Molt and its control in the varying lemming, Dicrostonyx groenlandicus. by William Fredrick Jacobson Download PDF EPUB FB2
The northern collared lemming or Nearctic collared lemming (Dicrostonyx groenlandicus), sometimes called the Peary Land collared lemming in Canada, is a small North American one time, it was considered to be a subspecies of the Arctic lemming (Dicrostonyx torquatus).Some sources believe several other species of collared lemmings Dicrostonyx groenlandicus.
book in North America are actually subspecies of Class: Mammalia. Reiter RJ, Guerrero JM, and Santana C () Nocturnal increase in pineal melatonin production in two lemming species, Dicrostonyx hudsonius and D.
groenlandicus. Gen Comp Endocrinol - Cited by: Anim. Behav.,16, BEHAVIOURAL BIOLOGY OF THE COLLARED LEMMING DICROSTONYX GROENLANDICUS (TRAILL): II. SEXUAL BEHAVIOUR BY EDWIN M. BANKS Department of Zoology, University of Illinois, Urbana, Ill., The collared lemming of North America occurs throughout the tundra of Alaska, Canada and Greenland (Hall & Kelson, ).Cited by: Role of prolactin and the gonads in seasonal physiological changes in the collared lemming (Dicrostonyx groenlandicus) Article (PDF Available) in Journal of Experimental Zoology (2) Development of collared lemmings,Dicrostonyx groenlandicus, is influenced by pre- and postweaning photoperiods Article (PDF Available) in Journal of Experimental Zoology (5) December.
Collared lemmings, Dicrostonyx groenlandicus, maintained in the laboratory under short-day photoperiods (2 h light: 22 h dark) grew faster than their cohorts kept under long-day photoperiods (22 h.
Behavioural Biology of the Collared Lemming [Dicrostonyx groenlandicus An attempt was made to determine the communicative function of each sound by correlating its occurrence with twenty previously defined non-vocal acts and postures and by observing responses of other lemmings to the calls.
Detailed quantitative analysis was applied to the. Control region diversity in the common hamster was found to be lower than in other murine species e.g. striped field mouse Apodemus agrarius but was in the range of lemming populations Dicrostonyx.
Differences between Lemmus and Dicrostonyx are determined by secondary compounds and the physical characteristics of the plant species preferred by each. Comparison of ingestion rates and digestibility coefficients indicate that Dicrostonyx has a greater capacity than Lemmus in dealing with the negative characteristics of plants, such as.
From toa field study of reproductive strategies of Lemmus sibiricus and Dicrostonyx groenlandicus in high-arctic tundra was undertaken at Igloolik Island and the Melville Peninsula, Northwest Territories. Both species of lemmings were scarce in and and increased rapidly in abundance in and Milton H.
Stetson's research works with 3, citations and 1, reads, including: Photoperiod effects on body mass, body composition, growth hormone, and thyroid hormones in male collared. The Arctic fox ( Kg) is ther- moneutral during the winter at 0. The smaller varying hare (=;lKg) is about x BMR in the summer and x BMR during the winter at 0 (see Hart et al., ).
In the summer, energy expendi- ture of the collared lemming ( Kg) is x BMR whereas in the winter at 0 its energy expendi- ture is just about 3. From the standpoint of water balance the collared lemming (Dicrostonyx groenlandicus) has a higher total body water content (71, vs 61%) than the tun- dra vole.
Water turnover is slightly faster in the vole but both species have much higher turnover rates than low temperate desert species that have been studied (Holleman & Dieterich, ). In Greenland, the only potential IH is the Greenland (collared) lemming (Dicrostonyx groenlandicus). However, field and laboratory studies indicate that the collared lemming, despite being a close relation to the brown lemming (Lemmus trimucronatus), is not a suitable host for E.
multilocularis (Ohbayashi et al., ; Rausch, ). A lemming is a small rodent, usually found in or near the Arctic in tundra gs make up the subfamily Arvicolinae (also known as Microtinae) together with voles and muskrats, which form part of the superfamily Muroidea, which also includes rats, mice, hamsters, and popular culture, a longstanding myth holds that they commit mass suicide.
the varying lemming, Dicrostonyx groenlandicus, in nature and captivity. Arctic, 7: The requirements and biology of the collared lemming Dicrostonyx torquatus Pallas,in captivity. Saugetierk. Mitteil., 4: his methods did not permit control of animals entering the experiment.
Collared lemming: Dicrostonyx groenlandicus: Prey: N Canada, N Alaska, N and NE Greenland, some Arctic islands The strong genetic control of SCC moult has long been evident from translocation experiments and common garden studies.
