Activity #4: Pollination Brainteasers

Lesson #4: Amazing Pollinators!

Objectives: To demonstrate the critical importance of flowers to natural

ecosystems. To understand how wild flowers are designed to match specific

pollinators.

Introduction to Activity: In order for students to truly appreciate the importance

of plant conservation, they need to know that plants play essential ecological

roles. Plants are primary producers that are the foundation of food pyramids.

They provide oxygen to breathe, habitat for other living things, and they help

keep soil in place so that it does not wash away.

For plants to survive, they must be able to reproduce. Pollination is a vital

ecological process, upon which our continued survival, and that of other living

things, depends. Oddly, despite its critical importance, it is often forgotten in

science text books.

Students should become aware that the entire spectrum of pollinators is required

in an ecosystem to pollinate all of the plants. Likewise, a diverse plant population

is needed to provide food for the ecosystem’s pollinators. Plant and pollinator are

dependent upon one another for survival. Maintaining plant and pollinator

diversity is, therefore, essential in healthy habitats. Students need to know how

significant pollination is and how easily humans can inadvertently disrupt it.

Some, hopefully, will also find the complex relationship between flowers and

pollinators fascinating.

Materials Needed:

• a copy of the “Pollination Brainteasers” worksheet for each student

• a copy of “Pollination: Part Two” and accompanying worksheet for each

student (to be completed at home in preparation for Lesson #5)

• photographs of examples of pollinators visiting plants

Activity:

Begin the activity by reviewing key points in the assignment for the day

(“Pollination—Part One”). You might ask your students the following questions:

• What is pollination and why do plants need to be pollinated? (Pollination is

when pollen travels from the anthers on flower stamens to the stigmas on

female carpals. Pollination is part of the reproductive cycle of flowering

plants.)

• Do you know examples of things that can pollinate flowers? (Examples

include bees, flies, moths, hummingbirds, bats, and the wind. Even some

small mammals pollinate certain flowers.)

• Why do you think flowers are so different in color, size, and shape? (They

are attracting very specific pollinators, which are drawn to particular scents

and colors.)

• Do you think a particular flower could be pollinated by bees as well as

moths and birds? (In order to maximize the chances that pollen will be

picked up and delivered to the carpal of another flower of the same

species, most flowers have a size and shape designed for specific

pollinators.)

Pass out a “Pollination Brainteasers” worksheet to each student. Explain that the

packet has facts about important pollinators. The students should read through

these facts and use them as clues to help them predict the characteristics (shape,

color, scent, etc.) of a flower that needs this particular pollinator to help it

reproduce. By going through this thinking exercise, it is intended that your

students understand that flowers are designed for specific purposes. They may

be surprised to learn that human logic and natural processes can, in the case of

pollination, arrive at the same conclusion! Allow students to work together in

small groups. Once they have had time to complete the packet, review the

answers with the class and show the photo examples provided.

Wrap-up the activity by reviewing the following key points:

• Pollination is a key part of reproduction in flowering plants.

• Without pollination, many of our food crops would disappear (bananas,

apples, oranges, cherries, grapes, mango, peas, tomatoes, squash,

potatoes, almonds, peanuts—basically, almost all of the fruits and nuts

that are eaten around the world).

• Flowers come in diverse sizes, shapes, and colors in order to attract

specific pollinators. (If you have already covered the concept of co-

evolution, this is a good place to make the connection.)

• When a flower species goes extinct or even has its population fall

dramatically, the pollinator population also declines and can go extinct.

Then, things that rely on the pollinator are also affected, and a chain

reaction goes through the ecosystem. (If you have already covered food

chains and food webs, this is a good place to make the connection.)

• Thus, protecting plant diversity is vital to protecting animal pollinators and

other living things. Likewise, preserving pollinator diversity is required to

protect plant diversity. Plant diversity is essential to healthy habitats.

At the end of the activity, pass out the assignment for the next class,

“Pollination—Part Two” and its accompanying worksheet.

Pollination Brainteasers

Student name: ____________________________ Class/section:

Below you will find facts about important pollinators. Read through them and use

them as clues to help you predict what characteristics plants might have to attract

each type of pollinator. When you are done, we will review the answers to see

how closely you and nature agree.

