the nesting habits of the malaysian wood rai - e-JTAFS

MARDI Res.Bull., (1984)12,I: (81-85)
THE NESTING HABITS OF THE MALAYSIAN WOOD RAI IN THREE
COCOACROPPINGSYSTEMS
KAMAL A. KAMARUDIN*
Keywords: Malaysianwood rat, Nest sites,Nestingmaterials,Nest numbers,Population
correlation.
RINGKASAN
Artikal ini menerangkan tabiat membuat sarangbagi tikus belukar, Rauustiomanicus (Miller) bagi
tiga sistem tanaman koko. Pertalian di antara bilangan sarang dengan anggaranpopulasi tikus juga telah
diselidiki.
Adalah didapati bagi tanaman koko di bawah pohon lindungan Albizzia, tikus membuat sarang
mereka dengan menyusun daun-daun koko ke dalam serpihan kulit kering pohon lindungan tersebut yang
telah jatuh ke atas kanopi koko atau di atas tanah. Bagi koko di bawah lindungan kelapa rendah pula,
sarang dibuat di antara ruang di pangkal pelepah dan batang kelapa. Bahan yang digunakanadalah
d a u n - d a u n k e l a p a d a n k e l o p a k k e r i n g . D a u n k o k o j u g a s e r i n g k a l id i j a d i k a n b a h a nm e m b u a ts a r a n g .B a g i
tanaman koko di bawah lindungan kelapa tinggi. sarangdibina di kanopi pohon koko di atas ranting yang
m a n a d i j a d i k a n p e l a n t a r a nb a g i m e n v o k o n gl o n g g o k k a nd a u n v a n g t e l a h d i s u s u nd i a t a s n v a .B a h a n y a n g
d i g u n a k a n a d a l a hd a u n - d a u nk o k o ,
T e r d a p a t p e r t a l i a ny a n g j e l a sd i a n t a r ab i l a n g a ns a r a n gd e n g a na n g g a r a np o p u l a s it i k u s b a g is i s t e m
k o k o y a n g d i t a n a m d i b a w a h p o h o n l i n d u n g a nk e l a p a r e n d a h .
INTRODUCTION
sites.In the former. the cocoaare planted
v'ith Albizzia speciesas shade. As for the
l a t t e r , c o c o a a r e i n t e r p l a n t e dw i t h c o c o n u t
v a r i e t i e sY e l l o w d w a r f a n d M a l a v a n t a l l . I n
all three areas, the cocoa trees were spaced
about three meters apart. Thev were about
s e ! ' e nt o t e n v e a r so l d a n d b e a r i n g .
The nesting habits of the Malaysian
wood rat, Rattus tiomanicus(Miller) has not
been fully investigated. MEowey (1969)
described that the rat builds loose spherical
nests from green leaves, dry grasses or
similar materialson the ground under shelter
or in higher places in tree stumps or the
crown of oil palms. In cocoa, no mention of
the rat's nest has been recorded except that
the animal is arboreal (KnvnnuorN,
Rnus
TuRrzeN
BaHaRt and Aeo.
Sungai Buloh Estate
Periodic observations about every
three months beginning April 1980 to
D e c e m b e r 1 9 81 w e r ec a r r i e do u t i n a m a r k e d
t r a p p i n g g r i d o f 1 0 x 1 0 s q u a r ep l o t . E a c h
trap-point was nine meters apart, and covers
a total area of about 0.8r1ha. During these
occasions, animals were live-trapped for
three trap nights. A total of 200 traps were
utilized of which 100were placed at the base
of the trap-point (a cocoa tree) and the other
100above ground (tied to a tree branchofthe
same trap-point). Fresh coconut meat was
used as bait. Rats caught during each
trapping round were identified to species,
tallied and removed. Nest counts for the plot
were carried out after each trapping round.
The animal populations were estimated
removal
techniques
the
based on
Mnur-un,1983).
This paper proposes to describe and
discuss the nesting habits of the Malaysian
wood rat in three different cocoa cropping
systems: 1) monocropped cocoa, 2) cocoa
intercropped with dwarf coconut, and 3)
cocoa intercropped with tall coconut. The
interrelationship between nest numbers to
rat population estimatesis also examined.
