volume 7, NuMber ?

March/April 1978

Contents

3 Mother & Young

Il ZooNews

15 Bluebirds

21 BookNews

23 FONZNEWS

Front Cover: Ties between mother and baby

hoofed animals, like these scimitar-horned

oryx, is the subject of a fascinating NZP-

FONZ study at the Zoo.

Back Cover: Kodiak cubs are just one of

several bear happenings at the lower end of

Beaver Valley. Come fall, the entire valley

will open with dramatic exhibits of seals, sea

lions, otters, wolves, foxes, and of course,

beavers.

Design-Production:

Monica Johansen Morgan

Copy Editor:

Mary Massey

Photographs on front cover, pp. 4, 7, 8, 9, 10,

12, 14, and back cover by Francie Schroeder;

p. 3 by Sabin Robbins; p. 5 by Beth Meritt;

p. 6 courtesy of Smithsonian Institution, Of-

fice of Photographic Services; pp. 15, 18, &

20 by Lawrence Zeleny; pp. 16 & 17 by Gee

Gee Geitgey; illustration on p. 21 courtesy

of Johns Hopkins University Press by Alfred

Godin.

Friends

of

the

National

is a non-profit organization of individuals and

families who are interested in supporting Zoo

education, research, and conservation.

As a FONZ, you and your family receive

FONZ Board of Directors 1977-78

Stephen T. Hosmer, President

John S. Brown, First Vice President

Nancy Porter, Second Vice President

M. Anthony Gould, Treasurer

Victor Delano, Secretary

Nella Manes

Cecil McLelland

Sheila D. Minor

Robert L. Nelson

Peter C. Andrews

Theodore Babbitt

Edward G. Boehm

Janice A. Booker

Montgomery S. Bradley John B. Oliver

Timothy V.A. Dillon Whayne Quin

Ronald J. Field Ross Simons

Donna Grosvenor Julia V. Taft

Julie P. Hubbard Lee Talbot

Sally S. Tongren

FONZ Staff

Sabin Robbins, Executive Director

Dennis Baker, Associate Director

Donna Schlegel, Volunteer & Educational

Services

Monica Morgan, Membership & Publications

Danny Daniels, Food Services

Lonnie Wornom, Merchandising

Renee Caldwell, Parking & Maintenance

many benefits — publications, discount

privileges, and invitations to special pro-

grams and activities — to make your zoo-

going more enjoyable and educational.

THEZOOGOER is published bi-monthly and

copyrighted © by Friends of the National

Zoo, c/o National Zoological Park, Wash-

ington, DC 20008, third class mailing permit

44282. Subscription fee is $4 a year (of

annual dues).

Zoo Staff

Dr. Theodore H. Reed, Director

Mr. Edward Kohn, Deputy Director

Office Chiefs

Mr. Jaren Horsley, Animal Management

Dr. Christen Wemmer, Conservation &

Research Center

Dr. Mitchell Bush, Animal Health

Dr. Richard Montali, Pathology

Dr. John Eisenberg, Zoological Research

Mr. Emmanuel Petrella, Facilities Manage-

ment

Mr. Robert Engle, Construction Management

Mr. Joseph Reed, Management Services

Mr. Robert Mulcahy, Graphics & Exhibits

Ms. Judy White, Education & Information

Mr. Samuel Middleton, Police & Safety

other & Young

other-Young Ties

in Hoofed Mammais

by Dr. Katherine Ralls

Research Zoologist

common sight at the Zoo

A last spring and summer was a

FONZ observer stationed in front

of a hoofed stock enclosure.

Equipped with clipboards, data

sheets, stop watches, and often

binoculars, these volunteers log-

ged over 700 hours of behavioral

observations.

The presence of one of these ob-

servers was a sign that a baby had

recently been born, for these vol-

unteers were gathering data for a

study of mother-young | inter-

actions in ungulates, or hoofed

animals, like zebra and wilde-

beest. My colleagues and | in the

Office of Zoological Research are

interested in comparing the re-

lationship between mother and

baby in different species and

seeing how this relationship

changes as the baby matures. (Be-

cause there are so many terms,

such as calf, kid, fawn, lamb, and

foal, used to describe baby

ungulates of different species, we

decided to simplify matters by re-

ferring to them all as babies.)

Previous Page: Wobbly but walking, the

Zoo’s day-old zebra will keep close to his

mother while growing up.

The Zoo’s hoofed mammals, like this duiker mother and child, are being studied by FONZ

volunteers to learn more about mother-young relationships in different species.

Baby ungulates come in two

basic “models” —those that initi-

ally stay close to their mothers,

then gradually spend less time

with them as they get older, and

those that spend the first days of

their life at some distance from

their mothers, usually concealed

in vegetation, and gradually

spend more time with them as

they get older. These two types

are often loosely called “fol-

lowers” and “hiders.”