BATS

Throughout most of the United States and Canada,

bats feed strictly on flying insects. In tropical areas,

however, bats feed on a variety of foods, depending

on the species of bat. They might eat frogs, fish,

blood (vampire bats), fruit, pollen and nectar. The

bats that concern us at the moment are those that

feed on pollen and nectar. If you were a plant, how

would you attract them? Here are some clues:

• Bats have a good sense of smell. (Remember,

many eat pollen and nectar.)

• Bats have a good sense of sight. (They are

not blind, although they are colorblind. They

can see light and dark.)

• Bats are relatively large for a pollinator, at

least compared with insects.

Photo: Rex Walters

• What time of day are bats active?

• How much food would a bat need compared with, say, a bee?

If you were a flower designed to be pollinated by a bat, what characteristics

would you have? (Fill in the blanks below.)

Color:

Size:

Location of flower on the plant:

Shape:

Scent:

Time of day when in bloom:

MOTHS

• Their mouth parts are like long soda

straws that they carry curled up like

New Years novelty toys. Therefore,

their food must be liquid. They do not

have jaws.

• Most moths come out at night, as

opposed to butterflies which are

mostly active during the day.

• They see fairly well at very short

distances, and they can see color.

Photo: Davis Kwan

• Their sense of smell, like most insects, is truly amazing. They can detect a

few molecules of a scent in the air.

If you were a flower designed to be pollinated by a moth, what

characteristics would you have? (Fill in the blanks below.)

Color:

Shape:

Time of day in bloom:

Scent:

What the flower might provide the visiting moth:

FLIES and CARRION BEETLES

Photo: Laszlo Ilyes

• These charmers like nothing better than

to find a dead possum or a pile of dung

on which to lay their eggs. The eggs will

hatch into maggots and will have a

perfect place to feast. Bon appetit!

• Like moths, they see only fairly well at

short distances. (You can sneak up on

them pretty easily with a fly swatter.)

• They have an amazingly good sense of smell.

If you were a flower designed to be pollinated by flies or beetles, what

characteristics would you have? (Fill in the blanks below.)

Scent:

Color:

Why might flies and beetles visit the flower?

BEES

A huge variety of bees pollinates flowers,

ranging from tiny sting-less bees to

bumblebees to honeybees. Here are

some facts about bees, in general:

• They search out pollen and nectar.

Some bees make honey to feed

their young.

• They have jaws, not soda-straw

mouths like moths.

Photo: Joost Witteveen

• They see colors at the short

wavelength end of the spectrum, not long wavelengths. Thus, they cannot

see red, but they can see ultraviolet light, which we humans cannot see.

• Their vision is OK, but they have a great sense of smell.

If you were a flower designed to be pollinated by a bee, what

characteristics would you have? (Fill in the blanks below.)

Scent:

Colors:

HUMMINGBIRDS

These birds are only found in the Western

Hemisphere.

• They have long, needle-like bills.

• They see the same colors that people see.

• They cannot smell.

• They feed on tiny insects and nectar.

• They usually hover when feeding, like a

miniature helicopter. They rarely perch

when feeding.

• How could a flower attract hummingbirds,

but not attract bees and other animals that might steal its nectar and not

pollinate your flowers?

Photo: Windell Oskay

If you were a flower designed to be pollinated by a hummingbird, what

characteristics would you have? (Fill in the blanks below.)

Color:

Scent:

Shape:

Location of anthers and stigmas:

WIND

• Can wind-pollinated plants actually attract wind?

• What flower design might help the wind carry off pollen most effectively?

• What are the chances that a single pollen grain, when blown by the wind,

will land on the right flower?

If you were a flower designed to be wind-pollinated, what characteristics

would you have? (Fill in the blanks below.)

Color:

Scent:

Shape of flower:

Season of bloom in most parts of country:

Location of flowers on plants:

Amount of pollen produced:

Pollination Brainteasers Answer Sheet

Below you will find facts about important pollinators. Read through them and use

them as clues to help you predict what characteristics plants might have to attract

each type of pollinator. When you are done, we will review the answers to see

how closely you and nature agree.

