BEHAVIOUR OF AUSTRALIAN PTEROPODIDAE (MEGACHIROPTERA)
BY
JOHN E
. NELSON*
Zoology Depa men ,
Uni e si y o Queensland
.
In oduc ion
The genus
P e opus
(Megachi op e a) is a e y
success ul one, i s membe s
o ming camps
con aining many housands o indi iduals
. Al-
hough_ some obse a ions ha e been made on
he beha iou wi hin he camps (see Eisen au ,
1945, o e iew), no de ailed s udy has been made
o he social o ganiza ion wi hin he camp
.
Kulze {1961) s udied he beha iou in cap i -
i y
,
o
Rouse us
aegyp iacus,
and desc ibed a
la ge a ie y o beha iou al and senso y capabil-
i ies ha con as ed sha ply wi h
he highly
specialized beha iou and senso y abili ies
o
he Mic ochi op e a (G i in, 1958)
.
A s udy o he social o ganiza ion o
P e opus
no only allows a compa ison o he wo Chi op-
e an subo de s, bu i also allows compa ison
o a highly mobile mammal wi h less mobile
o ms such as he p ima es and elephan seals
.
Ma e ials and Me hods
The h ee species o
P e opus
which occu in
sou h-eas e n Queensland we e s udied, bu he
majo i y o obse a ions we e made on he mos
common species-P
.
poliocephalus
Temminck
1825
. O he o he wo species,
P
. gouldi
Pe e s
1867 was p esen a all imes in small numbe s
wi hin
he poliocephalus
camps, and
P
. scapula us
Pe e s 1862 was ound i egula ly
in ei he
poliocephalus camps, o in camps con aining only
scapula us
.
All gene al
s a emen s e e
o
poliocephalus
.
Se en camps wi hin 100 miles o B isbane
we e s udied egula ly, and i egula obse a-
ions we e made in o he camps bo h inside and
ou side he s udy a ea
. All camps in he s udy
a ea we e isi ed mon hly du ing 1961 and 1962
.
Some camps we e isi ed weekly o a mon h o
wo, and Mu willumbah was isi ed daily om
Ma ch 20 h o Ap il 8 h, 1961
. One camp (Eagle
Heigh s) was in a Na ional Pa k, and so was
ela i ely undis u bed by he ac i i ies o man
.
Ca e ul obse a ion o he undis u bed anim-
als and de ailed eco ding o hei beha iou a
he ime
o
obse a ion we e made wi h he aid
o a elescope and a ape eco de
. The lying
*P esen add ess
: Depa men o Zoology and Compa -
a i e Physiology, Monach Uni e si y, Vic o ia
.
544
oxes became dis u bed and ook o he ai as
he obse e en e ed he camp, bu soon se led
down and showed li le esponse o he p esence
o he obse e as long as he emained quie and
did no mo e quickly
.
Some indi iduals could be ecognized du ing
Ma ch and Ap il (when e i o ies we e being
de ended) by he pa e ns
o
bulle holes in he
wing memb anes
. Ou side o his pe iod, in-
di idual ecogni ion was possible only du ing
he sho pe iods o con inuous
obse a ion
(3 o 5 hou s)
.
Some obse a ions o mo he -young beha -
iou we e made on lying oxes held in wi e mesh
cages 50 x 50 x x 100 cm
., in an open- ield
shel e on he oo on he Biological Sciences
Building a he Uni e si y o Queensland,
B isbane
. These animals we e main ained on a
die o cul i a ed ui such as bananas and paw-
paws
.
1
. Locomo ion
Since he social o ganiza ion o an animal
species is g ea ly in luenced by i s mobili y and
senso y capabili ies, i is necessa y o desc ibe
b ie ly he locomo ion and senses o lying oxes
.
The chi op e a a e unique among mammals
in hei capaci y o sus ained ligh
. As well as
enabling lying oxes o explo e la ge a eas while
eeding a nigh , he abili y o ly allows hem o
escape apidly om an app oaching p eda o o
agg essi e membe o he species
.
When dis u bed, lying oxes mo e quickly
om he lowe (o en shaded) b anches, whe e
hey usually hang, o he highe and mo e open
a eas o he canopy whe e hey quickly lap he
wings un il hei bodies a e ho izon al, and hen
a e eleasing hei hold on he b anch hey ly
away
.
Slow mo emen s along he b anch a e made
bipedally
. (The lowe leg bends o wa d om
he knee
.) Fas mo emen s a e made by a quad-
upedal "walk" on he unde side
o
he b anch
. In
he la e , he humb claw a o ds pu chase o
he o elimb, he inge s and ou e memb ane
o
which a e olded along he o ea m
.
Flying oxes usually climb la ge e ical limbs
and unks o ees by an inch-wo m mo ion in
NELSON
: BEHAVIOUR OF AUSTRALIAN PTEROPODIDAE
which bo h humbs a e mo ed up oge he and
g ip a ound he limb and hen he legs a e d awn
up
. Smalle limbs, and occasionally la ge limbs,
a e climbed by al e na i ely ex ending humb
claws and hen al e na i ely o simul aneously
d awing up he legs
.
Landings on exposed b anches a e made ei he
by passing o e he b anch, hen g ipping i wi h
he ee claws so ha he body swings down on
opposi e side o app oach o by hal olling on
app oach side and hen g ipping wi h claws as
he body passes unde b anch
. In mo e con ined
b anches, ho e ing may occu b ie ly while he
ee s e ch owa ds he b anch
. The humb claws
some imes assis in landings
. On he olia ed
edges o he canopy, landings may occu wi h he
ex ending wings p o iding he ac ion un il he
oo claws g asp he b anch
.
