Content uploaded by James M Trappe
Author content
All content in this area was uploaded by James M Trappe on Nov 29, 2014
Content may be subject to copyright.
Wildlife Research
CSIRO Publishing
PO Box 1139 (150 Oxford St)
Collingwood, Vic. 3066, Australia
Telephone: +61 3 9662 7622
Fax: +61 3 9662 7611
Email: publishing.wr@csiro.au
Published by CSIRO Publishing
for CSIRO and the Australian Academy of Science
www.publish.csiro.au/journals/wr
All enquiries and manuscripts should be directed to:
Wildlife
Research
Volume 28, 2001
© CSIRO 2001
Publishing
© CSIRO 2001 10.1071/WR00105 1035-3712/01/060643
Wildlife Research, 2001, 28, 643–645
Mycophagy by the swamp wallaby (Wallabia bicolor)
A. W. ClaridgeAE, J. M. TrappeBC and D. L. ClaridgeD
ANew South Wales National Parks and Wildlife Service, Threatened Species Unit,
Southern Directorate, PO Box 2115, Queanbeyan, NSW 2620, Australia.
BCSIRO Sustainable Ecosystems, GPO Box 284, Canberra, ACT 2601, Australia.
CDepartment of Forest Science, Oregon State University, Corvallis, OR 97331-7501, USA.
DDepartment of Forestry, The Australian National University, Canberra, ACT 0200, Australia.
ETo whom all correspondence should be addressed. Email: andrew.claridge@npws.nsw.gov.au
Abstract. Microscopic analysis of the scats of swamp wallabies (Wallabia bicolor), collected from a variety of
forested sites in south-eastern mainland Australia, indicates that the species consumes a diversity of species of
hypogeous (underground-fruiting) fungi. The mycophagous (fungus-feeding) dietary behaviour seemingly extends
to habitats recently burned by fire, implying that W. bicolor may be critical in dispersing fungal spores and perhaps
in re-establishing mycorrhizal associations of these fungi with forest trees and shrubs. Such an interrelationship has
been previously demonstrated only for more heavily mycophagous species of ground-dwelling mammal.
Mycophagy by t he swamp wallabyA. W. Claridge
etal.
WR00105
A. W. Claridge, J. M. T rappe and D. L. C laridge
Introduction
Although swamp wallabies (Wallabia bicolor) are among the
more common and widely distributed marsupials in eastern
Australia, few studies of their ecology have been published.
Relevant work includes aspects of home-range size and
activity periods (Edwards et al. 1975; Troy and Coulson
1993), diet (Edwards and Ealey 1975; Hollis et al. 1986) and
habitat selection in relation to forest disturbance history
(Lunney and O’Connell 1988). While often bracketed as
generalist browsers that consume a wide range of plant
materials (Edwards and Ealey 1975; Hume 1999), swamp
wallabies also have been documented as eating a
considerable quantity of fungus through much of the year.
Hollis et al. (1986) reported fungi to occur in 3–29% of food
in forestomachs of culled animals from north-eastern New
South Wales, depending on season; the annual average of
fungi was 15%. The origin of this fungal material was not
determined.
This study was undertaken as the result of a fortuitous
observation on a burned forest site near Orbost in East
Gippsland, Victoria. The site had been burned by prescribed
fire some three weeks previously. Numerous remains of
partially eaten fruit-bodies of the hypogeous fungus
Mesophellia glauca were distributed across the site,
generally in association with shallow scratchings in the soil
profile. These scratchings could not be readily attributed to
any species of ground-dwelling mammal. However, we also
noted recently deposited swamp wallaby scats throughout
the general burned area. This suggested that the wallabies
were excavating and eating the M. glauca fruit-bodies.
Microscopic examination of the scats confirmed that this
was the case. Accordingly, we collected wallaby scats from
other localities to determine how widespread this feeding
behaviour might be.
Methods
In May 1996 we collected fruit-bodies of M. glauca from the burned
forest referred to above (for site details see Millington et al. 1998).
M.glauca is broadly distributed across south-eastern Australia (Trappe
et al. 1996), and is known to form ectomycorrhiza with roots of various
eucalypts (Claridge et al. 1992). Swamp wallaby scats, which are
distinctive from those produced by other macropods, were collected at
the same site from discrete clusters more than 10 m apart. These
samples were frozen in plastic specimen jars for later microscopic
analysis.
Given our observations from the single burned site in East
Gippsland, we decided to further examine mycophagy (the eating of
fungi) by swamp wallabies from across a broader geographic region.
This later opportunity arose during May and June 1999 when we were
sampling fruit-bodies of hypogeous fungi from across 136 plots (50
×20 m) distributed widely over East Gippsland and adjacent south-
eastern New South Wales (described in Claridge et al. 2000). One
sample of swamp wallaby scats was collected from each of 19 sites
during that sample period; only fresh scats, as determined by their soft,
moist texture, were collected to ensure that they represented food
ingested during the cur rent fungal fruiting period. These scats were
dried in a portable food dehydrator and stored in envelopes for
microscopic analysis.
