Cormorants on Skootamatta Lake

Sep 07, 2013

While kayaking in Sheldrake Bay today I spotted 4 Double Crested Cormorants sitting on rocks.  I've heard reports of cormorants being on Skootamatta but never have seen any myself. I know they look similar to loons at a distance but up close they are unmistakeable.

Anyone that has visited Presquile Provincial Park near Brighton or any of the Great Lakes has seen cormorants.  Cormorants are native to Ontario although they are extending their range northward as numbers grow.  They were in low numbers during the 1950-70's when DDT use was prevalent but are now on the rebound.

Cormorants are of interest if they take hold in an area and begin nesting.  They nest on islands, isolated from predators.  They nest in deciduous and coniferous trees or on bare rocky ground.  The number of nests can range from a few dozen to thousands in a nesting colony.  Guano build-up will kill most vegetation in nesting colonies.  Even sizable trees can be affected in as little as 3 years.  Total defoliation of an island is not uncommon.  This can result in property value decline if you live near a colony.  Anglers will argue they compete for sport fish which seems to be the main thrust for eradication efforts in the US and Canada.

Eradication can be by shooting, destruction of nests and other means.  One of the most effective ways of controlling nesting populations is to spray vegetable oil onto the eggs in the nest.  The embryo will die of suffocation however the parent cormorants will continue to incubate the eggs not knowing the chicks will never hatch.  Simply crushing of the eggs may trigger another clutch of eggs to be laid if not too late in the season.

The Ministry of Natural Resources is involved in the management of cormorants. Since 2004 they have allowed the shooting of over 10,000 cormorants at Prequile Park with many more thousands shot in Georgian Bay and Lake Huron regions.  Many US states have their own eradication programs aimed at controlling the nesting colonies or simply shooting adults.

Barry Wilson is the Bancroft Conservation Officer (613-332-3940) and is very interested in the Skootamatta Lake cormorant sighting.  He's spotted cormorants on Denbigh and Mazinaw Lakes and knows they have been seen as far north as Temagami. The cormorants we are seeing on Skootamatta are not likely nesting (yet).  Sometimes males wander north from the Great Lakes after nesting season - it is unknown why.  In September, cormorants typically migrate south along the Mississippi and Missouri River waterways and along the eastern seaboard to the southern states where they overwinter.  They begin to migrate north again in March-April.  Normally they are sexually mature at 3 years of age and produce around 2 young per year.

At this point in time the MNR is monitoring cormorants on inland lakes.  They wish to be kept informed about sightings on new lakes and if any nests are found.  Residents should watch the islands for any evidence of cormorant nesting and report it to Barry Wilson of the Bancroft District MNR Office (613-332-3940).

A few good links for more information:

Submitted by: Ken Hook
kenhook@45degreeslatitude.com



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