We hear a lot about habitat loss, but what does that mean for pollinators? And what, if anything, can we do about it?
Although habitat loss comes in many forms, we usually see three major types: habitat destruction, habitat degradation, and habitat fragmentation. Let’s look at these forms one by one.
Three types of habitat loss
Habitat destruction is very much like it sounds. An ecosystem, which is a naturally-occurring assemblage of plants and animals and their physical environment, becomes obliterated. It simply disappears. If you take a wild meadow, for example, cover it with asphalt and erect a shopping center, you have destroyed any trace of the natural environment and all the things that once lived there. Obviously, this is not good for pollinators nor any other living thing.
Habitat degradation is a reduction in the quality of an ecosystem. In other words, the land may still look like a wildland or a place where pollinators might live, but closer inspection will reveal that things aren’t quite right. An example is invasion by non-native plant species. If an area becomes overrun with say Japanese knotweed, kudzu, or Scot’s broom, the native plants gradually disappear. The native plants cannot compete with some of these invaders for sun, nutrients, water, or space. When the native plants disappear, the animal species that were dependent on them disappear as well.
Other things besides invasive plants can degrade a habitat. Industrial pollutants, pesticides, excessive shade or excessive sun, water diversion, or grazing animals can all degrade a habitat to the point that some of the original species can no longer survive.
The last one, habitat fragmentation, is perhaps the most insidious because it is deceiving. Habitat that is fragmented may look perfect, may have all the original components and none of the bad ones, but still be unfit for certain species to survive. How does that work?
An imaginary town
Let’s invent a town that is perfectly square, a mile per side. A square mile contains 640 acres. The developers of this town were forwarding-thinking individuals who decided to put a natural preserve at each corner of the town. Each preserve is 20 acres and left in a natural state. Sounds nice.
But these 80 acres are fragmented—fragmented because they are cut off from each other. Now, for some species this is okay. Even for honey bees, this is okay, and maybe even bumble bees. Honey bees and some bumbles can cover the distance between the four preserves.
But for most bee species, this is a serious situation. Most bees can travel only a few hundred yards from their nest, so in small isolated areas like this, the species become inbred. The bees living there are cut off from the larger pool of genetic material because the only bees to mate with are the ones already there.
It doesn’t happen instantly, but when you have small, isolated, in-breeding populations, “bad genetics”—usually in the form of double recessive genes—begin showing up. Genetic problems arise more frequently in a closely-related population because there is a limited number of alleles (genetic variations of a gene) available. The situation only gets worse if no new blood is coming in.
If an inbred population is then confronted with an unusual circumstance, it may not have the genetic variability to survive. Unusual events like drought, extreme cold, a disease, or a new parasite may wipe out the entire population because it didn’t contain enough genetic variation to assure some survivors.
What island biogeography tells us about fragments
The study of island biogeography illuminates what happens to fragmented populations. Island biogeographers examine populations that are cut off from each other. Remember Darwin’s finches? They presumably got dispersed to different islands, blown there by storms, and once there, each population developed different kinds of beaks because the food sources were slightly different.
That was a good result of separation, but more frequently the results are not so good. Small populations cut off from larger ones often do not survive.
From an evolutionary point of view, habitat fragments are like islands and the same processes affect them. Today, ecosystems everywhere are fragmented by cities, roads, airports, housing developments, farms, and industry. Fragmentation can even affect migratory animals like butterflies and birds because the fragments may be so far apart that the animals cannot find sufficient food or safe resting areas.
Wildlife corridors and how you can help
Maybe you’ve heard the term “wildlife corridor.” A wildlife corridor is a method of connecting various natural areas so that individuals can freely travel between them and encounter a larger selection of mates. Utility easements, for example, can be used as corridors by simply leaving them natural.
Individuals living in cities and suburbs can build corridors by planting wildflowers, keeping pesticide-free gardens, planting trees, and leaving a few weedy patches and some bare ground for the pollinators to use. While a single flower pot or a few milkweeds behind the garage may seem insignificant, they can make a huge difference. They give pollinators a way to connect with others, travel safely to other areas, and expand their genetic resources.
Put a flower pot on your porch
So do your part and plant that flower pot with something that blooms. Your pollinator friends will be glad you did . . . and so will you.
Honey Bee Suite
Great post. Very clear and informative with good examples. Hope it reaches those who haven’t thought about these issues.
The design of your page name and logo changed, didn’t it?! Am I so absent-minded that it happened a while ago or is it recent? Now I wish I had a record of the previous one so I could compare! Maybe you could do a post about that (and maybe you did!). Anyway, just thought I would say something. I noticed!
Yes, I changed it about two weeks ago and you’re the first to mention it. Actually, it’s still not right. I’ve got some other ideas but no time to play around with them. The font is the same, but my husband doesn’t like it. He likes the cartoon bee, but I’m wishy-washy on that. What I need is a really good designer. Let’s just say it’s a work in progress.
Thanks for your reply. Have fun with the process!
