Dicrostonyx groenlandicus: Cassola, F.

2016 ◽  
Author(s):  
Keyword(s):  
Dicrostonyx Groenlandicus

Differences in behavior help to explain lemming coexistence

2019 ◽  
Vol 100 (4) ◽  
pp. 1211-1220 ◽  
Author(s):  
Douglas W Morris ◽  
Angélique Dupuch ◽  
MaryJane Moses ◽  
Kaylee Busniuk ◽  
Helen Otterman
Keyword(s):  
Open Field ◽  
Exploratory Behavior ◽  
Behavioral Response ◽  
Habitat Preferences ◽  
Canadian Arctic ◽  
Field Tests ◽  
Repeated Testing ◽  
Dicrostonyx Groenlandicus ◽  
Components Analysis ◽  
Innate Behaviors

Abstract Collared (Dicrostonyx groenlandicus) and brown (Lemmus trimucronatus) lemmings coexist in tundra habitats across much of the middle and lower Canadian arctic. Their coexistence, and response to predation risk, appears mediated by behavior. We analyzed field-collected videos of open-field tests to assess potential differences in innate behaviors between the two species. Collared lemmings were less active and exhibited less exploratory behavior than did brown lemmings, which were more active under cover than in the open. Similar behaviors scaling along axes of activity and curiosity were revealed by principal components analysis. Each axis defined different aspects of brown lemming personality, but repeated testing of the same individuals yielded a striking dependence of their behavioral response on open-field treatments. Even so, the differences between species in behavior correlate well with their habitat preferences that resolve competition and govern their coexistence.

Thermoregulation, growth, and reproduction in Alaskan collared lemmings: role of short day and cold

1991 ◽  
Vol 261 (3) ◽  
pp. R522-R530 ◽  
Author(s):  
H. A. Maier ◽  
D. D. Feist
Keyword(s):  
Food Intake ◽  
Thermal Conductance ◽  
Reproductive Condition ◽  
Reproductive Morphology ◽  
Short Day ◽  
Long Day ◽  
Dicrostonyx Groenlandicus ◽  
Before And After ◽  
Growth And Reproduction

To assess factors controlling seasonal thermoregulatory and reproductive changes, collared lemmings (Dicrostonyx groenlandicus) were exposed for 16 wk to long day (LD, 22 h light: 2 h dark) and warm (15 +/- 3 degrees C), LD and cold (1 +/- 0.5 degrees C), short day (SD, 4 h light: 20 h dark) and warm, SD and cold or acclimatized to outdoor winter conditions (OUT). Hair length and color, body mass, and food intake were monitored weekly. Resting metabolic rates (RMR) and nonshivering thermogenesis (NST) were estimated several times by measuring oxygen consumption before and after norepinephrine injections. Body composition and reproductive condition were determined at the end of the experiment. SD and OUT groups had a 15.8% lower (P less than 0.01) RMR at 7 degrees C than the LD groups. Lower thermal conductance in SD and OUT animals appears due to molt to white winter pelage, which occurred by week 3 in SD but not in LD groups. Neither SD, cold, nor OUT altered NST or reproductive morphology. SD-exposed lemmings showed 19.2% greater growth than those in LD, resulting primarily from a 29.2 and 15.0% increase in lean and ash components, respectively. Cold exposure increased food intake by 34.7%. Results suggest that the pineal gland, which mediates SD effects, may influence molt and growth but not NST or reproductive morphology.

Pre- and postnatal effects of photoperiod on collared lemmings (Dicrostonyx groenlandicus)

1994 ◽  
Vol 267 (4) ◽  
pp. R879-R887 ◽  
Author(s):  
B. A. Gower ◽  
T. R. Nagy ◽  
M. H. Stetson
Keyword(s):  
Subsequent Development ◽  
Serum Prolactin ◽  
Hair Length ◽  
Dark Cycle ◽  
Guard Hair ◽  
Short Day ◽  
Dicrostonyx Groenlandicus ◽  
Offspring Growth ◽  
Pelage Color ◽  
Long Photoperiod

We investigated the hypothesis that photoperiod information received during the prenatal and/or early postnatal periods influences subsequent development in collared lemmings. Pregnant lemmings were exposed to either a short [8:16-h light-dark cycle (8:16)] or long (22:2) photoperiod throughout gestation. On the day of birth, pups were cross-fostered to dams housed in either short or long photoperiod. After an 11-day experimental lactational period (LACT), all animals were transferred to an intermediate photoperiod (16:8), the response to which depends on prior photoperiod exposure. Pups remained on this photoperiod until death at postnatal day 90. Information received during gestation (GEST) influenced offspring growth, pelage color, guard hair length, presence of the bifid claw at weaning, testes mass at 10 wk postweaning, and serum prolactin (PRL). Parameters measured at weaning reflected directly the photoperiod experienced during GEST (e.g., short-day GEST pups had white pelage). Conversely, parameters measured at 10 wk postweaning reflected the change in photoperiod experienced between GEST and 16:8 (e.g., short-day GEST young had gray pelage, indicative of an increase in photoperiod). Information received during LACT influenced growth and the presence of the bifid claw at weaning.

Phylogeography and mitochondrial DNA (mtDNA) diversity in North American collared lemmings (Dicrostonyx groenlandicus)

2000 ◽  
Vol 9 (3) ◽  
pp. 329-337 ◽  
Author(s):  
D. Ehrich ◽  
V. B. Fedorov ◽  
N. C. Stenseth ◽  
C. J. Krebs ◽  
A. Kenney
Keyword(s):  
Mitochondrial Dna ◽  
North American ◽  
Dicrostonyx Groenlandicus ◽  
Mtdna Diversity

Dauerlarvae of Pelodera strongyloides (Schneider, 1860) (Nematoda: Rhabditidae) in the conjunctival sacs of lemmings

1978 ◽  
Vol 56 (10) ◽  
pp. 2117-2121 ◽  
Author(s):  
G. M. Cliff ◽  
R. C. Anderson ◽  
F. F. Mallory
Keyword(s):  
Apparent Effect ◽  
Dicrostonyx Groenlandicus ◽  
First Time

Dauerlarvae of Pelodera strongyloides (Schneider, 1860) Schneider, 1866 were found for the first time in the conjunctival sacs of Dicrostonyx groenlandicus (Traill) and Lemmus trimucronatus (Richardson). Prevalence of dauerlarvae was significantly higher in D. groenlandicus than in L. trimucronatus. The larvae were cultured and populations of P. strongyloides were obtained. Dauerlarvae obtained from the cultures were transmitted to various rodents in the laboratory. Larvae remained in the conjunctival sac for a maximum of 5 days. They had no apparent effect on rodents and were not morphologically different from those reared on agar.

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