One Bite out of Three and Wildlife

So, we all agree that we owe one third of our food to pollinators. Now let us stop thinking about us; instead let us devote a few minutes to our companions on planet Earth. Does wildlife need pollinators as much as we do? It seems that nobody has looked at this matter systematically, thus, it is not an easy question to answer. Yet, we can try.

I will try to look at the diets of some feathered and furred creatures, mammals and birds and ignore for now the scaly or slimy sorts, amphibians, fish and reptiles. I will merely list the foods that need the services of pollinators, rather than attempting to estimate percentages for lack of information in the matter. What we are trying to see is whether wildlife requires the services of pollinators. Also, I will not bore you with long lists of animals and their diets, simply limit myself to some better known examples.

Birds that come to our backyard feeders are easy to observe. They show a preference for sunflower, thistle and peanuts. Summer and winter, many birds depend on berries, from blueberries to raspberries to crabapples to holly. Of course, not all their food is insect pollinated like the ones mentioned above. Many birds feed on insects and or grass seed. You can learn more about the role of pollinators on the diets of some of the most beloved songbirds such as wood thrushes and blue birds at the North American Pollinator Protection Campaign fact sheet.

Another common wildlife of our forests and backyards is the squirrel. The eating habits of squirrels are similar to ours as a look at the way they dig through our leftovers proves. When there is no human garbage around, they go through a variety of berries, seeds and tender leaves. It would be safe to conclude that they are as indebted to pollinators as we are. The same could be said of raccoons.

One animal that symbolizes wildlife more than most is the bear. Let as take a quick look at what a bear eats through the year. When it comes out of hibernation, there isn't much plant life around, except for skunk cabbage, and skunk cabbage becomes its breakfast, lunch and dinner with some Jack-in-the-pulpit as a side dish. A bear must have a strong stomach because these plants have tiny salt crystals that would make most other animals, including us, very, very sick. I mentioned in previous posts that skunk cabbage and Jack-in-the-pulpit are both pollinated by small flies, which are the only pollinators flying around so early in the season.

Other foods become available later on. A bear will add some vegetables to a wide range of other things. When fall comes and berries ripen, it is the time to eat berries. In areas where blueberries are abundant, a bear is likely to spend long hours in blueberry fields, gorging itself. Do I need to repeat that most berries are pollinated by insects?

The many herbivores, deer, bison, skunk, rabbit, may eat mostly wind-pollinated grasses; but they also need other nutrients that can only be obtained from flowering plants, from clovers to asters.

Finally, if you are wondering, even meat-eaters benefit from pollinators, since much of their food, the herbivores, feed thanks to them.

Now, we have further reasons to be grateful to pollinators. It isn't just us, humans, who are in their debt, but practically all other animals of our fields and forests.

One Bite out of Three
One Bite out of Three Before Columbus

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© Beatriz Moisset. 2013

Monarchs and their Enemies

Male monarch butterfly. © Beatriz Moisset

We are told that monarch butterflies are well protected against predators and indeed they are. Their caterpillars feed on milkweeds, rich on highly toxic substances known as cardenolides. Having developed resistance against these chemicals, the monarchs themselves are poisonous so predators avoid them. A young, inexperienced bird that takes a bite off of a caterpillar or a butterfly spits it out in disgust and may be sick afterwards. It learns its lesson after no more than one trial.

Are monarchs completely free from enemies, then? Not so, there are exceptions. A number of predators and parasites have also become tolerant or immune to the cardenolides. Thus, they can feed on monarchs with relative impunity. The list of predators includes birds, mice and insects. Monarchs can also become victims of certain pathogens.

Robin. © Beatriz Moisset

Brown thrashers, grackles, robins, cardinals, sparrows, scrub jays and pinyon jays are known to feed on monarchs. Some of these birds avoid the body parts with higher concentrations of cardenolides by eating only the abdomens or by eating this kind of food in moderation. When monarchs arrive in their wintering grounds in Mexico they are plump with stored fats that will keep them through the winter. A whole new set of predators is eagerly awaiting them. Mice feast mostly on dead and dying butterflies that have fallen to the ground. Several species of birds, especially black-backed orioles and black-headed grosbeaks take a heavy toll on the millions of wintering butterflies. A few months after their arrival in Mexico, the monarchs may have lost a fair amount of toxins, making them more appetizing. It is estimated that between 7 and 40% of them fall victims to predation in their roosting grounds.