Inter‐sexual differences in moult phenology in the spring are likely related to varying levels of gonadal. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class.
No classification system is universally accepted; McKenna & Bell () and Wilson & Reader () provide useful recent compendiums. George Gaylord Simpson's "Principles of Classification and a Classification of Mammals" (AMNH Bulletin v. 85, ) provides systematics of mammal origins.
GOWER BA, NAGY TR AND STETSON MH. Role of prolactin and the gonads in seasonal physiological changes in the collared lemming (Dicrostonyx groenlandicus). J Exp Zool [ Links ] HETH G, BEILES A AND NEVO E.
The highly variable moulting costs can be explained by interactions between moulting strategies, life histories and environmental conditions. Photoperiodic effects on post-weaning growth and food consumption in the collared lemming Dicrostonyx groenlandicus.
Control of molt in birds: association with prolactin and gonadal. Two species of arvicoline rodents, the brown lemming, Lemmus trimucronatus, and the collared lemming, Dicrostonyx groenlandicus, occurred near Barrow during our study (Pitelka ). Collared lemmings occurred only sporadically and at much lower densities, and.
Molt-X is an emulsifiable concentrate containing % by weight azadirachtin. It has been evaluated on a wide variety of ornamental, forestry, and food crops. No phytotoxicity at directed field rates has been observed.
Molt-X is an insect growth regulator and does not control adult insects. However, Molt-X is also effective as a. A graphic model for individual selection determined by the logarithmic growth rates, dN i /N i dt, is developed for studying optimal demographic strategies at different phases of microtine cycles.
In a density-independent situation (no crowding) selection leads to maximization of total life-time reproductive output (or equivalently, the Malthusian parameter, m) at the expense of competitive. The ecological significance of molt lies in its link with other life-history traits within the annual cycle.
For instance, in species that molt shortly after the breeding season is completed, molt can serve as an indicator for the end of the breeding season if breeding is difficult to quantify directly (Orell and Ojanen ; Reed et al.
J Cell Physiol. Oct;50(2) Spontaneous activity of the lemming Dicrostonyx groenlandicus richardsoni Merriam as indicated in hour records of oxygen consumption. In alpine habitats in the Scandinavian Arctic, another study found that the lemming (Dicrostonyx groenlandicus), a typical arctic alpine species, made up 80 percent and voles 20 percent of the prey items in scats of arctic foxes (Frafjord ).
Red foxes at the time favored lowland habitats where they preyed exclusively on voles. In the temperate zone, the proximal cue for molt initiation is day length, which has an effect on the hormone levels that ulti-mately control molt progression.
Molting is very costly. The bird replaces 25 – 40 percent of its dry mass, drawing on protein and energy reserves to. The highly variable moulting costs can be explained by interactions between moulting strategies, life histories and environmental conditions. Photoperiodic effects on post-weaning growth and food consumption in the collared lemming Dicrostonyx groenlandicus.
Zool. – (/jtb Control of molt in. Peak numbers of varying lemmings (Dicrostonyx groenlandicus) at high latitudes in North America appear to be far less than peak numbers recorded at lower latitudes where both the varying lemming and brown lemming (Lemmus trimucronatus) occur in the same areas, or in those areas where extraordinary numbers of only brown lemmings occur at times.
The European water vole or northern water vole (Arvicola amphibius, included in synonymy: A. terrestris), is a semi-aquatic is often informally called the water rat, though it only superficially resembles a true rat.
Water voles have rounder noses than rats, deep brown fur, chubby faces and short fuzzy ears; unlike rats their tails, paws and ears are covered with hair. The oldest known fossil among the Eutheria ("true beasts") is the small shrewlike Juramaia sinensis, or "Jurassic mother from China", dated to million years ago in the late Jurassic.
A later eutherian relative, Eomaia, dated to million years ago in the early Cretaceous, possessed some features in common with the marsupials but not with the placentals, evidence that these features were.Abstract.
Research on lemurs contributes importantly to evaluation of hypotheses on primate development and evolution.
A central question about social behavior has asked why adult females in many lemur species socially dominate males while this trait is .Full text of "Syllogeus" See other formats mm NATIONAL MUSEUM OF NATURAL SCIENCES (a lÊI [a [b la [a [a [s [3 [a [s la [a [si [a [â [a EYAAOrEYZ [g [g [3 Is B S B [s Ë Is [3 S Is [3 Ë Isi la H.V.
Danks MUSÉE NATIONAL DES SCIENCES NATURELLES No. 25 ARTHROPODS OF POLAR BEAR PASS, BATHURST ISLAND, ARCTIC CANADA MUSÉES NATIONAUX DU CANADA OTTAWA NATIONAL .