Prothonotary Warbler

Prothonotary Warbler

Tuesday, 10 November 2015

Oh Deer! The story behind the deer cull.

Some of you may have heard the media announcement in the last couple of days: there is a deer herd reduction going on at Rondeau Provincial Park. Yes, deer are going to be shot. How many remains to be seen. And while that will not be good news for the individual deer, for the overall park's ecology, and the deer population itself, that is excellent news.

Ever since settlers came on the scene in southwestern Ontario, the ecological balance in natural areas has been spiralling downward. Predators such as Eastern Cougar, Black Bear and Timber Wolves, all of which at one point occurred here and fed on White-tailed Deer among other things, have been eliminated. And so the deer flourished. Rapidly. Increased numbers of deer were even more apparent at Rondeau, where more than 3200 hectares of natural area existed. While many park visitors relished the thought of seeing deer easily and up close....sometimes really close.....it played havoc with the overall park ecology. Deer eat vegetation....a lot of vegetation. When the numbers of wintering deer get way out of proportion to what an ecosystem can stand, the results are devastating.

In recent years, we have been used to seeing the forest ecosystem in a reasonably healthy condition. The forest floor is covered with wildflowers and greenery in spring.

Carpet of Mayapple
It wasn't that many years ago when this next image was more than likely to be the look of the forest floor. (Note to reader: you might guess that most of the next few images are scans of slides from well before the digital era, so the quality is not as good as current technology.)
This photo above was taken in late May of 1986, as evidenced by the leaf development on the trees. But note the almost entire lack of ground vegetation. Also note the browse line, indicating how high the deer were able to reach in order to feed themselves. Twigs, leaf buds and the leaves themselves were gobbled up, as was much of the new growth on the wildflowers as they began to grow. This was the normal look of the forest, from the late 1970s until the mid 1990s. Winter populations of deer in the park were as high as almost 600 animals! Such a huge population was eating itself out of house and home.

At the time Rondeau became a provincial park in 1894, there were no deer in the park. It was crown land, as it is today, and had been leased out as a private hunting reserve in part. As a result deer were eliminated. In the early years of Rondeau's existence as a provincial park, deer were re-introduced. The numbers rose quickly and in a short time, the numbers were deemed too high, so from then up until the early 1970s, deer were regularly culled to keep the population at a level that the park's ecosystem could handle. Deer were considered a public attraction, however, and so a deer enclosure was maintained just south of the current maintenance compound, where the public were guaranteed to see and even feed deer. There were other wildlife pens in the park, some of which housed non-native species. For example there were Prairie Chickens (native to Ontario, but not to Rondeau) and even Peacocks (not native to North America). The next image from the park files was taken in 1961. I vaguely remember this enclosure from my youth.

However when the park began its Master Planning process in 1974, there was an outcry by a few people who indicated that shooting Bambi was wrong, and that more humane methods should be used to keep the numbers down, if in fact lower numbers were necessary. In fact some of them argued vehemently that the general public seeing deer was almost more important than the health of the park's ecosystem. The deer culls were therefore put on hold while other methods were proposed and investigated, including:
-trap and transport to other areas away from the park;
-re-establishing large predators;
-instituting birth control.

Indeed.

Since it took several years for the methods to be investigated and the political will to determine the best solution, the numbers of deer steadily increased and stayed at an abnormally high level. As mentioned, the winter population approached 600 animals. Even the summer population was excessively high. Some local people took it upon themselves to bring in food such as bags of corn, and this next image was not an uncommon sight. The first photo, taken by a park colleague, shows me taking the second photo.

It became a White-tailed Deer feedlot, and deer were so hungry that at times if you even stopped the car along the roadside, they would wander out of the forest and come up to the car looking for handouts.

