Least Bittern

Scientific: Ixobrychus exilis Gmelin
French: Petit butor
Status: Threatened

Description: L 33cm (13 in) ws 43 cm (17 in)  
The least bittern is a small member of the heron family. It is about the size of a common grackle. The species is generally buffy-brown and reddish brown in color with prominent light buff upper wing patches. Males have a blackish back and crown. Females are lighter brown in these areas. There are two distinctive tan stripes that run down the back. Legs are off-green and the bill is yellow with a darker upper mandible. The immature are similar to the females.

Eggs: 4-5 oval or long oval 31-23 mm bluish or greenish. Incubation by both sexes, 17-20 days, 2 broods.

Nest: It nests and inhabits wetlands of sedges, reeds and cattails. The nest is composed of marsh plant matter and is often placed close to the water level in dense standing vegetation.

Habitat: Their cryptic color and lack of movement allows them to blend into the surrounding vegetation. They will move into the marsh rather than fly when surprised. It is for these reasons that these birds are difficult to find.

Life History: The sharp needle-like bill is used for piercing aquatic fish, amphibians or invertebrates. The bird will stay motionless over a small pool and wait for the unsuspecting prey to swim by. The long toes and claws coupled with the light weight allow this species to balance in precarious positions within the wetland. The species can perch in an upright position that matches the stalks of the cattails and sedges.

Similar Species: Adult green herons are larger, predominantly blue grey with reddish neck and lack of buffy wing patches.

Ecological Role: Rare wetland species.

Threats: These birds have become scarce due to predation and loss of marshland habitat due to land development and associated drainage.

What you can do: Report evidence of breeding; active nest, flightless young or adults to the local OMNR.

Compiled by: Chris Blomme, Department of Biology, Laurentian University, Sudbury.