Body size in Hastings River MousePseudomys oralis(Rodentia: Muridae) from new and old locations

7 Pages·1993·5.5 MB·English

by  D. G. Read

Body size in Hastings River Mouse Pseudomys oralis
(Rodentia: Muridae) from new and old locations
D. G. Read
School of Biological Science, University of New Sourh \\'ales, PO. Box I, Kensington, New South Wales, Australia 2033
This paper presents information on the Creek catchment and by 2.5 km further south
geographical distribution of the rare rodent, in the Fal Brook catchment. There are now
Pseudomys oralis. Body measurements are given five known localities in this state forest and
on 15 male and 30 female adults, representing potentially suitable habitat occurs in the adjoin-
almost 30 per cent of the total number of ing Barrington Tops National Parks and
adults known. Pseudomvs oralis is similar in surrounding private land.
appearance to a common species, Rattwf uscipes - A
I captured animals at 12 localities in the
and features that distinguish these species are
ranges from Mt. Royal (Barrington Tops)
described. Possible confused identification with
3Z010'5"S, 151°19'3"E), north to Billilimbra
the common rat species may partly account for
State Forest (south-west from Casino)
the paucity of locality records for P. omlis.
(29"14'43"S, 152'20'45"E); all within the
History has shown that for a few species their
known geographical range of P. oralis. Twenty-
status as rare was partly due to inaccurate
five of the 48 individuals were trapped at nine
identification in the field. The rare species was
previously unpublished locations (Table 1).
too readily confused with a common species.
Separate localities for the species are defined
However, once this confusion was recognized
as places where a capture site is more than
and correct identifications made, then in many
1 km from any other capture site. The species
cases the rare species was found to be more
was first found at two of these sites in October
common. This may be the situation with the
and December 1990 prior to my trapping:
rare Hastings River Mouse, Pseudomys oralis.
resoectivelv. at Billilimbra bv A. Gilmore. and
There is little information available on the
distribution and biology of P. oralis. Although
Previous published information on the body
two specimens were found in the 1840s it was
dimensions of this species has been based on
not until 1969 that other specimens were
one or only a few individuals (Watts and Aslin
recognized (Watts and Aslin 1981). To date the
1981; Kirkpatrick 1983; Dickman and
total number of captured individuals is at least
McKechnie 1985). The range in head plus
150. More than 70 per cent of these have been
body length given by these authors is
captured since 1985, due to the increased
130-170 mm and the tail length slightly
number of surveys specifically for this species.
shorter; hind-foot length 30-34 mm; and mass
Pseudomys oralis is known from widely 90-100 g. However, there is information based
separated localities and the new locations on more individuals from several unpublished
reported here indicate that their distribution is reports in files and libraries of the Forestry
more continuous than previously thought, Commission of NSW at Coffs Harbour, New-
albeit in very low densities (Map 1). The species castle, and Pennant Hills (Read 1988, 1989a,
was found in creeks and gullies, but some sites 1989b).
were in open forest with a grassy understorey.
In this paper I report measurements taken
Sedges, mainly Cyperaceae and Juncaceae,
on 45 live adult individuals that I captured
were present at all sites. The photographs
during the period 1987-93, including those in
show some of the habitats and capture sites of
Read (1988, 1989a, 1989b) (Table 2). Females
P. oralis. In the Mount Royal State Forest two
with a mass of 55 g had perforated vaginas and
individuals were caught within a small patch of
this mass was used as the lower limit for classifi-
sedges which was approximately 8 m X 15 m
cation as adults. Body measurements followed
in area. Sites in this state forest occur in
the definitions in Watts and Aslin (1981) with
terraces, in gullies and on ridges between
the minor change that the head plus body
gullies.
