Published: May 27, 2022

By Mark Seth Lender

Great blue heron lands at the nest (Photo: (c) Mark Seth Lender)

Living on Earth's Explorer-in-Residence muses on the importance of communication and trust between a great blue heron couple as they share equally the duties of raising their young.

Great blue herons engage in a high degree of cooperation with their mates. Both male and female work equally hard, taking turns at the tasks at hand. Early on, the primary requirement is thermoregulation of the eggs and early hatchlings and also protection. The nest at this stage cannot be left unguarded. Whoever is on the nest must wait for the other member of the pair to return to be relieved before heading off to feed.

To cooperate, a high degree of communication is de rigueur. Early in the season, before and just after eggs are laid the greetings are elaborate and vocal. Later, as the season progresses and the responsibilities mount, much of what herons say to each other is not said, but understood. Or betrayed by a look. Implicit is a high degree of confidence each in the other. For the one waiting to be relieved, some assurance must exist that relief will come. Less of a challenge is the actual changing of the guard. Usually...

That is what makes this story so unusual. The male had to literally, physically, prod his mate with his enormous foot - gently, but nonetheless – to encourage her to go. Shifts can be hours long during which time the guardian neither eats nor drinks. Hunger and thirst must have been upon her. Yet she was reluctant to go. When the male prodded her, she vocalized her objection! Perhaps there was another reason, something that I missed, that made her want to stay. But it certainly seemed like a matter of trust.

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