BATS

Throughout most of the United States and Canada, bats feed strictly on flying

insects. In tropical areas, however, bats feed on a variety of foods, depending on

the species of bat. They might eat frogs, fish, blood (vampire bats), fruit, pollen

and nectar. The bats that concern us at the moment are those that feed on pollen

and nectar. If you were a plant, how would you attract them? Here are some

clues:

• Bats have a good sense of smell.

• Bats have a good sense of sight. (They are not blind, although they are

colorblind.)

• Bats are relatively large for a pollinator, at least compared to insects.

• What time of day are bats active?

• How much food would a bat need compared with, say, a bee?

If you were a flower designed to be pollinated by a bat, what characteristics

would you have? (Fill in the blanks below.)

Color: white or pale in color since bats are active at night

Size: relatively large (bats are large)

Location of flower on the plant: at top or on the outside where the flower is

exposed and the bats can find it

Shape:

open at the top so bat can get its head inside

Scent:

sweet smell to advertise the nectar the flower provides bats

Time of day when in bloom:

evening—that is when bats are active

MOTHS

• Their mouth parts are like long soda straws that they carry curled up like

New Years novelty toys. Therefore, their food must be liquid.

• Most moths come out at night, as opposed to butterflies which are mostly

active during the day.

• They see fairly well at very short distances, and they can see color.

• Their sense of smell, like most insects, is truly amazing. They can detect a

few molecules of a scent in the air.

If you were a flower designed to be pollinated by a moth, what

characteristics would you have? (Fill in the blanks below.)

Color: white or pale colored since moths are active at night

Shape: long, skinny tube for the moth’s soda-straw tongue

Time of day in bloom: evening, since most moths are active at night

Scent: fabulously sweet, to advertise the sweet food that flowers provide

moths

What the flower might provide the visiting moth: nectar

FLIES and CARRION BEETLES

• These charmers like nothing better than to find a dead possum or a pile of

dung on which to lay their eggs. The eggs will hatch into maggots and will

have a perfect place to feast. Bon appetit!

• Like moths, they see only fairly well at short distances. (You can sneak up

on them pretty easily with a fly swatter.)

• They have an amazingly good sense of smell.

If you were a flower designed to be pollinated by flies or beetles, what

characteristics would you have? (Fill in the blanks below.)

Scent: a foul odor like rotten meat

Color:

dark reddish-brown or brown, like the color of rotten meat

Why might flies and beetles visit the flowers?

The fly or beetle thinks it has

found a perfect place to lay eggs, but it has been tricked! The flower doesn’t

provide anything. Instead, the fly or beetle unknowingly pollinates the flower

as it flies from bloom to bloom.

BEES

A huge variety of bees pollinates flowers, ranging from tiny sting-less bees to

bumblebees to honeybees. Here are some facts about bees, in general:

• They search out pollen and nectar. Some bees make honey to feed their

young.

• They see colors at the short wavelength end of the spectrum, not long

wavelengths. Thus, they cannot see red, but they can see ultraviolet light,

which we humans cannot see.

• Their vision is OK, but they have a great sense of smell.

If you were a flower designed to be pollinated by a bee, what

characteristics would you have? (Fill in the blanks below.)

Scent: sweet since bees have a good sense of smell and seek nectar

Colors: short wavelength colors such as blues and purples. Even white and

yellow will work. Often, white flowers have streaks of color that can be seen in

ultraviolet light. Bees can see these streaks, but we cannot. Bees are not

attracted to red.

HUMMINGBIRDS

These birds are only found in the Western Hemisphere.

• They have long, needle-like bills.

• They can see the same colors that people see.

• They cannot smell.

• They feed on tiny insects and nectar.

• They usually hover when feeding, like a miniature helicopter. They rarely

perch when feeding.

• How could a flower attract hummingbirds, but not attract bees and other

animals that might steal its nectar and not pollinate your flowers?

If you were a flower designed to be pollinated by a hummingbird, what

characteristics would you have? (Fill in the blanks below.)

Color: orange and red: birds can see these colors and they stand out among

greenery

Scent: no scent; birds don’t have a sense of smell, so producing a scent

would be a waste of energy

Shape:

tubular shape to fit the hummingbird’s bill

Location of anthers and stigmas: protruding from the flowers, where they

come into contact with the hovering bird

WIND

• Can wind-pollinated plants actually attract wind?