length (HBL) was taken from the nose tip to
The July 1993 captures of the Hastings the tail base (measured dorsally) and not the
River Mouse in the Mount Royal State Forest total length minus the tail length (TL). I
extend its known range within this region by included the head length (HL) as the length
more than 4 krn northwards into the Davis from the nose tip to the occipital at the back of
Australian Zoologist, Val. 29(1-2) 117
:*YZ
Fip'.I (nfie1,pH1.a srinss River IIouse. This adult fem:rleI 'eishcd 89 g. She Fig 2 (aboi,e)-.l akine:r heacll cngth nteasul-ellcllt. fhc long soft fLrr.i ts
\{its captrlrecl in the Clourls Clreek State Forest in an oDen fot.est open fluffl lexture,:rncl its clzrrkg r-er,colorationt o the basal two-
l'ith a gl'assvu nderstorcv on flat grorrn{l. Clirntps of ieclsesa re thirds of thc hair-s hafts at.ee t.iclenti n this photoeraph.
firuncl scatterecl through thc gr:rss\,e rounclcover. (I'hotog|aph: N{ichelleT hornpson.)
(Photograph: \'Iichelle Thompson. )
I:tg- 3 (aboi't). Tl're heacl plus boclv lenctlr is tire most rlifllctrlt ro meilsLrreo n :l lire
Hastillgs Rivcr NIcltrsc.I tr comtnon rgith clther merlber-s of tlre gerrus
Pseudonls,t lie t;ril can not be pulle(l becausct hc skin rerr casilt Irrcak--:srr rcl
stripso fl. lea'ing the ra*'flesh of the tail. I-hisr .v tail tlics :r.cl rh,,ps.ff'
lea'r'g a st.m1t, Care is takc'n'lre. pulli'g o'thc hirrrll egst ,, hririg rhe
sprne into a srr-aightl ine. phoroeraph: \Iichclle Thontspon.;
Fig'.I (abot,e1I.' l.rca uthor-ueighing a H:rstingsR iver Nlouse
-fltc
in a pl;rsticb as. surlounclins grass is tr'pical of
P. orali.sh abitat in ClloudsC lrcekS tatc !-orest
(l'hotoer:rlth: \lichelle Thonrlrson.)
Itig. 5 (ltft1. .,\ rnalc Hastines River Nftnsc (99 g.) phoro-
grapherl in its habit:rt besicle[ ]r'land (lreck, Blicks
I{iver t-kx:r Rcserve.T he pr,,1t,,rti"nirll\ J:rr-grte stes
:rre evirlent.
11 B AustralianZ oologist,V ol.2 9(1-2) August1 993
Map 1. The region of easternA ustralia that contains the extant
^fhe
distribution of Pseud,omyosr alis. area below 500 m
elevation is shaded grey. Placesn umbered on the map
are referred to in the following table which shows the
dates when individuals were caught, the vicinity and
source of the data.
Date
Place month/
No. year Vicinity Source
I n.a./1969Main Range N.P. Kirkpatrick and Martin
(r971)
2 n.a./1969Swan Creek Kirkpatrick and Martin
( le7 l)
3 n.a./1969Emu Vale S.F. Kirkpatrick and Martin
(197r)
n.a./I969 Gambubal S.F. Kirkpatrick and Martin
(r97l)
8/1993 Gambubal S.F. S. Phillips, pers.c omm.
4 +10/1981Werrikimbe N.P. 1,.G ibson, pers.c omm.
2n982 Werrikimbe N.P. King ( I984)
+I0/1984 Werrikimbe N.P. S. Phillips,p ers. comm.
*3/199I Werrikimbe N.P. S. Wilkes, pers.c omm.
5 10/1982 Blicks River F.R. King (I984)
l0,r1 /1984Hyland S.F. T. Tweedie, pers.c om.
*2/1985 Blicks River F.R. G. King, pers.c omm.
6 l0/r984 Mount Royal S.F. Dickman and
McKechnie (1985)
li 1988 Mount Royal S.F. Read( 1988)
711989 Mount Royal S.F. Read (1989a)
7 r2n984 ForestL and S.F. King and Mackowski
( I 986)
2/1985 ForestL and S.F. King and Mackowski
( l 986)
8 2/1985 Marengo S.F. King and Mackowski
( I 986)
12t1987 Marengo S.F. Read (1988)
I 12/1985 Werrikimbe N.P. S. Phillips,p ers.c omm.
10 10/1987 Chaelundi S.F. P. Catling, pers.c omm.
