Friday, October 10, 2008

Large Water Birds

Although I've posted a similar photo of this Goliath Heron with its "catch" before, I believe its so special that I'm adding it again today. Larger than all the other herons (about 1.4m), it also tends to hunt in deeper waters than most of the other herons. The Goliath heron tends to stand motionless for long periods of time - waiting patiently for prey to appear - or otherwise is seen walking about slowly.

Even if the Blackheaded Heron isn't as large as the Goliath heron (just under 1m), I still think of it as an imposing water bird. It is known as a more commonly found resident than the Goliath heron, yet I've seen the former more often than the Blackheaded heron. The Blackheaded heron isn't only found near water, but also frequents grassland/pastures/farmlands.

The Grey Heron is similar to the Blackheaded heron (size-wise & profile), but differs in that it has a white (instead of black) crown and a yellowish bill. The Grey heron also tends to stand motionless for long periods or creeps stealthily forward in a crouched way whilst skimming the water for prey.

Another large water bird that tends to crouch stealthily whilst hunting, is the Great White Egret (similar in size to the above-mentioned herons), otherwise its also found standing motionless in shallow water. The Great White egret's habitat is rivers, dams, estuaries and flood-plains, and it's distinguished by its entirely black legs and feet. This egret's normally orange-yellow bill turns black during the breeding season.

Did you know that egrets are herons? The "secret" is in the colour - the white ones are know as egrets.

At approx. 64cm, the Little Egret is much smaller than the birds mentioned above. This egret is a slender and fairly common resident with a black bill and legs - but yellow feet. The Little egret is always found near water and is known as an "active" hunter - darting, twisting and turning to catch its prey. When food is aplenty, Little egrets sometimes gather in hundreds, although otherwise known as solitary feeders.

I tend to think of the most commonly found Cattle Egret as a "chameleon" heron/egret because of its variable form - it's "buffed" during the breeding season whilst more slim and appearing taller at other times. The iris is yellow (> red during breeding season) and the bill is yellow (> red-orange when breeding). Immature Cattle egrets can be similarly classified as "variable" in that they have black legs and feet - in contrast to the adults with yellow or coral-coloured legs. Although the Cattle egret tends to feed on insects disturbed by grazing animals, they are also often seen perched on the backs of large animals (mammals) - yet it's also a water bird and and sometimes fishes in shallow water. Large flocks of Cattle egrets are known to gather during evenings around dams and pans, where they drink before roosting.

Did you know that although the Cattle Egret is often thought of as a "tick-bird", ticks are seldom part of its diet? Instead the Cattle egret feeds mainly on other insects like grasshoppers, earthworms and caterpillars, other than spiders, scorpions, lizards, frogs and even nestling-birds.

Other, larger birds found near water include cormorants - known as mainly fish- and frog-eating waterbirds. The Cape Cormorant is an abundantly found resident along our coastal regions which, like all cormorants, habitually stands perched out of the water with its wings outspread to dry. Cape Cormorants habitually fly in long lines over the sea and tend to fish in flocks.

Did you know that cormorants hunt their prey under water and then surface to swallow it?

When seen from afar, I've often overheard people (to my silent amusement) identifying the Whitebreasted Cormorant as a penguin. This confusion doesn't occur though when this cormorant is standing perched statue-like, spreading its wings to dry (now don't confuse this cormorant - on the right - with an eagle = "Reichs-Adler" in German!! ha-ha). At approx. 90cm, the Whitebreasted cormorant is the largest of the southern African cormorants, frequenting coastal areas or large inland waters.

Last (but not least) today is one of my photos of a Darter, which can be distinguished from cormorants by its longer and thinner neck with its characteristic "kink". A Darter's bill is also straight (> hooked) and it has a more slender appearance than cormorants. Darters swim with only their heads and necks visible above water (> parts of their back) but like cormorants, also perch with outspread wings to dry after swimming.

No comments: