Vegeation Crisis -- Leslie Street Spit

[norman]

Vegetation damage? Okay, then ... Well, here we go again -- we build perfect habitat for a species, on our garbage dump, and now we have to kill them to um, save the vegetation on our garbage dump. I hope they're not eating all our fish again. I wonder what's new on the Anglers and Hunters' and like-minded websites?

If you haven't seen the colony, get yourself to the banding station down there, and take the trail westward until you stop at a "back in time" spectacle.

More info when I check.




Coalition member Susan Krajnc says the Toronto and Region Conservation Authority is considering the measures to reduce the number of cormorants nesting on the spit, which is already heavily populated by Canada geese and ring-billed gulls.

Trees and vegetation near the point of the spit, which has one of the largest water bird colonies in the Great Lakes basin, have been ravaged in recent years by the bird population, which has prompted the conservation authority to consider measures to also cull the cormorants, said Krajnc.

"By seeing so many birds nesting, you might think there are too many of them, but they don't deplete their food supply, so we think it's a natural process that should be allowed," she said.

Cormorants have come under attack at other points on their migration route by government agencies that want to control the population, said Krajnc, including the U.S. Fish and Wildlife Service and Ontario's natural resources ministry, which have resorted to shooting the birds in some places, including Point Pelee in Lake Erie.

The conservation authority has for years been destroying the eggs of Canada geese and ring-billed gulls on the spit by coating them with mineral oil, which causes the embryo inside to suffocate, and disrupting their nests, Krajnc said, adding it will decide on the cormorant proposal at a May 23 meeting.

Opponents of the plan are asked to contact the conservation authority or Mayor David Miller's office to complain about it before the meeting, said Krajnc.

[frozenice7885]

good i agree they should do something about the cormorants poor little green herons are running out of trees to nest in and those stupid cormorants are killing the trees and making the whole landscape look ugly so yes i agree that the cormorant numbers have to be reduced because they just destroy habitat not create it

[Anonymous]

As a former student in the Fish and Wildlife Technician program at Fleming College and a volunteer with fisheries groups such as Anglers and Hunters, my opinion is split on this one.

While it's nice to see Cormorant numbers back up, it is clear that they do decimate vegetation in any area they inhabit which compounds problems for any other resident wildlife which may call the area home.  And for the record, we didn't build their perfect habitat - they created it themselves.  We created a monster sized landfill that became a natural environment for ALL types of animal and bird life in an area that we knew was familiar to many types of transient birds.  Yet it is the Cormorants fecal matter which created for them their perfect environment - aided by zebra mussels and a desire by many to actually clean up our waterfront that goes beyond our current Mayor.

Do they eat fish?  Yes.  Are they the sole reason for the depletion of salmon stocks in Lake Ontario? No. Is their spread throughout the Kawartha Lakes region cause for concern?  Yes. Should they be stopped from coming to the Kawartha's in large numbers?  Yes.  Are they a vital species of bird which help with an ecological balance? Yes.  

Are there issues within the MNR as to how they handle this matter?  Absolutely.

There are too many unanswered questions with regards to this issue, and we as birders should do our best not to become part of the polarizing arguments that tend to happen on both sides of this debate.

[norman]

Of course there are any number of opinions re the double-breasted cormorant population increase on Lake Ontario and elsewhere, but there is a recurring theme in most information available:

http://www.waterkeeper.ca/content/fish/ ... out_of.php

http://www.flintsteelheaders.com/cormorant_control.htm

http://www.ofah.org/Cormorants/News.cfm?A=Grab&DocID=9

These were the first three sites I looked at. Finding 'hard science' on the subject is tricky, because many biologists have taken up positions with special-interest groups. Guano run-off? How about going after the industrial polluters first? Vegetation destruction? Please ... it happens, for sure, but it's an afterthought by these folks, used to bolster their, ahem, arguments.

Attila's reasoned statement on all this is most welcome. However, we did create the habitat for cormorants -- no spit, no trees out there, no vegetation to destroy, no guano.