5/I 988 Chaelundi S.F. P. Catling, pers.c omm.
I l r I/1987 Blicks River F.R. Read( 1988)
l0/1988 Blicks River F.R. D. Read,u npubl. data
7/1989 Blicks River F.R. Read (1989b)
12 7/1989 Wild Cattle Creek T. Tweedie, pers. comm.
S.F.
13 7/t990 Chaelundi S.F. This paper
*8/1992 Chaelundi S.F. S. Phillips, pers.c omm.
7n993 Chaelundi S.F. T. Tweedie, pers.c omm.
14 *9/1990 Dalmorton S.F. A. Gilmore, pers.c omm.
l5 *10/1990 Billilimbra S.F. A. Gilmore, pers.c omm.
6/1991 Billilimbra S.F. This paper
*7/ t99l Billilimbra S.F. S. Phillips, pers.c omm.
rl l/1992 Billilimbra S.F. S. Townley, pers.c omm.
16 r2lr990 Clouds Creek S.F. T. Tweedie, pers. comm.
2/r99r Clouds Creek S.F. This paper
17 2tr99r Timber Reserve P. Catling, pers. comm.
No.80004
18 2lt99r Carrai S.F. P. Catling, pers.c omm.
19 2lr99r Werrikimbe N.P. P. Catling, pers.c omm.
7t1993 Werrikimbe N.P. P. Catling, pers.c omm.
20 3/199r Mount Royal S.F. Shieldsetal(.1 991)
21 8/1992 Carrai (Crown This paper
Land)
*3/1993 Carrai (Crown A. Gilmore, pers.c omm.
Land)
22 711993 Hyland S.F. T. Tweedie, pers.c omm.
23 711993 Mount Royal S.F. This paper
24 711993 Mount Royal S.F. This paper
*Data obtained from the data base held by the National Parks
and Wildlife Seroice of New South Wales. Abbreviations: n.a.,
not available;N .P., National Park; S.F.,S tate Forest; F.R., Flora
Reseroe.
August1 993 AustralianZ oologist, Vol. 29(1-2) 119
Fig. 6 (aboae). In July 1993 a female Hastings River Mouse was captured Fig. 7 (aboue). A terrace of suitable habitat in the Davis Creek area of
in this terrace of sedges, Carex sp., which are about 80 cm high. Mount Royal State Forest. Three individuals of P. oralis were
The site is only 40 m from the cresr of a high ridge in the Mount caught here: among rhe ferns to the right foreground; at rhe edge
Royal State Forest. The ferns and understorey vegetarion of the shorter sedges lit by sunlight in rhe centre of the photo-
surrounding the sedges are more dense than the vegetation at graph; and at the edge of the tall reeds, Phragmites sp., in the
other drier sites in the state forest. middle distance (bleached in photograph). Suitable habiiat at this
. site extends for nearly 150 m and is 10-20 m wide. The habitat is
grazed and heavily trampled by brumbies.
Fig 8 (aboae). A capture site among the sedges shown in photograph 7. Fig 9 (aboxe). This flat area of sedges and grasses in the Mount Royal State
There are at leasr rhree species of sedge here and shorter firni and Forest is home to the Hastings River Mouse and several were
herbs are visible. The vegeration is about 70 cm tall. caught in the area from the log'to the ferns and blackberries to the
left of the photograph. A seepage of water runs down the slope in
Fig. 10 (belou). Habitat of P. oralis in the Crown Land area at Carrai. A the background to saturate the flat area before flowing on down
female was caught among the green tea-tree shrubs in the centre the slope to Fal Brook.
of the photograph. The flat boggy area exrends for more than 100 Fig. I1 (belou). Capture site of P. oralis at Carrai. Among the grasses there
m and is over 50 m wide. Beneath the shrubs there is a dense are several sedge species.T his capture site is at the heaa ofa gully
ground cover of sedges. The New Holland Mouse, pseudomls where.waterseeps to the surface forming boggy conditions. Cully
noaaehollandiae, was also caught here. heads like this one are often good habital foi p. oralis.
