Both birds are territorial and not shy about pushing others away.
The Great Blue Heron has the advantage here, and uses it.
Even after the Egret moved off the Heron made a big show of landing and being sure the Egret knew he was there.
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Claiming His Territory, Heron, Egret
Claiming His Territory, Heron, Egret
Claiming His Territory, Heron, Egret