scholarly journals Food availability, temperature, and day length drive seasonal variations in the positional behavior of white‐headed langurs in the limestone forests of Southwest Guangxi, China

2021 ◽  
Author(s):  
Jingjin Zheng ◽  
Kechu Zhang ◽  
Jipeng Liang ◽  
Youbang Li ◽  
Zhonghao Huang
Keyword(s):  
Food Availability ◽  
Seasonal Variations ◽  
Day Length ◽  
Positional Behavior

scholarly journals Activity budget of Rhinopithecus bieti at Tibet: Effects of day length, temperature and food availability

2010 ◽  
Vol 56 (6) ◽  
pp. 650-659 ◽  
Author(s):  
Zuofu Xiang ◽  
Sheng Huo ◽  
Wen Xiao
Keyword(s):  
Food Availability ◽  
Activity Budget ◽  
Day Length ◽  
Feeding Time ◽  
Activity Budgets ◽  
Rhinopithecus Bieti ◽  
Resting Time ◽  
Positive Functions ◽  
Energy Balances ◽  
Foraging Time

Abstract How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availability, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets of Rhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities (activities besides feeding, moving and resting). Time spent resting and doing "other activities" is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time (feeding + moving) takes priority over rest and other activities. Day length and foraging time (as independent variables) were related to the time spent in the other two activities besides feeding/moving (as dependent variables). Both time spent resting and in "other activities" were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over "other activities" time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets .

Seasonal variations in testis size, testosterone and LH basal levels, and pituitary response to luteinizing hormone releasing hormone in the brown hare, Lepus europaeus

1989 ◽  
Vol 67 (7) ◽  
pp. 1626-1630 ◽  
Author(s):  
M. Caillol ◽  
M. Meunier ◽  
M. Mondain-Monval ◽  
P. Simon
Keyword(s):  
Luteinizing Hormone ◽  
Seasonal Variations ◽  
Day Length ◽  
Lepus Europaeus ◽  
Testis Size ◽  
Brown Hare ◽  
Mating Season ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Testosterone Secretion

In the brown hare, fertile mating takes place from the beginning of December to September. Seasonal variations of testis size, plasma levels of LH and testosterone, and pituitary and testicular responses to a monthly i.v. injection of 5 μg LHRH were studied in adult hares. Testis recrudescence began in October, 2 months before the beginning of the breeding season. The gonads were fully developed between January and July, and regressed thereafter. The increase of testosterone basal levels paralleled testicular growth, despite undetectable levels of LH. These LH levels increased slightly from April to August, when testosterone secretion decreased. Luteinizing hormone releasing hormone (LHRH) injection was always followed by a release of LH; the LH value peaked 15 min after injection and returned to basal concentrations 2 h later. The pituitary response to LHRH was significantly higher in July (76.4 ± 11.2 ng/mL, n = 5) and August (60.1 ± 5.6 ng/mL, n = 5), at the end of the mating season. The LH surge induced by LHRH was always followed by a secretion of testosterone lasting approximately 2 h. This testosterone secretion was maximum in January (88.6 ± 23.9 ng/mL, n = 5) and February (81.3 ± 18.6 ng/mL, n = 5), when the testis is fully developed. This suggests an increase in the pituitary content of LH in July and August, when day length decreases and testosterone negative feedback is less effective. These high LH levels might be responsible for the testis recrudescence 2 months later.

Food intake, growth, and reproduction as affected by day length and food availability in the pond snail Lymnaea stagnalis*

2007 ◽  
Vol 23 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Andries Ter Maat ◽  
Cor Zonneveld ◽  
J. Arjan G. M. de Visser ◽  
René F. Jansen ◽  
Kora Montagne-Wajer ◽  
...  
Keyword(s):  
Food Intake ◽  
Food Availability ◽  
Lymnaea Stagnalis ◽  
Day Length ◽  
Pond Snail ◽  
Growth And Reproduction

Seasonal Variations of Water Temperature, Food Availability, Size, and Reproduction on the Hemocyte Parameters in the ScallopChlamys farreri