2
. Senses
Moeh es (1953) and Moeh es & Kulze (1956)
ound ha he pu e od eye o
P e opus
is well
sui ed o wiligh ision and dep h pe cep ion,
and ha
Ple opus
o ien a es isually e en in e y
dim ligh , bu e uses o ly in comple e da kness
.
I canno na iga e acous ically as he mic o-
chi op e a do ul asonically and he mega-
chi op e an
Rouse us
does audibly (G i in
e
al
.,
1958
; No ick, 1958)
.
Kolme
(1911)
and
Rochon-Du igneaud
(1943) ha e desc ibed he unique olding o he
e ina and cho oid o
P e opus
in o 20,000 o
30,000 conical papillae so ha he ods si "like
he ees in a ange o moun ains
.
. .
. P esum-
ably he ba sees he isual ield a a gi en dis-
ance as a ( ela i ely!) sha p e iculum, he
lacunae o he lace-wo k being much mo e badly
blu ed
." (Walls, 1942)
.
In camps, lying oxes a emp o loca e
g ound dis u bances isually by swaying he
body om side o side abou he hips wi h he
head lexed en ally o do sally
. Used in his
way, a "lace-wo k" e ina would p obably be
e y e icien o isual loca ion among he
ege a ion o a ain o es
.
The senses o ision and hea ing no mally
complemen each o he
. Once he sou ce o a
sound made by he obse e has been loca ed
acous ically, lying oxes ix he sou ce isually
and con inue o ollow he mo emen s o he
obse e a ound he cage
. While "s a ing" a he
sou ce, he pinnae do no oscilla e iolen ly wi h
each new sound
. In con as , he pinnae o an
animal whose eyes ha e been ea ed wi h
a opine, so ha he pupil is dila ed causing em-
po a y blindness, do oscilla e iolen ly wi h each
54
5
sound
. Such ea ed animals a e e y ne ous,
shi e ing and u ina ing con inually and hanging
wi h hei muscles con ac ed, no does he
animal s ike wi h he humb claws a objec s
held close o i s head, o "s a e" a he obse e
.
Howe e , he ea ed animal is able o loca e
ood placed in he cage
. Un ea ed
P
. polio-
cephalus
we e able o loca e ood placed in
open pape sacks which we e placed unde boxes
on he loo o an 8 oo high cage
. The lying
oxes did no no mally come down o he loo
o he cage o ood and wa e we e usually
placed in ays suspended om he oo
.
Rouse us,
a genus ela ed o
P e opus,
is
able o loca e 100 millig ams o banana sub-
s ance and o dis inguish be ween he banana
subs ance and he banana essence (Moeh es &
Kulze , 1956). Kulze (1961) showed ha
Rou-
se us
used i s ol ac o y sense o
. loca ing ood,
o iden i ying he home cages
; and o ecog-
nizing indi iduals
.
Al hough Moeh es & Kulze (1956) ound ha
P e opus
we e e y sensi i e o c ackling noises
such as he b eaking o s icks, no quan i a i e
measu emen s o hei audi o y abili y ha e been
published
. Some neu al il e ing o he noises in
he camp mus occu , o , al hough sleeping
lying oxes espond o noises by qui e ing
mo emen s o he pinnae, hey open hei eyes
and sea ch o he sou ce only when unusual
noises a e hea d
.
P
. poliocephalus
1
. Camps
The e a e wo ypes o camps-summe camps
and win e camps
. The summe camps a e occu-
pied om Sep embe o Ap il o June, and he
win e camps a e occupied om Ap il o June
o Sep embe
. Mos summe camps a e occupied
egula ly each yea and some ha e been o a
leas 80 yea s
. Each win e camp is occupied
con inuously o seasonally o only 2 o 3 yea s
.
In he summe camps he young a e bo n and
aised, he selec ion o a ma e is made, e i o ies
a e es ablished and de ended and concep ion
occu s
. The peak popula ion in hese camps
occu s du ing Decembe and Janua y when
selec ion o a ma e is being made, and be o e
e i o ies a e se up
.
The lying oxes in he win e camps a e
sexually seg ega ed and con ain a la ge pe -
cen age o imma u e animals
. The ul ima e
ac o con olling he popula ion in bo h sum-
me and win e camps is he ood supply (Nelson,
1%5)
.
5
46
~
ANIMAL BEHAVIOUR, XIII, 4
Du ing he day he lying oxes o en g oom
(by combing he u wi h he claws o he ee
and by licking he u and memb anes), sc a ch
(wi h he oo claws), an hei wings, a he mo-
egula o y esponse (Ba holomew
e al
.,
1964),
and sleep wi h hei wing memb anes olded
abou he body
. They a e mos ac i e in he
camps abou dawn and dusk, bu he e a e al-
ways some ac i e a any ime o he day
. The
lying oxes a e leas ac i e du ing ainy pe iods
when hey w ap hei "wa e p oo " memb anes
abou hemsl es and sleep
.
Females a e p egnan om Ma ch o Oc obe
and lac a ing om Oc obe o Janua y o la e
.
Females a e ecep i e o males om abou
Janua y o Ma ch
. Males ha e spe ms in he
epididymis all he yea and will a emp o ma e
wi h emales a any ime
. Tes is ac i i y is
g ea es in he mon h p eceding concep ion and
leas when he species is dispe sed
.
2
. Rep oduc i e Beha iou
(i) Sexual Seg ega ion be o e Concep ion
F om ea ly Sep embe un il ea ly Decembe
he sexes end o be seg ega ed, bu he ex en o
he seg ega ion a ies
. Some imes a ee con-
ains only one sex, o p edominan ly one sex,
and a o he imes bo h sexes a e p esen in
simila numbe s, bu wi h one sex p edominan ly
highe in he ee and he o he lowe down
.
