An annual insectivorous smorgasbord laid out for birds and other critters.
Yesterday morning Antelope Island itself was slow for birds but the west end of the causeway was buzzing with birds and bugs. The infamous brine flies of the Great Salt Lake are near their peak and gluttonous birds are taking full advantage, gulls especially but others too.
Near the shore the flies are so thick it can be very difficult to focus on the birds as they run through the flies to stir them up and gobble them down. Some of my photos of this California Gull were less than sharp for that reason.
Yes, all that dark stuff on the shore is layers and layers of brine flies.
Typically gulls will run one direction gobbling flies and then the other, back and forth until they’re satiated. And then they’ll just stand there among the flies, so full they can hardly move.
Yesterday many other birds were taking advantage of the food glut including but not limited to Wilson’s Phalaropes, Willets and Long-billed Curlews. But during ‘fly season’ one of my favorites is the strikingly handsome Franklin’s Gull.
Franklin’s Gulls have two strategies for hunting flies. Brine flies spend most of their time in thick mats on the ground along the shore rather than in the air so like the California Gulls the Franklin’s Gulls will often run along the shore to stir the flies into flight and then snatch mouthfuls of them right out of the air.
But Franklin’s Gulls sometimes use a second strategy by standing still and snatching individual flies out of the air. This second strategy yields far fewer flies but it also takes less energy since they aren’t running. Besides, many of them are just too damned full to run…
Gulls in particular don’t seem to gobble flies right off the ground, presumably because that method would have sand mixed in with their meal.
But birds aren’t the only recipients of the Dipteran bounty.
This time of year large spiders in almost unbelievable numbers and variety take advantage of the brine flies as a food source by spinning their webs on almost any plant or human structure near the lake where flies are thick. Most of them are various types of orb weavers like this one I photographed yesterday. This year the largest concentrations of spiders seem to be found along the west end of the causeway rather than on the island itself.
Antelope Island State Park holds an annual Spider Festival in early August but this year it will be expanded to a week-long virtual event because of the pandemic. The festival includes a spider photo contest so those who may be interested in participating in the contest should get their submissions in by August 1. I don’t enter photo contests but this year I’m one of the judges.
So if you like birds or insects or spiders you might want to consider making a trip to the island soon. The west end of the causeway is particularly productive for all three right now. And don’t worry, brine flies don’t bite. They’re completely harmless, as long as you keep your mouth shut if you decide to walk amongst them.
But then maybe you’ll be hungry during your visit…
Ron
Amazing feeding behaviors. Just the thought of inhaling one of those flies has me gacking.
They should have a dipteran photo contest, but that might have 0 entrants since you don’t enter photo contests.
Thanks, Lyle. Yeah, inhaling one or several of them wouldn’t be a lot of fun.
Spiders and their incredible architecture blow me away.
A mass of bugs like that would totally freak me out . I am glad that others can see and take advantage of the bounty. I would be slinking rapidly away. Mouth tightly shut.
Happy judging Ron.
Thanks, EC. Methinks you’d likely be more interested in them than you admit.
Yum? *shudder* That’s a lot of flies. 😬 At least it makes things relatively easy for the birds and I’m all for that.
That orb weaver is gorgeous! We used to get a bunch in our garden from time to time, but now I’m lucky if I see one or two. I miss sitting out on the patio and watching them. Congrats on being a judge — well done! I’m looking forward to hearing about your experience.
Thanks, Marty. Being a judge really isn’t a big deal. It’s a small amateur contest but I was asked so I said yes.
I’m having an invasion of Cluster Flies that, to me, seem almost as thick as those brine flies…nightmarish, because I’m not a spider and am an OLD “girl” not a gull….
Cluster Flies are a new one to me, Patty.
Who would have thought fly’s would be a bountiful feast for so many❗️A useful purpose for a fly, love it 😁
Agreed, Diana.
Too many flies for me, but then I’m not a bird. Beautiful Spider!
Good point, Jean.
I am always greatly amused by the Franklin’s sitting in mass along the shoreline snapping at flies. All they do is open their beaks repeatedly.