Both following and hiding help

protect the babies from being

attacked by predators. A hiding

baby is isolated, inactive, and

concealed for most of its early

life, thus making it unlikely that a

predator will see or hear it.

Furthermore, the mother usually

eats the afterbirth, drinks the

urine, and eats the feces of baby

while it is in the hiding stage. It is

thought that in some species the

baby’s scent glands do not pro-

duce scent for the first weeks of

life. All of these factors make it

difficult for a predator to find a

baby by smell.

In fact, the hiding system seems

to have so many advantages for a

young, helpless animal that one

wonders why there are species in

which babies do not hide. To

understand this, one must know

that most of the hiders belong to

species in which the father plays

Baby Nile hippos, like rhinos, reindeer, and zebra, are called “followers” because they

stick close to their parents for protection instead of hiding in isolation.

no part in defending his offspring.

Defense of the baby is up to the

mother alone, and she may be

helpless against predators much

larger than she is or that travel in

packs. Some follower species,

such as rhinos and hippos, are

very large animals, so the mother

alone may be able to do a good

job of defending her baby against

predators. Others, like zebras, be-

long to a tightly-knit family group

containing a stallion who helps

defend the baby. The babies of

gregarious, migratory follower

species, such as reindeer and

wildebeest, must be extremely

well developed and able to run

behind their mothers soon after

birth. In a sense, these babies are

“hiding” in a dense herd of their

own species rather than in con-

cealing vegetation. Such species

also tend to have a very short

birth season. So many babies are

born in such a short period of

time that predators are simply

overwhelmed .

Although these basic facts are

well known, a more detailed,

quantitative comparison of the

mother-baby relationship in dif-

ferent ungulate species has never

been made. Many scientists have

studied a single species, but it is

often difficult to compare their

results with those of other studies

because two investigators rarely

collect data in the same way.

The basic nature of the mother-

baby relationship seems relatively

unaffected by captive conditions.

Hiders hide and followers follow

whether they are born in the wild

or in captivity. Thus, the behavior

of mothers and babies is a good

field of study for a zoo.

Present theories on mother-baby

interactions in mammals are

based mainly on studies of small

mammals, such as rats and cats,

and of primates. Because these

studies were done on captive

animals, data on zoo ungulates

should be comparable.

The Zoo's young giraffe was among the 20 babies of ten species observed in an important

study to learn more about how different hoofed animals use different techniques to protect

their young.

The National Zoo’s collection lets

us compare followers and hiders

-\ both within and between related

_ groups of ungulate species. In the

cervidae, or deer family, muntjac

and brockets are hiders while

reindeer are followers. In the

bovidae, or cow and antelope

family, the dorcas gazelle, sable,

bongo, and scimitar-horned oryx

are hiders while the blesbok and

white-bearded wildebeest are

followers. All babies in the

equidae, or horse family, like

zebras and onagers, are followers,

and so are those of all the hip-

popotamus and rhinoceros species.

Observers in 1977 collected data

on 20 babies of ten species: three

dorcas gazelles, three reindeer,

six oryx, two wildebeest, and one

each of bongo, sable, pygmy

hippo, Nile hippo, giraffe, and

waterbuck. Each baby was ob-

served for one hour on three

mornings a week until it was 12

weeks old.

Although many baby ungulates

are charming and attractive crea-

tures, the task of the observer is

not always pleasant. Observa-

tions must be done on schedule

regardless of the weather, and

pesky insects sometimes plague

both animals and observer. Either

A newborn wildebeest may be helpless at

birth, but in minutes it can stand, walk, even

run.

mother or baby may disappear

from view by going in a building

or behind a clump of trees. Ob-

servers watching dorcas gazelles

have a particularly difficult time

for the first three weeks or so be-

cause these babies are expert

at finding good hiding places.

Furthermore, merely discovering

a telltale nose or foot protruding

from a clump of weeds or from

behind a fallen log is not enough.

There are often three or four

babies of similar age in the dorcas

gazelle yard, and the observer

must identify the correct one.

Beautiful at birth, a baby bongo antelope has the same striking striping as its parents.

Sometimes binoculars are needed

to check the colored ear tag of

the baby.

The information recorded by ob-

servers includes the number of

times the baby and mother ap-

proach and leave each other,

nursing times, and identity of the

animal closest to the baby, the

distance between the mother and

baby, and whether or not the

mother and baby are lying down.

Some interesting results have al-

ready emerged, although it will

probably be necessary to con-

tinue the study for at least two

more years to obtain an adequate

sample size. The Nile and pygmy

hippos were similar in a number

of ways. Babies of these species

spent most of their time close to

their mother, usually touching.