Thus, mos o he social con ac s a his ime
a e be ween indi iduals o he same sex
.
Agg essi e beha iou is no p onounced, be-
ing exp essed in he b ie mild con es s when
he ac i i y o one animal dis u bs ano he
.
Each lying ox shows in e es in i s neighbou ,
and may ouch one wi h a humb claw (and
ecei e a
c y
o p o es ) o lean owa ds one and
un he nose om he ea o he wing inse ion
.
The scapula glands, om which he peculia
odou o lying oxes o igina es, lie unde his
a ea
.
P egnan emales and especially emales wi h
new bo n young a e ne ous, and ly away a
he leas dis u bance
. The males occasionally
app oach emales and a emp o lick he geni al
a ea
. The emales objec o his by ocalizing
and/o bi ing he neck o he male
. I he male
pe sis s in his a emp s, he emale lies away
.
Du ing his pe iod, bo h sexes some imes
engage -in homosexual beha iou , which is
mo e common in he males
. Each pa ne w aps
he wing memb anes a ound he o he , gen ly
bi es and licks he ches and memb anes o he
o he , pulls he claws o he leg h ough he
o he 's u , and ubs he neck and head along
he ches and neck o he o he . This beha iou
is e y simila o he mu ual g ooming which has
been obse ed in such animals as he p ima es
(Washbu n, 1962), and oden s (Eibl-Eibes eld ,
1958)
.
Tha g ooming may ha e a sexual unc ion,
as well as a cleaning one, is u he indica ed by
he obse a ion ha a male occasionally e ec s
i s penis when cleaning i s own memb anes
.
E ec ion also occu s in males which spasmodic-
ally ub he unde side o he chin and side o he
neck along a b anch
. This beha iou is a low
in ensi y o m o "ma king" which is ully
de eloped la e in he b eeding season (Feb ua y
o Ap il)
.
(ii) Pa u i ion
Females gi e bi h o a single young each yea
be ween la e Sep embe and la e Oc obe
.
Du ing pa u i ion he emale hangs by he ee
and some imes by a humb claw oo
. Fo some
ime be o e he appea ance o he oe us a he
opening o he agina, he emales pe iodically
licks he geni al a ea cleaning i o amnio ic luid
.
In all o he obse ed pa u i ion, he young we e
bo n head i s
. The oe us is posi ioned so ha
i s wings a e olded a ound he head
. When he
head appea s a he aginal opening he emale
begins o lick igo ously, in e up ing he lick-
ing only o in es iga e local dis u bances
.
The expulsion o he oe us con inues smoo h-
ly un il all o he head is ou o he aginal
opening, and hen he e is a b ie pause o 10
minu es o longe
. A his s age, he " oe us"
has i s eyes open, wi ches i s ea s slowly bu
wi h no appa en o ien a ion o sound, u ns i s
head abou , and licks i s lips and nose
. The
shoulde s appea slowly
. Then, wi h a iolen
con ac ion, he shoulde s and he es o he
oe us a e o ced ou o he agina
. The emale
uses he mou h and he claws o one leg o hold
he young and o guide i o e he body o he
axilla y nipple
. The newbo n a emp s o
suckle any p o ube ances esembling he ea ,
and can ocalize immedia ely a e bi h
.
Some minu es a e bi h he emale ceases o
clean he u and memb anes o he young, and
begins o chew h ough he umbilical co d close
o he aginal opening . Appa en ly he emale
ea s he placen a, as no aces o i we e ound
on he loo o he cages, o on he g ound unde
he camps, and as pue pe al emales sho a his
ime had blood in he lumen o he undamaged
gu ,
NELSON
: BEHAVIOUR OF AUSTRALIAN PTEROPODIDAE
~
547
(iii) Mo be -Ye eg
Reh ionships aid he De el-
cpiwi o he Youg
The newbo n a e naked on he ches , abdomen
and unde side o he chin, and spa sely hai ed on
he snou
. They a e dependen upon he emale
o main ain hei body empe a u e wi hin he
no mal adul ange (Ba holomew
e al
., 1964)
.
The milk ee h a e pos e io ly cu ed, and he
claws o he ee and humbs ha e hook-like
g ow hs on he inside cu e o he claw acili a -
ing he a achmen o he u o he emale
.
These ju enile ips (which la e all o ) ha e
been desc ibed in
Rouse us leschenaul i
by
McCann
(1941)
.
By ca ching hese claws on he
u and bi ing on he nipple, he young emains
i mly a ached o he emales e en in ligh
. All
mo emen s o he newbo n a e poo ly co-
o dina ed
.
By 3 o 4 weeks he young a e well co-o din-
a ed. They can hang sepa a ely wi h hei wings
olded a ound he body, sc a ch wi h one leg
while hey hang by he o he , clean hemsel es,
h ea en wi h ou s e ched wings when iolen ly
dis u bed ( hough hey do no s ike wi h he
humb claw), climb along b anches, and loca e
dis u bances isually and acous ically
. The u
has g own on he en al su ace and he young
a e able o egula e hei own body empe a u e
.
Howe e , hey a e unable o ly
.
F om bi h un il hey a e weaned a abou 4
mon hs he young become p og essi ely inde-
penden o he emale
. Fo se e al days a e
bi h hey a e a ely seen away om he nipple
.
They g adually become mo e ac i e, i s hanging
om he emale wi h one leg holding he b anch
(Pla e VIII, Fig
. 3) and la e hanging beside he
emale
.