• What flower design might help the wind carry off pollen most effectively?

• What are the chances that a single pollen grain, when blown by the wind,

will land on the right flower?

If you were a flower designed to be wind-pollinated, what characteristics

would you have? (Fill in the blanks below.)

Color:

neutral colors such as green, tan and brown; wind is not attracted to

colors so the plants don’t waste energy producing petals with bright colors, or

sometimes any petals at all

Scent: no scent; wind is not attracted by scent

Shape of flower: something exposed to the wind; many dangle like wind

chimes. Anthers are exposed so wind can catch their pollen and carry it away.

Season of bloom in most parts of country: early spring; most wind-pollinated

trees produce pollen before the leaves come out. This makes it easier for the

pollen to reach flowers when it is blown. Leaves would block a lot of the

pollen. Stigmas are exposed to catch the pollen as it blows by.

Location of flowers on plants: at the ends of branches for exposure to the

wind

Amount of pollen produced: an enormous amount; wind pollination completely

relies on chance, and most pollen never reaches its intended target. (Have

you ever wondered why pollen covers our car windows and so many people

have hay fever at certain times of year?)

Photo: William C. Taylor @ USDA-NRCS PLANTS Database

Photo: Brian Sanders

Photo: Jennifer Anderson @ USDA-NRCS PLANTS Database

Photo: Brian Sanders

Photo: Karen Tucker

Assignment: Pollination—Part Two

In the last reading, you learned that most plants depend upon things in the

environment, usually the wind and various kinds of animals, to pollinate their

flowers. Plants have to do this successfully; otherwise, they will not be able to

reproduce. But if plants all want to accomplish the same thing, why do their

flowers look so different from each other? Why aren’t they all designed the same

way to do the same task?

It turns out that flowers vary so much in shape, size, and color because they are

all trying to match different pollinators. A flower attractive to a bee, for example,

will not necessarily appeal to a bat, butterfly, or bird, and will probably not be

capable of being pollinated by the wind. The great diversity of flowers in nature,

then, is largely due to the great diversity of pollinators the flowers are trying to

match. With this in mind, you can often understand why flowers are designed as

they are. Indeed, if you have a specific pollinator in mind, you can even predict

what a flower designed to match it will look like!

Take flowers pollinated by hummingbirds,

for example. Hummingbirds are

incredible animals. The smallest birds in

the world, they are no bigger than large

moths and butterflies, and, like these

insects, they like to feed on flower nectar.

To reach the nectar, they often hover like

miniature helicopters in front of blossoms

and insert their long beaks and tongues

deep inside them to reach their sweet,

liquid food. The Eastern United States

has one species, the ruby-throated

hummingbird, but more than a dozen

species live in the western United States.

Central and South America have hundreds of different species.

Photo: Jessica Merz

If you were a flower and your goal in life was to be pollinated by a hummingbird,

what would YOU look like? First, you would want to be noticed. It turns out that

hummingbird vision is a lot like humans’, so many hummingbird-pollinated

flowers are red and orange, because these colors stand out against the green

background of plants growing in forests and fields. How would you smell?

Hummingbirds, like most birds, have no sense of smell, so flowers designed to

match them typically have no scent, whatsoever! How would you be shaped?

Take a look at the hummingbird photograph, and you can see that its bill is long

and needle-like, like most hummingbirds. So, the typical flower pollinated by

these birds is long and tubular, like a miniature trumpet. How would you arrange

to cover the hummingbird with pollen, so it would do what you want

(unintentionally!) and carry it off to another blossom? You would have your

anthers sticking out of the blossom, ready to brush pollen on the head or bill of

the bird hovering in front of you. If you were designed like this, you would stand

a good chance of being pollinated by a hummingbird. (Congratulations!)

But, would you also succeed in being

pollinated by a bumblebee? Not as likely,

for several reasons. First, bumblebees

cannot see the color red very well, but

they can perceive blue, violet, and even

ultraviolet, which neither humans nor

hummingbirds can see. Secondly,

bumblebees, like most insects, have

extraordinarily sensitive senses of smell.

