A door opens into the complex socio-political life of the Acorn Peaks.
Competition for power is one of the most complicated issues, even in the world of an acorn woodpecker. Dozens of birds, united in alliances, can fight fatally from day to day, while spectators will fly nearly 3 kilometers away to witness a battle for fertility. .
And the war will get hotter and hotter, to the point that when the death of a bird creates a void in the mainland, the struggle to fill it will erupt in minutes and distant spectators will be able to fly to ‘so’ in less than a few minutes. ‘one o’clock.
The giant “food barns” of Acorn Peak.
That’s one of the findings of a study published in Current Biology, when scientists tracked an unusual and socially complex bird population in California, United States. And the payoff for the tough battle is quite remarkable. This is fertile ground for a group of birds that come together to raise children and share precious oak stocks that will help them overcome food shortages. But the cost of a battle can be enormous.
“You can see the birds with their eyes gouged out, blood on their feathers – they get their feet in the fight and fall together to the ground, ”said Sahas Barve, lead author of the study. They are sharp in the mouth and therefore can do a lot of damage. “
The chaos and chaos of a power struggle make it difficult to visualize what is going on. Barve and his colleagues therefore used radio beacons to track the movements of other groups of birds in the area.
“We were surprised to find that these so-called ‘warriors’ spend up to 10 hours a day fighting, and spectators leave their territory for about an hour. more just to come see, ”said Barve.
Radio tags are attached to the birds’ legs for research purposes.
The research has led to a better understanding of a species with complex social and behavioral networks. Acorn Woodpeckers live in groups of up to 16 in oak habitats, stretching from Oregon and California to Mexico, Central America and northern Colombia.
Each social group has many males and females raising each other’s chicks, helped by the older ones. The relationships overlap so much that scientists are unable to determine which offspring belongs to which adult, but taking active steps to ensure their eggs are safe is a common task.
To ensure there is enough food when flies or other insects are scarce, Acorn woodpeckers drill holes in thick oak bark or in structures such as utility poles to store oak. Over time, each “barn” accumulates many holes – from a few hundred to tens of thousands – making it a resource that other groups of woodpeckers covet. But the Acorn Woodpeckers have proven to be wise strategists, and also fiercely defenders of these territories.
The fight between Acorn birds is fierce and loud.
When all of the large males or females in a group of birds die or disappear for some reason, a new power struggle is unleashed. And only birds of the same sex will come to compete in the battle. This fight will be divided into groups of two or three birds together until only one group wins. Groups of children usually consist of sisters or a mother with daughters in the herd. Research shows that up to 12 alliances engage in a single battle, which can last anywhere from 5 days to a week, to fight for a large “pot of food”.
“The battle can be so fierce it can be heard from a distance from a football pitch,” Barve said.
The society of birds is much more complex than you might think.
For the benefit of the public, birds watching from nearby trees before returning to their nesting grounds are not entirely clear. But swapping the risks to get here suggests they seem to have been given some useful information. The Acorn Woodpecker is known to have broad relationships outside of its group, and they themselves follow the change in membership of bird groups in other territories. According to Barve, a previous population study showed that the bird spies regularly, visiting an average of six territories per day.
“They watch very closely and care about everything – where other people live, how they’re related and where they should be living,” added Brave. And observing the arrival of other flocks, he claimed that if neighboring flocks were out of balance, the birds would immediately ally with each other and start a new war.
“Their societies are much more complex than we think,” concludes the scientist.
