dead starlings
In early February we learned of two cases of mysterious mass deaths of birds in Ukraine and Russia, while back in mid-January a similar report came out of Mexico.

The first incident was reported on February 8th and involved large numbers of dead starlings found on a road alongside the Dnieper River in Ukraine. Here are some of the images from that event:

dead starlings
dead starlings
dead starling
dead starling
The other incident was recorded in Crimea's Donuzlav region on February 11th.

The article (with translation by Google) contains the following:
According to an eyewitness who wished to remain anonymous, dead ducks are on the entire bank of the spit from the side of Lake Donuzlav.

"They are lying everywhere: on the shore, in the water, on the road leading to the Sand Quarry, which is at the entrance to the lake. What happened - I do not understand, I was there a week ago, this was not," the user writes.
Here is a video from this second event, showing numerous dead long-tailed ducks along the water's edge:


The incident in Mexico reportedly occurred on January 17th. At least 40 dead birds were discovered along a 300m length of cyclepath in the city of Ciudad Obregón. Here are some images taken by locals:

dead bird
dead birs
dead
dead
dead birds
These incidents should be seen in the context of a long series of similar mysterious events over the last decade. The following is a short compilation of such events from across the planet: Any number of things can be causing these sudden deaths of flocks of birds, not least something occurring in the atmosphere to 'stun' them en masse. Perhaps a short, sharp shock from the blastwave of an exploding meteor, which occurs higher up in the stratosphere but can send its shockwave down to levels birds fly at, or some kind of electrical discharge (and not necessarily lightning).