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Diet and prey selection of the southern marsupial mole: an enigma from A ustralia's sand deserts
Author(s) -
Pavey C. R.,
Burwell C. J.,
Benshemesh J.
Publication year - 2012
Publication title -
journal of zoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 96
eISSN - 1469-7998
pISSN - 0952-8369
DOI - 10.1111/j.1469-7998.2011.00889.x
Subject(s) - biology , predation , marsupial , invertebrate , generalist and specialist species , forage , foraging , ecology , abundance (ecology) , habitat , zoology
The two marsupial moles are the sole extant members of the order N otoryctemorphia, an ancient A ustralian lineage, with extreme adaptations for fossoriality. We tested whether the order conforms to the expectation that the low productivity of subterranean environments results in subterranean mammals being generalist feeders. To do this, we examined diet, invertebrate availability in foraging areas and prey selection by the southern marsupial mole or Itjaritjari N otoryctes typhlops , which occupies the sand deserts of southern and central A ustralia. Because the species is so infrequently encountered, we examined digestive tracts from museum specimens which themselves are rare; we obtained access to ∼12% of all specimens available in A ustralia's museums. Our invertebrate sampling protocol was based on a novel survey method, which, for the first time, enables quantification of the distribution and habitat use of N . typhlops . We sampled topographic positions on sandridges and areas of the soil profile (0–70 cm) where marsupial moles forage. Rarefaction methods indicated our sample size was sufficient to record the majority of prey items. Material in digestive tracts of 16 specimens consisted of five insect orders ( C oleoptera, H ymenoptera, I soptera, L epidoptera and O rthoptera), scorpions, spiders and plant material. N . typhlops consumed two main prey types: social insects (ants and termites) and the larvae of beetles. Ants, termites and beetle larvae were also the main invertebrates captured in soil cores on sandridges; other invertebrates combined contributed <5% to abundance. Prey selection assessment using J acobs' index and B onferroni confidence intervals indicated an active avoidance of termites ( D = −0.61), whereas ants ( D = −0.13) and beetle larvae ( D = 0.57) and all other prey categories were taken in proportion to availability. Our results show that N . typhlops is best classed as a dietary generalist despite its specialized adaptations for a subterranean lifestyle.