40 PROCEEDINGS OF THE NATIONAL MUSEUM

NO. 3595

ANOLIS LINEATOPUS — ^RAND 41

given in coiirtsliip

and

agonistic situations. Like bobbing, it seems also to serve as an advertisement display.

Orientation:

Though

orientation

by

itself is not a display, certain stereotypedchangesinorientationareimportant

components

ofalmost

all displays. In courtship a

male

orients toward the female,

who

is

usually oriented

away from

him.

He may

turn his

head

to one side so thathis

dewlap

is

more

visible to her. In adispute,

A.

lineatopus frequently does not face its

opponent

directly but turns so that it

presents a side view.

The amount

of turning varies

from

turning the

head

slightly to one side, through a position in

which

the lizard is at right angles to its opponent, to one in

which

the lizard is facing almost directly

away from

its opponent. In disputes in which both lizards aredisplaying, theyfrequentlyapproach one anotherobliquely rather than directly.

In watching a prolonged fight

between two

males, it is possible to predict, on the basis of the angle of each,

which

one will attack next. Lizards that are parallel to one another will usually display rather than attack.

The

closer alizard is to facinghis opponent, the

more

likely he will approach the other; the farther

away

he is facing

from

his opponent, the

more

likely hewillretreat.

Posture: Associated with lateral orientation are postural displays that increase the apparent size of the lizard

when

seen in side view.

In lizards of all sizes the sides are pulled in or flattened so that the

back

is arched

and

the belly extended with the result that the

body

appearsdeeper.

The

throatisgorged: thebase ofthehyoidispulled

down

^so that the throat appears swollen. Frequently the

mouth

^is opened slightly

and

thetongue,

which

isshort

and

broad,israised

and pushed

forward so that the tip appears as a small ball

between

the ends of the jaws.

Finally,

and

in the males only

and most

conspicuouslyin adults, the tissue along the center of the neck

and back

can be raised into nuchal

and

dorsal crests.

The

total effect of these changes is to

make

the lizard,

when

seen

from

the side, appear almost twice as bulky asitnormally is.

The

postural displaysare all associated with disputes

and do

not occur in courtship.

Jaw

fencing:

Though

fighting is not properly considered display,

combat between A.

lineatopus adult males is usually so ritualized that is should be considered here.

Each male

approaches the other slowly until the

two

are an inch or so apart,

head

to head.

They

lungerepeatedlyateachother'ssnoutfora

moment

orso,asiffencing for a hold.

They

then lock jaws,onebiting theother'ssnout

and

the latter biting the former's lower jaw.

The two

lizards then ^strain against one another, each apparently attempting to dislodge the other

from

the perch.

When

one succeeds, the other

may

^fall to

thegroundordangleinmidairfora

moment.

Alternately, onelizard

may

^{attempt to escape, opening his}

mouth and

scratching with a front foot at the ^other's snout. This wrestlingwithlockedjaws

may

last for several minutes

and may

be repeated

two

or three times.

Usually one ^of these encounters is decisive

and

the loser retreats immediately after the bout. I

have

never seen a defeated lizard so injured orexhausted that it

was

unable torun away.

Damage

sometimes results from thesebouts

and

blood ^is drawn, though the

wounds

are restricted to the snout.

Some

males are found with a swelling on one of the mandibles, probably

wounds

from

this sort of

combat

that

have become

infected. (Schmidt, 1928, suggested the

same

thing for A. cristatellus in Puerto Rico.)

The

infected

wounds

apparently are painfid.

One

noosed

male

with an infected

jaw

repeatedly bit

and

released

my

fingerrather than biting

and

holding as a

male

normally does.

The

^preceding descriptions of display provide a foundation for discussing therolethatsocialbehaviorplaysinthespatialorganization of A. lineatopus.

Two

^{sorts of} social behavior

seem

unportant:

courtship

and

agonisticbehavior.

Courtship. —

^{This behavior brings together}

^{male and}

^female

^when

theyare ready to copulate. Evidencesuggests thatit also influences males

and

females to establish

and

maintain overlapping activity ranges

and

in effect toform pair bonds.

This pattern, a

male

with a

home

range shared

by

one or several females that are his mates, is

common among

vertebrates. It is

perhaps

most common among

bu'ds

and mammals

in which the

male and

female shareincareoftheyoung. Itseems widespreadinlizards, particularly iguanids (Anolis sagrei, Evans, 1938a, Oliver, 1948;

Sceloporusolivaceous, Blair, 1960; Utastansburiana, Tinkle,etal, 1962;

Basiliscus vittatus, Ilirth, 1963a;

and Agama

agama, Harris, 1964).

The

role of courtship in establishing this pattern is far

from

clear.

Blair (1960) ^feels that the males of Sceloporus olivaceous seek out the females. In

Agama

agama, Harris (1964) has evidence thatit is the females that

make

the choice, joining a

male

that has established a

home

range.

Hunsaker

(1962)

showed

experimentally that in the Sceloporus torqiiatus group it

was

the

male

bobbing display that

was

attractive to females,

and Hunsaker

suggested that this influenced

them

to settle near the male. Perhaps dewlap displays of the adult

male

A. lineatopus are similarly attractive to females.

Though

the

male

A. lineatopus spends a considerable

amount

of time chasing

and

bobbing

and

dewlapping to females, I observed copulations infrequently. Chases, though frequent, are seldom per- sistent,

and

I never

saw

a

male

catch a female that

was

trying to avoidhim.