Energy cost and return for hunting in African wild dogs and Cheetahs

African wild dogs (Lycaon pictus) are reported to hunt with energetically costly long chase distances. We used high-resolution GPS and inertial technology to record 1,119 high-speed chases of all members of a pack of six adult African wild dogs in northern Botswana. Dogs performed multiple short, high-speed, mostly unsuccessful chases to capture prey, while cheetahs (Acinonyx jubatus) undertook even shorter, higher-speed hunts. We used an energy balance model to show that the energy return from group hunting and feeding substantially outweighs the cost of multiple short chases, which indicates that African wild dogs are more energetically robust than previously believed. Comparison with cheetah illustrates the trade-off between sheer athleticism and high individual kill rate characteristic of cheetahs, and the energetic robustness of frequent opportunistic group hunting and feeding by African wild dogs

Hydrothermal Synthesis of Cr2Se3 Hexagons for Sensitive and Lowlevel Detection of 4-Nitrophenol in Water

We report a simple hydrothermal method used for the synthesis of Cr2Se3 hexagons (h-Cr2Se3) and its application towards electrochemical sensing of 4-nitrophenol (4-NP). The formation of h-Cr2Se3 was confrmed by using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray difraction, and X-ray photoelectron spectroscopy. The electrochemical activity of the h-Cr2Se3 modifed screen-printed carbon electrode (SPCE) towards 4-NP was studied using cyclic voltammetry (CV) and amperometric i-t techniques. Typically,the obtained results were compared with those for a bare SPCE. The CV result clearly reveals that h-Cr2Se3 modifed SPCE has higher catalytic activity towards reduction of 4-NP than bare SPCE. Hence, h-Cr2Se3 modifed SPCE was concluded as a viable sensor for sensitive determination of 4-NP. Under optimized conditions, h-Cr2Se3 modifed SPCE demonstrates the excellent capacity to detect the 4-NP in a linear range from 0.05µM to 908.0µM. The LOD and sensitivity in detection of 4-NP were determined at 0.01µM and 1.24µAµM−1 cm−2 respectively. The sensor is highly selective and stable and shows reproducible recovery of 4-NP in domestic supply and river water samples