Very sad. Wonder what kind of "farm" it was and what kind of pesticides, animal waste pits or diseases they could have ended up getting into? I hope the cause is identified quickly, especially if it was disease.
Presently have six Greenwing Macaw (17 yo), Red Fronted Macaw (12 yo), Red Lored Amazon (17 y.o.), Lilac Crowned Amazon (about 43 y.o.) and a Congo African Grey (11 y.o.)
Panama Amazon (1 Y.O.)
Well the poisoning theory sounds like the most plausible one...
They poison the mice/rats/other pests to get rid of them, without thinking about the consequences of what happens to "nature's clean up crew" the animals that eat other dead animals.
They eat the animals that have been poisoned, and consume the poison themselves. They die too...
It wouldn't be the first time.
Could be pesticide exposure, but... this sounds more likely.
If you do research you will see that every year there are a ton of incidents where birds fall out of the sky dead. Sure some of those can be freak weather patterns that mess the flock up and cause them to fly into something. But most of the time it's due to poisons.
They don't usually get much publicity because frequently it will be starlings or house sparrows who are considered an invasive species, so no one cares, or considers it good riddance.
the problem with this is those are birds in HUGE flocks so that is why it's highly noticed. It may go unnoticed when it's just a couple eagles or other less invasive birds. Also predator birds will eat those poisoned birds and may die, but it may take quite sometime so it goes unconnected.
Hopefully they are able in this case to identify what has happened.