نتایج جستجو برای: reproduction season

تعداد نتایج: 121519  

Journal: :American journal of human biology : the official journal of the Human Biology Council 2009
Susanne Huber Martin Fieder

Epidemiological studies on premodern and modern Western societies indicate that birth season may influence female reproduction. Nothing is known, however, about this effect in developing economies. Many of the latter are characterised by tropical climates with a rainy season associated with lower food availability and a greater prevalence of infectious diseases. We therefore predict that an ass...

Journal: :Ecosphere 2021

Variation in nutrient allocation can influence the timing of breeding and ultimately reproductive output. Time space constraints might exist, however, if fewer food resources are available to meet costs reproduction early during season. Here, for first time, we test whether nutrient-allocation strategies a shrub-dependent avian species differ with different ecoregions: high-elevation landscape,...

2017
Junpeng Mu Yulian Yang Yanling Luo Ruijun Su Karl J Niklas

Gentiana leucomelaena manifests dramatic flower color polymorphism, with both blue- and white-flowered individuals (pollinated by flies and bees) both within a population and on an individual plant. Previous studies of this species have shown that pollinator preference and flower temperature change as a function of flower color throughout the flowering season. However, few if any studies have e...

Journal: :Hormones and behavior 2003
Ignacio T Moore Tim S Jessop

While the hypothalamo-pituitary-adrenocortical (HPA) response to stress appears to be conserved in vertebrates, the manner in which it is activated and its actions vary. We examine two trends in the stress biology literature that have been addressed in amphibian and reptilian species: (1). variable interactions among stress, corticosterone, and reproduction and (2). adrenocortical modulation. I...

Journal: :international journal of advanced biological and biomedical research 2014
nematollah dayyani

the number of lambs sold per ewe mated in the breeding flock has a considerable impact on sheep operation profitability. this depends primarily on fertility, prolificacy (# of lambs), and lamb survival, mothering ability, milk production of the ewe and lamb growth rate. optimal reproduction does vary by environment and management system – some sheep operations don’t want a lambing rate over 200...

Journal: :Integrative zoology 2007
Rhodes H Makundi Apia W Massawe Loth S Mulungu

The multimammate rat, Mastomys natalensis Smith 1834, is a dominant species in agro-ecosystems in Sub-Saharan Africa, but adapts quickly to changes in non-agricultural landscape, particularly woodlands and forests. In this study we report on reproduction and population dynamics of M. natalensis in deforested high elevation localities in the Usambara Mountains, north-east Tanzania. We conducted ...

2015
Jennifer K. Frey Donald Kramer

Hibernation is a key life history feature that can impact many other crucial aspects of a species' biology, such as its survival and reproduction. I examined the timing of hibernation and reproduction in the federally endangered New Mexico meadow jumping mouse (Zapus hudsonius luteus), which occurs across a broad range of latitudes and elevations in the American Southwest. Data from museum spec...

2014
Carlos Passos Bettina Tassino Federico Reyes Gil G. Rosenthal

The intensity of mating competition and the potential benefits for female of mating with certain males can be influenced by several extrinsic factors, such that behavioral decisions can be highly context-dependent. Short-lived species with a single reproductive season are a unique model to study context-sensitive mating decisions. Through exhaustive sampling in the field and simultaneous choice...

2015
Zheng-miao Deng Xin-sheng Chen Yong-hong Xie Ya-jun Xie Zhi-yong Hou Feng Li

Seedlings and vegetative ramets may contribute differentially to the recruitment of clonal populations in different growth phases, but this has rarely been investigated. In this study, we quantified the number and survivorship of seedlings and vegetative ramets monthly in juvenile and mature populations of Carex brevicuspis. During the first growing season after flooding (from October to Januar...

Journal: :Frontiers in Ecology and Evolution 2021

Ecological restoration is widely used to mitigate the negative impacts of anthropogenic activities. There an increasing demand identify suitable management strategies for specific habitat and disturbance types restore interactions between organisms degraded habitats, such as pollination. In Tibetan Plateau, alpine meadows have suffered severe degradation due overgrazing climate change. Protecti...

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