120 Australian Zoologist, VoL 29(1-2) August1 993
Table I. Some new locations for Preudm~so rnlir.
Number
Location Latitude Loneitude cauehr Date
Billilimbra S.F.
Chaelundi S.F.
Chaelundi S.F.
Chaelundi S.F.
Clouds CreekS.F.
Carrai (Crown Land)
Mount Royal S.F.
*Mount Royal S.F.
*Mount Royal SF.
Mount Royal S.F.
*These sites are 700 m apart and form one location.
Tobk 2. Body measurements taken on Pseudomy oralii adults: M, male; F, female. See text for abbreviations
Body Standard Sample
parameter Sex Mean emor size Range
HBL (mm)
TL*(rnm)
HL (mm)
1.6 30 36.7-43.7
HFL (.m m.) 0.9 15 30.533.5
F 31.4 1.3 30 28.2-33.7
Mass (g) M 82.3 9.7 15 65-99
F 74.6 11.2 30 55-99
*Some individuals had short tails due to previous injury and1 were excluded from ihr analysis.
the skull. Measurements of HBL and TL were are unlikely to be confused with P. oralis. How-
recorded to the nearest 5 mm graduation on a ever, R. Juscipes looks superficially very similar to
straight rule, but the HL and hind-foot length P. oralis and captures of what appeared to be
(HFL) were recorded to the first decimal place juvenile or sub-adult R. fuscipes may have been
using vernier callipers. Differences between P. oralis. Such possible confusion may partly
sexes are not significant and there is no sexual account for the lack of locality records and also
dimosphiim in this species (Table 2). This is for the lack of records between the 1840s and
demonstrated for head length, which is the 1969. Perhaps due to this similarity P. oralis has
measurement likely to show least variation. been confused with R.f wcipes and so overlooked.
Mean values for each sex are almost identical. In Appendix 1 I describe some features that
The maximum dimensions reported here are help to distinguish between the two species.
in agreement with previous reported
measures, although the larger sample reported
ACKNOWLEDGEMENTS
in this paper included animals smaller than
reported previously. The scope of this paper was greatly
enhanced by critical comments from two
To date there is no published description of
referees and the editor. Financial assistance for
P. oralis juveniles and in Table 2 I did not
some of these surveys was provided by the
include three young individuals: a juvenile
Ethel Mary Read Research Fund from the
male, 16 g; and two sub-adult females, 47 g
Royal Zoological Society of New South Wales.
and 48 g. The fur on the head and body of the
The majority of the surveys was funded by
juvenile male was a smoke-grey colour but the
Earthwatch and its Research Corps. I am grateful
distinguishing features of this species; black
to the 60 Earthwatch volunteers for field assist-
eye-ring, white feet and bi-colonred tail, were
ance and to the Forestry Commission of New
obvious. Some of this grey colour was still evi-
South Wales for the substantial support of staff,
dent in the sub-adult females, although the
vehicles and accommodation for the
adult coloration was predominant.
Earthwatch expeditions. Data also came from
Throughout its range P. oralis is frequently surveys conducted under Special Purpose
found in habitats shared by the Swamp Rat, Permits and specific survey agreements with the
Rattvs lutreolus particularly, and the Bush Rat, Forestry Commission. National Parks and Wild-
R. fuscipes. Swamp Rats have short dark tails, life Service personnel, particularly Mr Murray
dark feet and dark grey to dark brown fur and Ellis, provided substantial assistance with the
August 1993 Australian Zoologist, Vol 29(1-2) 121
" +i;i
Fig. 12 (aborte).N ot all captlrre sites of P. oralis have lush vegetation. A Fig. l3 (abrne1.H abitat of P. oralis irr Clhaelundi State !-orcst u'here a
ver)' small trickle of rvater along this rockl' gullv in thc N,{alenE;o female nas caught inJuly 1990. Further up this gulh, a small seep-
State Forest ivas sufficient to naintain clusters of sedges.A I'emale age supplied \vater to nourish the sedges th:tt gr-e\\,in clustels