This was in contrast to all the deer

and antelope babies, who act-

ually touched their mothers in-

frequently, usually when _ being

nursed or licked. Contact be-

tween mother and baby is com-

mon in the taxonomic group to

which the hippos belong (subor-

er suiformes) and in many other

aquatic mammals, such as sea ot-

ters, manatees, and grey whales.

The reindeer and _ wildebeest

babies were similar in many re-

spects, although in general, wilde-

beest proved to be _ better

“followers” than reindeer, spend-

ing more of their time close to

their mothers.

A helping nudge from mother launches this

newborn scimitar-horned oryx on its walking

way. Although classified a “hider,” oryx

young behave like “followers” in spending

less and less time with the mother as they

grow up.

The “hiders” proved to be a more

diverse group. Subdividing them

into smaller groups of species

showing similar behavior patterns

and trying to understand the

reasons for the variability of be-

havior from group to group may

ultimately turn out to be the most

fascinating aspect of the study.

For example, although the scimi-

tar-horned oryx resembled other

“hiders” in some ways, time spent

close to their mothers decreased

as they grew older. This pattern is

typical of “followers,” such as

wildebeest and reindeer, and

the opposite of that found in

other “hiders,” like the bongo,

dorcas gazelle, waterbuck, and

sable, all of whom spent more

time close to their mothers as

they grew older. Will next year’s

baby oryx show the same pattern?

If so, how does this behavior re-

late to their life in the wild?

Sable antelope babies are “hiders” not “followers.” As they get older and stronger, they will

spend more and more time with their parents.

10

week shift for a month or more.

Volunteers always have the op--

—_— — :

once

Animal behavior is one of the

most vital and growing areas or

: research in the Zoo. FONZ vol- :

-unteers have stood in winter _

“snows to record the mating be-

havior of red pandas, sweltered

under the summer sun watch-

ing mother/young interactions

in hoofed stock, and kept mid-

-night vigils in the Elephant.

House. The time commitment _ |

involved depends on the ~

specific watch. It may bea

one-time three-hour shift, as in

the yearly giant panda watch, or

an on-going once- or twice-a-

tion of saying “no” when asked

‘if they would like to peiclea :

ina given watch.

The next Lainie for this pro-

gram will be in the fall. It will |

be two consecutive Saturday

mornings from 10:00 a.m. to

12:00 noon. The two classes

are required for participation

in behavior watches. If you are

interested, please call cee

Morton at 232-7703.

ZOOS

Bald Eagle Born;

First in Five Years

by Sheryl Gilbert, Pam

Kramer, & Paul Tomassoni

Bird Keepers

After struggling 24 hours to peck

out of its shell, the fuzzy, pale

gray chick staggered to its feet,

then squeaked loudly for food. It

was early on the morning of April

19, and the Bird House staff had

just witnessed the hatching of a

bald eagle—the first in five years

at the National Zoo.

Unlike its emblematic parents,

the ungainly little creature had a

large head and belly, nearly

straight beak, and tiny feet. But

to the Zoo staff that had worked

years for this moment, the perky

chick was a beautiful bird! Ap-

propriately, it was named “‘Ira-

teba,” a Mohave Indian word for

“beautiful bird.”

The day after hatching, lIrateba

was fed every two hours between

6:00 a.m. and 8:00 p.m. on a diet

of raw chicken, vitamins, and

minerals devised by the zoo’s

nutritionist. From the beginning,

the eagle’s appetite was out of all

proportion to its tiny size. It vor-

aciously swallowed the bits of

meat which were offered with for-

ceps, and in the first four weeks,

had grown from 70 to 1,300

grams. Later, between two and

three weeks of age, it learned to

eat from a dish. At a month, Ira-

teba’s feet were large and well

developed, but still not very func-

tional. The eaglet usually lay on

its belly, only rising to sit on its

hocks during meal times and

move clumsily around the cage.

lrateba was housed in an “iso-

lette’—a hospital incubator for

infants—and later moved to a

two- by four-foot pen lined with

green indoor-outdoor carpeting.

This move was possible because

as it grew larger, the eaglet could

regulate its body temperature.

Careful consideration had been

given to Irateba’s future. The

first choice was to put it in a wild

bald eagle nest, where it would be

raised by its own kind. Several

suitable nests were located, but

on the day of departure, a swell-

ing was found on _Irateba’s

head. The zoo veterinarian ad-

vised a delay until the bird had

completely recovered.

To date, Irateba_ is still sched-

uled to become a member of the

wild population of bald eagles,

but if it must stay in the Bird

House for a lengthy recovery, it

will be kept until it can fly, then

released to live independently.