In the laboratory, specimens were thawed if frozen or rehydrated in
water if dried, then macerated in 95% ethanol with a mortar and pestle.
The suspension was stirred and a drop extracted and placed on each of
two microscope slides. Once the ethanol had mostly evaporated it
was replaced by a drop of 3% KOH on one slide and a drop of Melzer’s
644 A. W. Claridge et al.
reagent on the second slide, the latter solution being necessary to detect
the amyloid reaction of the ornamentation of spores of the Russulaceae
and the dextrinoid reaction diagnostic for the genus Hysterogaster.
Mounts on all slides were covered with a cover slip and then scanned
under a compound microscope at ×400 magnification and, when
necessary for spore identif ication, at ×1000. Spores were identif ied as
from hypogeous species (bilaterally symetric spores) or epigeous
(bilaterally asymmetric spores), then to species when possible, or, if not
possible, to genus or family. Because of differences in relative
digestibility of fungi compared with browse plants, it is not possible to
estimate relative ingestion of these different food items from faecal
samples. Similarly, different fungi produce different-sized spores and in
different proportions to the digestible fruit-body volume, so relative
ingestion of the different fungi cannot be accurately assessed from
faecal samples. Accordingly, we estimated proportions of spores of
different fungal taxa in the faecal samples as present (+, 1–25% of
faecal sample), common (++, 26–50%), or abundant (+++, >50%).
These would probably approximate the lower and higher ranges of
undigested fungal material found in swamp wallaby forestomachs by
Hollis et al. (1986). The initial three samples were replicated 5 times,
but the macerated suspension was uniform enough that the same
estimate resulted from each replicate. Consequently, only one slide was
prepared for each reagent for each sample.
Results
All four scat collections from the initially sampled burned
site comprised 25–50% by volume of spores of Mesophellia.
These spores were exactly the same size, shape and general
appearance of spores from the partially eaten fruit-bodies of
M. glauca that were abundant on the same site. Scats from 13
of the 19 subsequently sampled fungus plots contained
fungal spores, ranging from one to nine species per sample
(Table 1). These results further confirm that mycophagy by
swamp wallabies is not restricted to discrete vegetation
types, but rather is a common feeding habit regardless of
habitat.
Discussion
The consumption of Mesophellia glauca in a recently burned
habitat by the swamp wallaby is noteworthy. Thus far, similar
foraging behaviour has been observed only for heavily
mycophagous ground-dwelling mammals such as bandi-
coots, potoroos and bettongs (see Claridge 1992 for
Table 1. Relative abundance of spores of different fungal taxa in scats of the swamp wallaby, Wallabia bicolor
The material was collected during late autumn 1999 from a selection of forest sites in East Gippsland, Victoria, and south-eastern New South Wales.
Site numbers conform to those cited in Claridge et al. (2000). A single sample was collected from each site. Estimated percentage of faecal volume:
+ = 1–25%, ++ = 25–50%, +++ = >50%. (E) = epigeous species; all others are hypogeous
