Dissertation Research: Banner-Tailed Kangaroo Rats and Cache Molds: A Possible Vertebrate-Fungus Mutualism

While many arthropod.fungus mutualisms are known, no comparable vertebrate.fungus systems have been documented. Based on similarities to arthropod.fungal mutualists, banner.tailed kangaroo rats, >Dipodomys> >spectabilis>, are good candidates to be fungal mutualists. In laboratory trials >D>. >spectabilis> consumes moldy seeds and manipulates seeds to influence seed water content and moldiness. Under natural conditions, up to 30 species of fungi, including many important toxigenic genera, were recovered from cached seeds in >D>. >spectabilis> mounds and cheekpouches sampled near Portal, Cochise Co., Arizona. Many of these molds are economically important causes of seed deterioration in human grain storage systems, yet relatively little is known about their ecology in non.human systems. At least some molds associated with >D>. >spectabilis> are unique; five new varieties of >Penicillium> which produce antibiotics, but not mycotoxins, are known only from these caches and cheekpouches. This research will investigate the identity and variability of molds associated with >D>. >spectabilis> compared to molds associated with soil and with seeds of food plants. The impact of molds on the nutritional composition of seeds will be assayed. Field choice trials will be conducted to determine the relative attractiveness of non.moldy and moldy seeds to foraging >D>. >spectabilis.>