By 3 weeks, al hough hey a e unable o ly,
he young a e le in he camps a dusk when he
emales ly ou o eed
. All o he young a e le
in he same a ea which con ains well olia ed
ees, and which may be on he edge o he day
camp, whe e he lea es a e o en s ipped om
he b anches by he ac i i y o he adul s (Pla e
VII, Fig
. 2)
.
The emales ly wi h hei young o his a ea
a dusk, and hen begin o lick hei o sp ing,
which place i s one leg and hen he o he on he
he b anch
. In he dim ligh i is no possible
o see i he emale is gen ly o cing he young
away om he body wi h he snou
. Bo h hang
oge he o a while be o e he emale lies away
.
The emales e u n be o e dawn, and ci cle
his a ea calling o hei young
. The young eply
as he emale lies abou ho e ing, changing
di ec ion, and inally landing nea one o hem
.
The emale smells he young's ches , and ei he
accep s i by d awing back he wings o expose
he ches , o ejec s i by pushing i away wi h
he humbs and wings, and hen lying away
.
The emale licks he accep ed young igo ously
as i climbs on o he ches , and hen olds he
wings a ound i
.
Labo a o y expe imen s indica ed ha he 3
week old young does no ecognize i s pa en ,
and a emp s o climb on o any emale ha
app oaches i , bu he emales a e able o ecog-
nize hei o sp ing, appa en ly by ol ac ion
.
Females whose young had been emo ed be-
came e y agi a ed when p esen ed wi h clo h
sacks con aining c ying young, bu , once hey
had smelled he sacks, hey emained agi a ed
only nea hei own young
. Kulze
(1961)
e-
po ed ha
Rouse us
emales simila ly iden i ied
sacked young
. He also epo ed ha he young
we e silen when a s ange emale was nea he
sack
.
In an mo ali y is p obably highes du ing he
pe iod when he young a e le in he camps
be o e hey can ly
. Young ha all below he
canopy usually die because, al hough hey can
c awl easily o e hin b anches, i is di icul o
hem o climb he ee- unk o he emales
which a e always eluc an o come below he
canopy o he camp
.
The young a e p esen in he nigh camps om
ea ly No embe o la e Ma ch
. A i s hei
numbe s a e small
(e.g
.
20) bu hey g adually
inc ease o a peak (
.5,000) in Decembe -
Janua y, and hen g adually dec ease
.
The young ly a 3 mon hs (Janua y)
. Thei
pe manen ee h a e de eloped, and hey lea e
he camps a nigh o eed
. Two 3-mon h old
young, held since bi h in cages oo small o
allow ligh , we e unable o ly when eleased
.
When he emales i s lea e hei o sp ing in
he nigh camps, he young lap hei wings as
he emale lies away, bu do no elease hei
hold on he b anch
. As hey g ow olde he
young hal - all, hal - ly om one b anch o
ano he as he emale lies away, o as she lands
on a neighbou ing b anch on he e u n a dawn
.
La e he young ly sho dis ances om ee o
ee, and hen ly sho dis ances om camp a
dusk, be o e hey e u n o se le in he nigh
camp
. They g adually ly g ea e dis ances om
he camp, un il hey ly ou wi h he adul s o
eed
. Fo some ime a e hey can ly, he young
in he day camps mo e o he emales when
ala med, and a e ca ied away by hem
. By 3
5
4
8
~
ANIMAL BEHAVIOUR,
XIII, 4
mon hs, he o sp ing ly o independen ly when
ala med, hough he emales usually lea e i s
.
The e is much a ia ion in he pe iod
o
lac a ion
. Some young lea e he emale a 4
mon hs and join he ju enile packs (see below),
while o he s suckle o a leas 6 mon hs and a
his age (weigh 400 g
.) may e en be ca ied by
he emale (w
. 700 g
.) in ligh
. E en a e he
young can clean hemsel es, he emales egula -
ly clean he u , memb anes and geni al a ea o
hei o sp ing
. Labo a o y young
we e i s
seen in e ing o de aeca e a 6 weeks
.
One
emale and he 4-mon h old young we e seen
mu ually "g ooming" as desc ibed
abo e in
homosexual beha iou
.
(i ) Selec ion o Ma e
Du ing Decembe and Janua y, when
he
peak popula ion occu s in he summe camps,
mos o he social con ac s a e hose made be-
ween he sexes, and in his pe iod he selec ion
o he ma e is made
.
Females, appa en ly wi h hei mobili y e-
duced by nu sing young, end no o mo e abou
he camp unless dis u bed
. Thus he ini ial con-
ac is made by he app oach o a male
. The
emale wi h he o sp ing a he nipple u ns
away om he male, laps he olded wings
agains he sides o he body, and
. calls wo o
h ee imes
. Excep ha he wings a e olded,
he lapping o he emale's wings is simila o
he lapping o he wings be o e she lies away
.
The emale wing- lap may be analogous o some
o he i ualized beha iou pa e ns desc ibed in
bi ds, such as appeasemen beha iou (Tinbe -
gen & Moynihan, 1955)
. The wing lap and
accompanying ocaliza ion inhibi s he agg ess-
i e and sexual beha iou o he male which
u ns away om he emale and ei he ans o
g ooms himsel o else w aps his wing mem-
b anes abou himsel and goes o sleep
. I he
emale emains nea he male, he may s e ch
owa ds he and smell he scapula a ea o a -
emp o lick he geni al a ea
. The emale objec s
a i s , bu g adually ole a es i o longe
pe iods
. In la e Janua y mu ual g ooming be-
ween males and emales is e y common, and
may las as long as hal an hou
.
