Monday 27 January 2014

A Messy Surprise but Lucky Deer



Seldom is there a time of year when beast or human can travel through or over the fen in the Fletcher
Creek Ecological Preserve in Puslinch Township.

At the end of January the snow cover on the fen was about 35 cm deep. With the freeze thaw cycles that we have been experiencing the snow was very crusty. Not hard enough to support a person on foot but on cross country skis or snow shoes you didn’t sink at all. Also taking advantage of this crusty snow were some deer making their way out over the fen with their tracks visible in a number of places.

Other than at times like this, deer are not likely to travel onto the fen because of the very soft wet soils. The sparse vegetation growing on the fen in the spring and summer is also not likely to be at the top of their menu choice.

What is a fen anyway?  A fen is one of the four types of wetland and they are very rare in Southern Ontario. A fen for many of us might look like a wet field. By definition a fen is a wetland that has water flowing through it all year but the water has a low amount of nutrients in it and thus the vegetation that can grow in it are only plants that have adapted to grow in wet and low nutrient environments.At our fen the vegetation is mostly sedges, rushes, some grasses and mosses. We might want to call this fen a marsh as marshes have water flowing through them as well but the water in a marsh carries higher levels of nutrients and you find plants like cattails, smartweeds and other succulent emergent water plants. Marshes are highly productive wetlands with plants that grow quickly and can recover from disturbance fairly well.  The plants in fens grow slowly and disturbances in fens may last for countless years before they can heal themselves.

The fen in the Fletcher Creek Ecological Preserve (FCEP) is likely the only fen in the watershed of the Hamilton Conservation Authority. It is a couple of hectares in size. The water flowing through our fen is low in nutrients because it comes from springs that are found in and around FCEP. These spring waters are one the major sources of Spencer Creek. The springs come from the aquifer known as the Galt moraine that lies at the northern boundary of FCEP. The rain water flows down through the gravelly hills of the moraine, a glacial deposit, and some of this water comes back to the surface as springs. When the water comes out of the ground it is clean and pure, low in nutrients and 10 degrees Celsius all year round. The creeks draining these springs in the FCEP never freeze in winter because the water starts off so warm.   

The fen at FLCP is special in its own way. It sits on top of about 2 meters of peat. Anything trying to travel over the fen will simply sink most of the time. The plants are sparse and their root network is not strong enough to support the weight of large mammals. This peat has been accumulating in a shallow depression left on the landscape after the glaciers left this area around 16,000 years ago. Over this time what started out as shallow lake has filled in with organic debris, peat, and today we have our fen.

There is a small creek that meanders through the fen and it carries a lot of water but water also travels
through the entire fen, just slower. Think of the fen as a giant sponge about 300 m or so across and 2 meters thick. Wow!

The creek here is special too. It is kind of floating on the fen as it travels through it. Creeks are usually found at the bottom of a ravine or valley. Our creek here has a visible current at the surface but it is running over 2 meters of very very saturated muck. What looks likes a creek to your eyes is almost bottomless to your foot. Once the creek leaves the fen and travels through the forest it has a hard gravelly bottom like most creeks do.

So back to the deer and why they might not travel in the fen very much. Take a look at the picture. (Sorry, it is not the best photo.) Here two deer were travelling over the crusty snow and tried to jump the creek that winds its way through the fen. Normally jumping this short distance for a deer would be easy but the crusty snow gave it a spongy take off platform and they only made it half way across the creek . When the deer landed in the middle of the creek they would have sunk almost completely into what scientists refer to as loon muck (they actually use another word because of the smell of this sulphur rich muck but we will just call it muck). To us it would be like jumping into quick sand. The deer would have had to struggle with great difficulty in trying to get a footing to get out the creek. Think of swimming in a pool of jello. The large amount of muck shown on the snow on the other side of the creek shows the amount of loon muck and yuck that fell from the deer and was shook off as they travelled towards the forest.

I can sort of hear the first deer say “Oh Muck, watch out” to the other one but the warning was too
late. As they headed towards the forest I think the second one was heard saying, “ Oh you just had to take the short cut, now look at us, we smell like Muck.”

In other areas of the fen where the deer travelled the creek is much narrower and the deer stepped across from one snow bank to another. Here the deer might have gotten a little too confident about the first step. If you are up in Puslinch Township and you see some dirty deer you now know why. They will likely stink for weeks.

In the Hamilton area we have only one fen, lots of marshes, lots of treed swamps and one true floating mat bog in Copetown. 

Bruce Mackenzie
Director of Customer Services