Only fools mess around with bees, wasps, and hornets as they collect nectar and go about their business while visiting flowering plants. Relentlessly curious predators and other trouble makers quickly learn that patterns of white, yellow, or orange contrasting with black are a warning that the pain and anguish of being zapped with a venomous sting awaits those who throw caution to the wind. Through the process of natural selection, many venomous and poisonous animals have developed conspicuously bright or contrasting color schemes to deter would-be predators and molesters from making such a big mistake.
Visual warnings enhance the effectiveness of the defensive measures possessed by venomous, poisonous, and distasteful creatures. Aggressors learn to associate the presence of these color patterns with the experience of pain and discomfort. Thereafter, they keep their distance to avoid any trouble. In return, the potential victims of this unsolicited aggression escape injury and retain their defenses for use against yet-to-be-enlightened pursuers. Thanks to their threatening appearance, the chances of survival are increased for these would-be victims without the need to risk death or injury while deploying their venomous stingers, poisonous compounds, or other defensive measures.
One shouldn’t be surprised to learn that over time, as these aforementioned venomous, poisonous, and foul-tasting critters developed their patterns of warning colors, there were numerous harmless animals living within close association with these species that, through the process of natural selection, acquired nearly identical color patterns for their own protection from predators. This form of defensive impersonation is known as Batesian mimicry.
Let’s take a look at some examples of Batesian mimicry right here in the Lower Susquehanna River Watershed.
Suppose for a moment that you were a fly. As you might expect, you would have plenty to fear while you spend your day visiting flowers in search of energy-rich nectar—hundreds of hungry birds and other animals want to eat you.
If you were a fly and you were headed out and about to call upon numerous nectar-producing flowers so you could round up some sweet treats, wouldn’t you feel a whole lot safer if you looked like those venomous bees, wasps, and hornets in your neighborhood? Wouldn’t it be a whole lot more fun to look scary—so scary that would-be aggressors fear that you might sting them if they gave you any trouble?
Suppose Mother Nature and Father Time dressed you up to look like a bee or a wasp instead of a helpless fly? Then maybe you could go out and collect sweets without always worrying about the bullies and the brutes, just like these flies of the lower Susquehanna do…
FLOWER FLIES/HOVER FLIES
So let’s review. If you’re a poor defenseless fly and you want to get your fair share of sweets without being gobbled up by the beasts, then you’ve got to masquerade like a strongly armed member of a social colony—like a bee, wasp, or hornet. Now look scary and go get your treats. HAPPY HALLOWEEN!
This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered. Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.
If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow. In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.
Still not ready to take the leap. Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides. There’ll be no pesticide residues leaching into the soil or running off during downpours. Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply. Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground. Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.
What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space? That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream. All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden. Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs. Look what we get for pennies a plant…
Here’s a closer look…
All this and best of all, we never need to mow.
Around the garden, we’ve used a northeast wildflower mix from American Meadows. It’s a blend of annuals and perennials that’s easy to grow. On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden. They even have a mix specifically formulated for hummingbirds and butterflies.
Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing. One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property. A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.
For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania. Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime. They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses. Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds…
Pasture, Grazing, and Hay Mixes
Warm-season Grass Mixes
Retention Basin Mixes
Floodplain and Riparian Buffer Mixes
Rain Garden Mixes
Steep Slope Mixes
Solar Farm Mixes
Strip Mine Reclamation Mixes
We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success. For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”. It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends. More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.
In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.
Why not give the Monarchs and other wildlife living around you a little help? Plant a wildflower garden or meadow. It’s so easy, a child can do it.
Inside the doorway that leads to your editor’s 3,500 square foot garden hangs a small chalkboard upon which he records the common names of the species of birds that are seen there—or from there—during the year. If he remembers to, he records the date when the species was first seen during that particular year. On New Year’s Day, the results from the freshly ended year are transcribed onto a sheet of notebook paper. On the reverse, the names of butterflies, mammals, and other animals that visited the garden are copied from a second chalkboard that hangs nearby. The piece of paper is then inserted into a folder to join those from previous New Year’s Days. The folder then gets placed back into the editor’s desk drawer beneath a circular saw blade and an old scratched up set of sunglasses—so that he knows exactly where to find it if he wishes to.
A quick glance at this year’s list calls to mind a few recollections.
Before putting the folder back into the drawer for another year, the editor decided to count up the species totals on each of the sheets and load them into the chart maker in the computer.
