The last week in August, 2024, brought a flight of immature Little Blue Herons (Egretta caerulea) to the Maritimes. One was at the Ducks Unlimited Marsh in Miramichi City on 21 August. One was along the edge of the Nashwaak River at Marysville (Fredericton) on August 23. One was at Saints Rest Marsh in Saint John on August 27. One was at Bridgewater, Nova Scotia on August 30. In all cases the birds stayed for a few days.
The Little Blue Heron is a rare visitor to New Brunswick. Most records come from areas near the Bay of Fundy. The very first record came from Kent Island in 1936. Usually the reports are for single adults. However, in 1971 there were 3 at Little Dipper Harbour.
It is unusual for immature Little Blue Herons to arrive here. Why was there a flight to the Maritime provinces this summer? Little Blue Herons breed on the east coast along the southeastern, south-central and Atlantic Coast of North America. They also breed in extreme southern California. Those breeding north of southern New Jersey and in the interior migrate to the southern Atlantic and Gulf Coasts for the winter. Fall migration is normally from late July to late November. After nesting the young are prone to migrate and some wander as far north as Newfoundland and other parts of southern Canada. Understanding this and the fact that some breed and winter as far north as southern Maine, we can now understand why we had at least 4 individuals arrive here (assuming we have 4 separate individuals).
The arrival of the individual in Miramichi required a bit of careful observation and study to differentiate this individual from a Snowy Egret. Both species are about 60 cm tall and mostly all white. The immature Little Blue has a heavier, bicoloured bill (dark tipped and blue-gray at base), pale blue lores, greenish yellow legs and feet and sometimes dark tips to its primary feathers. Snowy Egrets have a thinner, mostly black bill and lores that are distinctly yellow. An immature Snowy Egret has greenish yellow legs and feet, so careful observation is sometimes required. The immature Snowy Egrets I have seen had a black line running down the shins of their greenish yellow legs. Another good way to tell the immature Little Blue from the Snowy Egret is its behaviour. The Little Blue is a slow-moving, methodical hunter. It usually hunts with its neck extended. The Snowy Egret usually hunts while holding its neck in an “S” curve.
The Reddish Egret, which is very rare here, rarely has a white morp,. It is a larger bird standing 76 cm tall. It has a heavier, bicoloured bill (pink with a black tip) and the bird is much shaggier. Its behaviour identifies it because it is very active and wildly runs around the shoreline as it feeds.
The Little Blue Heron keeps its white wing feathers until the next year of its life, usually May. It then appears white with patches of blue wing feathers showing, looking quite piebald sometimes.
The population size of the Little Blue Heron is declining. Since this species does not have long showy plumes in the breeding season it, fortunately, escaped the decimation of the millinery trade in earlier years. It is declining in recent years because of its exposure to heavy metals. Development along coast lines, nest predation and parasites are other reasons. Another interesting reason for nest failure is that if Cattle Egrets are nesting nearby, the Cattle Egrets, being later nesters, sometimes steal the sticks from the Little Blue nests.
Perhaps with the appearance of at least 4 immature Little Blues here this summer, it might mean the population in the northeast is increasing or at least healthy. We can hope so.
No comments:
Post a Comment