We set up two deer exclosures in 1978, one just south of Bennett Ave and the other just south of Gardiner Ave, both of which are still in existence and you can visit them today. In just a few years, the differences inside compared to the outside were dramatic. Inside, the forest vegetation was starting to reappear, where as just outside of the fenced area, vegetation continued to be almost non-existent. These next two images were taken in late spring of 1989, less than a decade after the exclosures were put up.


There were little patches of greenery around the forest, such as what this next photo shows.
Unfortunately, the only greenery on the forest floor here is the non-native and highly invasive shrub known as Japanese Barberry. In looking at the next image, a close-up of the plant stem, it might be evident that it is something that delicate deer tongues would not want to browse on! Those thorns are very sharp!

The delay in determining what to do with the excessive deer population resulted in several things:
-during the colder winters, we found that some deer were so starved, they simply sat down and died;
-many does were in such poor condition that most of them were not able to give birth, and those young that were produced did not survive all that well;
-the Rondeau deer were the smallest sized deer in the entire province;
-the forest health continued to decline;
-ground-nesting birds, such as Ovenbird, were almost non-existent;
-spring wildflowers were the exception not the rule, and those that one could find were very small;
-in some extremely over browsed areas, the forest floor was dominated by less palatable grasses, not wildflowers;
-some tree species that were not as preferred by deer as food such as Blue Beech increased. Other species that deer found more palatable such as Tulip-tree declined, thus shifting the forest make-up as entire age classes of some tree species were on the verge of disappearing.

There were many side issues related to this dilemma of what to do with the excessive numbers of deer, not surprisingly. I was in the midst of this whole process to various degrees, while I was the park ecologist until the mid 1980s and the MNR district ecologist after that. But I will not go off on those tangents, hopefully.

It turns out that the simplest and most effective way of keeping the park's ecosystem healthy, including the deer population, was to cull the herd and keep it to a winter-time population of between 100-150 animals. So in the mid-1990s, a deer herd reduction (DHR) program was begun again. The results have been pleasing to say the least. Virtually all of the negative things listed above, were reversed.

More fawns were being seen, and they were looking healthy.
Adult deer even in late winter when they are likely the most susceptible to a lack of food, and during the years of high population you could see their ribs showing, were now looking bigger, fatter and healthier.
April deer, 2011
Bucks looked more formidable....not the scrawny things they used to look like during the peak population years.

I remember congratulating the park superintendent of the day, several years after the DHR was re-instituted, by saying that for the longest time one had to photograph wildflowers with a macro lens and zoom in to single flowers. However after the park had a few years to recover, one could photograph the forest floor with a wide angle lens and capture many wildflowers such as shown in this next image.
So with the continuation of a DHR program for most of two decades, the park's vegetation and the deer population is healthier than it has been for almost half a century.

Keep up the good work MNR&F!














4 comments:

  1. Story on the deer cull-----well done Allen !!---and equally well
    illustrated !! I've watched thru' the whole cycle, and agree 100% .
    And, yes, our 3 kids saved table scraps, etc. all week long to take to
    the Rondeau deer every Sunday. In the 60's there were several deer
    plus other critters enclosed in a fenced in area behind the Maintenance.
    But--that was long ago ! And I don't remember a "Gate Fee' then ! :}

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    1. Hi Irene....thanks for the comment. I've inserted an image from 1961 showing the deer enclosure.....perhaps it was your family??

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  2. Predation is a necessary ecological function, or "service" which serves as the contemporary economic description. As a unique landscape the park is far more valuable with a stable ecology. Along with Wolves, Cougers and Bears, the Chonnonton (Erie Neutral) People from 500 years ago and earlier kept deer in pens and off the landscape. The Mascouten, Nation of Fire, regularly modified the landscape through controlled burning, creating Oak Savannah as a means to a clear shot. One might even speculate that Oak Savannah is an extension of the development of the bow. Human landscape management in this area has often had a predation component and only recently have the decendents of European Settlers realized our realized our relationships brother bear and wolf.

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    1. Thanks, Ken. The interruption of the predator/prey relationship has most definitely had a major impact on natural systems.

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