Flocks of Woodpeckers?

Waterfall display of Russian over-the-horizon radar signal on 20 meters.
(From IARU Region 1 Monitoring System website)

The International Amateur Radio Union's Region 1 Monitoring System is reporting that Russian over-the-horizon radar signals have been picked up on the 40, 30, 20 and 17-meter ham bands, along with Russian military communica- tions on 40, 30, 20 and 15 meters. 

The ARRL Letter reports that the radar signals are 12 kHz wide, making 40 sweeps per second and using FM on pulse. An additional over-the-horizon radar was reported in northern Iran, operating between 6.078 and 7.022 MHz, with 81 sweeps per second and AM on pulse over a 44-kHz bandwidth. 

(For those of you too young to remember it, the woodpecker reference in the title refers to early Russian OTH radar, back in the 1970s, which sounded like a woodpecker as it swept through the HF bands.)