Ontogeny of cardiac rate regulation and brown fat thermogenesis in golden hamsters (Mesocricetus auratus)

It was shown previously in infant rats (Rattus norvegicus) that the ability to produce heat in the cold using brown adipose tissue (BAT) is closely related to the ability to maintain cardiac rate. When the limits of BAT thermogenesis were exceeded, interscapular temperature (which reflects the temperature of the interscapular BAT depot) and cardiac rate fell together. As an extension of this earlier study, the relation between BAT thermogenesis and cardiac rate was examined here in the golden hamster (Mesocricetus auratus), a species whose young do not exhibit BAT thermogenesis until the end of the 2nd week postpartum. It was found that 3 to 12-day-old hamsters were unable to increase shivering or nonshivering thermogenesis in the cold and exhibited decreases in cardiac rate that proceeded in lock-step with decreases in interscapular temperature. In contrast, as the thermogenic capability of hamsters increased after 12 days of age, cardiac rate was maintained within narrow limits across a wide range of air temperatures. These results support the hypothesis that heat produced by BAT helps to warm the heart and thus aids in the maintenance of cardiac rate during cold exposure. Accepted: 16 August 1997     

白冠长尾雉的越冬生态

白冠长尾雉的越冬生态方成良丁玉华（河南省信阳林业学校,４６４０３１）Ｏｖｅｒ＿ＷｉｎｔｅｒｉｎｇＥｃｏｌｏｇｙｏｆｔｈｅＷｈｉｔｅ＿ｃｒｏｗｎｅｄＬｏｎｇ＿ＴａｉｌｅｄＰｈｅａｓａｎｔ．ＦａｎｇＣｈｅｎｇｌｉａｎｇ,ＤｉｎｇＹｕｈｕａ（Ｘｉｎｙａｎｇ...     

白鹇海南亚种的生态和现状

海南白鹇是仅分布于我国海南岛的特殊的白鹇海岛亚种。其结群个体少；雏鸟孵出后，每群雏数少；亲鸟损失严重，有极其罕见的纯雏群现象；种群繁殖力低，出生率仅７７．５％；保护区核心区种群密度１９７８年２０．２只／ｋｍ~２，１９９２年１２只／ｋｍ~２。天敌、人类危害是种群数量严重下降的主要原因。目前全岛有白鹇分布的残存林区面积仅７４０ｋｍ~２，乐观估计白鹇数量已不足８８００只，白鹇海南亚种已处于渐危至濒危级别，必须尽快采取有效的保护措施。     

Experimental evidence that a large raptor can detect and replace heavily damaged flight feathers long before their scheduled moult dates

Because many species of large birds must remain capable of flight during moult and breeding, complete replacement of all flight feathers often takes two or more years, with the result that their plumage normally includes many faded, worn and sometimes even broken feathers. It seems adaptive for such birds to have the ability to quickly replace severely damaged feathers. In search of such a feather replacement mechanism, we cut rectrices on a captive Golden Eagle Aquila chrysaetos and found that feathers cut in their first year of use were replaced, on average, after 11.4 months, whereas uncut feathers before and during the experiment were moulted, on average, after 24 months of use. Feather cutting advanced moult, on average, in excess of a year and thereby demonstrates the existence of a previously undescribed neurophysiological mechanism for preferentially replacing damaged feathers.     

增施磷、钾肥对大花蕙兰炭疽病防治效果的影响

通过施用3种不同氮、磷、钾比例的肥料并结合常规药剂防治,对大花蕙兰黄金小神童炭疽病防治效果进行比较试验。结果表明,增施钾肥的[N：P(P2O5)：K(K2O)=15：15：30]和增施磷肥的[N：P(P2O5)：K(K2O)=15：30：15]防治效果显著,防治效果分别达到76．54％、73．71％,显著高于未增施磷、钾肥的(N：P(P2O5)：K(K2O)=15：15：15]防治效果(47．79％),说明增施磷、钾肥有助于提高对兰花炭疽病的防治效果。     

Male golden hamsters (<Emphasis Type="Italic">Mesocricetus auratus</Emphasis>) are more reactive than females to a visual predator cue