To attract them with pollen or nectar to eat,

you would do well to have a sweet scent

to advertise your wares. And, it wouldn’t help to dangle your anthers out of the

blossom, because the bumblebee will probably land on the flower and miss them

entirely. So, bumblebee-pollinated flowers are often blue or violet. Some of

them are also white or yellow with stripes that reflect ultraviolet light, which bees

can see but humans can’t. Bumblebee-pollinated flowers also have sweet scents

to advertise their nectar and pollen, and they are usually sturdy to suit a relatively

heavy insect.

Photo: David Wilbanks

Photo: Eric Milot

You can see, then, that flowers are not

designed randomly, but rather to match

specific pollinators. So, butterfly-pollinated

blooms, such as milkweed, are often yellow,

pink, or orange and flat across the top to

provide a landing strip for the insects to stand

on as they sip nectar (left photo). Flowers

pollinated by night-flying moths typically

bloom at night, are sweet-smelling, and are

long and tubular in shape to fit the moths’

long tongues. In the American southwest, such as Texas and Arizona, bats serve

as pollinators. The flowers that attract them also bloom at night and are white

(so they might be seen on moonlit evenings) and sweet-smelling, but they are

also very big to hold large amounts of nectar and pollen needed to attract these

relatively large pollinators. They also stand exposed at the ends of high branches

where they can be noticed. The flowers of the spectacular saguaro cactus of

Arizona and the agave plant of Texas are examples of bat-pollinated flowers.

Some flowers, however, offer no nectar or pollen or anything else to bribe

pollinators to carry off pollen. Examples are flowers pollinated by wind.

Obviously, they don’t try to attract the attention of the wind, since wind can’t see

or smell; they simply wait for the wind to come along and pollinate them. Wind-

pollinated flowers often escape our attention; they typically have tiny or even

non-existent petals, are green or brown, and have no scent. Their stamens and

pistils often dangle exposed to the air, so that the slightest breezes will be able to

pick up their pollen and deposit it on the desired flowers. Whether the pollen

does this will depend entirely on chance, so wind-pollinated flowers produce

massive amounts of pollen, because most of it will be wasted. Most of the trees

and grasses in the United States are wind-pollinated. Though we often don’t

notice the flowers themselves, we do notice their effects: All this blowing pollen

brings about the watery eyes and runny noses of hay fever.

Then, there are some flowers that attract pollinators through deception. Instead

of offering food, they misrepresent themselves to trick pollinators into serving

them without receiving anything in return.

One example is the skunk cabbage (right

photo), found commonly in swampy

areas in the eastern United States. The

skunk cabbage receives its name from

the unpleasant odor its leaves give off

when crushed. The flower, too, has a

bad smell. Blooming in late winter, it is

maroon in color and shaped like a

monk’s hood. What could find this

strange flower attractive? It turns out

that flies come to the flower readily, but

not for nectar and pollen to eat. Instead,

they are looking for dead animals and

even animal excrement on which to lay their eggs, and they think that’s what the

skunk cabbage flowers are! The flies unintentionally carry pollen from flower to

flower in their futile quest for a place to lay their eggs.

Photo: hiromama

And then there are a few flowers

that live along the Mediterranean

Sea in southern Europe. These

actually look and even smell like

female bees (left photo). Male

bees visit the blossoms and

attempt to mate with them, in the

process picking up pollen that they

carry from flower to flower in their

quest for romantic fulfillment!

You can see that the world’s

incredible variety of flowers is

specially designed to attract an

equally amazing variety of

pollinators. There is no “one size

Photo: Gunnar Norman

fits all” flower that is pollinated by everything possible: birds, bats, wind, bees, etc.

Likewise, no super pollinator exists that is capable of pollinating everything that

blooms. This is very important to keep in mind when we think about how to

protect biological diversity on our planet.

If we want to protect a flower, we have to protect its pollinators too. We have to

be careful with our insecticides so we do not kill off the bees, moths, butterflies,

and other insects that pollinate so many of our plants. We also have to protect

the habitats of all of the birds, bats, and other animals that play vital pollination

roles. Likewise, to protect animal diversity in our world, we have to protect the

many plants that feed them nectar, pollen, and other foods. It is not sufficient to

simply preserve only a few pollinators, because that will leave many flowers

unpollinated and unable to reproduce. It is not enough to preserve only a few

plant species, because many pollinators will be unable to find the food they need.

Plants and pollinators depend upon one another for their survival. We humans

depend on them as well. Most of our food plants except for grains and cereals,

for example, depend upon animals to pollinate them. Preserving both plant and

pollinator diversity is not only vital for a healthy, beautiful, and fascinating planet,

it is essential for our continued well-being.

Glossary

Deception: trickery

Habitat: a place where a plant or animal can get the food, water, shelter, and

space it needs to live; there are many different habitats for various species

Insecticides: chemicals used to kill insects; they are used by farmers on crops as

well as by homeowners in their homes and yards

Nectar: a sweet liquid secreted by the flowers of some plants and consumed by

its pollinators

Pollen: the dust-like specks that hold male sperm cells found on the anthers of

flowers; some plants produce pollen in large quantities, providing food for their

pollinators that visit the flowers because of this food source

Ultraviolet light: electromagnetic (light) waves that are slightly shorter in

wavelength than the visible colors that we see; they are invisible to us but can be

detected by the eyes of some insects

Worksheet: Pollination—Part Two

Name: ________________________________ Class/Section:

1. Look at the photographs of flowers below and decide what you think pollinates

each flower, and list your reasons why.

This flower has a very sweet smell.

What pollinates this?

_________________________________________

List the reasons for your answer:

______________________________________________

Photo: Elisa Bracco

This flower has no smell.

What pollinates this?

______________________________________________

List the reasons for your answer:

______________________________________________

Photo: Josh Rosenbaum

Photo: Karol Miles

This flower has a sweet smell.

What pollinates this?

_____________________________________________

List the reasons for your answer:

_____________________________________________

Photo: Karol Miles

This flower has a sweet smell.

Photo: bcanna

What pollinates this?

_________________________________

List the reasons for your answer:

_________________________________

This flower has a foul smell (to humans)

to mimic excrement and dead animals.

What pollinates this?

________________________________

List the reasons for your answer:

________________________________

Photo: Ben Tubby

________________________________

This plant has no noticeable smell.

What pollinates this?

________________________________

List the reasons for your answer:

________________________________

Photo: c rite thru

2. If we want to preserve plant diversity, why do we need to preserve pollinator

diversity as well? Why can’t we just preserve a few pollinators, like honeybees

for example, to pollinate flowers?

Answer Sheet: Pollination—Part Two

Name: ___________________________ Class/Section: _________________

1. Bumblebees

i. Color: Blue, Violet, Ultraviolet markings

ii. Scent: Sweet, to advertise nectar

iii. Shape/design: Sturdy for heavy insects

2. Hummingbirds

i. Color: Red, orange

ii. Scent: No scent; hummingbirds can’t smell

iii. Shape/design: Tubular, protruding stamens and stigmas

3. Bats

i. Color: White

ii. Scent: Sweet to advertise nectar and pollen

iii. Shape/design: Large, bowl-shaped, flowers high on ends of

branches

4. Moths

i. Color: White

ii. Scent: Sweet to advertise nectar

iii. Shape/design: Tubular, nectar often kept in spurs or tubes to

accommodate moth mouthparts

5. Flies

i. Color: Maroon, brown, dark red

ii. Scent: Foul (to humans), to mimic excrement and dead

animals

iii. Shape/design: Varied

6. Wind

i. Color: Green or brown

ii. Scent: No scent

iii. Shape/design: Petals small or absent, dangling stamens and

protruding carpals, great quantities of sticky and very light

pollen

7. If we want to preserve plant diversity, why do we need to preserve

pollinator diversity as well? Why can’t we just preserve a few pollinators,

like honeybees for example, to pollinate flowers?

Answer: Flowers and pollinators are specifically suited to each other. No

flower attracts every single pollinator, and no pollinator is adapted to

pollinate every flower. To preserve plant diversity, it is essential to

preserve both plant and pollinator diversity. Losing plant diversity would

harm pollinator diversity and vice versa.