Small milkweed bug. © Beatriz Moisset

Invertebrates may be worse than mice and birds at decimating the populations of monarchs. Eggs, caterpillars and pupae are all vulnerable. The small milkweed bug doesn't just eat milkweed. It becomes carnivorous in occasions and catches milkweed caterpillars.

Spined soldier bug. Podisus maculiventris. © Beatriz Moisset

The spined soldier bug is an indiscriminate predator of many species and is not averse to feeding on monarchs. It impales caterpillars larger than itself and feeds on the internal fluids. (View of a spined soldier bug feeding on a monarch caterpillar).

Polistes paper wasp. © Beatriz Moisset

Paper wasps, Polistes, sometimes attack monarch caterpillars or pupae to feed their young. Recent reports suggest that this form of predation is more common than originally thought. (View of several paper wasps collecting food from a monarch chrysalis).

Asian lady beetle or ladybug. © Beatriz Moisset

In addition to all these native predators, the introduced Asian lady beetle is becoming a serious enemy of monarch eggs and caterpillars.

Tachinid fly. © Beatriz Moisset

Several tachinid flies and parasitic wasps lay their eggs on the monarch caterpillars for their larvae to feed on. All these insect predators and parasites probably consume a substantial number of monarchs before they even reach maturity.

Parasitic wasp, Pteromalid. © Beatriz Moisset

You may feel sorry for the monarchs; but this is the way of nature. Everything is interconnected and monarchs are not the exception. Sad as it seems, these butterflies serve a purpose by being part of the food chain. They produce enough eggs to survive and prosper despite the attacks. They could go on for thousands of years as they have already done, feeding on milkweeds and providing food for other forms of wildlife. The biggest threat to them does not come from those that feed on them but from the changes we are introducing in the planet.

Another frequent enemy of monarch caterpillars is a predatory stink bug, Stiretrus anchorago (Anchor stink bug).

Further readings:
Parasites Affecting Monarchs. University of Georgia
Parasites and Natural Enemies. University of Minnesota
A Butterfly's Flashy Colors.

Beginners Guide to Pollinators and Other Flower Visitors

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© Beatriz Moisset. 2012

Gardening for Honorary Butterflies (Mint Moths)

Not all moths fly at night and not all are drab. Some deserve the name of honorary butterflies. In fact sometimes they are mistaken for them. Sorry I tricked you by using the word butterflies in the title (not really); but I was afraid that most would ignore this article if they just saw the word moths. The fact is that there are ten times more species of moths than of butterflies; that they are very important components of ecosystems and worth welcoming in our gardens. Some are very beautiful and can give visual enjoyment to the gardener. To me, most if not all are beautiful each in its own way. But I know people who dislike, fear or hate moths in general. I hope that at least they take time to look and learn to love the pretty ones.

I will save some of the most striking ones, such as hummingbird, imperial and Luna moths for later. I will start with some that many people are unaware of and amazed when they first see them.

The crambid snout moths represent a family (Crambidae) with more than 850 species in North America. They get their common name from the appendage that sticks out on front of their heads. Some of them, the members of the genus Pyrausta feed on plants of the mint family, so I will be calling them mint moths, although they don't really have a common name. Most of them are brightly colored and are seen during the day.

Pyrausta orphisalis (Orange Mint Moth) on mountain mint
©Beatriz Moisset

The larvae of the orange mint moth (Pyrausta orphisalis) feed on a variety of mints and sometimes you cans see signs of their feeding, especially at the buds and newer leaves. But the damage is not known to reach serious proportions. It is good to remember that caterpillars are bird food. So it is a good idea to have a few well behaved caterpillars such as these ones to attract birds to the garden. It is also a pleasure to spot this very attractive moth resting on a plant of mint.

Pyrausta signatalis (Raspberry Pyrausta) on mint
©Beatriz Moisset

The raspberry mint pyrausta (Pyrausta signatalis) is also richly colored and earns its name because of the raspberry color of its wings. The larvae feed primarily on spotted beebalm (a member of the mint family), they also feed on a few related plants such as wild bergamot and scarlet beebalm.

