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this population which will be a major research focus during the next five

years. This troop has been exempted from Species Survival Plan management,

a program of the American Association of Zoological Parks and Aquariums,

providing freedom to pursue several interesting lines of inquiry. One of

these has to do with the impact of traditional management regimes on

certain life history parameters. The second investigation will pursue

experiments designed to prepare the troop for reintroduction to suitable

habitat in India in five to seven years.

The lion-tailed macaque is by nature a highly social mammal. Group

members are organized in a social hierarchy that appears to remain stable

over many years. Individual troops are highly xenophobic. This trait,

combined with natural aggressiveness, results in potentially fatal conflict

when new individuals are introduced. In the wild state, males will leave

their natal troop at sexual maturity and join a new one. Females remain in

their natal troops throughout their lives.

Transfer by males is accompanied by a substantial amount of

aggression, but is presumably a necessary event to preclude inbreeding.

These natural attributes of wild troops would seemingly have profound

implications for the transfer of individuals, especially of females,

between zoological institutions to satisfy genetic and reproductive

objectives.

It is relevant to ask if the ongoing disturbance of the social order

through frequent inter-institutional transfers might negatively impact on

such parameters as infant mortality, female fecundity, and perhaps even the

neonatal sex ratio. Our kraal group has been together for the past 24

years, the only social disturbances having been the replacement of breeding

males. We have learned how to integrate new males into groups with a

minimum of social upheaval. We therefore have a unique opportunity to

compare findings from our relatively undisturbed population with those from

more traditionally managed populations in other zoos over the next several

years.

Preparation of this same troop for reintroduction to the wild has two

components. The first entails a number of experimental procedures designed

to "teach" natural foraging, avoidance of predators (including humans), and

appropriate social cohesiveness. In addition, the troop must be routinely

evaluated for any pathogens that would pose a hazard to the existing wild

population.

The second component is evaluation of potential release sites in the

wild. The area selected for a test-case reintroduction must not only be

protected from human activity, but must contain adequate food and shelter

to insure the long-term survival of the troop. CRES anticipates working

closely with Indian colleagues on this aspect.

NIGHTTIME IS THE NORM: LABOR AND BIRTH IN THE LION-TAILED MACAQUE

Lion-tailed macaque neonates (newborns) are born with black fur, and

their faces, hands, and feet are pink and hairless. Their characteristic

silver manes do not begin to grow in until the babies are several weeks

old, and their faces gradually acquire the black pigmentation of adults.

When the lion-tailed macaque breeding and management program began at

the CRES primate facility more than ten years ago, little was known about

the gestation, labor, and delivery of infants in this species. There was

extensive documentation of parturition in some other macaques, but no

comparable data were available on the much rarer lion-tailed macaque. How

long is the normal gestation length? At what time are births most likely to

occur? How long does labor last? What factors indicate that there may be a

delivery problem requiring veterinary intervention? Answers to these and

other important questions were needed in order to ensure the best captive

management procedures and to maximize the breeding success for this

species.

The primary reason these data had not been collected previously is

that most new infants were usually discovered in the morning, after the

keepers arrived at work. We began collecting data on each lion-tailed

macaque birth by setting up 24-hour "birth watches" that began several days

before the dam was due to deliver. Conception dates were determined

partially through hormone data from daily urine samples, and also by

keeping careful track of menstruation, sex-skin swellings, and mating

episodes. Parturition-date predictions were based on the 168-day gestation

length documented for the rhesus macaque. However, because this is an

average length, we began our observations about ten days before the due

date in order not to miss the early deliveries.

The birth watch involved round-the-clock observations at 15-minute

intervals during successive, 4-hour shifts. Observations were recorded by

keepers, technicians, and trained volunteers. As soon as any signs of

straining or birth fluids were noted, continuous notes were kept and each

subsequent contraction or birth-related event was timed and recorded.

Behavioral indications of impending labor included restlessness and manual

exploration of the vaginal area. Although these signs eventually proved

reliable, we used the first, clear contraction as the starting point for

measuring the duration of labor. (In human terms, this is equivalent to

second-stage labor. The usual criterion of first-stage labor, cervical

dilatation, cannot be observed in the wild primate unless restraint is

used.) During actual labor, several straining postures were noted; most

common were variations of squatting postures and arched-back stretches.

The first birth was to an experienced mother (this was her third

delivery) and was documented on videotape. After nearly 8 full hours of

labor and 188 contractions, the dam gave birth to a healthy, female infant.

These initial observations led us to believe that a labor of this duration

was not a basis for concern; however, we soon learned that this was far

beyond the average labor length and number of contractions common for this

species.

Over an 8-year period, we were able to collect data on 18 births from

8 different mothers in our colony. Our program has provided some valuable

information about species-typical birth patterns that we can now use to

direct management decisions. We found that the average length of labor to

expulsion of the fetus was about 2 hours and 15 minutes, and the shortest

labor was only 50 minutes total. The female that required eight hours to

deliver in the first case observed then delivered her subsequent infant in

only a little over an hour! Although our sample is still small, it would

appear that, on the average, first-time mothers have longer and more

difficult labors.

Our study determined that the average number of contractions to

delivery for lion-tails was 54. The female with the longest labor also had

the largest number of contractions (454). In her next delivery, the infant

arrived after only 14 contractions, the lowest number recorded during the

entire birth study. Based on the average number of contractions seen in 17

successful deliveries, and one ending in stillbirth, contraction

frequencies approaching 75 to 100 in number may serve as a warning that

intervention will be necessary.

The average length of gestation for 14 pregnancies in our colony was

169.5 days, with a range of 163 to 176 days. This is very similar to what

has been reported for other macaques. Our observers quickly discovered that

those who watched during the 7 to 11 P.M. shifts were the most successful

at being present when births occurred: labor began between the hours of

7:15 P.M. and 3:15 A.M. in every case but one. The exception was one first-

time mother that began straining in the early afternoon. This female had a

difficult labor, and a dead fetus was later removed by cesarean section

after 8 hours of straining and 193 contractions. All the other births

resulted in live offspring and occurred between the hours of 8:05 P.M. and

6:28 A.M. Based on previous primate birth records, daytime births are not

the norm and may indicate an increased risk to both fetus and dam.

Expulsion of the placenta always took place within about 20 minutes

after parturition, and usually it was immediately consumed by the mother.

In a few cases, first-time mothers carried the placenta around for several

hours, along with the infant, until it could be removed by keepers.

Whenever possible, a sample of the placenta is saved for analysis by Zoo

pathologists, who check it for abnormalities. After delivery, the mothers

carefully lick the birth fluids off their infants, and the neonates begin

nursing within a few hours. Each and every female in the study provided

excellent maternal care immediately following parturition.

The lion-tailed macaque breeding colonies are now located in the Sun

Bear Forest exhibit at the Zoo (one adult male and six females) and in a

large, off-exhibit kraal at the Wild Animal Park (one adult male, two

juvenile males, one infant male, and ten females). Together these represent

the largest captive group of lion-tailed macaques in the world -- about 20

percent of the total captive population. Eight years of patient monitoring,

birth watches, record keeping, and evaluation have brought us a long way in

the breeding and captive management of this macaque species.

ZOONOOZ, May, 1990 "Nighttime Is the Norm: Labor and Birth in the Lion-

tailed Macaque," by Helena Fitch-Snyder, Animal Behavior Specialist/CRES

and Donald Lindburg, Ph.D. Behaviorist/CRES.