P. oraLisn as causht here in 1987. arouncl the pzrtcheso f gt'avel in the gulll becl.
Fig. 11(aboue). A full grorvn male Hastings River Nlouse (87 g) captured Irig. 15 (abotte)A. close-up of a male Hastings River Nlouse (87 g) r:apturecl
in the N{ount Ro1'al Stare Foresr in July 1993. Distinguishing in the Mount Ro1'al State Forest. All inclividuals :rre numbered in
features of this species are the fine rins of black hairs around its sequence of their capture ancl a snall lrole punchccl in the point
eye and, perhaps not clear in this photoeraph, the black hair on of its rieht ear iclentifies this animal as No. 2. Ilv using clifferent
the top of its tail but rvhite hair on the underside of the tail. It is positions and both ears, these holes fbrm a system of permanenr
lhe colour of the hair on the tail that is significant, not necessarily marks. (Photograph: G. A. and NI. N{. Hove.)
the colour of the skin. The hair on the tail of P. oralisi s nearlv tn'ice
the length of hair on a Bush Rat's tail. Bush Rars have short grey
hairs on their tails. (Photoglaph: Ci. A. and M. M. Hoye.)
Fig. 16 (abou). Habitat of the Hastings River Mouse in a gully in the Fig. 17 (abote). An undescribed species of palasitic mire on the eyelid of
Mount Royal State Forest. Beneath the ferns, sedges and grasses a Hastings River N{ouse. 'I'hese mites would get on to the eyelid
rvater trickles over rocks and soaks through gravel beds; just the like this one for a ferv moments, as rhough drinking, before scurry-
conditions favoured apparently by P. oralis. Capture sites in gullies ing back into the fur. Most individuals carrv these very actir,e para-
elservhere do not have such a high cover of ferns but the sedges sites,l 'hich may be almost host specific.O nlr trsiceh ave I noticed
and grassesa re typical of these habitats. these mites on other small ntammals and in each instance thev
(Photoeraph: G. A. and N{. }I. Hoye.) n'ere parasites on Bush Rats, Rattusf uscipes.
(Photograph: G. A. and N,LN {. Hoye.)
cartography. Trapping equipment was LUNNEYD,. , 1983. The Bush Rar Raltufuciper. Pp. 44345
borrowed from the Royal Zoological Society, the in The Atuhalian Mwnrm Co~npieteB ook o / Awlraiion
Momrnak ed by R. Strahan. Angus and Robertson:
University of New South Wales, Charles Sturt
Sydney.
University -M itchell and Mount King Ecological
REAO,D . G., 1988. Sumeys /or the HmIings Riuer ~Woure
Surveys. Drs Barry Fox and Chris Dickman
(Pseudomys oralis) in the Marengo, Hyhnd, and ~Wounl
commented on a draft of the manuscript. Royol Stale ForesLr. Report to the Foresrry Commission
Photographs are by the author except where of New South Wales: Regional Office, Coffs Harbour.
credits are cited. ReD, D. G., 1989a. Caplures of the Halings River Moue
(Pseudomys oralis) in the Mount Royal Stale Forest, July
1989. Reporr to the Forestry Commission of Ne\\, South
REFERENCES
Wales: Regional Office, Newcastle.
DICKMACN., R. AND MCKECHNIEC,. A. 1985. A survey of READ,D . G., 1989b. Caplvres o/ the Harlingr River Mow
the mammals of Mount Royal and Barrington Tops,
(Pseudomys oralis) in Ihe Blickr Riiier Flora Resnue, July
New South Wales. Awl. Zaol. 21: 53143.
1989. Report to the Forestry Commission of New South
KING,G . C., 1984. Habitat utilized by Pseudomys omlls Wales: Regional Office, Coffs Harbour.
Thomas (Rodentia: Muridae). Awl. Mammal. 7: 13947.
SHIEI.DSJ,. M.. YORK,A . AND BINNSD, ., 1991. Flmn and
KINGG, . C. AXD Mxcsows~1C, . M..1 986. Two new localities /auno rumey, Mount Royal managonen1 area, Nnucorlk
for Psnulmyr oralis Thomas (Rodentia: Muridae) in Region. Forestry Commission of New South Wales:
New South Wales. Awl. Mammal. 9: 63-65. Beecroft, New South Wales.
