However, recent research has shown that, even when food is abundant, energy intake reaches a limit, even in animals with high nutrient demands, such as lactating females.
Scientists at the Research Institute of Wildlife Ecology in Vienna suggest that this is due to active control of maternal investment in offspring in order to maintain long-term reproductive fitness.
The research, to be presented by Dr Teresa Valencak at the Society for Experimental Biology Annual Meeting in Glasgow has shown that, when their energy reserves are low or when their offspring are kept in cooler temperatures, Brown hares are able to increase their energy turnover and rate of milk production above that normally observed.
This indicates that, ordinarily, the hares are operating at below their maximum capacity and shows that this is not due to any kind of physiological constraint, such as length of digestive tract or maximum capacity of mammary glands. Also, as the hares were provided with plentiful food, there could be no limitation of energy turnover due to food availability.
The way that females regulated their energy expenditure according to pup demand and their own fat reserves but did not exceed certain levels fitted with the group's theory that using energy at close to the maximum rate has costs for animals which may compromise their ability to successfully reproduce in the future.
If a hare puts most of its energy into a litter of pups then it will have little left over for growth and body repairs for example, which may shorten its life or make it less able to produce or care for young in the future. By actively limiting the rate of energy turnover, a mother can prevent this and maintain a higher level of reproductive success over her lifetime.
Tess Livermore | EurekAlert!
Two Group A Streptococcus genes linked to 'flesh-eating' bacterial infections
25.09.2017 | University of Maryland
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
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25.09.2017 | Physics and Astronomy