Breeding season has begun for great blue herons

Breeding season has begun for great blue herons

BY THE BAY: Breeding season for herons

Great blue herons' bills turn bright orange and they build stick nests crazily high up this time of year.

A stalking heron is the epitome of stealth.

It stands perfectly still, eyes focused intently, enormous bill poised, ready.

Then comes the strike and with deadly precision, the prey is grabbed and swallowed down that long, sinuous neck.

A few minutes to cope with the wriggling, then it is back to stalking.

This is a great time of year to watch great blue herons. Large groups gather in the shallow intertidal, ready to feed on starry flounder, shiner perch and other fish which move closer into shore as the water warms up.

It is the start of the heron’s breeding season. Their bills turn bright orange, delicate plumes adorn their necks, and they build stick nests crazily high up in maples and conifers along the shore.

The majority of great blue herons prefer company. Heron colonies are noisy, smelly places, with multiple nests in each tree and young herons soon splashing the leaves below with grey guano. Fallen dead chicks and fish remains add to the smelly debris.

Herons are sometimes mistakenly called ‘cranes,’ but these are a different family entirely. Great blue herons on the B.C. coast are a separate sub-species from elsewhere in North America and of “special concern” to the Committee on the Status of Endangered Wildlife in Canada.

These magnificent birds are sensitive to disturbance at nesting colonies. Their population is relatively small, and suitable nesting and feeding locations are becoming ever scarcer along our developed shorelines.

The increase in bald eagle populations since the pesticide DDT was banned has led to some bald eagles causing havoc in heronries.

The largest heronry in the Pacific Northwest was the one at Point Roberts, which was suddenly abandoned a few years ago. Most of those herons relocated to the Tsawwassen bluff overlooking Roberts Bank, and hundreds of herons can be seen flying over the ferry causeway to feed in the intertidal area.

Once the chicks are reared, the colony disperses and herons become more frequent in field margins and along ditches, where they catch frogs, snakes and voles.

Great blue herons are also commonly seen in wetland areas of Surrey and White Rock. Look for them along the tide line in Mud Bay, Boundary Bay, and Semiahmoo Bay, and roosting in neighbouring fields.

Anne Murray, the author of two nature books available in local book stores, writes monthly in the Peace Arch News –