Despite the habitat improvements in the garden, the trend is apparent. Bird diversity has not cracked the 50 species mark in 6 years. Despite native host plants and nectar species in abundance, butterfly diversity has not exceeded 10 species in 6 years.
It appears that, at the very least, the garden habitat has been disconnected from the home ranges of many species by fragmentation. His little oasis is now isolated in a landscape that becomes increasingly hostile to native wildlife with each passing year. The paving of more parking areas, the elimination of trees, shrubs, and herbaceous growth from the large number of rental properties in the area, the alteration of the biology of the nearby stream by hand-fed domestic ducks, light pollution, and the outdoor use of pesticides have all contributed to the separation of the editor’s tiny sanctuary from the travel lanes and core habitats of many of the species that formerly visited, fed, or bred there. In 2019, migrants, particularly “fly-overs”, were nearly the only sightings aside from several woodpeckers, invasive House Sparrows (Passer domesticus), and hardy Mourning Doves. Even rascally European Starlings became sporadic in occurrence—imagine that! It was the most lackluster year in memory.
If habitat fragmentation were the sole cause for the downward trend in numbers and species, it would be disappointing, but comprehendible. There would be no cause for greater alarm. It would be a matter of cause and effect. But the problem is more widespread.
Although the editor spent a great deal of time in the garden this year, he was also out and about, traveling hundreds of miles per week through lands on both the east and the west shores of the lower Susquehanna. And on each journey, the number of birds seen could be counted on fingers and toes. A decade earlier, there were thousands of birds in these same locations, particularly during the late summer.
In the lower Susquehanna valley, something has drastically reduced the population of birds during breeding season, post-breeding dispersal, and the staging period preceding autumn migration. In much of the region, their late-spring through summer absence was, in 2019, conspicuous. What happened to the tens of thousands of swallows that used to gather on wires along rural roads in August and September before moving south? The groups of dozens of Eastern Kingbirds (Tyrannus tyrannus) that did their fly-catching from perches in willows alongside meadows and shorelines—where are they?
Several studies published during the autumn of 2019 have documented and/or predicted losses in bird populations in the eastern half of the United States and elsewhere. These studies looked at data samples collected during recent decades to either arrive at conclusions or project future trends. They cite climate change, the feline infestation, and habitat loss/degradation among the factors contributing to alterations in range, migration, and overall numbers.
There’s not much need for analysis to determine if bird numbers have plummeted in certain Lower Susquehanna Watershed habitats during the aforementioned seasons—the birds are gone. None of these studies documented or forecast such an abrupt decline. Is there a mysterious cause for the loss of the valley’s birds? Did they die off? Is there a disease or chemical killing them or inhibiting their reproduction? Is it global warming? Is it Three Mile Island? Is it plastic straws, wind turbines, or vehicle traffic?
The answer might not be so cryptic. It might be right before our eyes. And we’ll explore it during 2020.
In the meantime, Uncle Ty and I going to the Pennsylvania Farm Show in Harrisburg. You should go too. They have lots of food there.
It’s sprayed with herbicides. It’s mowed and mangled. It’s ground to shreds with noisy weed-trimmers. It’s scorned and maligned. It’s been targeted for elimination by some governments because it’s undesirable and “noxious”. And it has that four letter word in its name which dooms the fate of any plant that possesses it. It’s the Common Milkweed, and it’s the center of activity in my garden at this time of year. Yep, I said milk-WEED.
Now, you need to understand that my garden is small—less than 2,500 square feet. There is no lawn, and there will be no lawn. I’ll have nothing to do with the lawn nonsense. Those of you who know me, know that the lawn, or anything that looks like lawn, and I are through.
Anyway, most of the plants in the garden are native species. There are trees, numerous shrubs, some water features with aquatic plants, and filling the sunny margins is a mix of native grassland plants including Common Milkweed. The unusually wet growing season in 2018 has been very kind to these plants. They are still very green and lush. And the animals that rely on them are having a banner year. Have a look…
I’ve planted a variety of native grassland species to help support the milkweed structurally and to provide a more complete habitat for Monarch butterflies and other native insects. This year, these plants are exceptionally colorful for late-August due to the abundance of rain. The warm season grasses shown below are the four primary species found in the American tall-grass prairies and elsewhere.
There was Monarch activity in the garden today like I’ve never seen before—and it revolved around milkweed and the companion plants.
Eaton, Eric R., and Kenn Kaufman. 2007. Kaufman Field Guide to Insects of North America. Houghton Mifflin Company. New York.