Congratulations on being a judge this year! It will be fun to see all the creative photos of orb weavers. We usually go for the spider festival. The mass of spiders is so interesting. They have only made my skin crawl one year when I walked down the metal plank at the marina and thousands of spiders dropped from their webs when they felt the first vibration of my foot step. Something about that mass movement bothered my pshychie.
It would probably bother me too, April. I’ve actually never walked out to the boat docks – maybe now I know why.
HAHAHA, overall, it’s a good strategy to keep your mouth shut! I know when I’m out and about in The Great Out There, the open-mouth thing was generally paired with looking up and walking simultaneously. I’m not good at that combination, akin to simultaneously walking and chewing gum, so it’s a good thing I live in the desert now. There are way fewer opportunities to require looking up with an open mouth 😉
I love the orb weaver spiders. I’ve always welcomed them. Now, I’ve got several black widows in my garage. For the moment, they’re safe but I’ll ultimately have to evict them.
The sheer number of brine flies gobsmacks my brain! I mean YOWZER! Another YOWZER goes out to the outrageous number of brine flies required to fill up the gulls (and other birds) to the point where they can’t fly while also leaving enough flies to make this swarm happen again next year! Amazing!
Nature just takes my breath away on a regular basis. I mean, REALLY! THINK about that. It’s a really good ponder, especially now, during this pandemic and all the other political stuff. Ponder Nature! It will boggle your mind in a good and healthy way!
Laura, I used to keep black widows as ‘pets’ in my window wells, throwing an insect snack into their webs every so often. Sometimes I even named them.
The Franklin’s Gull is so handsome ! Although I grew up in Salt Lake City,
I never saw one before. They must not come into town to scavenge, like
their cousins do ? Do the brine flies bite ?
Nope on both counts, Kris. I don’t see them in town and the brine flies don’t bite.
Glad it’s not the gnats! Still wouldn’t want to be in the swarm of the brine flies tho! 😉 Critters certainly do take advantage of the bounty when it’s available – have to – stock up for the lean times…. The different strategies are interesting. BEAUTIFUL spider. 🙂 Was terrified of them growing up including Daddy Long Legs – better now as long as they aren’t on me……
Judy, it’s too hot for biting gnats in mid-summer. Yesterday I didn’t notice them at all.
Gives me the creepy crawlies! The spiders that is! The flies are like the May Lake flies were get here at Lake Winnebago and the communities around it. I avoid the area at all costs during those days. Fortunately it lasts a very short time but what a mess. Everything is covered with them…
Kathy, I don’t walk through the sagebrush during spider season. If I do I can feel those webs on me for the rest of the day!
Amazing how that fine sticky stuff can drive you nuts! 😉
That is truly amazing!
And, don’t those brine flies know about social distancing?
😀
Nope, they don’t Arwen. Brine flies are known conspiracy theorists…
HAHAHAHA! You made me snort my coffee! Good one!
What an incredible thing to witness. Those gulls and other shore birds are going to be increasing their weight by a couple pounds gobbling up that many flies. Reminds me that because our monsoon season has just gotten started it won’t be long before the mosquito explosion. I am confident that you will be a fair and square unbiased spider photo contest judge 🙂
“I am confident that you will be a fair and square unbiased spider photo contest judge”
You can count on it, Everett. Various types of cheating in photo contests is one of the reasons I don’t enter them.
We are visiting in Park City through mid-sept and plant to go to antelope island. Now wold be a worthy time. Thanks for the cool pics.
I hope you enjoy your visit, Linda. Your timing’s good, in part because the biting gnats are laying low in the heat. I’d suggest you visit in early morning or in the evening.
Man, even in these times, I’d be there if I lived closer! What a sight, what an experience! Many thanks for the pictures. Love em!!
Especially like the last picture of the Franklin’s Gull and brine flies, you caught the flies well there.
That doesn’t take anything away from the spider.
Thanks for sharing and stay safe.
Dick, it’s completely safe to visit the island if you take obvious precautions, which I ALWAYS do. I wish you lived closer because I know you’d enjoy it out there.