MATERIALS AND METHODS
Sungai Buloh Estate, Bukit Rotan
Kuala Selangor and Kuala Bernam Estate,
near Telok Intan were selectedas the study
(Cnucsr-pv,1977).
*Cocoa-coconut Branch, MARDI
81
Kuala Bernam Estate
Sirnilar plot sizesand trapping grids
uere used. For cclccla
p l a n t e d l r n d e rv a r i e t t
N{alalan tall coconut. the trappingrnethod o l o - e ra n d n e s tc o u n t i n gw e r e s i m i l a rt o t h a t
c l e s c r i b e dp r e r i o u s l r ' . B u t f o r c t t c o a u n d c r
\ l t r i c t \ Y c l l o r r t l u A r t c o c o n u t \ .t r i l p p i n !u. i t \
a t r n o r e f r e q u e n t i n t c r ra l s . e r e r r l l l 9
davs. Anirnals captureclu ere car-tagged
' , r . i t hn u r - n b e r e N
d 'Ionel-rneta
Nlo . I f i n g e r l i n c
t a g s . S i m i l a r r e c o r c i s r ' , e r e c o l l e c t c c lb r , r t
a n i m a l s r i . e r e t h e n r e l e a s e da t t h e p o i n t t t f
c a p t u r e .T h e r a t p o p u l a t i o n \s\ e r e e s t i m a t c d
r - r s i ntgl r em u l t i p i er e c a p t u r et e c h n i q u eb a s e c l
o n t h e c o m p u t e rp r o g r a r n$ r i t t e n t r r K R E e s
(l97l).
T h e c o r r e l a t i o nu r l r l r s i sh e t n e c n r r c s t
n u n t b e r sa n c l t h e c s t i r n a t e
cl rat populutiorrs
* ere analvzed usinc thc SPSS c()llrputcr
(Ntp.
progranr
HL,t-t-. Jt,.r.'xlr-s.
. rll\ rhc
SrerNeRENxER
a n c lB r , x r . 1 9 7 . i ) O
r c l a t i o n s h i p sf o r c o c o au n c i e rd u a r f c o c o n u t s
u c r e a n a l v z e db e c a u s en r ( ) r cd-; i t a* e r c a r l i i l l t h l e l t s c o n r p a r c ctio t h c o t l i r : r i ' , 'o, i r r c i r s .
RI'ST'I-TS
At SungaB
i u l o h E s t a t c .t h c r a t sc a L l g h t
\ \ ' e r e r r o s t l v R d t t t t s t i o r r t u r t i t ' t r .(sN . l r l l e r ) .
-l-her
b u i l t t h e i r n e s t si n f a l l e nc l e a db a r k so f
the .-1/bi::ia shacletrees that got loclgeclin the
c o c o a c a n o p i c s( F i g u r e / a / . D e a d h a r k st h a t
fell on the grouncl\\crc als()founclto he
s u i t a b l en e s t i n gs i t e s T
. h e n e s t s\ \ ' e r eb u i l t h r
s t a c k i n gg r e e na n c lo l d d r i e d l e a re s i n t o t h e s c b ar k s .
S i r n i l a r l ra t K u a l a B e r n a m E s t a t e .R .
t i o n t u n i c t t s\ \ ' c r e c a u g h t m o s t . F o r c o c o a
i n t e r c r o p p e dn i t h d u a r f c o c o n u tv a r i e t vt h e
n e s t s i t e so l t h e r a t s u e r e l t t c i r t e du i t h i n t h e
c o c o n u tc r o \ \ ' n s( F i g u r e1 b i . N e s t su ' e r eb u i l t
i n b e t u ' e e n t h e s p a c e sa t t h e i i x i l s o f t h e
coconut frorrds or inf'lorescenceand the tree
t r u n k s . T h e n e s t i n gm a t e r i a l sw e r e o l d f r o n d
sheaths and coconut leaf blades with the
m i d r i b s r e m o v e d . S o m e t i m e sc o c o a l e a v e s
w e r e a l s o u s e d , a n d t h e s e m a t e r i a l sn ' e r e
l i n e d a n d s t a c k e di n t h e s es p a c e s .
A s f o r c o c o ap l a n t si n t c r c r o p p e du i t h a
t a l l c r c ( ) c o n u t r a r i et l . t l r c n e s t s \ \ ' e r e
o t r s e r r e c il n t h e c o c o ac a n o p i e s( F i g u r c l t ) .
N e s t s ' u r . e r be u i l t h l s t a c k i n gq r e e n a r r d o l c l
c l r i e dc o c o l rl e u re so n t o p t l f c o c o ab r a n c h e s .
The leavcs \\'ere arranged such that the
b r a n c h e sp r o r i d e d t h c f r a n t e u o r k s u p p o r t .
N e s t s u e r e a l s o o t r s e n n e ci rl r l o o s e c o c o n u t
f r L r i t h u r r c h s t a l k s u h i c h h a d c l e t a c h e cai n d
g o t l o d g ed i n t h e c o c o ac a n o p i e s1Fi g u r eI d t .
N e - s t i n gr n a t e r i a l sc o r n p o s e dm a i n l r o f c o c t l a
l e a v e s s t a c k c d i n t h e b o a t - s h a p e csl p i r t h e .
I - o o s cc o c o n u t f r c i n d st h a t f el l a n d r e m a i n e d
()n the coc()a canopics also prorided
e r c e l l c n t f r a m c uo r k \ u p p o r t f o r n e s t
llLillLltng.
\\'ith lhe exceptionof nestsbuilt in
c o c ( ) n u tc r ( ) \ \ ' l r st.h e n e s t i n gm a t e r i a l sc o m l r o s e d n i t ' r s t l ro f c r ' r c o al e a V e s .\ e r " l v b u i l t
l t c s t sc a n b e d i s t i n g u i s h e df r o r n o l d o n e s b ' n
the decrcc ot qreeness in the ncsting
r r a t e r i a l s .N c s t s u i t h n r o s t l vb r o w n . d r i c d
l u n do l d c o c o a l e a r e s i n c l i c a t eo l d n e s t st h a t
L r s u a l l vh l i t l b e c - na b r r n d o n e d .
Durirrg most of the irest-inspection
r o u n d s i n a l l t h r e e a r e a s .i t \ \ ' a sn o t e d t h a t
( ) n ec o c o n u to r c o c o at r c e $ ' i l l o n l Vh o u s eo n e
nest. The inhabitants of occupied nests
u s u a l l vi n c l u d e de i t h e ra f e m a l e .a p a i r w i t h
) ( ) u n g so r r " i t h o u t .( ) r \ ( ) m c t i n l c j\u \ t \ o u n p \
( I - J r o u n g s) . D r i e d c o c o a b e a n s u ' e r e
l r e q u e n t h o b s e r v e di n t h e s en e s t s .
T h e c o r r e l a t i o na n a l v s i sb e t w e e nn e s t
n u m b e r s a n d t h c e s t i r n a t e dr a t p o p u l a t i o n s
r . ri t h i n t h e t r a p p i n g g r i d s o f c o c o a i n t e r cropped u'ith duarf coconut w'assignificant
( P < i ) .0 I ) . T h e i n t e r r e l a t i o n sihp w ' a sp o s i t i v e
( P e a r s o nc o r r r = 0 . 7 1 - 1 51 .2 : 0 . , 5 1 0 5 ,n :
30. see Figure2).
DISCUSSION
Knowledge of the nestinghabits of the
Malaysian wood rat the dominant rodent
species in most cocoa plantings (FlaN and
BosE. 1980; KaUaRUDIN et ul., 1983),
would be an invaluable assetwhen initiating
c o n t r o l p r o g r a m s .T h e a b i l i t v t o r e l a t e t h e
82
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83
frl
30
40
50
60
100
110
Numberof nests
Figure 2. Interrelationship of nest counts and the estimated rat population at Kuala Bernam Estate
(cocoa under dwarf coconut) betweenApril 1980to December 1981.
rats' nesting sites to the types of cocoa
croppingsystemspractisedfor that particular
The obvious
area would be advantageous.
approach then would be towards habitat
manipulationto reducethe attractiveness
ol
the cocoaeco-system
for rats' inhabitation.
Through good culturaland sanitarypractices
such as regular canopyshapingand pruning
of the cocoatrees,suitablenestingsitescould
be reduced.The rats are deniedof suitable
nest framework and support for nest
building.
For those cocoa intercropped with
dwarf or tall variety coconut palms, removal
of loose coconut fronds that had got lodged
in the cocoa canopies would help restrict not
only the rats movementsbetween canopies,
but also reduce their potential of being a nest
site. Old fruit bunch stalks which provide
excellent nesting sites should also be periodically removed.
Good sanitary measures have been
neglected by most cocoa growers. The
concept behind good sanitation is to lower
the carrying capacity of the area for rat
habitation. Such a practice would provide
the first line of defence and fits into today's
approach for integrated pest control.
In addition, for monocroppedcocoa
(under Albizzia shade trees) periodic
removal of the dead tree-barks that got
lodged in the cocoa canopiesand on the
ground needsto be undertaken.Perhapsa
shadetreethat doesnot easilydebarkshould
be planted instead.
Since there was a good correlation
between nest numbers and the estimated rat
84
density, the former can be usedas an index to
estimate the rat's population for a particular
area. But as has been reported elsewhere
(KavenuorN, 1982), it must be cautioned
that unless the true estimatesof the animal
numbers have been derived, nest counts in
this study only explained 51 percent of rhe
variability of the estimatedrat populations.
ACKNOWLEDGEMENTS
Choon (Sungai Buloh Estate) and Mr. Loh
Hang Pai (Kuala Bernam Estate) for access
to their plantations. Interest shown by the
former Director of Perennial Crops,
MARDI and the Head of Branch on the
study were appreciated. The author also
acknowledged the assistancerendered bv
Raub. Turizan. Haji. Bokhari. tdris. Zainil
and members of the Crop Protection Unit,
MARDI Hilir Perak.
The author thanked Mr. Tan Hens
SUMMARY
T h e n e s t i n g h a b i t s a n d i n t e r r e l a t i o n s h i p so f n e s t n u m b e r s t o e s t i m a t e d r a t p o p u l a t i o n so f t h e
Malaysian wood rat, Rqttustiomanicas (Miller), in three cocoa cropping sysremswere investigated.
For
monocropped cocoa, the rats built their nests in the dead barks of A/blzlla shadetrees. Nesting materials
composed mainly of cocoa leaves.For cocoa planted under dwarfcoconut variety, the rats built their nests
i n t h e c o c o n u t c r o w n s , a n d n e s t i n gm a t e r i a l sw e r e m a d e u p o f o l d f r o n d s h e a t h sa n d l e a f b l a d e s .
The rats
built their nests from cocoa leaves on branches in the cocoa canopies if cocoa were planted under
tall
coconut variety. There was a good correlation between nest numbers and the estimated rat populations
in
t h e s t u d y p l o t o f c o c o a u n d e r d w a r f c o c o n u tp a l m s .
REFERENCES
CaucHl-Ey, G. (1977). Analysisof vertebrate populations. John Wiley and
Sons,New York, 234pp.
Kness, C.J. (1972) Computerprogramsfor
the analysisof demographic
datafrom
smallmammalpopulations.University
of BritishColumbia,Mimeo., 17pp.
HAN, K.J. and BosE, S. 0980). Some
studies on the mammalianpests in
cocoaplantedundercoconuts.Planter,
KualaLumpur,56,273-283.
Meowey, Lono, (1969).Thewild mammals
of Malayct and Singapore. Oxford
UniversityPress,New York, 128pp.
KanRnuolN, K.A., TURrzaNBRsanr and
Aso.
Raue
MauLuo
fl983).
Komposisidantabiatrodensiaperosak
koko. Teknol. Pert.1. 101- 107.
KRuaRuorN, K. A. (1982).The ecology,
peststatusandcontrolof the Malaysian
wood rat, Rattustiomanicus(Miller), in
a cocoa-coconutplantation. Ph. D.
Thesis,MichiganStateUniversity,111
pp.
Acceptedfor publication on ITth November, 1983
85
NrE, N.H., Hur-I, C.H., JENTINS,
J.G.,
STE,NBREN'NER,
K. and BENT, D.H.
( 1975). Statisticalpackogefor the social
sciences (Second edition). McGraw
Hill Book Company, New York. 675
pp.