate samples of two other species: S. roboratus Hollister, 1913 and S. isodon Turov, 1924, collected in a peak year 1989 only. The maximal density in 1989 corresponded to the lowest level of breeding success and developmental stability and, vice versa, minimal density in 1986 was accompanied by the highest level of breeding success and developmental stability. These data suggest that overpopulation caused by high density of various small mammals adversely affects an organism's condition. Thus, developmental stability may be used to monitor possible changes in a population even in cases where direct estimation of fitness is difficult.
6

Aging and cohort dynamics in Sorex shrews

84%
Gliwicz J., Jancewicz E.
Acta Theriologica
|
2001
|
tom 46
|
nr 3
In the shrews Sorex araneus Linnaeus, 1758 and S. minutus Linnaeus, 1766 a short period of fast post-natal development in the nest is followed by a longer summer period of developmental stasis and then by autumn regression. The aim of this paper has been to test whether this period of developmental stability also is accompanied by inhibited development of the eye lens - the most continuously growing organ of the mammalian body. If it is not, then can this be used as an age indicator in studies on shrews, and can it serve in distinguishing seasonal cohorts of young born in consecutive summer months? This aspect was examined on material comprising dead shrews collected from live traps and pitfalls set for rodent research in the marshy habitat of a river valley in Białowieża Forest, Poland, in 1997-1999. In fact, the eye lens in shrews was shown to increase in size continuously; therefore it may be used as a reliable age indicator. Body mass of weaned young shrews also continued to increase slowly with age until autumn. On the basis of the distribution of individuals in successive lens-mass classes, three age groups (cohorts) of young could be distinguished each season in the S. araneus popu­lation, and two in S. minutus. In the former species, consistent patterns to the relative abundance of the three seasonal cohorts were observed. The consequences of time of birth on individual fitness in Sorex shrews are discussed.
7

Does the reduction of locomotor activity serve as an aggression avoidance mechanism in shrews [Soricidae]?

84%
Zwolak R., Rychlik L.
Electronic Journal of Polish Agricultural Universities. Series Biology
|
2004
|
tom 07
|
nr 2
The hypothesis, that shrews avoid intra- and interspecific aggression through a reduction of their loco-motor activity, was tested. In 55 neutral arena tests (each of 30-min-duration), 10 subadult individuals of Sorex minutus, 14 of S. araneus, 9 (including 1 adult male) of Neomys anomalus, and 13 of N. fodiens were used. Loco-motor activity and sum of conflicts (attacks, chases, escapes and threats) in 1st-5th minutes of interactions (phase I) and 10th-15th minutes (phase II) were compared. In all the species, both in intra- and interspecific interactions, a reduction of mobility between phases I and II was observed (in 6 out of 16 comparisons the difference was statistically significant, and in the 7th comparison it was fairly significant). The highest reduction of activity was observed in the smallest S. minutus, and the lowest reduction (no difference was significant) in the largest, dominating N. fodiens.
8

Comparative chromosome analysis in three Sorex species: S.raddei, S.minutus and S.caecutiens

84%
Biltueva L. S., Perelman P. L., Polyakov A. V., Zima J., Dannelid E., Borodin P. M., Graphodatsky A. S.
Acta Theriologica. Supplement
|
2000
|
tom 45
|
nr 1
9

Comparison of population characteristics of three species of shrews and the shrew-mole in habitats with different amounts of coarse woody debris

84%
Lee S. D.
Acta Theriologica
|
1995
|
tom 40
|
nr 4
Seasonal fluctuation and its causes for three species of Sorex shrews and the shrew-mole Neurotrichus gibbsii Baird, 1857 were investigated in three sites with high amounts of coarse woody debris (CWD) and three sites with low amounts of CWD in managed forests of western Washington, USA. Sorex trowbridgii Baird, 1857 was more abundant on sites with high amounts of CWD (captures per 100 trapping nights), and had higher reproductive rates than in sites with low amounts of CWD. Sorex monticolus Merriam, 1890 showed higher reproductive rates on sites with high amount of CWD. Population of Sorex vagrans Baird, 1857 fluctuated greater and abundance was higher in sites with low amounts of CWD. Most reproduction occurred from January to April and declined rapidly in May. Previous studies also have shown an early onset of breeding in Coastal California and Oregon. It seems that local species of soricids and Neurotrichus gibbsii gain reproductive benefits by breeding primarily in January through May.
10

Habitat and food preferences in a guild of insectivorous mammals in the Western Pyrenees

