scholarly journals Parameters of the autumn migration stopover of the chiffchaff (Phylloscopus collybita Vieillot, 1817) (Sylviidae, Aves) in the conditions of the middle taiga in the Eastern Russian plain

Author(s):  
G. L. Nakul

Parameters of the autumn migration stopover of the chiffchaff Phylloscopus collybita (Vieillot, 1817) in the taiga zone of the Eastern Russian plain were estimated. The studies were carried out in 2015–2019, a total of 1,634 birds were included in our analysis. It has been established that migrating chiffchaffs can be conditionally divided into two groups. The first group consists of transit individuals leaving their stopover just on the day of arrival, without delay. The other group includes individuals who make stopovers for a longer period (4.87 days on average). For the birds of both groups, changes in their body weight and fat accumulation rate were revealed during one day and throughout the entire migration stopover. During an average migration stopover, birds retain their energy reserves at a certain level. In general, they accumulate no more than 5% of the average body weight in the population during the average stop period. A smaller proportion of migrants make multi-day stops when the fat accumulation rate is low. Every day of staying at a migration stopover leads to temporary surges and losses in body weight, with no increase in body fat. Birds, at the end of their migration season, spend more time and energy for looking for food. The part of migratory birds deciding to stop finds themselves in the most optimal conditions. This small group is the main reserve for preserving the population during the difficult period of migration. 

2007 ◽  
pp. 13-22 ◽  
Author(s):  
T. K. Yurkovskaya

I have focused only on some features of structure in the taiga vegetation cover. In conclusion I would like to tell some words about the causes of complicated space structure of the taiga and tundra vegetation cover. The causes of latitudinal differentiation are climatic undoubtedly, but heterogeneity of vegetation cover within the limits of tundra and taiga subzones is accounted for different factors. In tundra abiogenic factors prevail, first of all the permafrost processes. That is the reason why tundra vegetation cover is so sensible to any disturbances and so hard regenerates after various transformations. In taiga the space structure is mostly the result of self-regulation and self- restoration of biota. The abiotic factors, certainly, play significant role, but they recede to the second plan. So we showed that in the north and middle taiga the structure of vegetation cover, during the Holocene up to present time, is determined in many respects by the increasing role of mires. Suffice it to look at the map of distribution of mires in order to estimate their role in vegetation cover of the easteuropean taiga (Yurkovskaya, 1980). So, the increase of mire area on the Russian Plain in m2/year per 1000 ha varies between 200 and 700, the average increas is ca 300—400 m2/year (Elina et all., 2000). The mires favour peniplenization and unite the separate areas of forest communities into the whole by means of forming the buffer paludificated territories (various hydrophilous variants of forest communities). But if mires, at all their stability, after destroying practically don't restore, the forests even after continuous cuttings restore their structure and composition through the series of successional stages unless an ecotope is damaged completely. Hence the space structure of taiga is the result, first of all, self development and self regulation of its vegetation cover. But, as it is known, at present time the process of destruction of natural biota has gone too far that the question arises not only about supporting its state and structure but also about the survival of the mankind itself. In this regard the vegetation map of Europe is the invaluable basis, which gives the starting point for all conservational, ecological and economical measures. But it is important to learn reading and using the map. And this is one of our actual goals.


2012 ◽  
Vol 2 (1) ◽  
pp. 21-27
Author(s):  
Yosi Fenita

The objective of the research was to evaluate to effect of feeding mengkudu on performances of broilers. The research design used was completely randomized design. One hundred broilers were distributed into five treatments. The treatments were different levels of mengkudu meal (0, 0.75%, 1.5%, 2.25 % and 3%). The observed measured were feed consumption, average body weight (gain) and feed conversion. Results showed that feeding mengkudu (Morinda Citrifolia L.)  no effect significant (P>0.05) on feed consumption, average body weight and feed conversion.  In conclusion, feeding mengkudu meal up to 3% (in diet) does not negatively affect feed consumption, average body weight, and feed conversion.


