Increases in consumer abundance following a resource pulse can be driven by diet shifts, aggregation, and reproductive responses, with combined responses expected to result in faster response times and larger numerical increases. Previous work in plots on large Bahamian islands has shown that lizards (Anolis sagrei) increased in abundance following pulses of seaweed deposition, which provide additional prey (i.e., seaweed detritivores). Numerical responses were associated with rapid diet shifts and aggregation, followed by increased reproduction. These dynamics are likely different on isolated small islands, where lizards cannot readily immigrate or emigrate. To test this, we manipulated the frequency and magnitude of seaweed resource pulses on whole small islands and in plots within large islands, and we monitored lizard diet and numerical responses over 4 years. We found that seaweed addition caused persistent increases in lizard abundance on small islands regardless of pulse frequency or magnitude. Increased abundance may have occurred because the initial pulse facilitated population establishment, possibly via enhanced overwinter survival. In contrast with a previous experiment, we did not detect numerical responses in plots on large islands, despite lizards consuming more marine resources in subsidized plots. This lack of a numerical response may be due to rapid aggregation followed by disaggregation or to stronger suppression of A. sagrei by their predators on the large islands in this study. Our results highlight the importance of habitat connectivity in governing ecological responses to resource pulses and suggest that disaggregation and changes in survivorship may be underappreciated drivers of pulse-associated dynamics.

中文翻译：

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消费者对孤立居所和连通居所中实验性脉冲补贴的反应。

饮食变化，聚集和生殖反应可促使消费者在资源脉冲后的丰度增加，而综合反应有望导致更快的反应时间和更大的数值增加。先前在巴哈马群岛大岛屿上的地块工作表明，蜥蜴（Anolis sagrei）随着海藻沉积脉冲的增加，丰度增加，这提供了更多的猎物（即海藻有害生物）。数值反应与快速的饮食变化和聚集有关，随后繁殖增加。在孤立的小岛上，这些动态可能会有所不同，在这些小岛上，蜥蜴无法轻易移民或移民。为了测试这一点，我们在整个小岛上和大岛内的地块中操纵了海藻资源脉冲的频率和大小，并监测了四年来蜥蜴的饮食和数值响应。我们发现，无论脉冲频率或幅度如何，添加海藻都会导致小岛上的蜥蜴丰度持续增加。由于最初的脉冲促进了种群的建立，可能通过增加的越冬存活率导致了丰度的增加。与先前的实验相反，尽管蜥蜴在有补贴的土地上消耗了更多的海洋资源，但我们并未在大岛上的土地上检测到数值响应。缺少数字响应的原因可能是由于快速聚集后再进行分解，或者是由于更强的抑制在这项研究中，由食肉动物在大岛屿上捕食的A. sagrei。我们的结果凸显了栖息地连通性在控制对资源脉冲的生态响应中的重要性，并表明分类和生存能力的变化可能是脉冲相关动力的未被充分认识的驱动力。