For some time, bald eagles have

been declining in the United

States. Many of their eggs have

been crushed in the nest, because

the shells were weakened by pes-

ticides. Those that hatch face an

increasingly hostile environment,

and few survive to four years,

when they are ready to reproduce.

To help reverse this alarming

trend, ornithologists have fol-

lowed two approaches. One is to

increase the number of eggs laid

by encouraging some birds to lay

two or three times each season,

hoping to make up for those

which are not laying at all. The

other is to increase the number of

young reaching adulthood by

rearing some incubator-hatched

chicks in the protected environ-

ment of a zoo or laboratory and

by offering others to pairs of

eagles who will raise them as their

own. Irateba’s story illustrates

these two strategies at work.

Under natural conditions when

birds lose their eggs or their young

to predators or bad weather, they

often repeat the breeding cycle

by laying a second set of eggs.

This phenomenon, called “re-

cycling,” is now being used to

double the number of bald eagle

eggs available. Working with cap-

tive birds at Patuxent Wildlife

Research Center, Dr. Stanley Wie-

meyer was the first to deliberately

remove the first clutch from a

pair of bald eagles in order to

stimulate them to lay again. He

then succeeded in hatching his

eggs in an incubator, while the

parents hatched theirs in the nest.

Such techniques have led to the

production of increasing numbers

of incubator-hatched young,

ready and able to supplement the

wild population. The incubator-

hatched eaglets may be placed in

the nests of wild eagles that have

not succeeded in hatching their

own eggs or that have hatched

only one young, rather than two

or three.

Young eaglets “adopted” in this

way have the benefit of parental

care and training, and it appears

that the adult birds are only too

happy to have a new mouth to

feed. Alternately, the eaglets can

be hand-reared until they fledge

and then released to cope in the

wild on their own.

In 1973, eleven years after their

arrival from Canada’s Calgary

Zoo, the National Zoo’s pair of

bald eagles nested for the first

time. Their first clutch failed, but

they recycled, laying a second

clutch. To the delight of the staff,

All fluff, feet, and beak, the Zoo’s baby bald

eagle could be a stand-in for Sesame Street's

“Big Bird.”

one young hatched and was suc-

cessfully reared by its parents.

Although the eagles were ex-

pected to repeat their perfor-

mance, it did not happen. Each

year they nested conscientiously,

but no young hatched.

In 1977, the Bird House Curator

decided to take action. Hoping to ,

find the cause of these repeated;

failures, he removed the first eggs

laid and put them in an incu-

bator. When they did not hatch,

he sent them to a laboratory for

analysis. Removing the eggs

prompted the eagles to lay again,

demonstrating their ability to re-

cycle and increasing the Zoo’s

chance of success. Nevertheless,

no eggs hatched in 1977, and the

problem remained a mystery.

This spring, the procedure was

repeated. A keeper carefully

observed the birds’ behavior.

When the pair gave signs of start-

ing to nest in late February and

early March, sticks were provided

for rebuilding of the same nest in

the outdoor flight cage they had

used for five successive years. On

March 9th, the female laid her

first egg. It was removed the next

morning and put in an incubator.

Then on March 18th, two more

eggs were found and removed.

All three eggs were dipped in an

antibiotic solution before being

put in an incubator, kept at a con-

stant temperature and humidity

for 36 days. After a week, the eggs

were candled (exposed to bright

light) to see what was happening

inside. The first two eggs were in-

fertile, but happily, the third had

a live embryo, which was devel-

oping normally. In the meantime,

the adult pair had laid and begun

to incubate two more eggs.

The chick inside the artificially in-

cubated egg pipped a tiny hole in

the shell on the 18th of April and

finally emerged on the morning of

the 19th. Washington’s bald eagle

population had just shot up by 50

per cent!

Zoolab Offers

Hands-On Learning

by Judith White

Chief, Office of

Education & Information

Perhaps you have seen a new

symbol at the Zoo and wondered

what it meant. You might have

looked a little closer and read its

title: ZOOLAB.

As the sign on the entrance ex-

plains, ‘“Zoolab is a place to go

before and after seeing the Zoo,

to find out more about the ani-

mals by exploring, looking, touch-

ing and reading. Zoolab is for

all ages.”

Located in the Education-Admin-

istration Building, Zoolab is es-

sentially a library, or resource

center, of books and objects re-

lating to zoo animals. Bird nests,

antlers, feathers, skeletons, snake

skins, eggs, and samples of zoo

animal food are some things you

may find there. You are welcome

to touch and explore all the ob-

jects. FONZ volunteers are avail-

able to help you find materials

and answer questions.

