scholarly journals The biomechanics of foraging determines face length among kangaroos and their relatives

2018 ◽  
Vol 285 (1881) ◽  
pp. 20180845 ◽  
Author(s):  
D. Rex Mitchell ◽  
Emma Sherratt ◽  
Justin A. Ledogar ◽  
Stephen Wroe

Increasing body size is accompanied by facial elongation across a number of mammalian taxa. This trend forms the basis of a proposed evolutionary rule, cranial evolutionary allometry (CREA). However, facial length has also been widely associated with the varying mechanical resistance of foods. Here, we combine geometric morphometrics and computational biomechanical analyses to determine whether evolutionary allometry or feeding ecology have been dominant influences on facial elongation across 16 species of kangaroos and relatives (Macropodiformes). We found no support for an allometric trend. Nor was craniofacial morphology strictly defined by dietary categories, but rather associated with a combination of the mechanical properties of vegetation types and cropping behaviours used to access them. Among species examined here, shorter muzzles coincided with known diets of tough, resistant plant tissues, accessed via active slicing by the anterior dentition. This morphology consistently resulted in increased mechanical efficiency and decreased bone deformation during incisor biting. Longer muzzles, by contrast, aligned with softer foods or feeding behaviours invoking cervical musculature that circumvent the need for hard biting. These findings point to a potential for craniofacial morphology to predict feeding ecology in macropodiforms, which may be useful for species management planning and for inferring palaeoecology.

2012 ◽  
Vol 21 (3) ◽  
pp. 197 ◽  
Author(s):  
Lucy G. Halliday ◽  
J. Guy Castley ◽  
James A. Fitzsimons ◽  
Cuong Tran ◽  
Jan Warnken

Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.


2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.


EDIS ◽  
2019 ◽  
Vol 2019 (3) ◽  
Author(s):  
Martie Gillen ◽  
Beatrice Pierre

As risks evolve and diversify, approaches to conducting business require a targeted focus on risk management, particularly in agriculture. This new 3-page document explores risk in agriculture, the need to understand risk, formation of strategies to manage risk, and government programs that exist to help growers and producers manage risk. Written by Martie Gillen and Beatrice Pierre, and published by the UF/IFAS Department of Family, Youth and Community Sciences, May 2019.  http://edis.ifas.ufl.edu/fy1482


Author(s):  
JG Calado ◽  
SN Veríssimo ◽  
VH Paiva ◽  
R Ramos ◽  
PT Vaz ◽  
...  

Author(s):  
D.L. Roke

The growth in horticultural and some industrial development in selected areas of Northland has led to a need for more specific and careful planning and control of limited resources in a number of major catchments. The potential irrigation demands for horhculture comprise over 60% of Northland's potential water requirements. By contrast, farm water supply needs are only 11% of these needs. Because of their importance to the Northland economy, and in the legislation these needs are given a high priority in water resource management planning. Land uses, including pastoral farming, require careful operation to reduce diffuse sources of pollution.


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