Pyrausta tyralis
  © Bob in swamp Flickr

 Another member of this genus, even more striking in its coloration is the Coffee-loving pyrausta (Pyrausta tyralis). This one breaks the mold with its feeding habits, a peculiar feat. It gets its name because it likes wild coffee (Psychotria nervosa) found in Florida. It also feeds on some Asteraceae such as dahlia and bidens.

It is worth mentioning that there are many species of mint moths in Europe. Here is a gorgeous one: the golden mint moth (Pyrausta aurata).

Pyrausta aurata © Bramblejungle Flickr

In summary, if you want to attract these honorary butterflies to your garden plant a variety of mints including beebalm which by the way is also good at attracting hummingbird moths and hummingbirds.

Moth as Pollinators
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THE WEB OF LIFE. The Bear, the Waxwing and the Bee

You may be wondering what bears, waxwings and bees have in common. We'll get to that later.

Let us start with a black bear, the formidable resident of forests and broad spaces. An encounter with one of them can be an unforgettable experience. It is surprising to realize that an animal built up with such powerful claws and jaws is seldom a hunter; in fact perhaps only 10 or 15 percent of its diet consists of animal matter and a good part of that is carrion or insects. So, what does a bear eat? With great versatility it finds a wide range of plant food in the course of the year. In early spring, fresh out of hibernation it may find skunk cabbage to its liking as well as sprouts from plants in the pea family, horsetails and sedges. Later in the season it will find the growing cow parsnips and dandelions, as well as flowers of several kinds. It may supplement this vegetarian diet with some animal protein, from caterpillars to the occasional newborn elk; but still about 80 percent of the summer diet is vegetable. In the fall, it is the time to feast on berries; blueberries, raspberries and everything in between. It can devour enormous quantities of this food because it needs to fatten for the long winter ahead. It is hard to believe that such diet can become many pounds of fat in the short period of a couple of months.

And now for cedar waxwings, those attractive birds that are so much fun to watch. They are especially interesting when they are engaging in their peculiar tradition of passing berries from one to another. Cedar waxwings eat an assortment of berries through the year. In summer, when they are raising young, they enrich their diet with insects; but berries are the main staple of their diet.

Finally, let us talk about bees. Let us make it clear that I am not referring to the domestic honeybee but to any of the numerous native bees and bumblebees that feed on pollen and nectar of wild flowers. If we want to be more specific we can choose the blueberry bee. This industrious little bee is very specialized on the pollen it chooses to feed her family. It goes almost exclusively to blueberry flowers. When doing so it carries some pollen from flower to flower and from plant to plant, providing the plant an invaluable service, pollination. Once the flowers are pollinated they can start setting seeds and developing fruits.

Now, you see the link between bees and birds such as the cedar waxwing and larger animals such as the black bear. They feed on the berries that have been pollinated by the bees or, in the case of the bear, on other plant parts that also require pollination to multiply.

Experts on pollination remind us frequently that one third of our food comes to us courtesy of pollinators; most fruits and vegetables require the services of these little go-betweens, most of them bees. What they forget to mention is the large number of other species that also depend on pollinators for a good part of their diet. The bear and the waxwing are just two examples of a very long list that intertwines the little bees with the more visible birds and mammals.

Another twist in this intricate web, the bear and the waxwing digest the berries but not the seeds. So they end up dropping them farther from the mother plant and surrounded with an amount of excellent fertilizer. So, the pollinator, in turn, also depends on the seed dispersers.

But the final, and perhaps most marvelous twist, is that the plants, so dependent on pollinators and seed dispersers are actually making use of them. They are very skilled in attracting their attention and supplying their needs, either with rich pollen and nectar or with juicy, nutritious fruits. At the same time, they make sure that not all the pollen gets eaten and that the seeds can safely go through the intestines of the berry gluttons.
Thus the web is complete: flowering plants need the pollinators and the seed dispersers; bees need the flowers and the seed dispersers and, finally, bears and birds need the plants and the pollinators. When you walk through the woods or the meadows, think about this invisible web and what it is doing to make everything possible.

Bear feeding: BearDiet

Cedar waxwing feeding: Appalachian Mountain Club: Bird of a Feather...