Let's look for the real science on this ... it's in short supply at the sites posted above.

[Anonymous]

Norman - I could just as easily cite other special interest groups who want the cormorant numbers to grow even higher than they are and we all know where that would leave us.

Below I've attached a link to an Environment Canada report which provides a whole range of factors which helped the Cormorant population get back to the numbers we see today, and in the same document they state that while some of the arguments made by special interest groups are not well founded, others are.  Anyone who has time to read this entire document would definitely achieve a better understanding of the situation and the many factors which effect it.

Here's the link -> http://www.on.ec.gc.ca/wildlife/factshe ... nts-e.html

Attila

[norman]

Thanks for the information, Attila. I think it puts the boots to the extreme views on both sides (there is a middle ground here).

Let's just hope that emotion and convenience is detached from reason on this issue, and good science dictates ...

It will be interesting to hear MRTCA's side.

[Jaedon]

What an awesome article you linked for us Atilla.  Thanks for that.  Very informative.  

That being said.. I still don't like those birds.  Their very destructive nature can be witnessed with your own eyes by walking in the brush under the trees in the nesting area during the "open" season to see the amount of dead trees lying in the forest.  While this does work to the animals own detriment I think that the habitat loss will affect other birds before the Cormorants population and have a greater impact on the other birds as well.  With their current population maintaining stability or even slightly decreasing annually it will be interesting to see how things progress in the years to come.

[Tyler]

Well Jaedon if Cormorants learned to sing a good tune would you like them then? Loons in the early 1900s were not admired like they are now. They were appreciated then about as much as cormorants are now.

As for destructive nature I guess you have not seen other destructive nesting species like heron/egret rookeries, gull, and tern colonies, goose colonies, Gannet colonies, penguin colonies, etc.

Bird colonies = damaged vegetation.

That said Guano runoff = more nutrients into the lake = more phytoplankton= more food for invertebrates and small fish = more food for larger species= etc. etc.

I always like fishing close to large colonies, for alot of the bait fish there bring in alot of large predator fish.

Well with the Type E botulism killing 100s of loons, grebes, Long-tailed Ducks  and basically it has destroyed the Great Black-backed Gull local breeding population. It is also killing alot of Cormorants.  These large unaesthetic(to some) cormorant colonies  may start to suffer even more

[angelicque]

Well Jaedon if Cormorants learned to sing a good tune would you like them then?

i couldn't agree with you more!

i personally like cormorants - i think they are beautiful birds! i was extremely touched the first time i saw the leslie street spit nesting site - they are very hard working fellows! watching them fly back and forth between the nesting sites and the lake water, carrying lake weeds to build their nests, was humbling to see!

i understand the arguments on both sides, however, i'd like to believe there is another solution other then killing the poor birds. last spring the herons and egrets seemed to be doing just fine in the nesting area, and their numbers in the GTA (from what i saw of them) seemed high!
but if it came down to, for me, a bird surviving or a tree/plant surviving - i choose the bird. hands down.


(and on a side (geek) note - the guano produces mass shrub vegetation in the fall, which is a great habitat for orb weaving spiders - last September i stumbled upon at least 1,000 of them residing in the shrubs below the cormorant nesting site. this is not only great for the spider population, but it is also a good food source for other birds living in the area - plus, correct if i am wrong, the baby birds that fall from the nests and perish are a good food source for the coyotes, yes?)

[Anonymous]

2006 MNR Cormorant Report - http://www.mnr.gov.on.ca/STEL02_196676.pdf

Remember everyone, there is more to this issue than simply fish.

Jaedon - I disagree with you.  Habitat loss in the area on the Spit is negligable, given that there is an annual migration of not only waterfowl but raptors to the area during winter months.  These birds are used to open spaces, and the decimation of trees is partially responsible for them using this area as an overwintering point.  The fact that predators feed on mice, rabbits, and other birds all winter shows that the area is sustainable - for the time being.