2010 ◽  
Vol 15 (4) ◽  
pp. 262-266 ◽  
Author(s):  
Won-Hee Choi ◽  
Ji-Yun Ahn ◽  
Sun-A Kim ◽  
Tae-Wan Kim ◽  
Tae-Youl Ha

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Alexander M. Mills

AbstractProtandry, the earlier arrival of males than of females on breeding areas, occurs in many taxa, including many migratory birds. Numerous hypotheses have been generated to explain protandry. Using bird-banding records, I show that protogyny, the earlier migration of females, frequently occurs in the autumn, though it is less universal and less dramatic than spring protandry. In one species, it occurs in both hatch-year and adult birds. When (1) spring and autumn, (2) departures and arrivals, and (3) breeding and wintering ground conditions are considered, hypotheses generated only to explain spring protandry can be more thoroughly evaluated. Using that approach, the most parsimonious explanation of differential migration between the sexes explains earlier male arrival in spring and later male departure in autumn through either (1) indirect selection operating on intrasexual male competition for territories or (2) direct selection operating on intersexual relations requiring males to be present on breeding territories when females are present. In autumn-protogynous species, males may ”play chicken,” balancing the benefits of remaining longer than females and protecting territories for subsequent years against the costs of remaining in the north under deteriorating conditions and delaying the acquisition of a good winter territory.Protogynie et migration automnale: Est-ce que les mâles ”jouent les dégonflés”?


2021 ◽  
Vol 9 (1) ◽  
pp. e001431
Author(s):  
Long Li ◽  
Caoxin Huang ◽  
Hongyan Yin ◽  
Xiaofang Zhang ◽  
Dongmei Wang ◽  
...  

IntroductionExercise training has been shown to be the most effective strategy to combat obesity and non-alcoholic fatty liver disease. However, exercise promotes loss of adipose tissue mass and improves obesity-related hepatic steatosis through mechanisms that remain obscure.Research design and methodsTo study the role of interleukin-6 (IL-6) in high-fat diet (HFD)-induced adiposity and hepatic steatosis during treadmill running, IL-6 knockout (IL-6 KO) mice and wild-type (WT) mice were randomly divided into lean, obese (fed a HFD) and trained obese groups (fed a HFD and exercise trained).ResultsAfter 20 weeks of HFD feeding and 8 weeks of treadmill running, we found that exercise obviously reduced HFD-induced body weight gain, inhibited visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) expansion and almost completely reversed obesity-related intrahepatic fat accumulation in WT mice. However, IL-6 knockout (IL-6 KO) mice are refractory to the benefits of treadmill training on body weight, VAT and SAT mass elevation, and hepatic steatosis. Moreover, a panel of lipolytic-related and thermogenic-related genes, including ATGL, HSL and PGC-1α, was upregulated in the VAT and SAT of WT mice that received exercise training compared with untrained mice, which was not observed in IL-6 KO mice. In addition, exercise training resulted in a significant inhibition of hepatic peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in WT mice, and these effects were not noted in IL-6 KO mice.ConclusionThese results revealed that IL-6 is involved in the prevention of obesity and hepatic fat accumulation during exercise training. The mechanisms underlying these antiobesity effects may be associated with enhanced lipolysis and thermogenesis in white adipose tissue. The improvement in hepatic steatosis by exercise training may benefit from the marked inhibition of PPAR-γ expression by IL-6.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1511
Author(s):  
Joseph P. Gulizia ◽  
Kevin M. Downs

Two trials were conducted to determine feed color effects on broiler performance. A completely randomized design was used. Trial 1 included four treatments: control (complete broiler starter diet), red, green, and blue; and Trial 2 included four treatments: control, orange, yellow, and purple. Each trial had 4 treatments with 4 replicates (60 birds/treatment) fed to 240 male Cobb 500 broilers during a 21 d grow out. Data were analyzed using the GLM procedure. In Trial 1, there were no treatment effects on average body weight, body weight gain, and feed consumption (p > 0.05). Adjusted feed conversion for control (1.23) was less than red (1.27; p = 0.001) and green (1.26; p = 0.009), with blue (1.25; p = 0.056) tending to be different during the experimental period. In Trial 2, there were no treatment effects on average body weight, feed consumption, and adjusted feed conversion during this study (p > 0.05). Body weight gain between d 1 to 14 for purple (490.78 g/bird) was more than orange (467 g/bird; p = 0.013) and yellow (461 g/bird; p= 0.004), with control (474 g/bird; p = 0.052) tending to be different. Results indicate that these feed colors had some, albeit limited, influence on broiler performance parameters.


Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 824
Author(s):  
Egor Dyukarev ◽  
Evgeny Zarov ◽  
Pavel Alekseychik ◽  
Jelmer Nijp ◽  
Nina Filippova ◽  
...  

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shi-Peng Zhu ◽  
Yu-wei He ◽  
Huan Chen ◽  
Zhi-Fang Sun ◽  
Na Ding ◽  
...  

Objective. To observe the effect of preventive acupuncture and moxibustion on blood lipid of menopause rats.Methods. Seventy 10-month-old SD rats with estrous cycle disorders were divided into three control groups and four treatment groups (n=10/group) and another ten 3.5-month-old female SD rats were chosen as young control group. Preventive acupuncture and moxibustion were applied at Guanyuan (CV 4). Body weight growth rate has been recorded. Plasma total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high density lipoprotein (HDL) levels and uterusE2level were measured.Results. Compared to young control group, plasma TC and LDL increased and uterusE2reduced significantly in 12-month-old control group. Compared to 12-month-old control group, plasma TC and LDL level and body weight growth rate decreased while HDL level increased remarkably in preventive acupuncture 12-month-old group. Compared to 14-month-old control group, plasma TC level and body weight growth rate decreased remarkably in preventive moxibustion 14-month-old group.Conclusions. Preventive acupuncture and moxibustion can significantly decrease the plasma TG and LDL, increase the plasma HDL, and prevent fat accumulation. Our finding suggests that preventive acupuncture and moxibustion have beneficial effects on blood lipid. Different treatment effects were found between preventive acupuncture and preventive moxibustion.


2021 ◽  
Vol 31 (3) ◽  
pp. 218-226
Author(s):  
S Akter ◽  
SC Das ◽  
AS Apu ◽  
T Ahmed ◽  
A Lahiry ◽  
...  

The present study was conducted to determine the early sex in turkeys by observation of the differences in body weight between male and female birds. A total of 30-day old black color unsexed poults having almost similar body weight at hatching were considered for the experimentation and housed at the Poultry Farm of Bangladesh Agricultural University, Mymensingh-2202, Bangladesh. All birds were reared up to 12 weeks of age under intensive management with supplementation of commercial broiler starter and grower feeds. Birds were reared under similar management conditions. Significantly higher (p<0.01) body weight was attained in male poults (104g/bird) than the female (90g/bird) at the end of 1st week of age. Similarly, at the end of 2nd week of age higher (p<0.01) body weight attained by male poults (198.31g/bird) than the female (162.13g/bird). At the end of 3rd weeks of age male poults attained higher (p<0.01) body weight (307.23g/bird) than the female (251.33g/bird). After 4 weeks of rearing, male turkeys attained significantly higher (p<0.01) live body weight (424.46g/bird) than the female turkeys (347.87g/bird). The weekly average body weight gains of male and female birds were 94.18g/bird and 76.5g/bird, respectively. Thus, the male and female birds were successfully identified on the basis of differences in their body weight. Weekly feed intake for both the male and female birds was also increased with their age. Up to 4 weeks of age, both the male and female poults consumed same amount of feed (753.46g/bird). The FCR of male and female poults differed non-significantly in 1st, 3rd and 4th week. On the contrary, in 2nd week of age the FCR of male poults (1.60) was significantly lower (p<0.01) than female (2.11). Survivability was 100% up to 4th week of age irrespective of sex of the poults. The birds were reared up to 12 weeks of age until to confirm their sex by observation of the phenotypic appearance. Results of the phenotypic observation of male and female birds correspondence hundred percent accuracy with the results obtained in body weight based differences between male and female birds. It is therefore concluded that farmers can identify male or female poults as early as first week of age on the basis of body weight differences. Progressive Agriculture 31 (3): 218-226, 2020


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