Figueroa Adrian, Chernyavskiy Pavel, Greenacre Michael, Herrera Alyssa, Cuni Lydia, Villate Jennifer, Galetti Mauro, Liu Hong, Whitfield Steven
Department of Wildlife Ecology and Conservation University of Florida Gainesville Florida USA.
Department of Earth and Environment Florida International University Miami Florida USA.
Ecol Evol. 2024 Nov 18;14(11):e70585. doi: 10.1002/ece3.70585. eCollection 2024 Nov.
Consumers employ a variety of foraging strategies, and oftentimes the foraging strategy employed is related to resource availability. As consumers acquire resources, they may interact with their resource base in mutualistic or antagonistic ways-falling along a mutualism-antagonism continuum-with implications for ecological processes such as seed dispersal. However, patterns of resource use vary temporally, and textbook herbivores may switch foraging tactics to become more frugivorous in periods of greater fleshy fruit availability. In this study, we investigated how fleshy fruit consumption of a generalist herbivore-the gopher tortoise ()-shifts intra-annually following seasonal precipitation and subsequently examined how this shift toward increased frugivory influences the suite of plant syndromes dispersed. We noted a clear intra-annual shift toward a more frugivorous diet which coincided with seasonal precipitation and subsequently observed a marked shift in the plant syndromes dispersed with increasing frugivory. We found that as this generalist herbivore became more frugivorous, it dispersed a greater variety of plant syndromes at low levels of frugivory. However, when the gopher tortoise exhibited high levels of frugivory, the seed load was dominated by those exhibiting the endozoochory syndrome. This study illustrates a functional shift in a seed-dispersing herbivore toward that of a classical frugivore, suggesting that temporal variation in foraging strategy and the temporal scale in which foraging habits and seed dispersal interactions are quantified have implications for the suite of plant syndromes species disperse. Furthermore, trade-offs may exist that provide plants with the endozoochory syndrome with a competitive advantage over seeds with contrasting traits, such as the foliage is the fruit syndrome which is expected to experience greater dispersal by classical herbivores.
消费者采用多种觅食策略，而且通常所采用的觅食策略与资源可利用性有关。随着消费者获取资源，它们可能以互利或对抗的方式与资源基础相互作用——处于互利共生-对抗连续统一体上——这对诸如种子传播等生态过程具有影响。然而，资源利用模式随时间变化，典型的食草动物可能会改变觅食策略，在肉质果实可利用性较高的时期变得更加食果。在本研究中，我们调查了一种泛食性食草动物——穴小龟（）的肉质果实消费量如何随季节性降水在一年内发生变化，随后研究了这种向食果增加的转变如何影响所传播的植物综合征组合。我们注意到一年内明显向更食果的饮食转变，这与季节性降水相吻合，随后观察到随着食果增加所传播的植物综合征有显著变化。我们发现，随着这种泛食性食草动物变得更加食果，在低食果水平时它传播的植物综合征种类更多。然而，当穴小龟表现出高食果水平时，种子负载主要由那些表现出内果皮传播综合征的种子组成。这项研究说明了一种种子传播食草动物向典型食果动物的功能转变，表明觅食策略的时间变化以及量化觅食习性和种子传播相互作用的时间尺度对物种传播的植物综合征组合有影响。此外，可能存在权衡，使具有内果皮传播综合征的植物相对于具有不同性状的种子具有竞争优势，例如叶-果综合征的种子预计会通过典型食草动物得到更多传播。