2012 ◽  
Vol 31 (3) ◽  
pp. 663-670 ◽  
Author(s):  
Tingting Lin ◽  
Kai Zhou ◽  
Qifang Lai ◽  
Zongli Yao ◽  
Ziniu Li ◽  
...  
Keyword(s):  
Water Temperature ◽  
Food Availability ◽  
Seasonal Variations

scholarly journals Contingent trade-off decisions with feedbacks in cyclical environments: testing alternative theories

2020 ◽  
Vol 31 (5) ◽  
pp. 1192-1206 ◽  
Author(s):  
Steven F Railsback ◽  
Bret C Harvey ◽  
Daniel Ayllón
Keyword(s):  
Food Availability ◽  
Day Length ◽  
Physical Habitat ◽  
Light Cycle ◽  
Competition Theory ◽  
Trade Offs ◽  
Multiple Behaviors ◽  
Almost All ◽  
Base Selection ◽  
Selection Of

Abstract Many animals make contingent decisions, such as when and where to feed, as trade-offs between growth and risk when these vary not only with activity and location but also 1) in cycles such as the daily light cycle and 2) with feedbacks due to competition. Theory can assume an individual decides whether and where to feed, at any point in the light cycle and under any new conditions, by predicting future conditions and maximizing an approximate measure of future fitness. We develop four such theories for stream trout and evaluate them by their ability to reproduce, in an individual-based model, seven patterns observed in real trout. The patterns concern how feeding in four circadian phases—dawn, day, dusk, and night—varies with predation risk, food availability, temperature, trout density, physical habitat, day length, and circadian cycles in food availability. We found that theory must consider the full circadian cycle: decisions at one phase must consider what happens in other phases. Three theories that do so could reproduce almost all the patterns, and their ability to let individuals adapt decisions over time produced higher average fitness than any fixed behavior cycle. Because individuals could adapt by selecting among habitat patches as well as activity, multiple behaviors produced similar fitness. Our most successful theories base selection of habitat and activity at each phase on memory of survival probabilities and growth rates experienced 1) in the three previous phases of the current day or 2) in each phase of several previous days.

scholarly journals An examination of factors potentially influencing birth distributions in golden snub-nosed monkeys (Rhinopithecus roxellana)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2892 ◽  
Author(s):  
Zuofu Xiang ◽  
Wanji Yang ◽  
Xiaoguang Qi ◽  
Hui Yao ◽  
Cyril C. Grueter ◽  
...  
Keyword(s):  
Food Availability ◽  
Reproductive Activity ◽  
Day Length ◽  
Circular Statistics ◽  
Rhinopithecus Roxellana ◽  
Average Temperature ◽  
Conception Date ◽  
Reproductive Events ◽  
Free Ranging

Many species of primates are considered seasonal breeders, but the set of factors, such as food availability, day length and temperature, that influence the timing of reproductive events for both wild and captive individuals remains unclear. Here, we examine the role of factors in shaping breeding patterns inRhinopithecus roxellana, a temperate colobine primate. We used circular statistics to describe and compare the patterns of reproductive seasonality among individuals in 13 captive groups and two free ranging but provisioned groups at various locations throughout China. Almost 90% of births occurred in March, April and May in adult females residing in both free ranging (n = 131) and captive groups (n = 407). Births occurred principally in 2–4 months prior to the peak of food availability, while conceptions occurred in 1–2 months after the peak of food availability in free ranging but provisioned groups. Day length (latitude) had a significant effect on the timing of reproduction. However, females that experienced a wide variation of temperature between the lowest and highest monthly average temperature had a later conception date. These results support that day length and temperature might be factor influencing the timing of reproductive activity.

Seasonal variations in guanaco diet (Lama guanicoeMüller 1776) and food availability in Northern Patagonia, Argentina

1996 ◽  
Vol 34 (2) ◽  
pp. 215-224 ◽  
Author(s):  
Silvia Puig ◽  
Fernando Videla ◽  
Susana Monge ◽  
Virgilio Roig
Keyword(s):  
Food Availability ◽  
Seasonal Variations ◽  
Northern Patagonia

Meal patterning of rats with changes in day length and food availability

1980 ◽  
Vol 25 (6) ◽  
pp. 953-958 ◽  
Author(s):  
Annemie Kersten ◽  
Jan H. Strubbe ◽  
Nello J. Spiteri
Keyword(s):  
Food Availability ◽  
Day Length
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