I was no possible du ing his pe iod o de e -
mine he ex en o he associa ion be ween males
and emales
. Du ing con inuous obse a ions, o
3 o 4 hou s, a male pe iodically landed nea a
emale, bu i could no be de e mined whe he
i was he same o a di e en male ha was
obse ed each ime,
( ) Es ablishmen o Te i o ies
F om la e Janua y onwa ds, he males each
wi h one o mo e emales g adually become mo e
agg essi e as hey begin o es ablish hei e -
.
i o ies
. Figh ing be ween he males
is e y
in ense in la e Feb ua y, bu is less in ense in
Ma ch when he bounda ies o he e i o ies
ha e been lea ned
. (I he camp is dis u bed a
his ime, and he lying oxes mo e o he highe
unoccupied ees, igh ing is e y in ense
.) The
males ma k he e i o ies by ubbing he
scapula glands, which a e maximally de eloped
a his ime, along he b anches
. The male is
much mo e ale and agg essi e han he emale
and so does almos all o he igh ing
. I he
male is asleep he emale may begin a e i o y
igh , bu he ac i i y hen wakes he male who
quickly inishes he igh
.
( i) Composi ion o B eeding Camp
Du ing Ma ch and Ap il he e i o ies a e
es ablished, and he numbe s wi hin he camp
a e oughly cons an
. The densi y o lying oxes
in he camp inc eases om he ou side edge
(whe e he e a e' only I o 5 animals in a ee,
and whe e no all ees a e occupied) o he
cen e (whe e 400 may be ound in each ee)
(Pla e VIII, Fig
. 4)
.
Fou di e en social g oupings a e p esen
in hese camps
:
(a) Gua d g oups, ex ending a ound he pe -
ime e o he camp
.
(b) Family g oups comp ising he majo p o-
po ion o he camp
. These g oups consis o a
male, a emale and a young concei ed by he
emale in he p e ious b eeding season
.
(c) Adul g oups di e ing om he amily
g oups in ha (1) he e a e no young p esen
and (2) he male may be ei he monogamous o
polygamous
.
(d) Ju enile packs
.
( ii)
Gua d G oup
Since ac i i y on he pe ime e is low, he
ees a e well olia ed and no s ipped as in he
cen e o he camp
. The small numbe s o lying
oxes on he edge hang a a ying heigh s in he
ees
.
Bo h sexes a e ound in his a ea bu males
a e mo e common han emales, each o which is
associa ed wi h a male
.
The males p esumably ha e been unsuccess ul
in e i o y igh s in he cen e o he camp and,
in being o ced o he edge, ac as gua ds agains
g ound p eda o s, When he obse e en e ed
NELSON
: BEHAVIOUR OF AUSTRALIAN PTEROPODIDAE
he camp, a leas one o hese gua ds was dis-
u bed
. I ga e an ala m
c y
and, i s acous ic-
ally and hen isually loca ed he dis u bance
.
The nea by lying oxes i s loca ed he one ha
ga e he ala m and hen by obse ing he o ien-
a ion o i s eyes and pinnae loca ed he dis-
u bance
.
( iii) Family G oup and Adul G oup
The males in he amily g oup a e always
monogamous while hose o he adul g oup may
be ei he monogamous o polygamous
. Males
a e dominan o emales, and s op igh s be-
ween emales
o
he polygamous g oups by
mo ing be ween he igh ing pai
. The males in
he adul g oup a e mo e agg essi e and ma k
hei e i o ies mo e o en han hose o he
amily g oup
. The e i o ies in he o me g oup
a e usually smalle han hose in he la e
. The
e i o y o a amily male was o en a ond o a
palm ee and in a la ge ain- o es ee i occu-
pied abou 3 ee o a b anch and a 4 o 6 ee
diame e cylind ical olume abou i
.
In bo h g oups he males ma k he b anches
in wo places-one whe e he male hangs and
he o he whe e he emale hangs
. The ma ked
a ea and he su ounding b anches wi hin
each a e de ended by bo h he male and he
emale, bu he male usually inishes igh s
s a ed by he emale
. Al hough he male is 100
o 200 g
. hea ie han he emale, sexual dimo -
phism is no p onounced, and bo h sexes ha e
la ge canines
.
The membe s o a uni appea o ecognize
each o he by ol ac ion . They o en smell each
o he 's scapula a ea (Pla e IX, Fig. 5), and
especially so when an in ude has been d i en
away om he e i o y and when he e a e dis-
u bances in he camp. Whene e he emale
e u ns o he e i o y, he male mo es om his
posi ion on he b anch o he emale, smells he
scapula egion, and quickly mo es back o his
b anch
. The e is also an exchange o sho so
calls
.
When a male lands among a g oup o adul
uni s, he nea es male gi es a e i o y wa ning
c y
. The o he males o he g oup epea he c y
and mo e o he edges o hei e i o ies,
h ea ening he in ude who is quickly smel
and hen d i en om one e i o y o ano he
un il he lies away
. These h ea s and igh s a e
less in ense when a male belonging o hei
g oup lands and passes h ough hei e i o ies
o his own
. Since he e i o ies ha e been lea n
by his ime, his sugges s ha "as he egocen ic
549
in ag oup agg ession declines, co-ope a ion in
in ag oup agg ession inc eases" (Collias 1944)
.
Some imes a e a male has d i en an in ude
away, he u e s a e i o y c y while lapping one
o bo h pa ly-opened wings o e his ches
.
his male wing- lapping is e y common a
a
when he lying oxes e u n o hei
e i o ies
. A his ime males a e e y ale ,
ac i e, and agg essi e
.
