Water use (L day−1) by kangaroos was just 13% that of sheep, and kangaroos were able to concentrate their urine more effectively than sheep, even though the kangaroos’ diet contained a high amount of high-salt chenopods, providing further support for potentially lower grazing impacts of kangaroos compared with domestic sheep in Australia’s arid rangelands. ”
“Blood parasites are often considered Antiinfection Compound Library cell line as indicators of immunity in birds, and data on parasite prevalence and intensity of infections are essential to reveal information about the condition of both individuals and populations. We prevented parasite
vectors from biting and infecting nestling great tit Parus major by using insect repellent inside nest boxes. We found that in the absence of blood parasites, great tit nestlings had higher concentrations of haemoglobin, and they survived at significantly higher rates through the nestling phase and also during the first weeks of their fledgling period. This is the first demonstration so far of the impact these parasites selleck chemical have on haemoglobin levels of the hosts, which reveals one mechanism of adverse impact by blood parasites. This study shows that the effects of blood parasites can be assessed without using anti-malaria drugs, which can cause additional risk of oxidative stress. ”
“Most studies of
the function of feeding muscles in fish have implanted electromyogram electrodes unilaterally to understand the motor pattern associated with a behavior.
The few studies that have implanted bilaterally have found that paired muscles may be activated asynchronously, often resulting in visible kinematic asymmetry. We investigated modulation of pairwise asynchrony (modulation in the activation patterns of left and right members of a muscle) of feeding muscles during capture and processing of two types of prey in spiny dogfish Squalus acanthias and little skates Leucoraja erinacea (Elasmobranchii). Two asynchrony indices quantified the degree to which muscles in a pair were activated out of phase (lag index, AIlag) and the degree Bacterial neuraminidase to which durations differ (duration index, AIdur). Feeding behaviors for both species were compared according to these indices and total event duration using principal components analysis. Both species modulated pairwise asynchrony according to prey type, exhibiting more asynchronous motor patterns when feeding on more complex prey items (those requiring more processing); however, the motor patterns underlying this asynchrony differed between species. Dogfish process complex prey using head-shaking, which requires alternating activation of contralateral head muscles (i.e. high lag index value). In contrast, little skates process complex prey using a completely unilateral behavior in which prey is moved to one corner of the jaws and jaw muscles are activated on that side only (i.e. high duration index value).