Some of the objects are organ-

ized in learning boxes that you

can borrow to look at in the

room. You can, for example,

spend time looking at ‘How Birds

13

Fly,” “Zoo Diets,” “Teeth,” or

“Animal Coverings.” The boxes

fascinate all ages and are de-

signed for family sharing. Cards in

each box describe the objects or

explain how to look at them with

a “scientific eye.” Cards have

been written with the family in

mind, so that parents can read

them to their children without

having to interpret scientific lang-

uage or complex concepts.

Zoolab also contains many books

for browsing and reading. Again,

they have been selected with

families in mind. Some books

have been created from photos of

ZOO animals. These are guessing

games to test a user’s powers of

observation. A Zoo Animal File

has folders on almost every

species in the Park for those who

want specific information.

A try-on corner with keeper’s uni-

form and tools of the trade is sure

to delight children. One entire

wall serves as a changeable bulle-

tin board displaying pictures

drawn by young visitors. An easel

is sometimes set up and paper

provided for drawing. Another

occasional activity is making rub-

bings from a scaly snake skin.

After you leave Zoolab, you may

be invited to “take a Zoo-search.”

Giveaway brochures have been

designed to help you use what

14

you learned in Zoolab out in the

Park. They challenge you to hunt

for antlers or bird nesting sites, for

example. Hopefully, some of the

things you touched, looked at,

and read about in Zoolab will

help you better understand and

more carefully observe the Na-

tional Zoo’s animals.

At Zoolab, a visitor learns about “teeth and eating” by examing casts of animal teeth and

jaws.

od

Declining Bluebirds

Studied by Zoo

by Gee Gee Geitgey

Research Volunteer

44

he bluebird... is American

Tideatisns personified—a_fly-

ing piece of sky, a living poem, a

crystal note, an emblem of na-

ture’s moral conscience,” wrote

Stan Shetler, former president of

the Audubon Naturalist Society.

Unfortunately, the eastern blue-

bird, which once flourished in

rural farms and suburban gar-

dens from Nova Scotia to Mexico,

has suffered severe population

declines in recent years. Though

the sight and song of the blue-

bird were once common exper-

iences of many Americans, few

people under 30 today have ever

seen this symbol of happiness or

heard the gentle song with which

it greets each spring.

Man’s relationship with and ef-

fect on the eastern bluebird have

changed markedly since the first

settlers arrived from Europe in the

1600's. Until the 1950’s, few spec-

ies of North American birds prob-

ably benefited as much from

man’s activities as did the blue-

bird. Early colonists cleared the

Previous Page: Symbol of spring but increas-

ingly silent, bluebirds are being studied at

the Zoo’s Conservation-Research Center in

Front Royal, Virginia, as part of a FONZ-

supported conservation effort.

16

deciduous forests to create fields,

pastures, and orchards, and ob-

tain lumber for houses and barns.

Bluebirds typically forage for

food and rear their young in rel-

atively open areas containing

scattered trees or fences. When

foraging, they perch in a tree or

on a fence, search the ground for

insects, and then drop down to

feed. The presence of occasional

trees or fences in the bird’s habi-

tat is also important because they

provide conspicuous perches

from which the males can attract

females and defend their ter-

ritories through song and detect

predators during the nesting sea-

son. This increase in land cleared

by the colonists undoubtedly con-

tributed to a rise in the eastern

bluebird population, which even-

tually reached its highest levels in

the mid to late 1800’s.

However, man’s relationship with

the bluebird changed sharply in

the 20th century as a result of

both technological developments

and simple human folly. The

bluebird population gradually

dwindled because of several of

man’s activities which influenced

the bird’s habitat and breeding

success. In time, the decline in

the population became dramatic;

some experts estimate that the

current population is only one-

tenth of what it was just 40 years

ago. Though threatened, the

closely-related western and

mountain bluebirds have not suf-

fered similar declines.

Primary causes of the decline of

the eastern bluebird have been

the gradual destruction of its hab-

itat and reduction in suitable

nesting sites. With few excep-

tions, bluebirds nest only in cavi-

ties or enclosures found in open

fields or on the periphery of

Clearing dead trees has reduced natural

nesting holes for bluebirds.

woods. Ideal nesting sites include

old woodpecker holes and de-

pressions in dead trees and decay-

ing wooden fence posts. In the

past, bluebirds have often nested

in cavities located in farm or-

chards and fields. However, the

advent of large single-crop farms,

the use of metal fence stakes, and

the frequent pruning of dead

trees have eliminated many

nesting sites.

The breeding success of the

eastern bluebird has also been in-

fluenced by the bird’s ability to

compete with other cavity-nest-

ing species, such as chickadees,

titmice, swallows, wrens, star-

lings, and house sparrows, for

available sites. To their advan-

tage, bluebirds begin nesting in

early spring and often occupy

sites before chickadees, titmice,

and swallows return to their

breeding areas. House wrens,

however, are major competitors

because they nest at approxi-

mately the same time as blue-

birds, are far more aggressive in

disputes over nesting sites, and

will actively evict bluebirds from

an occupied site by piercing or re-

moving bluebird eggs or nestlings

from their nests. In addition, blue-

birds must compete with mice

and paper wasps, which also pre-

fer to live in cavities.