Klnr~A~nlTc.~ H,. , 1983. Hastings River Mouse Pseudomy Wxr~sC, . H. S. AND ASLIN,H . J., 1981. The Rodenls ofAurt-
oral& P. 394 in The Awlrnlian Mwmm Complele Bwk $ ral$. Angus and Robertson: Sydney.
A~rlralion Mammals ed by R. Strahan. Angus and
Robertson: Sydney.
KIRKPATRICKT, . H. AND MARTIN,J . H. D., 1971.
Uncommon native fauna. Qld Aq. J. 97: 174-75 (cited
in King- 1984).
APPENDIX 1
Some features chat distinguish the Hasrings River Mouse, Pseudomy omli~f,r om the Bush hr,R attwficiper.
The similarity in coloration and body size makes it easy to noticeably longer in P. oralb rhan in R./urcipes. The skin on
confuse P. omlb with R. jkcipe~u nless one is aware of the rhe underside of the tail in P. walk is white but in
subtle differences. Compare measurements for P. oralis R./wicpes it is generally pale grey although some individuals
(Table 2) with measurements for R, /wipes obtained from have tails with ve9 light skin colour. Surrounding the eye
Watts and Aslin (1981) and Lunney (1983). Measurements in P. oralis is a narrow, about I mm across. ring of black hair
for R./wcipef: HBL, mean 165 mm and range 90-205 mm; but in R. ficipes the fur coloration is uniform right to the
TL, mean 158 mm and range 105-195 mm; Mass, mean eyelid. The fur coloration on the tail and the black ring
125 g and range 65-225 g. The HFL in R./ucipes ranges around the eye are significant features that distinguish P.
23410 mm. On average P. oralh is slightly smaller than oralis from R.&cipes.
R,fwcipes bur there is substantial overlap in body size. Also,
In P. oralis the mil is about equal to the head plus body Although all rodents have six pads on the sole of the hind
length but in ~ , f i ~ ithpee ta~il is shorter than HBL. foot, differences in the shape and relative positions of these
E~~~ of p. ma& are much thinner than the thick, fleshy ears pads are useful characters for distinguishing different
of ~./usnp~~p.ro file, the nose of p. oralis is very rounded species. Pads on the hind foot of P, oralis individuals are
but the nore of R, jkciper is stmighter. Another physical smooth, oval or rounded in the smaller ones. and uni-
difference is that females of p. oralis have on~?n op irs of formally raised around their perimeter. Pads on the hind
teats set dose together in the inguinal region. ~~~~l~~ of R. foot of R. /wciper individuals have various shapes and are
ficipes may have four or five pairs of teats; three well sepa- not uniformally raised. The long narrow pad, nearest the
rated pairs in the inguinal region. heel, upers level with the sole at irs heel end. The pads of
the centre pair are triangular with the raised apex towards
The dorsal body fur is similar in both species, being a light the toes and are slightly ~h~ inner pad of the pair
brownish-grey. Belly fur in P. oralis tends to be fawn to off nearest the me, tends to be triangular with its apex towards
rvhire whereas in R.fwcipes it is light grey to brown. Fur on the heel anduniformally raised.There areorher more subtle
P. oralis individuals is long and tends to be softer, more open differences.
and fluffy in appearance compared with the more compact
fur ofRfwcipes individuals. Hind feet of P. orolir have white With experience, there are behavioural mannerisms when
hair which extends generally beyond the clans but feet of R, the species are handled that are noticeably different between
/..ips individuals usually have pale grey hain that do not P. oralb and R. Jicipes: rhe former is gentle. calmer and
extend beyond the claws. A distinguishing feature of P. arolh unhurried but the latter is quicker and more agitared. Body
is that the hair on the dorsal surface of the tail is black but odour is also different: P. ornlls has a delicate sweet almost
on the underside it is white. In R. Jucciper the tail hairs, pleasant aroma bur R,/ wipes has a strong, rather pungent
above and below, are uniform pale grey. The tail hair is smell.
Australian Zoologist, Vol 29(1-2) 123