67%
Castien E., Gosalbez J.
Acta Theriologica
|
1999
|
tom 44
|
nr 1
The use of trophic and spatial resources in a guild composed of five species of insectivorous mammals (Galemys pyrenaicus, Talpa europaea, Neomys fodiens, Sorex coronatus, and Sorex minutus) was studied. The characteristics of the macrohabitat were studied based on data from trap lines. Those pertaining to the microhabitat were examined through a study of the sites where each animal was caught. The diet was studied by analysis of the digestive tract as well as the availability of resources in various microhabitats. The results show a high level of segregation in the use of trophic resources. The microhabitat used on the ground surface has a low level of segregation among the shrews. A comparison of the diet of each species with the results from the invertebrate sampling carried out in different microhabitats (water, subsoil, humus, ground surface) shows that there is a relation between the food consumed and its availability in the microhabitats utilised by each species. This study suggests that the coexistence among the insectivorous species studied may be ex­plained by the use of the microhabitat and diet segregation. The differences in diet would be a consequence of the use of different microhabitats. Servicio de Conservacion de la Biodiversidad, Gobierno de Navarra, C.I Alhóndiga 1, 31002 Pamplona, Spain (EC); Departament de Biologia Animal, Facultat de Biologia, Universität de Barcelona, Avgda. Diagonal 645, 08028 Barcelona, Spain (JG)
11

Overlap of temporal niches among four sympatric species of shrews

67%
Rychlik L.
Acta Theriologica
|
2005
|
tom 50
|
nr 2
Hypotheses about the dependence of circadian activity from metabolic rate and the segregation of temporal niches among competing species were verified by the study of activity patterns in a shrew community of two semiaquatic species,Neomys anomalus Cabrera, 1907 andN. fodiens (Pennant, 1771), and two terrestrial species,Sorex araneus Linnaeus, 1758 andS. minutus Linnaeus, 1766, co-existing in wet habitats of Białowieża Forest (E Poland). In ten trapping sessions, performed in early summer between 1991 and 2000, traps were open 24 hours continuously and patrolled at 1:00, 5:00, 10:00, 15:00, and 20:00. All the shrew species were most active between 20:00 and 1:00, and least active around mid-day (10:00–15:00). However, activity of the twoSorex species was lower than that of the twoNeomys species in the period 20:00–1:00, but higher in the period 15:00–20:00. BothNeomys species displayed clearly nocturnal, unimodal patterns of activity. In contrast, activity of bothSorex species was relatively evenly distributed over 24 hours and they increased their activity earlier (ie after 15:00) than bothNeomys species (after 20:00). These results confirm the idea that small shrew species with higher metabolic rate have more frequent and more equally distributed activity bouts than large species. Overlap of temporal niches was the highest within genera (99.29% between bothNeomys species and 98.36% between bothSorex species), the lowest betweenN. fodiens andS. araneus (88.26%) andS. minutus (89.34%), and intermediate betweenN. anomalus and bothSorex species (91.78 and 93.34%, respectively). Such high interspecific overlaps in activity suggest a joint-action of other mechanisms that separate ecological niches of these species also in other dimensions (eg food, microhabitat).
12

Cestodes of shrews [Insectivora, Soricidae] from the Magadan region, North-East Siberia

67%
Novikov M. V.
Acta Parasitologica
|
1995
|
tom 40
|
nr 1
Five species of Sorex shrews (S. caecutiens, S. isodon, S. daphaenodon, S. gracillimus and S. minutissimus) were studied for helminths in North-East Asia. 11 cestode species were described. For 5 of them S. isodon and S. gracillimus were recorded as new hosts. Geographical distribution and community structure of found cestodes are briefly analyzed. A role of different shrew species in the helminth circulation is also discussed.
13

Distribution of small mammals along a deforestation gradient in southern Gansu, central China

67%
Giraudoux P., Quere J. P., Delattre P., Bao G., Wang X., Shi D., Vuitton D., Craig P. S.
Acta Theriologica
|
1998
|
tom 43
|
nr 4
Small mammals were surveyed along a deforestation gradient in southern Gansu, China (2300-2600 m altitude), a high endemicity area for human alveolar echino­coccosis. Rodent distribution was assessed using removal trapping in six habitat types from timbered forest to farmland and villages, by index transects, and by the collection of specimens by local people, Species captured were 2 shrews: Anourosorex squamipes, Sorex sinalis-, 12 rodents: Eozapus setchuanus, Microtus limnophilus, Cricetulus long/- caudatus, Tscherskia triton, Apodemus agrarius, Apodemus draco, Apodemus penin- sulae, Micromys minutus, Mus muscitlus, Rattus noruegicus, Niviventer confucianus, Myospalax fontanieri\ and 1 lagomorph Ockotona thibetana. On the basis of trap success four rodent assemblages were recognized. Species richness decreases after deforestation, especially in the intermediate stage (scrubland-grassland).
14