The males in he amily g oup occasionally
igh wi h he young
. These igh s a e o sho
du a ion and low in ensi y
. No males we e seen
d i ing young away, bu he gene al agg essi e-
ness o he male owa ds he young, e en hough
sligh , may d i e he young o he ju enile packs
.
(ix) Ju enile Packs
In la e Janua y, 2 o 3 young may be ound
nea one adul -usually a male
. These g oups
g adually become la ge (as he numbe o
amily uni s become smalle ) un il la e Ma ch,
when hey may con ain 50 ju eniles and 15
adul s, wo- hi ds o which a e male
. These
males show no e i o iali y o agg essi e be-
ha iou owa ds each o he
. They will, howe e ,
d i e o adul in ude s and b eak up in ense
igh s among he ju eniles
. These adul s egula ly
smell each o he abou he scapula gland
.
The adul male does no s ike he ju enile
wi h he humb claws, as happens in many o
he lying ox igh s
. The claw is h us owa ds he
young bu s ops jus be o e i s ches o head
.
O en, only he insides
o
he pa ly olded wings
a e used in hese igh s
.
The ju eniles a e e y ac i e in hese packs,
mu ually g ooming and "play ully" igh ing and
smelling each o he
.
(x) Copula ion
Concep ion occu s in la e Ma ch
. Al hough
he males a emp o copula e wi h emales a
any ime, he emales a e ecep i e only du ing
his pe iod when he e i o ies ha e been es ab-
lished
. In a e i o y pai , copula ion, hough
no necessa ily ejacula ion, occu s se e al imes
a day h oughou his pe iod
.
When he male app oaches he emale o
ini ia e copula ion, his pinnae a e di ec ed back-
wa ds and downwa ds (Pla e VII, Fig
. 2), as a e
he pinnae o igh ened animals . (The pinnae o
young lying oxes end o be limp and so
di ec ed down and back
.) Since he ea s o an
ale o agg essi e animal a e di ec ed o wa ds
and upwa ds, he pinnae o lying oxes a e
used in isual communica ions, as a e hose
o
wol es and dogs
.
55
0
The male ini ia es p ecopula o y beha iou by
mu ual g ooming o by licking he
aginal
opening
. The emale may gen ly ebu he male's
ad ances o a while
. E en ually he male licks
he agina o long pe iods, ocking backwa ds
and o wa ds on he b anch so ha his nose is
h us well in o he geni al opening (Pla e VII,
Fig
. 2)
.
Occasionally he emale ini ia es p ecopula o y
beha iou by w apping he
wings and legs
a ound he male, so ha he suppo s he com-
ple ely, and hen mo ing back o he b anch
.
She epea s his un il he male begins o lick he
geni al a ea o begins he mu ual g ooming
.
Copula ion is pe o med do so- en ally wi h
he male holding he emale's wings be ween he
uppe -a m and his o ea m, and g ipping he
back o he neck wi h his ee h
. The male may
also hold he emale agains his body wi h he
claws o one leg which g ip he emale's abdo-
men
. The penis is e y lexible and can be
mo ed independen ly
o pel ic mo emen s
.
A e copula ion each pa ne g ooms he geni al
a ea and hen he gene al body su aces
.
(xi) Sexual Seg ega ion a e Concep ion
A e concep ion he emales lea e he e i -
o ies and o m g oups o p egnan emales
.
The males con inue o de end he e i o ies o a
ew days be o e hey join male g oups
. Al hough
his seg ega ion is mo e comple e han ha seen
in he summe camps be o e and du ing he
bi h o he young, odd males a e ound among
he emale g oups and ice e sa
.
The sexually seg ega ed g oups e en ually
lea e he camp, ei he sepa a ely in small num-
be s o oge he in la ge numbe s
. Thus 60 males
passed h ough Fishe man Island in ea ly Ap il,
1961, and 1,000 o so seg ega ed males and
emales e-occupied Mu willumbah in May, 1960
.
G oups o old males, occasionally con aining
some imma u e emales, a e he las lying oxes
o lea e he camps in Ap il
. I ood is abundan
as in la e summe 1960, he summe camps,
which a e no mally dese ed in Ap il, may be
e-occupied du ing May and June by seg ega ed
lying oxes
.
The onse o he non- ep oduc i e
phase
a ies h oughou he popula ion so ha some
lying oxes a e de ending e i o ies while o he s
ha e le hei e i o ies o join he seg ega ed
g oups lea ing he camps
. The esul o his is
ha la ge dese ed a eas appea
wi hin he
camps, agmen ing i in o a numbe o smalle
ANIMAL BEHAVIOUR, XIII
. 4
camps, each con aining abou 200 lying oxes
.
The indi iduals o he seg ega ed g oups hang
almos ouching each o he , ye exhibi no e -
i o iali y o agg essi e
beha iou , al hough
hey show g ea in e es in each o he , smelling
egula ly
. Mu ual g ooming is common, and
some males spasmodically ub hei necks along
he b anch once o wice and hen smell o lick
he a ea
.
The imma u e o he ju enile packs a e also
sexually seg ega ed a his ime, imma u e males
showing simila dec ease in size o he accesso y
sex o gans as adul males
. The ju enile packs
lea e he summe camps in Ap il, bu unlike
he adul s, which no mally dispe se h oughou
he species ange (Nelson, 1965), he ju eniles
o m win e camps
.
2
.
Non-Rep oduc i e Social Beha iou
(i) Win e Camps
The win e camps, i s occupied in mid-Ap il
while he summe camps a e b eaking up, no m-
ally con ain e y la ge numbe s o young in
app oxima ely he same p opo ion o adul s
as is ound in he ju enile packs
. In win e s when
he e is an unusually good supply o blossom,
adul s o m a la ge p opo ion o he camp
(Nelson, 1965)
. The numbe s o ju eniles in hese
camps a e such ha he young mus come om
a numbe o summe camps
.