Although bluebirds have in the

past competed successfully with

indigenous cavity-nesting species,

they have been unable to cope

with either the house sparrow or

the starling in competing for

available nesting sites. Both

species are exceptionally aggres-

sive, persistent, and adaptable,

and regrettably, both were in-

troduced to this continent by

man. House sparrows were im-

ported from England in 1851, and

80 starlings were brought from

Europe and released in New

York’s Central Park in 1890. Be-

cause of their incredible adapt-

ability, the populations of both

species rapidly expanded, as did

their ranges. By 1900, house spar-

rows had spread across the

United States, north into Canada,

and south into Mexico. Starlings

followed soon thereafter.

Bluebirds are not successful in

competing with house sparrows

and starlings for several reasons.

First, house sparrows do not mi-

grate. As a result, they lay claim

to most nesting sites in an area as

roosts during the winter and al-

ready occupy available sites

when bluebirds return to breed in

the spring. Second, house spar-

rows and starlings prefer to nest in

cavities (through they will nest

A two-week-old baby bluebird symbolizes the Zoo’s successful efforts to increase their

numbers.

7

elsewhere), so both compete di-

rectly with bluebirds for sites. Be-

cause they are gregarious and ag-

gressive in nature, they are nearly

always successful in either win-

ning disputed nesting sites or

evicting bluebirds from occupied

sites. To acquire an occupied site,

house sparrows and starlings will

puncture or remove a bluebird’s

eggs, kill nestlings by pecking

their heads (“scalping” their vic-

tims), and even kill the adult birds

defending a nest, if necessary,

and then construct their crude

nests over the carcasses. These

two alien species also frequently

evict woodpeckers from cavities

they have excavated, thereby

having a detrimental effect on the

populations of woodpeckers

which produce cavities often

used by bluebirds. The introduc-

tions of house sparrows and star-

lings to the United States have

therefore affected both the avail-

ability of nesting sites for blue-

birds and their ability to breed

successfully.

Other factors contributing to the

bluebird’s decline include the con-

tamination or elimination of its

food and increased competition

Singer of spring, the eastern bluebird is in

trouble because of man’s activities and com-

petition with other birds.

for the dwindling resources. Dur-

ing the spring and summer in the

Washington area, bluebirds eat

primarily earthworms and insects,

such as grasshoppers, crickets,

caterpillars, spiders, mealworms,

and locust. The widespread use of

insecticides has resulted in the re-

duction or elimination of many

types of insects that bluebirds

normally consume. In addition,

insecticides may have a direct ef-

fect on nestlings and adult birds

that eat contaminated insects.

The long-term effects of sublethal

dosages during the breeding sea-

son are not fully understood, but

it is clear that man’s use of in-

secticides and other biocidal

agents will hasten the disappear-

ance of the bluebird and other

insect-eating species. House spar-

rows and starlings feed predomi-

nantly on fruit, grain, and gar-

bage, so are not affected by

poisoned insects and worms.

The fall and winter food supply of

the eastern bluebird consists of a

variety of fruits, such as bitter-

sweet, dogwood, black gum,

holly, bayberry, and sumac. As

the eastern states have become

urbanized, many fruit-producing

trees and bushes have become

less abundant. Because supplies

of fruit are fixed for each winter

(i.e., not replenished until the

next summer) and are often

covered by ice or snow, com-

petition between bluebirds and

other species becomes increas-

ingly severe as winter progresses.

This is particularly true in more

northern areas where birds must

consume substantial amounts of

fruit to maintain body heat and

withstand prolonged winter con-

ditions. The bluebird’s struggle is

compounded by the fact that

flocks of starlings will pass

through an area and strip the

trees and bushes of berries early

in the season. Consequently,

bluebirds must travel greater dis-

tances and expend _ valuable

energy in search of dwindling

food supplies.

Eastern bluebirds have always

been victims of natural competi-

tion, .predation, and parasitism,

but in the last 75 years, they have

had to endure escalating pres-

sures imposed by man. Believing

that only major efforts can rescue

the bluebird from the road of ex-

tinction, ornithologists and bird

fanciers in North America are

studying the bird’s environmental

niche and interrelationship with

man. Hopefully, constructive

wildlife and land management

practices can be developed. Net-

works of nesting box “trails”

erected by professionals and

amateurs provide additional

nesting cavities for blue birds,

along with excellent sources for

data collection. Efforts are being

made there to control predation

and reduce competition from

starlings and house sparrows.