In most species of small mammals, males are exposed to higher levels of risk than females because they compete for mates, travel greater distances to find and procure mates, and/or defend a territory. This suggests that males and females might have different responses to risky situations, such as the presence of a predator. We tested responses to a visual predator cue (an owl silhouette) in male and female golden hamsters (Mesocricetus auratus). In a laboratory arena, there was no significant sex difference in the latency to enter the burrow or time spent in the burrow immediately after exposure to the owl silhouette. Males, however, were less likely to be active during the 3-min period following the animal’s exposure to the silhouette, indicating that male golden hamsters are more wary after exposure to an aerial predator cue than females. Most studies of responses to predators or predator cues have not considered sex differences, but our results show that males and females may have quite different responses to predator cues. Further work should be done to characterize and quantify sex differences in response to predators or predator cues.     

Winter foraging habitat selection of brown-eared pheasant (Crossoptilon mantchuricum) and the common pheasant (Phasianus colchicus) in Huanglong Mountains, Shaanxi Province

The foraging habitat selections of brown-eared pheasant (Crossoptilon mantchuricum) and the common pheasant (Phasianus colchicus) were studied in Huanglongshan Nature Reserve Shaanxi, China. Foraging habitat characteristics were measured on the basis of expected differences between species at 183 sites from November to December 2006 and January 2007. The results showed that both species selected foraging habitats with altitude (<1200 m), conifer forest, half sunny and half shady slope, sunny slope, density of trees (<5 individuals/100 m²), cover of shrub (>50%), visibility class (<10%) and distance to water source (<300 m). However, the brown-eared pheasant selected habitats with cover of trees (30–50%), middle or lower slope location, distance to edge of woods (<300 m) and human disturbance (<500 m), and the selection on density of shrub was not observed, compared to the selections on cover of trees (<30%), lower slope location, distance to edge of woods (<500 m) and human disturbance (<300 m), and density of shrub (>500 individuals/100 m²) for common pheasant. We also found that the common pheasant avoid predators by concealment whereas brown-eared pheasant evade predations by running away strategy.     

Alkali and alkaline earth metals in decomposing macrophytes in a wetland system

The foraging habitat selections of brown-eared pheasant (Crossoptilon mantchuricum) and the common pheasant (Phasianus colchicus) were studied in Huanglongshan Nature Reserve Shaanxi, China. Foraging habitat characteristics were measured on the basis of expected differences between species at 183 sites from November to December 2006 and January 2007. The results showed that both species selected foraging habitats with altitude (<1200 m), conifer forest, half sunny and half shady slope, sunny slope, density of trees (<5 individuals/100 m²), cover of shrub (>50%), visibility class (<10%) and distance to water source (<300 m). However, the brown-eared pheasant selected habitats with cover of trees (30–50%), middle or lower slope location, distance to edge of woods (<300 m) and human disturbance (<500 m), and the selection on density of shrub was not observed, compared to the selections on cover of trees (<30%), lower slope location, distance to edge of woods (<500 m) and human disturbance (<300 m), and density of shrub (>500 individuals/100 m²) for common pheasant. We also found that the common pheasant avoid predators by concealment whereas brown-eared pheasant evade predations by running away strategy.     

Winter diet composition of the golden jackal (Canis aureus L., 1758) in Serbia

The winter diet composition of golden jackals was determined by analysing the stomach contents of 248 specimens collected between December and February 2005–2009 at six localities in Serbia. The average weight of stomach contents was 189.9 ± 137.3 g. At all localities, livestock carcasses were the primary food category (frequency 56.1%, biomass 77.7%). The secondary food category consisted of small mammals taken as live prey (frequency 20.7%, biomass 5.2%). Other food categories were present less frequently (roe deer, wild boar, hare, and birds), and rarely (plant material, dogs, carnivores, lizards, and inedible inorganic material). No statistically significant differences were found in diet between jackals from different localities. The only difference was found between yearlings and adults with regard to the consumed biomass (%B). The analysis of the winter diet of golden jackals in Serbia indicates that the species has opportunistic feeding habits consisting primarily of easily accessible food sources.