Tyler - I disagree with you as well.  While it is true that bird colonies equate to damaged vegetation, one cannot compare the sheer numbers of cormorants vs. the species that you mentioned.  Even the one that does compare in numbers, the Canada Goose, doesn't cause as much nesting damage to its region as the cormorant does.  With regards to your argument about fishing, you're only stating one part of the reason there are more fish in an area like the spit (with regards to the pike population increase).  You must also factor in the presence of zebra mussels which cleared the water which enabled the pike to see their prey more effectively.  Add to that the fact that for the longest time nobody bothered fishing for them and you see why the pike population has exploded.  Finally, you're forgetting what happens to other regions in the province (think the Kawartha's) that don't have the same forage base as Lake Ontario does.  Believe me, I've seen damage done to lakes that not only have affected fisheries in the past but continue to today and tomorrow.

Angelicque - nice post, but guess what?  Passion isn't science.  Also, you can't compare the number of herons and egrets in the Toronto area to the number of cormorants.  With a ratio of almost 10:1, cormorants obviously vastly outnumber others.  Gulls have adapted to the point where they'll eat anything and as such they don't feed on fish as much as they used to - they'd much rather wait at a McDonalds and eat a fry.  Your arguments about cormorant chicks providing a food source is accurate, however, how many coyotes do you think are over on the spit?  Also, they'll take the time to feed on ground nesting birds like gulls and terns, not to mention mice and voles.

Cheers all, and remember, there is SO much more to this argument than the points we're making.  Do some reading, get all the facts...

Attila

[angelicque]

Angelicque - nice post, but guess what?  Passion isn't science.  Also, you can't compare the number of herons and egrets in the Toronto area to the number of cormorants.  With a ratio of almost 10:1, cormorants obviously vastly outnumber others.  Gulls have adapted to the point where they'll eat anything and as such they don't feed on fish as much as they used to - they'd much rather wait at a McDonalds and eat a fry.  Your arguments about cormorant chicks providing a food source is accurate, however, how many coyotes do you think are over on the spit?  Also, they'll take the time to feed on ground nesting birds like gulls and terns, not to mention mice and voles.

oh, i am aware passion isn't science
neither is compassion, for that matter...facts are facts, i know this!

i just wish the two could find some common ground, you know? i hate to see anything decimated by anything other then mother nature...and even then it's unfortunate

[Jaedon]

in self defense.. .I still don't like cormorants.... but my comments about their destructive nature were based simply on observation.  I have no doubt that there are more destructive species out there, but those are not nesting on the spit in as great numbers.

Regardless of my like or dislike however they are still living creatures and I believe that nature will find a balance all on it's own without our intrusion.  I disagree with the culling that happened in the fall. Walking around there this spring looking for owls was very disheartening as I walked over a Cormorant corpse every 3 feet or so.  I hate seeing any animals killed off needlessly.  Since their population was already in a natural decline (I believe the article said 6%) it would have been interesting to see how they declined on their own without our intervention.

[Tyler]

As a biologist (avian and fisheries primarily)  who has worked from the Caribbean to the Arctic and traveled throughout the Americas and the South Pacific I have seen alot of bird colonies and yes the vast majority of them have significant impacts on  vegetation

Attilla "While it is true that bird colonies equate to damaged vegetation, one cannot compare the sheer numbers of cormorants vs. the species that you mentioned. Even the one that does compare in numbers, the Canada Goose, doesn't cause as much nesting damage to its region as the cormorant does"

Please Attila show me a Canada Goose colony. There may be large numbers Canada Geese in North America but they do not breed in colonies. They will breed in an area with nests scattered loosely around the area, but very rarely in a true colony sense like say Lesser Snow Goose colonies (censused one in 1998 Jenny Lind island, Nunavut 75,000 birds). And there are other much larger colonies in the Arctic. They breed colonial and do have large effects on the vegetation within their colonies. Look at several CWS, UFWS, OMNR, MMNR, etc reports

Great Blue Herons heronries over time kill trees as well. Sure they are do not have the colony sizes of cormorants but their guano will kill their nest trees over time. One of the Great Blues largest heronries in the GTA has been reduced significantly over time. This heronry is on protected private property and been in existence for decades in a mature Oak /Beech/Maple forest.  Now  significant areas of the forest have been killed from long-term exposure to guano.  These trees are climax species and not short lived, and quick growing colonizing trees like the ones in the Cormorant colony on the spit.

