Archive for ◊ August, 2008 ◊

Author: Jo
• Saturday, August 16th, 2008

The seabird colonies of Hamilton Harbour are seated in what is hardly the most picturesque or naturalized part of the Great Lakes.  Their backdrop is the old Stelco Steel plant, with its billowing plumes and flare stacks, and their shoreline the twin bridges of the Burlington Skyway, a busy section of the QEW linking Burlington and Hamilton across the mouth of the bay.  The colonies themselves are built atop man-made islands of stone and sand, and large hydro poles fitted with lengths of planking support many cormorant nests.

 Caspian Tern, Hamilton Harbour  Caspian Tern and Starling, Hamilton Harbour
I arrived with the intent to get a look at a lifer American White Pelican who appeared about a week or so ago, and I quickly spotted him amidst a sea of black cormorant bodies.  I was itching to get some sketches of this prehistoric-looking bird, but as he was far too distant for this purpose I settled in to observe the flocks of Caspian Terns instead.

 Double-crested Cormorant and Caspian Tern, Hamilton Harbour  Immature Caspian Tern, Hamilton Harbour
A handful of fully grown juveniles remained, although the nearby adults seemed reluctant to give up their meals to the harassing youngsters.  Terns arriving with a successful catch were greeted by a swell of squawking throughout the colony as they sought a safe place to land with their prize.  Sometimes an adult would appear to approach one of the juveniles, hesitantly circling the begging bird and its gaping orange bill.  They all seemed to think the better of it, however, and would eventually devour the fish themselves.

 Caspian Tern, Hamilton Harbour

Author: Jo
• Saturday, August 09th, 2008

I hit Shouldice Road early in the morning to look for Sandhill Cranes (though they are uncommon breeders in this area, a pair regularly nests in North Dumfries).  Quiet, unpaved country roads are becoming less and less common these days.  I could hear the Sandhills calling when I arrived, but as they were quite distant and not in sight I took my scope down to the marsh instead.  A pair of Common Moorhens were foraging in the reeds, busy feeding their brood of three.

 Common Moorhen

Moorhen chicks, with their balding pink heads, aren’t what most people would call cute, but their bare scalps and colourful red and blue skin patches evolved to charm their stern and overtaxed parents.  Like many other members of the Rail family, Moorhens frequently punish their chicks by ‘tousling’ — grabbing them by the head and giving them a quick and violent shake.  It’s quite distressing to the chicks, who may become so traumatized by this abuse that they cease to beg for food altogether and starve to death.

 Common Moorhen  Common Moorhen
It seems bizarre and cruel, but there’s a good reason for it.  Food availability cannot be predicted at the time the parent birds begin laying, and so, like many birds, Moorhens will hatch more chicks than they can take care of on the off chance that food will be especially abundant that year.  When the hungry brood arrives, the parents are now faced with a dilemma — feed all chicks equally and possibly lose most of them to starvation or overcompensating sibling rivalry, or do their best to curb sibling aggression and focus their attention on the strongest chicks.  Tousling punishes those chicks who beg too forcefully, and the intensity of their skin colouration may help the parents to gauge which of their offspring is the hungriest (much like the gapes of songbirds).

Category: Field Sketches | Tags: ,  | One Comment