In ea ly win e , he beha iou o he ju eniles
is simila o hei beha iou in he ju enile
packs o he summe camps, whe e mu ual
g ooming and play ul igh ing a e common, and
whe e he in ense igh s a e b oken up by he
adul males in he pack
.
By la e win e , howe e , he sexual seg ega ion
is less appa en as he ju eniles mo e abou he
camp, and he adul males no longe in e e e
in ju enile dispu es
. Mu ual g ooming is com-
mon be ween he same and opposi e sexes, and
ju enile males lick he aginal openings o
ju enile emales, and a emp copula ion
.
O he wo win e camps obse ed in he s udy
a ea, one was dese ed in ea ly summe , he in-
di iduals p esumably mo ing
o a summe
camp, and he o he was occupied h ough he
summe
. Bo h we e occupied in la e summe
when e i o iali y and concep ion occu
. Mos
indi iduals sho a his ime we e i s
yea
adul s, and so he ju eniles had appa en ly e-
u ned o he camps o hei i s b eeding
season
. The young a e ma u e a 18 mon hs
(Nelson, 1965)
.
NELSON
: BEHAVIOUR OF AUSTRALIAN PTER
~
AE
~
551
(ii) Small G oups
Du ing
he win e mon hs he adul s dispe se
h oughou he ange o he species ei he singly
o in small g oups
. These small g oups, and
hose in he summe camps a he beginning and
end o hei occupancy, a e e y di icul o
loca e as he lying oxes hang quie and mo ion-
less among he lea es
.
Indi idual lying oxes eleased du ing he day
in small bushes in an open clea ing we e e y
eluc an o ly, and when o ced o do so, hey
we e a acked by bi ds as hey lew o, and hung
in, he nea es ee
. Small g oups o single lying
oxes no mally a oid hese a acks by bi ds by
emaining quie and well hidden in ees du ing
he day and by lea ing hese shel e s o eed
only du ing he nigh
.
(iii)
Noc u nal Feeding Fligh s
The lying oxes lea e hei camps a dusk in
wo o h ee long wide columns each mo ing in a
di e en di ec ion and each aking up o hal an
hou o ly o e a pa icula poin
. Al hough hese
columns mo e in he same di ec ion each nigh ,
he numbe s in each column a y h oughou he
summe
.
One lying ox may lead he column o a
while, bu will hen u n and ly back along i ,
so ha he leade s a e con inually changing
. The
size o he column g adually dec eases as he
lying oxes lea e i o d ink on he wing om
he i e s, o o eed on he blossom and ui
.
A numbe o lying oxes eed in he same ee
.
Each lying ox announces he possession o a
eeding e i o y by a eeding c y
. These c ies
a e mo e common when he lying oxes i s
a i e in hei eeding e i o ies, which ex end
o 3 ya ds o mo e in each di ec ion
.
The beha iou o eeding lying oxes canno
be clea ly seen in he dim ligh
. Howe e , he
analysis o ocal communica ions o eeding
animals (Nelson, 1964) indica es ha as well as
he igh ing beha iou associa ed wi h he de-
ence o hese eeding e i o ies, lying oxes
also engage in sexual beha iou and mo he -
young beha iou
. Since some o he sexual calls
we e eco ded a he ime when males and
emales o m ixed associa ions, he g oups in
he day camps may ex end in o he eeding
a eas
. The lying oxes e u n o he camp ei he
singly o in small g oups in he hou o so be o e
dawn
.
P
. scsP
W
n
Al hough he seasonal beha iou o his
species is ou o synch ony wi h he o he species,
he gene al pa e n is essen ially he same
. The
species was seen only in he pe iod No embe o
Ap il, and i is assumed ha i is nomadic om
Ap il o No embe
.
The e i o ies a e de ended du ing No embe
.
A e concep ion in la e No embe , he emales
lea e he e i o ies and o m emale g oups
.
The males con inue hei e i o iali y and in a-
g oup co-ope a ion o a ew days be o e hey
join he male g oups
.
Usually he species es ablishes e i o ies in
la ge camps con aining up o 100,000 indi iduals,
and hen a e concep ion i lea es hese camps,
and ei he o ms small
scapula us
camps o
joins
poliocephalus
camps
.
The young a e bo n in May when he species
is dispe sed h oughou i s ange, and a e ap-
pa en ly aised wi hou he p o ec ion o a la ge
popula ion as in he
poliocephalus
camps
. The
young a e ound in ju enile packs wi hin he
camps du ing No embe and Decembe
.
The indi iduals o all species main ain a
ce ain dis ance om one ano he a all imes
.
bu his dis ance is smalles jus a e concep-
ion, i
.e
. when seg ega ed g oups o m
.
P
. scapu-
la us
main ains a smalle dis ance han he o he
species, and a e concep ion he indi iduals lie
agains each o he , e en o ming clus e s o 20
o so wi h each membe o he clus e acing
inwa ds
. This may be a he mo- egula o y be-
ha iou pa e n (Ba holomew
e al
.,
1964)
.
In e speci ic Rela ions
Wi hin he
poliocephalus
camps,
Ple opus
gouldi
is always p esen in small numbe s, while
P
. scapula us
is occasionally ound in ei he small
o la ge numbe s
. The a ious species in mixed
camps usually o m sepa a e g oups, bu i he
numbe s o each species a e small
(e.g
.