Attilla: "one cannot compare the sheer numbers of cormorants vs. the species that you mentioned"

Let see some of the species I mentioned
Comparing to sheer size? Attilla have you not noticed the Massive Ring-billed Gull colony at the spit it is alot larger in population than the cormorants. Go up to Georgian Bay islands that have Gull and Tern colonies again alot are bigger than most cormorant colonies in the great lakes and vegetation is quite suppressed or absent due to the guano.

Many colonies of Gannet species equal and/or surpass  Great Lake cormorant colonies

I could go on and on of species mentioned that can easily compare to the sheer numbers of cormorants    

Ok lets clarify the fishing post now. I was leaning more towards Salmonids which prey primarily now on Alewife and Emerald Shiners now in Lake Ontario.
The Alewife and Emerald Shiners feed primarily on small invertebrates  which need plankton. Zebra mussels, being plankton filter feeders they take food out of food chain. guano runoff near these colonies help with plankton growth which in turn bring in the forage fish. Both the large predatory fish and the residents of the adjacent bird colony then benefit.

As for Pike in Lake Ontario, they have benefited alot more from Carp barriers then Zebra Mussels. Also the Pike fishery on Lake Ontario, there has been one long before you and I walked this earth. Maybe it is new on a relatively young place like the spit but other areas it is not.

Other Area affected by Cormorants. Cormorants hate human disturbance and most islands in the kawarthas have cottages on them, or are impacted by human activity and thus generally suppress breeding attempts. You did not mention 2 other large factors that have affected the Kawartha fishery in the last decade. The movement and introduction of Black Crappie and the colonization of Zebra Mussels through out the Kawarthas. Both those issues the MNR has been looking at in addition to cormorant and human altering of the environment and the effects on various fisheries within the kawarthas.

When I was a Biologist for the MNR in central Ontario 1993 I found a small cormorant colony and have followed it every since. The colony has never exceeded 12 nests and the fishery is still the same. The colony is at an equilibrium with the available limited resources. Most Great Lakes colonies are also at an equilibrium (population sizes obviously MUCH higher) Personally I am not against control (some oiling of eggs) in critical/endangered ecosystems habitats. I am against it in areas that are not, and in cases where it is done to appease special interests. The Spit is not a critical habitat. It is however one that is dynamic, young, and evolving. Over time breeding species will come to it and species will leave it. Who's to say that those dead and dying trees there could not provide a home for a Red-headed or Red-bellied Woodpecker in the near future.

Finally I do agree with Attila on this "Cheers all, and remember, there is SO much more to this argument than the points we're making. Do some reading, get all the facts"

But always look at the sources of those facts, for there are organizations out there with Strong Biases for and against cormorants. And they really want you to see their views are the right ones.

Cheers

Tyler

[Andreas Jonsson]

This is not a Birding report. It fits better in the General Discussion area, which is where I have moved it.

Good birding,

--Andreas (moderator)

[norman]

I didn't realize that the topic of cormorant, erm, "culling" at The Spit would attract this much attention (glad it did), and yes, Andreas, this is a better place to discuss it ...


I've yet to read anything scientifically persuasive which supports population control here -- just anthropocentric and/or emotional reactions, which are regrettable (and useless). Tyler has addressed some of the dodgier reasoning and provided much information, all with admirable diplomacy. Thanks.


I do know that the idea of shooting the birds at this site has been abandoned altogether. It's far noisier and public than oiling the eggs. So, why would the MRTCA sneak around like this, if their science is good?


Just wondering.