Differentiation and ultrastructure of the oncospheral envelopes in the hymenolepidid cestode Staphylocystoides stefanskii [Zarnowski, 1954]

67%
Tkach V. V., Swiderski Z.
Acta Parasitologica
|
1998
|
tom 43
|
nr 4
Ultrastructure of the oncospheral envelopes in developing and fully formed eggs of the hymenolepidid cestode, Staphylocystoides stefanskii (Zarnowski, 1954), is described. The uterus in this species is saccular, with deep infoldings of the uterine wall which form pocket-like structures. The uterine wall is composed by a flat syncytial uterine epithelium containing elongated nuclei with prominent nucleoli. The differentiating and mature oncospheres are surrounded by three envelopes: (1) an outer envelope; (2) an inner envelope consisting of three layers - an extraembryophoral cytoplasmic layer, a dense and relatively thick embryophore, and an intraembryophoral cytoplasmic layer; (3) a thin oncospheral membrane, surrounding the oncosphere. The outer envelope usually contains 2 nuclei in the preoncospheral stage, however, no nuclei were observed in this layer in the fully formed eggs. The inner envelope shows in sectioned material 1-2 nuclei in its intraembryophoral layer. The extraembryophoral layer of the inner envelope increases in thickness during the egg maturation. The embryophore was initially discontinuous, formed by the blocks of the electron-dense substance, and situated directly under the outer limiting membrane of the inner envelope. Later the neighbouring blocks fuse together and finally produce a continuous dense layer of embryophore. The embryophore remains slightly vacuolised for some time and finally forms a thick homogeneously electron-dense layer. The oncospheral membrane appears striated on the high-power micrographs. The ultrastructure of oncospheral envelopes in S. stefanskii is compared with those in other mammalian hymenolepidids.
15

Fossil remains of shrews (Soricomorpha: Soricidae) and desmans (Talpidae: Desmaninae) from Norfolk, England, with biostratigraphic implications for the Plio-Pleistocene boundary in East Anglia

59%
Harrison D. L., Parfitt S.A. S. A.
Acta Zoologica Cracoviensia. Ser.A Vertebrata
|
2009
|
tom 52A
|
nr 1-2
16

Factors influencing perceived community structure in nearctic forest small mammals

59%
Kirkland G. L., Sheppard P. K., Shaughnessy M. J., Woleslagle B. A.
Acta Theriologica
|
1998
|
tom 43
|
nr 2
Arrays of pitfalls and drift fences were deployed in five deciduous forest habitats in southcentral Pennsylvania to assess the characteristics, and temporal and spatial dynamics of forest small-mammal communities, and to determine the impact of precipi­tation, sampling method, and length of sampling period on perceived small-mammal abundance and community structure. Results revealed that soricid assemblages were more diverse and generally more abundant than rodent assemblages, which were dominated by the white-footed mouse Peromyscus leucopus. Precipitation dramatically increased the capture rates of shrews; the response was less pronounced in rodents. Individual species responded independently to precipitation. The response was more pronounced in three species of arvicoline rodents (Clethrionomys gapperi, Microtus pinetorum, and M. pennsylvanicus) than in P. leucopus, a sigmodontine. Comparisons of sampling with pitfalls and Museum Special snap-traps, with and without drift fencing, revealed that arrays of pitfalls with drift fences produced significantly higher capture rates for all small mammals, shrews, rodents, and P. leucopus, greater num­bers of species, and higher Shannon indices than other sampling methods, Comparison of the results of sampling for 3, 5, 7, and 10 days revealed that extending sampling to 7 or more days yielded significantly more species, higher Shannon indices, and greater numbers of individuals than sampling for less than 7 days.
17

Heteroxenous Coccidia [Apicomplexa: Sarcocystidae] in the populations of their final and intermediate hosts: European buzzard and small mammals

59%
Svobodova M., Vorisek P., Votypka J., Weidinger K.
Acta Protozoologica
|
2004
|
tom 43
|
nr 3
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