This is the time of the year that “midges” are as thick as flies on you-know-what at the Bear River Migratory Bird Refuge. They are so thick that they can look like tornadoes along side of the Auto Tour route as seen in the image to the left. A lot of people mistake midges for mosquitoes; they do look similar, and think that they will be bitten by the swarms of bugs in the air. There are biting and non-biting midges, biting midges are often called “no-see-ums” and truly they are miserable to get into because even though you can barely see them the bites let their presence be known.
The midges at Bear River Migratory Bird Refuge along the auto tour route are non-biting midges and they play an important role in the areas eco-system.
Midges have three stages in their lifetime, larval, pupal, and adult. In the larval stage midges are aquatic, they feed on algae, plankton and small aquatic plants. They are a food source in the larval stage for fish and their appearance is similar that that of mosquito larvae.
The female midge lays her eggs either on the water surface or on vegetation near the water. The eggs hatch in approximately 72 hours followed by a two day pupation before rising to the surface as adults. An important thing to remember is that the flying adult midges do not eat and have a short life span of about 10 days.
You can hear a humming sound with that many midges in the air though they do not have the typical “buzz” a mosquito has. Midges over winter in the larval stage in the water. The midges at Bear River Wildlife Refuge seem to be concentrated along the sides of the dirt road of the auto tour route hovering above the grasses, or on the vegetation along the road or nearby shoreline plants.
They can be a bother when you are driving along with your windows open for birding, bird photography or sightseeing. The outside and inside of the vehicle will literally have hundreds, if not thousands of midges attached to the interior and exterior. Not to worry though; if you leave the windows open a bit when you reach the paved road and higher speeds most will leave the vehicle.
They do tickle if they land on your skin and the sheer numbers of them can feel a bit overwhelming but they don’t bite.
They are; however, an important food source for many of the birds found on the refuge. The midges at Bear River MBR first appear around April and are often still being seen through June.
Many of the shorebirds found at the refuge begin to return about the time the midges are “hatching” in the spring. They are a favorite of Eared Grebes and a few other perching birds. I have many images where the midges are either present on the water surface or are in flight around the birds I photograph.
They can be troublesome to “clean” off the water surface and they can appear to be dust bunnies (aka sensor spots) in an image frame. Yesterday I could see one walking on my lens through the viewfinder, if that happens to you just blow it out, don’t try to smoosh it or your lens will get dirty!
Here are some of the birds that eat midges:
American Avocets are elegant, graceful and unique shorebirds found in great numbers in the Bear River MBR. According to the BNA (Birds of North America – a pay site) their freshwater diet includes:
In freshwater wetlands water boatmen (Hemiptera, Corixidae); adult and larval beetles (Coleoptera); fly larvae (Diptera), especially midges (Chironomidae).
I haven’t researched yet to see how many other shorebird species found in the refuge that eat the midges but I’m fairly sure that more of the shorebirds do benefit from the midges being in the refuge.
Another bird that seems to benefit from midges is the Yellow-headed Blackbird. In the image above you can see a few flying midges in the frame and I have watched these blackbirds snatch the midges right out of the air while they are perched. I’ve also seen the Yellow-headed Blackbirds feeding on the ground by grabbing the midges off of the vegetation. They probably have to eat a lot of the midges for the calories they need but the blackbirds don’t seem to make a dent in the millions of midges on the refuge.
Swallows start to show up at the refuge about the time the midges first start flying, I don’t think that is a coincidence since swallows prefer flying insects for their diet. Although I would prefer that swallows ate just the biting insects I won’t begrudge them eating the non-biting midges either.
Yesterday I was fortunate enough along the auto route tour to be able to get close to several Marsh Wrens that were calling in the cattails and I could see quite a few of the nests. I love wrens in general, they are tiny little birds with big attitudes that are amazingly fast and challenging to photograph. I was quite surprised to see one of them yesterday snatch a midge right out of the air.
Humans may think that midges are a nuisance yet the birds I have mentioned benefit tremendously from the presence of these insects. I have only touched on a few of the bird species that ingest these bugs. Midges and birds at Bear River MBR are important parts of its healthy ecosystem.
Food for thought on a windy, cloudy and rainy day in Utah.