Wednesday, January 25, 2012

Mouse on the Menu

Mousing is a fairly well-known behavior in some of the larger members of the heron family, Ardeidae.  While we generally think of herons and egrets as being waterbirds strictly eating animals living in water - fish, frogs, crustaceans, etc - herons such as Great Blue Heron and Great Egret are largely opportunistic yet formidable predators, eating just about whatever small animal crosses their path.  It is not uncommon to see either of these two species in farm fields or meadows, far from water, hunting rodents among other small terrestrial vertebrates. Herons, in general, are stalking predators, walking slowly and stabbing their prey in one quick motion with their dagger-like bills - an effective method to say the least.

On Monday, 1/23/12, at Las Gallinas Valley Sanitation District in San Rafael while waiting for the wintering Short-eared Owls to appear after sunset we watched a Great Egret catch at least two rodents in the marsh.  Though dark, I was able to obtain some photos of this interesting behavior.

We first noticed this Great Egret catching rodents just past sunset, so though dark, there was still enough light to get some photos.
A vole perhaps?
It manipulated the rodent in its bill for a short period of time before swallowing.

Check out the lump in its throat.

Got another one!

By Luke Musher

1 comment:

  1. They look like short-tailed Shrew's to me..