See all posts in the Birds of Carver County series
The Great Blue Heron (Ardea herodias) comes back to us in March with a splash, most of the time landing near where it grew up.
Rookeries with dozens of birds are situated in the thawed ponds and lakes throughout the county. Reaching their peak in April and May when breeding pairs are busy with nests, they will have a single brood, then usually depart by the end of October. If birds have found an ice-free stretch of water, they may over-winter in Minnesota. If not, they will travel to Mexico and Central America.
Blue Herons are the largest heron and at the top of the food chain. Taking advantage of their 48” height and long flexible neck, they can stand still and strike fish, frogs, reptiles, insects, small birds and mammals that are found near these statues around our shorelines.
A six-inch bill and lightning speed allow them to also feed in fields and farmlands. A six-foot wingspan and lightweight bones allow them to travel and glide throughout their chosen habitat and return to their rookery in the evening.
Their dark coloration and S-shaped neck flying posture separate them visually from the two other large birds – Sandhill Cranes (their necks are straight) and Great Egrets (they are all-white).
Similar to many other birds, when viewed at close range, they have a diverse covering of plumes, feathers and colors on their heads, throats and chests. According to Cornell Ornithology’s All About Birds, Great Blue Herons have specialized chest feathers that are used to scrape away accumulated fish slime and oils as they preen. Males and females look the same.
Males will collect nest materials and may build upon a nest they had used in the previous season. Females will choose a likely partner and stay with him until their brood has hatched (about 28 days) and fledged (another eight weeks). Both parents incubate the eggs (about four) and both will feed their young.
Racoons are a primary enemy and can exterminate a season’s nestlings at a rookery. Crows will also prey upon eggs and young birds. Predators will evoke alarm calls and other sounds and physical displays are associated with courtship, territorial ownership and arrival back at their nest.
Great Blue Herons provide a majestic touch to any of the wetlands, fields, streams and ponds in Carver County. In flight or slowly patrolling their territory, they are a visible sign that spring has arrived and our well-kept habitats can support them.
REFERENCES:
- Minnesota Nature Notes, Jim Gilbert
- The Sibley Guide to Birds, David Allen Sibley
- Reader’s Digest Book of North American Birds
- Breeding Birds of Minnesota, Pfannmuller, Niemi and Green
- The Audubon Society’s Encyclopedia of North American Birds, John K. Terres
- Online: All About Birds, Cornell Lab of Ornithology
- Online: Minnesota Seasons – Exploring Nature in Minnesota LINK
- Online: Minnesota Breed Bird Atlas
- Online: Birds of the World
