Foraging by mammalian herbivores has profound impacts on natural and modified landscapes, yet we know little about how they find food, limiting our ability to predict and manage their influence. Mathematical models show that foragers exploiting odour cues outperform a random walk strategy. However, discovering how free-ranging foragers exploit odours in real, complex landscapes has proven elusive because of technological constraints. We took a novel approach, using a sophisticated purpose-built thermal camera system to record fine-scale foraging by a generalist mammalian herbivore, the swamp wallaby (Wallabia bicolor). We tested the hypothesis that odour cues shape forager movement and behaviour in vegetation patches. To do this, we compared wallaby foraging in two odour landscapes: Control (natural vegetation with food and non-food plants interspersed) and +Apple (the same natural vegetation plus a single, highly palatable food source with novel odour (apple)). The +Apple treatment led to strongly directed foraging by wallabies: earlier visits to vegetation patches, straighter movement paths, more hopping and fewer stops than in the Control treatment. Our results provide clear empirical evidence that odour cues are harnessed for efficient, directed search even at this fine scale. We conclude that random walk models miss a key feature shaping foraging within patches.

哺乳动物食草动物的觅食对自然景观和改良景观产生了深远的影响，但我们对它们如何觅食的知之甚少，限制了我们预测和管理其影响的能力。数学模型表明，利用气味提示的觅食者优于随机行走策略。然而，由于技术上的限制，发现自由放牧的觅食者如何在真实，复杂的景观中利用气味是难以捉摸的。我们采用了一种新颖的方法，即使用先进的专用热像仪系统来记录通才的哺乳动物食草动物沼泽小袋鼠（Wallabia bicolor）的小规模觅食。我们检验了气味提示影响植被斑块中觅食者运动和行为的假说。要做到这一点，我们比较小袋鼠两种气味景观觅食：控制（散布有食用植物和非食用植物的自然植被）和+ Apple（相同的自然植被，加上单一的，可口的具有新颖气味的食物来源（苹果））。该+苹果治疗导致强烈的导演小袋鼠觅食：早些时候访问植被斑块，直移动路径，更跳频和比停较少的控制处理。我们的结果提供了明确的经验证据，表明即使在如此小的规模下，气味线索也可以有效地进行定向搜索。我们得出的结论是，随机游走模型缺少修补补丁内觅食的关键特征。