So after WWI Australia had a large number of former soldiers decide to take up farming. The problem was that most of the really good farm land was already in use. So you get a large number of farms springing up on fairly marginal lands. Which can work when times are good but Australia wasn't immune to the effects of the Great Depression. Farmers were encouraged to grow more and more wheat with promises of subsidies that never came. Wheat prices dropped like a stone and to make matters worse, Emus decided they liked this newly cleared land. All of this is the recipe for explosive discontent. And the Australian goverment decided a short, victorious little war would be just the thing.
So the looked around for a group they could declare war on. And they settled on these guys.
A Blood Thirsty Warrior Emu.
Now one of the things that the soldiers learned in WWI was that machine guns were amazing at killing people running over an open field. So the Australian goverment sent two soldiers with a Lewis Machine Gun and 10,000 rounds of ammunition along with a film crew to go after the Emu. And they figured "How hard can this be?" The Emu is flightless, it's not very bright and they've got machine guns. But they ran into some problems. First, the estimates where that there were 20,000 Emus terrorizing the farms by eating things and making hideous noises. Second, they had one machine gun and many groups of Emu. Third, the Emu is fast. It can sprint up to 50 km/h. Fourth, they are surprisingly durable.
The first encounter was with a small flock of 50 that settlers tried to drive into the machine gun emplacement. They killed "a number" which is military speak for "not very many" in this case. Then they tried an ambush. It didn't work much better. They tried to get mobile. They mounted the machine gun to a truck. This didn't work. And it became a bit of a laughing stock. By the time the machine gun team was withdrawn, they had fired 2,500 rounds and gotten maybe 200 Emu. Probably less.
If we had a military division with the bullet-carrying capacity of these birds it would face any army in the world...They can face machine guns with the invulnerability of tanks. They are like Zulus whom even dum-dum bullets could not stop. -Major G.P.W. Meredith, veteran of the Emu war.
But the plucky Australians proclaimed they wouldn't be defeated by the devil birds. More forces were poured into it. And they claimed a whopping 986 kills with 2,500 wounded. And soon the Australians realized that despite their proclamation...they were losing to the birds. So they withdrew their military again, did their best to forget about their loss and set up a much more effective bounty system.
Thus the Emu War ended.