Research on the eastern bluebird

has been conducted at the Na-

tional Zoo’s Conservation and Re-

search Center in Front Royal,

Virginia, under the direction of

Dr. Eugene S. Morton of the

Zoo’s research staff. In order to

monitor the breeding success and

study the behavior of a small pop-

ulation of bluebirds already re-

siding at the Center in 1975, Dr.

Morton set up 36 nesting boxes in

various habitats on the property.

Although observations of the

birds and nest boxes during the

first breeding season were infre-

quent, it was apparent that the

birds suffered from a very high

level of predation by raccoons

and snakes.

During the spring and summer

seasons of 1976 and 1977, the

author monitored the trail of nest

boxes every week, with assistance

from two undergraduate students

supported by FONZ summer

fellowships. In 1976, data on each

phase of the breeding cyles of 19

pairs of bluebirds were recorded

(nest construction, egg-laying, in-

cubation, rearing of the young,

fledging, etc.) and particular at-

tention was given to the incidence

and type of predation and other

causes of bluebird mortality.

19

Data were also collected on

species that competed with the

bluebirds for nest boxes (chick-

adees, house wrens, tree swal-

lows, and mice—starlings and

house sparrows have not been a

problem at the Center). Results of

the study indicated that fewer

than half (46.8%) of all bluebird

eggs layed in nests in the boxes

produced nestlings that survived

to fledge, and that only 60.8% of

all nestlings that hatched survived

to fledge. Most eggs and nest-

lings were lost as a result of

severe weather conditions and

predation by raccoons, snakes,

and bears. Throughout the sum-

mer of 1976, an undergraduate

student also observed and re-

corded data on the post-fledging

activities of young bluebirds.

Because of the high percentage of

losses during the 1976 season,

major efforts were made to re-

duce predation and _ weather-

related losses in 1977. Twenty-

six new boxes were constructed

and placed in what was thought

to be good “bluebird habitat.” All

of the new boxes were mounted

on tall, narrow aluminum poles,

which rendered the boxes less

accessible to predators; most of

the original boxes were also re-

mounted onto aluminum poles.

As an extra measure against

raccoons, the worst predators at

the Center, axle grease was ap-

plied in streaks along each pole,

and hot pepper was sprinkled on-

to the grease. Weekly observa-

tions of the boxes indicated that

the grease and pepper system was

effective in deterring both rac-

coons and snakes. Raccoons at-

tempted to climb several poles

to rob bluebird nests but found

the hot pepper to be so noxious

that they did not persist in trying

to reach the nest boxes. Though

there were only 17 pairs of adult

bluebirds at the Center in 1977

(two fewer pairs than in 1976),

twice as many young bluebirds

fledged that year than in 1976

(123 in 1977 versus 59 in 1976).

The percentage of eggs producing

nestlings which survived to fledge

increased to 71.7%, and the per-

centage of nestlings that fledged

increased to 86.0%. As in the

summer of 1976, an undergrad-

uate student observed and re-

corded data on the post-fledging

activities of juvenile birds in 1977.

Additional studies of the behavior

of the eastern bluebird are plan-

ned for this year. It is hoped that

further research will aid in the

preservation of the eastern blue-

bird for future generations of

Americans to enjoy. O

Learning how to save bluebirds has beena

FONZ-sponsored Zoo project.

BOOK A\\S

Editor’s Note: All books reviewed

are available through the FONZ

Bookstore and Gallery — 232-7705.

Wild Mammals

by Nell Ball

FONZ House Guide

WILD MAMMALS OF NEW ENG-

LAND by Alfred J. Godin, The

Johns Hopkins University Press,

304 pp., $25.

A work of fiction is often so enter-

taining that you cannot put it

down, but to find this quality in

a reference volume is rare. Wild

Mammals of New England is such

a book. Alfred Godin spent eight

years studying and gathering data

on the one hundred species

covered in the text. In addition to

the usual information on distri-

bution, ecology, and behavior,

Mr. Godin includes such fasci-

nating extras as age and sex de-

termination, myths and folklore,

and species hybridization. In the

process of compiling his informa-

tion, the author examined an

awesome number of specimens,

including 4,122 white-footed

mice, 2,527 short-tailed shrews,

and 1,880 meadow moles.

The information is presented in

an organized, easy-to-read for-

mat, starting with the characteris-

tics common to all mammals and

The bobcat is one of 100 species described and illustrated in a handsome new publication,

Wild Mammals of New England.

proceeding to a description of

those found in New England.

