Riddle me this one Batman…I often see birds, that are flying across a road or highway, dip down just enough to put themselves in danger of being hit by a car. What’s up? Do we have thrill seeking birds flying around or is it just a combination of stupid birds and turbulence?
Not being a bird for real and therefore not knowing for sure, there could be a few reasons:
[li] Bird is flying over the roadway and is affected by turbulence from the cars (heat from the traffic and roadways contributes to updrafts which are more condusive to flying - the birds gain lift and altitude without expending more energy)[/li][li] Bird is chasing insect or smaller bird for dinner (pursuer)[/li][li] Bird is being chased by larger bird as dinner (pursuee)[/li][li] Bird is carrying prey or nesting material and cannot get lift (nearly hit an osprey carrying a fish the other day)[/li][li] Bird is indeed having fun flying and dodging the vehicles**[/li]
**do chickens play “human” when they’re doing something stupid?
Good question, but I’d hesitate to call a bird “stupid” because it does not posess the knowledge you do in the same way you learned it. You recognize a strip of paving as a road, and therefore realize the potential for serious harm, a lesson taught to you usually by your parents or someone else. Birds and other creatures usually do not have this fore-knowledge except by trial-and-error. Some animals have learned to use human structures to their advantages: I’ve read observations where crows and ravens will harass squirrels out into busy traffic and BAM! instant dinner with less hassle.
And welcome to the boards.
Cars, and especially trucks, produce very strong vorteces. Most birds, especially light birds with large wings, will be strongly affected by these. I have seen sea birds ‘surfing’ the pressure wave created when a strong sea breeze meets the superstructure of a ship, sometimes for hours on end.
I’ve also seen a large raptor use a moving truck (mine) as a mask or blind when hunting crows. Dunno what kind of bird it was, but it tracked my truck in a pursuit curve, in a shallow dive, as I was driving across the Arizona desert one evening, and crossed the hood of my truck just as I came alongside a murder of crows. The bird in question was large enough that while it’s body was in front of my hood, it’s wing-tip feathers nearly brushed my windshield (I had a fairly small truck, but I’d guess the wingspan to be about 6 feet), and even this large bird was bounced upwards about a foot by the pressure wave comming off the front of my hood. That is to say, with no discernable wing motion, it rose about a foot, just clearing my hood, instead of slamming into me as I expected. This could’ve been, I suppose, also due to something the bird did to increase lift. I sure didn’t have much time to figure it out!
Once it had crossed over me, it slammed into one or more of the crows sitting on the roadside. I couldn’t tell how many it got, but there was big cloud of black feathers when it struck. Needless to say, I had to stop and regain my composure. And gawk. No camera, worse luck.
Oh, and welcome to SDMB.
This young turk, er uh buzzard, I mean gull, might take offense at such frivolous casting of nasturtiums by a mere mortal.
Turkey vultures, redtail hawks, and even the seemingly lowly seagull can behave in most interesting ways when confronted with nature, humans, and their constructs.
I had the pleasure of participating (to a minimal degree) in much of the filming of the aerobatic sequences for the referenced movie.
A master model builder had built a handful of special purpose radio controlled sailplanes in a manner that made them difficult to identify, at first look, at a hundred feet or so. The “birds” were probably 90% foam, with wooden stiffening structures as the other 5%. A very talented airbrush artist’s skills helped to complete the illusion.
Seagulls, when in foraging mode, have a strong tendency to drop into formation with anything moving at a reasonable speed, along coastal cliffs, while working the updrafts.
During the three or so months of filming, several of us peons became spotters for individual gulls that could be identified as regular visitors to the cliffs at Torrey Pines, California.
After the first month or so, three gulls became prime candidates for supporting roles, because of their willingness to follow most all of the model’s maneuvers. It didn’t hurt the overall game plan in the least that “catering” provided us with the foodstuffs to pepper the landscape with delectable seagull noshibles.
To make a long hijack shorter (hah), the monumental events occurred after much practice.
Some birds are built for terminal velocity dives - seagulls aren’t. Their feathers go all catywhompus at speeds beyond design. The totally non-aerodynamic sound of all that feather fluttering is most unusual.
Loops. A couple of the more rambunctious birds would follow a dive into a near head up vertical attitude, only to hammerhead stall turn bail out (sort of).
One time, one bird seemed to be totally engrossed in tracking 5 or so feet behind and a few feet to the side of the model. His attitude went maybe 15 or 20 degrees beyond vertical. With a wee bit of imagination, coupled with the visual display, it was undeniably obvious when “Jonathon” went, “Oh shit”. He was not designed for this. It took 50 or so feet for him to recover. It was not elegant. It was not caught on film.
The book has it’s place. The movie is by no means good. I recommend both for the novelty.
Stupid birds and turbulence, indeed. (smirk)