Immigrant Selection, Predation, and the Distributions of Microtus pennsylvanicus and Blarina brevicauda on Islands

Certain aspects of prey selection were studied in ermines (Mustela erminea) kept in an enclosed arena that simulated a temporary meadow. Four males and eight females were involved in the 12-h experiments. Four types of prey were used: (i) meadow voles (Microtus pennsylvanicus), (ii) deer mice (Peromyscus maniculatus), (iii) short-tailed shrews (Blarina brevicauda), and (iv) young albino rats (Rattus norvegicus). Males were more efficient at catching prey than females, both in number of individuals and number of species captured. Meadow voles and rats were the prey captured most regularly and rapidly by both males and females. Males were more efficient at catching deer mice, but shrews were rarely captured. There was a great similarity in the performance of the four males, but considerable variation was observed among the females. No food preference could be detected in these experiments. The results are discussed in relation to food preferences observed during studies of ermines in a natural environment.[Journal translation]

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Dimorphisme sexuel et régime alimentaire de l'hermine dans un agrosystème du Québec

Canadian Journal of Zoology ◽

10.1139/z84-087 ◽

1984 ◽

Vol 62 (4) ◽

pp. 594-600 ◽

Cited By ~ 4

Author(s):

Michel Raymond ◽

Jean-Marie Bergeron ◽

Yves Plante

Keyword(s):

Feeding Habits ◽

Microtus Pennsylvanicus ◽

Feeding Strategies ◽

Important Food ◽

Meadow Voles ◽

Blarina Brevicauda ◽

Food Components ◽

Dimorphisme Sexuel ◽

Sorex Cinereus ◽

Males And Females

Variations in the diet of the ermin (Mustela erminea) were studied from 1978 to 1980 in relation to the relative availability of meadow voles (Microtus pennsylvanicus), the dominant mammal of Southern Quebec agrosystems. The analysis of 328 ermine scat samples showed that the vole does constitute the main prey item, but that the masked shrew (Sorex cinereus), the short-tailed shrew (Blarina brevicauda), and various birds are also important food components. Male ermins have more flexible feeding habits than females, who eat mostly meadow voles whatever their relative abundance. Both males and females fail to make full use of the shrews and avoid prey that weigh more than 50 g. Overlap of their realized alimentary niches is thus considerable except when small mammals are scarce. In that case, males and females use different feeding strategies; however, the hypothesis suggested by J. H. Brown and R. C. Lasiewsky (1972. Ecology, 53: 939–943) does not seem to be confirmed. The evolution of size dimorphism in this small mustelid is discussed; our results confirm the intra-sexual selection hypothesis proposed independantly by S. Erlinge (1979. Oikos, 33: 233–245) and P. J. Moors (1980. Oikos, 34: 147–158).[Journal translation]

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Ectoparasites and other associates of some insectivores and rodents from New Brunswick

Canadian Journal of Zoology ◽

10.1139/z82-357 ◽

1982 ◽

Vol 60 (11) ◽

pp. 2787-2797 ◽

Cited By ~ 6

Author(s):

John O. Whitaker Jr ◽

Thomas W. French

Keyword(s):

New Brunswick ◽

Peromyscus Maniculatus ◽

Microtus Pennsylvanicus ◽

Clethrionomys Gapperi ◽

Blarina Brevicauda ◽

Tamias Striatus ◽

Host Individual ◽

Napaeozapus Insignis ◽

Sorex Cinereus ◽

Provincial Park

Ectoparasites and other associates were examined from seven species of insectivores and nine species of rodents from Mount Carleton Provincial Park, New Brunswick. The most abundant forms found were (at least 2.0 per host individual) the following: Orycteroxenus soricis and Amorphacarus hengererorum on Sorex cinereus and on Sorex (Microsorex) hoyi; A. hengererorum and O. soricis on Sorex fumeus; O. soricis, Miyatrombicula esoensis, and Ixodes angustus on Sorex gaspensis; O. soricis, I. angustus, Pygmephorus horridus, and Protomyobia americana on Blarina brevicauda; M. esoensis, Protomyobia claparedei, and Glycyphagus hypudaei on Sorex palustris; Orycteroxenus canadensis, O. soricis, P. horridus, G. hypudaei, Ctenophthalmus pseudagyrtes, and Haemogamasus ambulans on Condylura cristata. More abundant ectoparasites of the rodents were as follows: G. hypudaei, Listrophorus mexicanus, M. esoensis, Neotrombicula harperi, and Radfordia lemnina on Clethrionomys gapperi; G. hypudaei, L. mexicanus, M. esoensis, N. harperi, and Laelaps kochi on Microtus chrotorrhinus; L. mexicanus, G. hypudaei, Radfordia hylandi, Laelaps alaskensis, M. esoensis, Polyplax alaskensis, L. kochi, N. harperi, and Myocoptes j. japonensis on Microtus pennsylvanicus; Listrophorus synaptomys, Hoplopleura acanthopus, L. alaskensis, G. hypudaei, M. esoensis, I. angustus, R. hylandi, and N. harperi on Synaptomys cooperi; all of these except the last one on Synaptomys borealis; M. esoensis on Peromyscus maniculatus; Dermacarus newyorkensis on Zapus hudsonius; D. newyorkensis, N. harperi, Radfordia ewingi, and G. hypudaei on Napaeozapus insignis; Dermacarus hylandi, N. harperi, Megabothris acerbus, and M. esoensis on Tamias striatus.

