During my great-crested grebe (Podiceps cristatus) observations at the Gouwzee in July 2018, it became apparent that they don’t mind swimming about amid groups of Eurasian coots (Fulica atra).
It turned out, however, that the grebes can also be quite aggressive and one morning these birds treated me to a stunning display as they had six years earlier. This time it was not a peaceful event like their mating dance, however, but apparently a territorial dispute. Two pairs were each tending a young one near reeds in a cove on the Gouwzee side of a dike. It appeared that one adult had ventured into space that the other pair considered their own. An epic battle ensued – I wish I’d had the presence of mind to change my camera settings to get better photos, but it was so sudden and exciting that I was just glad to be able to get some shots. The whole dispute only lasted about three minutes but seemed to last much longer!
References I found in the literature online appear to indicate that researchers believe territorial aggression mostly takes place when the grebes are building nests and tending eggs. They mention that it stops once the young are born. This was obviously not the case for the two pairs that I observed; their young appeared to be several weeks past fledging age.
The birds first caught my eye when they faced one another, lying low in the water. This is said to be a common aggressive posture.
Suddenly, they erupted upwards, calling loudly and flapping their wings strongly to intimidate one another. (You can see larger versions of photos by clicking on them.)
A couple times, they surged upwards from the water to clash their chests together.
One appeared to have dunked his opponent in the water, although this happened so quickly that I didn’t really see how it occurred.
They would take a few second pause, making their mutual displeasure apparent.
This would be followed by another bout of confrontation. At one point, one grebe’s mate and young one swam closer to the action.
Finally, after a couple minutes, one “combatant” was driven off by his opponent.
He was joined by his mate and offspring and peace returned. And I walked away elated at having witnessed the behavioral exhibition, glad that no injuries had been sustained. 😊
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Wonderful series and great information.
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Thanks, Karla. I truly wish the photos had been better but I’m glad I was able to document the event, especially since it seems to show the birds may be territorial even after their young have gotten older.