Many animals rely on fat reserves, to keep them alive through extended periods of food shortage, such as the winter, and to provide additional energy for reproduction. Fat reserves, measured relative to an animal's size, are often referred to as the animal's body condition. The present study investigated how different levels of grazing by domestic stock in native grassland habitat affect the body condition of the pygmy bluetongue lizard (Tiliqua adelaidensis), and if these effects are related to changes in the abundance and size of grasshoppers which are the lizards primary source of food. The initial hypothesis was that lizards would have the highest body condition in moderately grazed paddocks, because those paddocks would have more grasshoppers than heavily grazed paddocks, and better visual conditions for lizards to catch those grasshoppers than in ungrazed paddocks. The results, however, showed that both lizard body condition and the abundance of grasshoppers increased with decreasing grazing intensity. The connection between lizard body condition and abundance of grasshoppers was complex. Within an activity season, lizard body condition generally declined from spring to summer, while the number of grasshoppers grew. The mean size of grasshoppers seemed to be more important, as lizard body condition was higher in spring, the time of year with the largest grasshoppers. These results show that the intensity of grazing by domestic stock influences the body condition of pygmy bluetongue lizards, but that this effect is not entirely due to the reduction in the number of grasshoppers resulting from grazing.

中文翻译：

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放牧方式对濒危侏儒蓝舌蜥（Tiliqua adelaidensis）相对体重的影响

许多动物依靠脂肪储备来维持它们在长时间的食物短缺（例如冬季）中存活，并为繁殖提供额外的能量。相对于动物体型测量的脂肪储备通常被称为动物的身体状况。本研究调查了本土草原栖息地中家畜不同程度的放牧如何影响侏儒蓝舌蜥 (Tiliqua adelaidensis) 的身体状况，以及这些影响是否与作为蜥蜴主要动物的蚱蜢的数量和大小的变化有关食物来源。最初的假设是蜥蜴在适度放牧的围场中的身体状况最好，因为这些围场比重度放牧的围场有更多的蚱蜢，与未放牧的围场相比，蜥蜴捕捉蚱蜢的视觉条件更好。然而，结果表明，蜥蜴的身体状况和蚱蜢的数量都随着放牧强度的降低而增加。蜥蜴身体状况与蚱蜢数量之间的联系很复杂。在一个活动季节，从春季到夏季，蜥蜴的身体状况普遍下降，而蚱蜢的数量却在增加。蚱蜢的平均大小似乎更重要，因为春季蜥蜴的身体状况更高，这是一年中蚱蜢最大的时候。这些结果表明，家畜放牧的强度会影响侏儒蓝舌蜥的身体状况，但这种影响并不完全是由于放牧导致蚱蜢数量减少。