After looking for the best place to put this post/question (and getting totally distracted by several articles and threads as I searched), I returned to this posting because I have a post/question about “food deserts for bees”.
I am now completing my fourth full year as a beekeeper in southwestern Virginia. I have kept careful notes and photos and videos of my four year “science experiment”. I think I am seeing an annual pattern, to wit: whether the season starts with a hive that survived the winter, a new package of bees, a spring nuc purchased from a local apiary, or an overwintered nuc purchased from a local apiary, the bee population grows quickly beginning in late February and takes off in March, April, and May as the trees and shrubs bloom.
By mid-May and certainly by June, my hives will have frames of capped brood, larvae and eggs surrounded by capped honey stores, and outer and upper frames filled completely with capped honey. This will usually be true of two and sometimes three brood boxes. Additional brood boxes and supers will be added (with or without a queen excluder – I’ve tried both ways) to limit “crowding” and hopefully to create a small store of honey to remove solely for my own personal use.
By July 4 my hives look like something out of a text book. Nicely built frames and good distributions of eggs and larvae, with tight patterns of capped brood, all surrounded by uncapped nectar and capped honey. But from that “high point”, conditions have worsened each and every year.
First of all, I must note that I have never had much more than one brood box full of honey at the peak in July. If I were a commercial honey farmer, I imagine I would be bankrupt. I have taken a few frames in two of my four years, just for a taste, but I am well aware that the bees need at least one full brood box to make it through winter.
Second, I live in a tight little residential valley with heavily wooded ridges to my south and to my north. Mostly oak and maple trees. Some locust. A few other large flowering trees. A smattering of ornamental trees. Typical back yard flower and vegetable gardens. No large fields of wildflowers or mono-crops. The trees and shrubs, with a few exceptions, finish blooming around July 4.
Third, by mid-August, my hives generally have large populations of bees, but very little stored honey. They sometimes have quite a bit of stored pollen, but, more often than not, they have little in the way of honey. And when they do have honey, it has never amounted to a full brood box of frames filled with capped honey stores. Perhaps a few brood frames with a border of capped honey cells, and a few partial frames in the upper hive.
Fourth, while there is a “fall bloom” in the form of Golden Rod, Black Eyed Susan, Butterfly Weed, and Joe Pye Weed in southwestern Virginia, there are few of those flowers within a two mile radius of my hives. As a result, I feed with sugar water and pollen substitute and pollen patties in an attempt to help the hives survive the winter. It never seems to create a set of stores equal to what I see in early July. And over the past two winters I have been unsuccessful with four of five hives.
So … is it possible that my hives are simply located in a “food desert for bees”? How else to explain year after year of only modest honey stores in the spring and the collapse of honey stores after the trees stop blooming? What, if anything, am I missing in this set of observations? What, if anything, can I do to reverse my annual experience?
Wow. Long question. I can offer some try-its, but I can’t guarantee results. With all those trees, especially maple and locust, you should have no trouble getting multiple boxes of honey, as long as it isn’t raining or cold during bloom times.
But first, a reminder. Colonies build up for six months of the year as the days get longer (about December 21 to June 21) and they get smaller during the other six months, roughly June 21 to December 21. That means your bee populations should peak around the end of June or first week of July which is exactly what you describe. Thereafter, populations will slowly decline, although it is hardly noticeable at first.
Second, we as beekeepers tend to think honey bees store food for winter, but we forget they also store it for nectar dearth, which generally occurs in the summer. So it is normal for bees to use much of their honey during that time. By fall, when the autumn flowers bloom, there are fewer bees available to collect nectar due to the natural rise and fall of bee populations.
So what to do about it. Many beekeepers make the mistake of raising bees on the spring flow, rather for the spring flow. In other words, a large part of the spring nectar is used up for raising bees, instead of being stored. So what you want to do is raise a cajillion bees before the nectar flow starts, so that when it happens, your populations are already built up and ready to go. This, of course, requires over-wintered colonies.
What you do is feed 1:1 syrup in late winter as soon as they will take it. Add a feeding stimulant like Honey-B-Healthy or anise oil. Feed and feed and feed until the nectar flow begins and then stop and add your honey supers. You now have a huge workforce to collect all that maple nectar.
The downside to this is early swarming, so you may have to checkerboard the frames above the brood box, or take whatever swarm measures you prefer.
I find that if I feed for spring, I don’t need to feed in the fall because usually there is so much stored honey I don’t have to worry about winter stores. So in this case, you are just substituting spring feeding for fall feeding.
I generally take all my honey supers off by June 30, simply because what follows is a summer dearth and I don’t want my bees to use the honey crop they just put up. I don’t keep all of it, but save some to give back to the bees if necessary. It’s odd but I find they are more apt to collect more if they think they are short.
In your case, if the spring build up is successful, you might want to try Tony’s method of upper entrances to reduce congestion and maximize honey stores. Tony got over 500 pounds of surplus honey this year from four hives and he’s in NYC.
In conclusion, I would say it’s not a bee desert, but just a management issue. I want a report on all this honey you’re going to get.