There are distribution maps for

each species together with pencil

sketches by the author. Addi-

tional chapters cover the physio-

graphic features of the region and

extirpated species; a comprehen-

sive glossary and bibliography

are included as well. Two intro-

duced species, the European wild

boar and the fallow deer, are

examined in detail, including the

events that led to their establish-

ment in this country. Brief men-

tion is made of mammals whose

presence in New England is

known only from fossil remains.

The section on Canidae discusses

the “coydog” (coyote/dog cross)

and the so-called New England

wild canid as well as the familiar

wolf, fox, and coyote. Breeding

experiments on the New England

wild canid have shown that it

possesses a stable genetic struc-

ture able to breed true. On this

basis, it is suggested that it be of-

ficially recognized as an East-

ern coyote.

Geewhiz facts fill the pages.

Certain mice drum with their tail

by beating against a hard surface.

Red squirrels so love maple sap

that they will hang upside down

from the underside of tree limbs

to get at the sweet liquid. Musk-

rats swim up to three miles per

21

hour and can paddle backwards

for some distance. The sound of a

sperm whale blowing carries over

eight hundred feet. Some bats

form maternity colonies of as

many as twelve thousand females.

Whether the reader is a serious

student of zoology or just trying

to learn something about the odd

beasts the cat drags home, this

book is a good one. Don’t miss it!

22

Snakes

by Jaren Horsley

General Curator

SNAKES: A Natural History by

H.W. Parker and A.G.C. Grandi-

son, Cornell University Press,

108pp, 1977, $8.95.

Several years ago the Head of the

Zoology Department at the Bri-

tish Museum, H.W. Parker, wrote

a little book titled Natural His-

tory of Snakes. Recently A.G.C.

Grandison, Curator of Reptiles at

the museum, thoroughly revised

it, complete with a new title. In

doing so she has added greatly to

its clarity and filled it with some

nifty pictures. Her book fills an

important niche in the world of

popular reptile information. It

gives the reader a glimpse into the

field of herpetology that just isn’t

seen enough in the picture books,

survey books, or numerous iden-

tification manuals on the market.

Understanding the anatomy and

physiology of animals can lead to

a better understanding of how

they have managed to survive. It

can develop the basis for learn-

ing how various forms evolved

through time. This little book pro-

vides such an approach to snakes

and does so in a lucid manner.

This makes it unique.

Animal books, like zoo exhibits,

often tend to emphasize animals

as being separate from one

another. They treat the family

tree and the “roots” of each

species as if it were of little im-

portance. Each type of animal is

presented as if it started and

ended the same way. Lizards are

not like snakes, and both are

totally separate from birds, and

none of them have any relation-

ship to the panda. Even zoo

people say things like, “What do

you know about cranes, you’re a

cat keeper?” Of course animals

are very much related to each

other, and there are a surprising

number of similarities beneath

those skin-deep differences. Evo-

lution, the main idea in zoo-

logy, often is ignored as too aca-

demic, and it is much easier to

put each type of animal in its own

compartment. Snakes: A Natural

History helps to reduce the dis-

tances between animals to

lengths that are real.

urvey Describes

“Typical” FONZ

Why are you a FONZ? What

benefits do you enjoy most? How

do you think FONZ can do a

better job?

To find these answers— and so

serve you better — FONZ in-

itiated a membership survey con-

ducted in the fall of 1977 by Pro-

fessor Hale N. Tongren and his

Business School students at

George Mason University.

Not surprisingly, a “typical”

FONZ visits the Zoo four or five

times a year. Four out of ten ac-

tively participate in such FONZ

programs as the popular Zoo

Night, film-lectures, trips, classes,

and volunteer opportunities.

Most members joined FONZ to

help the animals and support the

Zoo’s programs to save and breed

endangered species. The bi-

monthly magazine, ZooGoer, is

read and enjoyed by most. Junior

members particularly like Paw-

Prints, a newsletter with animal

features, games, puzzles, and

special “wild” projects just for

young students.

Behind-the-scenes activities were

especially enjoyed, and members

said they would like to have more

such programs. Others wanted to

see increased parking spaces and

to have more frequent announce-

ments about upcoming events.

Three out of four members de-

cided to join after a Zoo visit, be-

cause of a friend’s recommenda-

tion, or in response to a mailed

invitation. Many hear about

FONZ through television and

radio announcements or by see-

ing the colorful “Be a FONZ”

bumper stickers.

A “typical” adult FONZ is far

above the national average in

education. Nearly 1/2 of al// mem-

bers have graduate degrees. Fe-

males outnumber males three to

one in Individual and Senior

categories.

The 1977 survey reinforced many

of the findings of a similar study

done in 1975. Although FONZ has

grown substantially in size and

scope of activities since that

time, its members still emerge as

influential community leaders

and active supporters of wildlife

and conservation.

Such studies help us better tailor

programs to your interest and so

do a better job of being a Friend

of the National Zoo.