5 o 20),
and i all a e in he non- ep oduc i e phase, he
a ious species hang oge he
.
The seasonal pa e ns o beha iou o
gouldi
a e simila o and synch onous wi h ha o
poliocephalus,
so ha wi hin he camps he e is
compe i ion o space when e i o iali y is es ab-
lished
.
P
. gouldi
is la ge and mo e agg essi e
han
poliocephalus,
and his species, as sug-
ges ed by Ra cli e (1931) and indica ed in his
s udy by a sligh inc ease in hei numbe s
wi hin he camps o e he 3-yea pe iod, may be
eplacing poliocephalus
in he no he n a eas
.
55
2
~
ANIMAL BEHAVIOUR, XIII, 4
Howe e ,
gouldi
a ou s ui mo e han
polio-
cephalus,
and his inc ease o
gouldi
may by he
esul o he exploi a ion o he ela i ely un-
ouched ood supply
.
P eda o s-Wedge- ailed
eagles
(Aquila audax)
and
whi e-b eas ed
sea eagles
(Haliaces us
leucogas e )
we e obse ed a emp ing o ca ch
lying oxes by swooping in o he camps
. I a
lying ox sees an eagle app oaching, i gi es an
ae ial p eda o ala m c y, ale ing he o he
lying oxes, which begin o u e he gene al
ala m c y
. I he eagle lands in a ee, he lying
oxes mo e away om ha a ea, bu emain in
he ee, h ea ening he eagle wi h ou s e ched
wings and wi h ocaliza ions
. No eagle
was
success ul in ca ching a lying ox a e ailing
o ca ch one on i s ini ial swoop in o he camp
.
Goannas
(Va anus
sp
.) and py hons (Mo elia
sp
.) sho in he camps had lying oxes in hei
in es ines
.
Discussion
1
. G ooming
Females begin o g oom hei young as soon
as hey a e bo n, and by he ime hey lea e hei
mo he , he young a e spending, and will spend
o he es o hei li es, se e al hou s a day
cleaning he u and memb anes
. I is especially
impo an o keep he wing memb anes clean,
as uncleaned memb anes become less supple
due o in e e ence wi h he p oduc ion o he
oily sec e ion om he epi helial glands
.
In addi ion, g ooming helps o es ablish social
bonds (as i does in baboons (Washbu n, 1961),
which also g oom o long pe iods), and p ob-
ably aids in he de elopmen o sexual beha iou
pa e ns
.
Mos o he ea ly sensa ions o he young,
including g ooming, a e associa ed
wi h he
emale who is ne e a om he o sp ing
.
The
emale egula ly cleans he geni al a ea, as well
as he u and memb anes o he o sp ing, while
i li es li e ally on i s mo he
. The young also
spends much ime en olded wi hin he emale's
wings
. La e in i s li e, he young engages in
mu ual g ooming wi h i s mo he , and his be-
ha iou is iden ical wi h he adul homosexual
and he e osexual mu ual g ooming
.
The p ecopula o y licking o he emale
aginal opening by he adul male may o igina e
om he cleaning o he exc e o y p oduc s om
his a ea o he o sp ing by i s mo he
. Collias
(1956) d ew a simila co ela ion be ween he
smelling and licking o he emale's ex e nal
geni alia by he male goa and smelling and lick-
ing unde he ail o a young kid by i s mo he
.
While he elemen s o hei sexual beha iou
appea o be de i ed om hei associa ions
wi h he emale, he de ails o he agg essi e
beha iou a e lea n i s ly om he male in he
amily g oup and la e by play in he ju enile
pack
. In hese ju enile packs he young assoc-
ia es wi h animals o i s own size and own le el o
expe ience and is p o ec ed, by he adul males
p esen , om he dange s o lack o expe ience
in igh ing
. In hese packs he social bonds a e
g ea ly expanded, and he adul beha iou pa -
e ns, including he con en ions o agg essi e
beha iou , a e lea n
.
2
.
Agg essi e Beha iou
The con en ions
o agg essi e beha iou ,
which a e acqui ed in he p o ec ed a mosphe e
o he ju enile packs, include
ocaliza ions,
ba ing o he ee h, and he a oidance o ac ual
body con ac
. As occu s in se e al o he e e-
b a e species (Eibl-Eibes eld , 1961), igh ing in
lying oxes is i ualized, and a ely ends in dea h
o se ious inju y - o ei he comba an
.
In he summe camps, agg essi e beha iou
and he associa ed
e i o iali y we e
mos
ma ked in he polygamous males, less so in he
monogamous, and leas in he gua d males
. The
adul males in he ju enile packs showed no
agg essi e beha iou
. The o de o dominance
is p obably polygamous males, monogamous
males and gua d males
. In he monogamous
and polygamous g oups, he dominance o he
males s abilizes he g oups, and in he poly-
gamous g oups assu es ha he emale igh s will
be s opped wi hou inju y o he emales
. Al-
hough he male o he amily g oup ne e
ie cely a acks he young o he emale in his
e i o y, he gene al agg essi eness o he male
p obably d i es he young o he ju enile packs
.
3. Ol ac o y S imuli
The odou o a mammal is de i ed om he
ola ile subs ances p oduced by, o p esen in,
aeces, u ine, cu aneous glands and subs ances,
such as soil, which adhe e o he body, Thus he
odou can be a ec ed by ood, me abolism,
ep oduc i e s a e, locali y and o he ac o s
which make o high a iabili y in odou wi hin
he species
.
Cu aneous glands a e common among mam-
mals whe e hey a e ound in all pa s o he
body (see Bouli6 e, G asses')
. Some species ha e
se e al glands which p oduce di e en subs ances
