Use of vegetation chemical signals for digging orientation in the subterranean rodent Ctenomys talarum (Rodentia: Ctenomyidae)

Abstract

Sensory modalities involved in the localization and selection of food represent critical information for understanding the foraging behavior of subterranean rodents. The objective of this study was to determine if a subterranean rodent that forages on aboveground plant parts, Ctenomys talarum, is able to detect the presence of odorous chemicals released by the plants into the soil to guide its excavation, as has been shown for subterranean species that forage on roots and bulbs. Individuals were introduced into an artificial Y‐maze, whose arms were filled with sandy soil in which plants either had or had not been growing (control). Digging activity exhibited in each soil type was recorded. The following plant species, present in the natural habitat of C. talarum, were used: Panicum racemosum (three different concentrations), Cortadeira sp., Margiricarpus pignatus, Ambrosia sp. and Raphanus sativus. The individuals allocated more time to excavation in the soil in which vegetation had been growing in comparison with the control for the five analysed plant species, except in the case of P. racemosum at its lowest concentration. The number of individuals that completed excavation in the tube‐containing soil in which plants had been growing was significantly higher than in the tube‐containing soil in which no plants had been growing, with the exception of P. racemosum at its lowest concentration and R. sativus. The results of the present study suggest that C. talarum have the ability to use olfaction to orient their digging while foraging even though members of this species consume mainly aboveground plant parts.

Resource characteristics and foraging adaptations in the silvery mole‐rat (Heliophobius argenteocinereus), a solitary Afrotropical bathyergid

“…5. Kairomone-guided food location is a strategy that has been evidenced experimentally in several unrelated subterranean rodents in captivity (Heth et al 2002;Lange et al 2005;Schleich and Zenuto 2007). Our data indicates that even the silvery mole-rat can use this strategy.…”

“…For our last experiment, we tested whether silvery mole-rats can discriminate between the soil where food (carrot) has and has not been grown (sensu Heth et al 2002;Schleich and Zenuto 2007). We used 28 individuals kept in a laboratory at the University of South Bohemia.…”

Role of maternal odors on foraging behavior during postnatal development in a solitary subterranean rodent Ctenomys talarum

“…Olfaction represents one of the most relevant behaviors in subterranean rodents due to the singular characteristics of their habitat (Nevo 1999). In adult Los Talas' tuco-tucos, this behavior is related to individual and sex recognition (Zenuto and Fanjul 2002;Fanjul et al 2003), courtship (Zenuto et al 2002b), and digging orientation (Schleich and Zenuto 2007). In the present experiment, the pups displayed early sniffing behavior during ontogeny, and the presence of maternal odors produced relatively longer latencies to consume panicgrass, which suggests that a possible influence of maternal odors on food recognition and/or preference acquisition should not be discarded.…”

Evolution of Brain Size in a Highly Diversifying Lineage of Subterranean Rodent Genus <i>Ctenomys</i> (Caviomorpha: Ctenomyidae)

“…The functional analysis of the middle ear apparatus suggests acute auditory capabilities [Schleich and Vassallo, 2003;Schleich and Busch, 2004]. In addition, two recent studies suggest that tuco-tucos have the ability to use olfaction to orient their digging while foraging [Schleich and Zenuto, 2007] and to rely on chemical communication during the breeding season [Zenuto et al, 2004]. Finally, an experimental analysis using a complex labyrinth showed a highly developed spatial memory in the species Ctenomys talarum [Antinuchi and Schleich, 2003].…”

“…Notwithstanding the assumed simplicity of the subterranean niche, species of Ctenomys are able to perform complex behaviors [Zenuto et al, 2001[Zenuto et al, , 2002Vassallo, 2006;Begall et al, 2007;Echeverría and Vassallo, 2007]. Recent studies suggest that tuco-tucos have the ability to use olfaction to orient their digging during tunnel excavation [Schleich and Zenuto, 2007] and to rely on chemical and acoustic communication during the breeding season and for territory establishment [Zenuto et al, 2002[Zenuto et al, , 2004. To analyze brain size and encephalization of the subterranean genus Ctenomys we used the taxa within the suborder Caviomorpha (South American histricognath rodents) as a reference group.…”