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Trypanosomes of small mammals in southern Ontario

Canadian Journal of Zoology ◽

10.1139/z80-079 ◽

1980 ◽

Vol 58 (4) ◽

pp. 567-571 ◽

Cited By ~ 3

Author(s):

P. T. K. Woo ◽

D. R. Grant ◽

L. McLean

Keyword(s):

Small Mammals ◽

Mus Musculus ◽

Peromyscus Maniculatus ◽

Original Description ◽

Microtus Pennsylvanicus ◽

Blarina Brevicauda ◽

Tamias Striatus ◽

Southern Ontario

Using the haematocrit centrifuge technique, 53 of 619 small mammals from seven areas in southern Ontario were found to be infected with three species of trypanosomes. Trypanosoma microti was found in 10 of 374 (2.7%) Microtus pennsylvanicus examined from two of five locations. Thirty-five of 102 (34%) of Tamias striatus from one area were infected with Trypanosoma tamiasi and over 94% (33 of 35) of the infected animals were juveniles. This would indicate that the trypanosome is primarily a parasite of juveniles. A trypanosome which was tentatively identified as Trypanosoma soricis was found in 8 of 36 (22%) Blarina brevicauda; it was recorded from two of four areas where the shrews were caught. A detailed description of the trypanosome was given because the original description was inadequate. No trypanosome was found in 74 Peromyscus maniculatus, 31 Mus musculus, and 2 Zapus hudsonius examined.

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Effect of Blarina brevicauda on trap response of Microtus pennsylvanicus

Canadian Journal of Zoology ◽

10.1139/z82-059 ◽

1982 ◽

Vol 60 (3) ◽

pp. 438-442 ◽

Cited By ~ 14

Author(s):

Rudy Boonstra ◽

F. Helen Rodd ◽

David J. Carleton

Keyword(s):

Mus Musculus ◽

Peromyscus Leucopus ◽

Microtus Pennsylvanicus ◽

Rodent Species ◽

Lower Probability ◽

Blarina Brevicauda

The response of Microtus pennsylvanicus to traps with or without various prior occupants is described. Microtus were most frequently captured in traps previously visited by Microtus, but they showed a significant avoidance of traps previously visited by Blarina brevicauda. However, the probability of entry into such traps was no lower than into traps previously visited by other rodent species (Mus musculus, Peromyscus leucopus, or Zapus hudsonicus). There was an even lower probability of entry into traps which were previously empty. Blarina had a significantly higher probability of entering traps previously capturing Blarina than traps previously capturing Microtus or no one. We conclude that this evidence gives no support for the hypothesis that Blarina is a significant predator of Microtus pennsylvanicus.

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An 11-year study of small mammal populations at Mont St. Hilaire, Quebec

Canadian Journal of Zoology ◽

10.1139/z76-249 ◽

1976 ◽

Vol 54 (12) ◽

pp. 2156-2173 ◽

Cited By ~ 27

Author(s):

P. R. Grant

Keyword(s):

Small Mammals ◽

Small Mammal ◽

Sugar Maple ◽

Deciduous Forest ◽

Beech Forest ◽

Microtus Pennsylvanicus ◽

Blarina Brevicauda ◽

The Relationship ◽

Range Of Variation ◽

Relevant Factors

Mont St. Hilaire has an area of about 10 km2 covered by sugar maple and beech forest. Longworth traps were used on 46 grids from 1966 to 1976 in the snow-free period, mainly in June. One thousand and fifty-one individuals of 10 species of small mammals were captured. Two-thirds of these were Peromyscus, mainly P. maniculatus. Six female and one male Microtus pennsylvanicus were captured, all at least 1000 m from the nearest grassland, which is the usual habitat of this species.Within the forest the species apparently do not segregate into different habitats. Distribution, as measured by the number of grids on which each species was captured, is a function of total numbers. The relationship holds intraspecifically and interspecifically. Peromyscus (species combined), Clethrionomys gapperi, and Blarina brevicauda varied in June numbers from year to year. The range of variation was greatest for Peromyscus. Numbers of Peromyscus and Clethrionomys did not vary synchronously, and neither showed evidence of a regular periodicity in their fluctuations. Regular periodicity in fluctuations appears to be more prevalent in boreal forest populations than in deciduous forest populations. Some of the relevant factors are discussed.Le Mont Saint-Hilaire a une superficie d'environ 10 km2 et est recouvert d'une forêt d'érables à sucre et de hêtres. On a utilisé des pièges Longworth dans 46 sections d'un quadrillage, de 1966 à 1976, durant la période sans neige, surtout en juin. On a recueilli de cette façon 1051 petits mammifères appartenant à 10 espèces. Les deux-tiers de ces animaux appartiennent au genre Peromyscus, et ce sont surtout des P. maniculatus. Six femelles et un mâle de Microtus pennsylvanicus ont été capturés, tous à au moins 1000 m de la prairie la plus proche, environnement habituel de cette espèce.

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