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1.
This work is concerned with the extent of behavioural discrimination between three chromosomal races of the house mouse (the standard 40-chromosome race and a 32- and 36-chromosome races) found in the vicinity of a hybrid zone in northern Scotland. Mice were investigated for several elements of their social behaviour. Within-population dyadic encounters did not show consistent behavioural differences attributable to karyotype among five populations (two standard race, two 36-chromosome race, one 32-chromosome race). Between-population dyadic encounters revealed significant differences between three populations. The standard population examined appeared to be the most “open” to foreigners, the 32-chromosome population the most “closed” while the 36-chromosome mice displayed an intermediate response. Differences in behaviour displayed during between-population as compared to within-population dyadic encounters revealed the occurrence of behavioural discrimination between populations. The implication of these results on the dynamics of the hybrid zone are discussed. 相似文献
2.
3.
华中地区小家鼠生物学特性观察 总被引:8,自引:2,他引:6
华中地区农村小家鼠的个体较小,主要栖息于农舍,终年繁殖,繁殖高峰期为7月和8月,1-3月为繁殖低谷期;种群数量高峰在9月,低谷期在7-8月,冬季的种群数量水平较高,呈后峰型。在较高的密度条件下,雌鼠的怀孕率降低,性成熟延缓。 相似文献
4.
Bruce E. Young 《Oecologia》1993,93(2):256-262
I studied the life cycle of a botfly (Diptera: Muscidae: Philornis carinatus) and examined the effects of botfly ectoparasitism on nestling house wrens (Passeriformes: Troglodytidae: Troglodytes aedon) during three years in Costa Rica. At three study sites, I found that nestlings were relatively unaffected by botflies, in contrast to all other studies of birds infected with philornid botflies. At Monteverde, the main study site, infected chicks grew slightly slower and had slightly shorter tarsi and wing chords than uninfected chicks, but both groups fledged at similar weights. Since weight at fledging is the only growth character associated with post-fledging survivorship, botfly infections likely cost wrens little in terms of fitness. At all sites, fledging success did not differ between infected and uninfected nests. Botfly infections were more prevalent at two lower elevation sites than at the high elevation Monteverde side. Infection prevalence increased during the nesting season at all study sites, which suggests a botfly life cycle in which adult population levels increase during the wren breeding season and then decline during a dormant period when wrens are not nesting. Finally, botflies may attack chicks throughout the period before fledging, but there is no indication they locate nests before hatching. In sum, botfly parasitism on wrens appears to be benign, perhaps because the study sites are at the edge of the botfly's range or because wrens are not a preferred host. 相似文献
5.
Quinuclidinyl Benzilate Binding in House Fly Heads and Rat Brain 总被引:4,自引:3,他引:1
Abstract: House fly heads contain a binding site for 3-quinuclidinyl benzilate (QNB) that is quite similar in pharmacology to the muscarinic acetylcholine receptor of vertebrate tissues. The house fly site binds [3 H]QNB reversibly with a K d of 260 PM and Bmax of 1 pmol/g of heads from direct binding measurements. The Kd calculated from the ratio of the dissociation rate constant (2 × 10−4 sec−1 ) to the association rate constant (2.5 × 106 M−1 Sec−1 ) was 80 pM. The house fly site binds (-)quinuclidinyl benzilate preferentially, as do classic muscarinic receptors. The binding is also sensitive to other muscarinic antagonists and agonists. Nicotinic and other drugs are no more effective on the house fly site than they are on the rat brain muscarinic receptor itself. These binding studies suggest that the house fly QNB binding site is a muscarinic receptor. 相似文献
6.
Population Ecology - Female deermice housed from weaning with groups of five females, five males or five males plus five females had significantly smaller uteri at 35–38 days of age compared... 相似文献
7.
Atretic follicles regularly occur in the ovary of the house fly, Musca domestica. The frequency of ovarian follicular atresia and the proportion of atretic follicles per ovary are related to the stage of oögenesis and to the age of the females. Only vitellogenic follicles may become atretic. The atresia may occur at any stage of vitellogenesis, though most follicles become atretic in mid-vitellogenesis. Atretic follicles are completely resorbed within 24–36 hr. The follicle cells may play a synthesizing role during growth and disintegrating one during follicle resorption. The induction of glycogen synthesis by the cessation of RNA and protein synthesis and by vitellogenesis in normal follicles is discussed. The same processes occur prematurely in the atretic follicle which can be thus distinguished by a high content of glycogen. 相似文献
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9.
Summary Adult, male white-footed mice (Peromyscus leucopus) were subjected to a variety of social situations ranging from isolation during the 20 day experimental period to constant
contact with both females and other adult males. Contacts included grouping (three or four males per cage) and exposure to
fighters (once daily for 20 minutes). The following measurements were recorded: weights of the body, testes, epididymides,
vesicular glands, vesicular gland tissue (wet and dry), seminal fluid of the vesicular gland, adrenal glands, and baculum;
spermatozoan reserves of the testes and epididymides. Grouping significantly affected both the weight and spermatozoan reserves
of the testes and epididymides, as well as both the tissue and seminal fluid weight of the vesicular glands. The results suggested
a graded effect of all treatments on the reproductive tract. In order of magnitude of the associated response, from none to
greatest, the treatments may be ranked as follows: pairing with females, isolating, handling, fighting, and grouping. All
reproductive parameters measured showed this general ranking, suggesting that the response to the various treatments was similar
and differed only quantitatively. The results further suggested decreased secretion of LH and testosterone, although measurements
of testosterone did not substantiate this conclusion. The lack of significant effects of grouping on adrenal gland weights
strengthened the argument that adrenal involvement is not a necessary adjunct to the suppression of the reproductive tract
in groupedPeromyscus, but the adrenal may be involved if contacts between males result in overt fighting. 相似文献
10.