Site No. Fungal taxa Dominant tree and shrub species
6 None Acacia implexa, Eucalyptus albens
8 None Acacia mearnsii, Angophora floribunda, E. albens,
E. cypellocarpa
11 Hypogeous Cortinariaceae +, hypogeous Russulaceae +,
Zelleromyces ++
A. obtusifolia, A. terminalis, Angophora floribunda,
E. consideniana, E. gummifera, E. sieberi
20 None A. falciformis, E. cypellocarpa, E. meulleriana
21 None E. cypellocarpa, E. meulleriana
25 Chamonixia +, Cortinariaceae #1 + (E), Cortinariaceae #2 +
(E), Hydnangium carneum +, Hysterangium +
A. dealbata, E. cypellocarpa, E. obliqua, E. radiata
28 Chamonixia +, Cortinariaceae #1 ++ (E), Mesophelliaceae +,
Russulaceae +
A. dealbata, E. fastigata, E. radiata
53 Chamonixia ++, Gymnomyces + E. dalrympleana, E. radiata
56 Chamonixia +, Cortinariaceae #1 + (E), Mesophelliaceae +,
Scleroderma aff. mcalpinei +
A. dealbata, E. dalrympleana, E. dives
65 Hypogeous Russulaceae + A. stricta, E. baxteri, E. globoidea, E. sieberi
78 Austrogautieria +, Descomyces +, Gautieria +,
Hymenogaster +, Hysterogaster +, Mesophelliaceae #1 +,
Mesophelliaceae #2 +, hypogeous Russulaceae ++,
Scleroderma ++
A. dealbata, A. obliquinervia, E. dalrympleana,
E. pauciflora
89 Castoreum +. Hysterangium +. Gymnopaxillus +,
Scleroderma aff. mcalpinei ++
E. dalrympleana, E. dives, E. pauciflora
96 Cortinariaceae #1 + (E), Cortinariaceae #2 + (E),
Hysterangium ++
A. dealbata, A. kettwelliae, E. radiata, E. viminalis
108 Cortinariaceae #1 +, Hydnangium carneum +, hypogeous
Russulaceae +
A. dealbata, A. melanoxylon, E. radiata
110 None A. implexa, E. baueriana, E. tricarpa
135 Boletaceae + (E), Chamonixia +, Cortinarius aff.
globuliformis +
A. dealbata, E. dalrympleana, E. radiata
142 Hypogeous Cortinariaceae ++, Hysterogaster ++,
Zelleromyces ++, Russulaceae + (E)
A. falciformis, A. mearnsii, E. cypellocarpa, E. bicostata,
E. muelleriana, E. tricarpa
145 None A. dealbata, E. cypellocarpa, E. muelleriana
149 Cortinariaceae #1 + (E), Cortinariaceae #2 ++ (E) A. dealbata, A. melanoxylon, E. dives, E. viminalis
Mycophagy by the swamp wallaby 645
http://www.publish.csiro.au/journals/wr
summary). By way of their feeding behaviour, these latter
animals have been implicated in the dispersal of spores into
disturbed habitats, and consequently in the re-establishment
of mycorrhizal fungal associations in early seral stages after
fire (Claridge et al. 1992). This behaviour can be critical to
the regeneration of mycorrhiza-forming plants immediately
after disturbance, because mycorrhizal fungal associates
may be depleted or lost through the heating effects of fire, at
least near the soil surface (Pattinson et al. 1999). Our data
suggest that swamp wallabies may fulfil the same general
dispersal role as more heavily mycophagous marsupials. The
diversity of fungi ingested by swamp wallabies, and their
focus on hypogeous species, also suggests that they have a
role in maintaining fungal species diversity through their
spore-dispersal activity and perhaps in restoring such
diversity to disturbed sites.
In conclusion, we suggest that much remains to be
learned about the interrelationships among fire, some of the
less heavily mycophagous marsupials (including Wallabia
bicolor), mycorrhizal fungi and ectomycorrhiza-forming
forest trees and shrubs. Studies in this general ecological
field would not only be extremely profitable from the point
of view of better understanding the way in which Australian
forest ecosystems operate, but also may strengthen the
concept that maintaining forest biodiversity is a worthy
goal.
Acknowledgments
For assistance in the collection of samples we thank the late
Martha Claridge. While this manuscript was being written
J. M. Trappe was in receipt of a McMasters Fellowship,
based at the (then) CSIRO Division of Wildlife and Ecology.
At the same time A. W. Claridge was a Post-doctoral Fellow
supported by the Australian Research Council.
References
Claridge, A. W. (1992). Is the relationship among mycophagous
marsupials, mycorrhizal fungi and plants dependent on fire?
Australian Journal of Ecology 17, 223–225.
Claridge, A. W., Tanton, M. T., Seebeck, J. H., Cork, S. J., and
Cunningham, R. B. (1992). Establishment of ectomycorrhizae on
the roots of two species of Eucalyptus from fungal spores contained
in the faeces of the long-nosed potoroo (Po t o ro u s tridactylus).
Australian Journal of Ecology 17, 207–217.
Claridge, A. W., Cork, S. J., and Trappe, J. M. (2000). Diversity and
habitat relationships of hypogeous fungi. I. Study design, sampling
techniques and general survey results. Biodiversity and Conserva-
tion 9, 151–173.
Edwards, G. P., and Ealey, E. H. M. (1975). Aspects of the ecology of
the swamp wallaby Wal l a b i a bicolor (Marsupialia: Macropodidae).
Australian Mammalogy 1, 307–317.
Hollis, C. J., Robertshaw, J. D., and Harden, R. H. (1986). Ecology of
the swamp wallaby (Wa l l ab i a bicolor) in north-eastern New South
Wal e s . I. D i et. Wildlife Research 13, 355–365.
Hume, I. D. (1999). ‘Marsupial Nutrition.’ (Cambridge University
Press: Cambridge).
Lunney, D., and O’Connell, M. (1988). Habitat selection by the swamp
walla by, Wallabia bicolor, the red-necked wallaby, Macropus
rufogriseus, and the common wombat, Vombatus ursinus, in logged,
burnt forest near Bega, New South Wales. Australian Wild li fe
Research 15, 695–706.
Millington, S., Leach, D. N., Wyllie, S. G., and Claridge, A. W. (1998).
Aroma profile of the Australian truffle-like fungus Mesophellia
glauca. In ‘Flavor Analysis – Developments in Isolation and
Characterisation’. (Eds C. J. Mussinana and M. J. Morello.)
pp. 331–342. (American Chemical Society: Washington, DC.)
Pattinson, G. S., Hammill, K. A., Sutton, B. G., and McGee, P. A.
(1999). Simulated f ire reduces the density of arbuscular mycorrhizal
fungi at the soil surface. Mycological Research 103, 491–496.
Trappe, J. M., Castellano, M. A., and Malajczuk, N. (1996).
Australasian truffle-like fungi. VII. Mesophellia (Basidiomycota,
Mesophelliaceae). Australian Systematic Botany 9, 773–802.
Troy, S., and Coulson, G. (1993). Home range of the swamp wallaby,
Wallabia bicolor. Wildlife Research 20, 571–577.
Manuscript received 21 November 2000; accepted 3 September 2001
