Mississippi Valley Field Naturalists
January 3, 2013
Death’s Bounty in the Forest
The Mississippi Valley Field Naturalists’ (MVFN) 2012-2013 public lecture series, Nature Beneath Our Feet, continues January 17 with the fourth presentation, “Coarse Meaty Debris: The Significance of Large Dead Animals in Our Forests.” You do not need to be an expert to enjoy the presentations—just possess a curiosity or appreciation for wild nature. Cottagers, hunters, fishermen, canoeists, hikers, campers, artists and seasoned field naturalists alike will find something to interest them as we explore what lives in Lanark County and how best to protect it for future generations. Refreshments are offered at each lecture.
This lecture will be presented by Dr. Paul Keddy, a biologist and writer now living in the forests of Lanark County. A professor of ecology for 30 years, he has published over 100 scholarly papers. He achieved international designation as a Highly Cited Researcher, has received awards from several scientific societies, and locally, is an MVFN-designated Champion for Nature. He has published several books used in university courses, including Wetland Ecology: Principles and Conservation. His recent lectures have included Washington, Toronto, Madrid, and Lyon. This year he will start with a lecture in Almonte, on a topic that is new and timely, the role of death in winter forests.
Within hours on a sunny morning in March, a pile of trim on a beaver pond in Lanark County (above) attracted a bald eagle (below), a coyote and 21 crows and ravens.
To prepare us for death’s bounty, Dr. Keddy will first give us a brief overview of forest restoration. There are, he says, a few simple steps which we can all take to begin to restore our native forests. He wrote about these steps in a scholarly paper back in 1996 (see www.drpaulkeddy.com) and said encouragingly, “It is entirely possible for us to restore large tracts of native forest this century, to repair the damage our species has caused. This will require, of course, time, since trees grow slowly. Hence, it is better to start sooner than later!”
This background leads naturally and ultimately to the topic of death in our forests. Large dead trees and large dead animals are vital to healthy forest ecosystems, and can be considered two indicators of restored forests. There is a natural rate of mortality and the forest floor would at one time have been strewn with both dead trees (slow to decay) and dead animals (fast to decay).
The importance of dead big trees is already rather well understood Dr. Keddy says. Scientists have known for years about the importance of dead trees, both standing and fallen. Standing dead trees, sometimes known as snags, provide important wildlife habitat. They provide holes and dens for wild species including woodpeckers, flying squirrels, tree frogs and porcupines. Some have called such trees ‘apartment buildings for nature.’ Fallen dead trees, known as ‘coarse woody debris,’ have received somewhat less attention. However, fallen dead wood is vital to forests. Fallen dead trees also provide habitat for animals, particularly reptiles and amphibians (e.g., salamanders, frogs). A piece of coarse woody debris will be teeming with more life than when it was standing alive and erect—a life after death experience! Hence, when large logs are removed from forests, many plant and animal species suffer.
But what about big, dead animals? This will be Dr. Keddy’s main focus as we know least about this aspect of forest ecology. Today this means mostly deer, but in the recent past moose, elk and caribou were also important. He adds, “But I want to make it clear from the start that this general principle applies way beyond Lanark County and beyond forests. Think of a dead elephant in South Africa, or a dead Bison in Alberta. These are not aberrations, or tragedies, but the basis of an enormous food web and a sign of a healthy ecosystem.” We can call dead animals ‘coarse meaty debris’ to emphasize similarities to coarse woody debris. They are large pieces of biological material that, left in place, will support a rich variety of other species. Their great value in energy and nutrients contributes to their far more rapid disappearance relative to dead trees. A tree may take decades to disappear, while a carcass can take only days.”
Carcasses arise out of death. It may be death from starvation in deep snow, death from old age and disease, or death from a large carnivore such as a wolf. If you visit a winter carcass, the first thing that stands out is the amount of activity around it. The snow is often beaten flat, with trails radiating out in all directions. The carcass is gone in a matter of days, with even the bones scattered in all directions.
Large birds of prey such as Golden Eagles and Bald Eagles may arrive first. Smaller scavengers such as Crows and Ravens feed among the eagles. Turkey Vultures also come early. Many mammals including fishers, minks, and other weasels come to enjoy.
What is more surprising, perhaps, is the number of smaller birds that are attracted to carcasses, such as woodpeckers, nuthatches, and chickadees. Keddy says, “Think of all the birds that visit a feeder to eat suet. A suet feeder is really a small carcass for wild birds. It replaces a food source they used to find whenever wolves or cougars killed a moose or deer.”
Even the bones are soon dispersed. Bones contain phosphorus, a vital nutrient for producing more bones in living animals. Many kinds of small mammals arrive to gnaw on the bones.
Winter carcasses are vital to the survival of many animals. Summer carcasses have their own story, since many kinds of summer birds and insects participate in the feast. There may, or may not, be time for Dr. Keddy to talk about burying beetles, but the topic of carcasses is a good place to begin a long cold winter. Perhaps Sam McGee already knew this story.
Discover which species visit a winter carcass feeding station in Keddy’s forest and what may feed on you if you succumb to the cold while snowshoeing. Tell us about animals you have seen feeding on winter carcasses. Let’s start the conversation about how we get more large carcasses back in our forests. Dr. Keddy’s lecture “Coarse Meaty Debris: The Significance of Large Dead Animals in Our Forests” will be held at 7:30 pm on Thurs. Jan. 17, 2013, Almonte United Church, 106 Elgin St., Almonte. All are welcome ($5 fee for non-members). For further information please contact MVFN’s Program Chair Cathy Keddy at 613-257-3089.