What’s killing our grouse?

At first it sounds like the muffled booming of a distant jet. Or perhaps a moose thumping through the open forest over the next hill.

It starts slowly, a muted thump, thump, thump then increases to something similar to a far off sonic boom.

I don’t hear that sound often these days so I can be forgiven for not identifying it instantly. It is, of course, a ruffed grouse pumping its cupped wings against the air and creating a drumming sound.

Male ruffed grouse, or partridge, stand on a log or rock in the spring and drum to attract females. As he drums, a ruff of dark feathers expands around his neck and he arches his tail feathers into a broad fan.

Witnessing drumming and strutting is a joy of the spring forest. It is one that I experience less and less with each passing year.

Ruffed grouse populations are down throughout much of North America. Many upland game hunters have stopped hunting them.

I am reluctant to shoot  a grouse in the fall, despite the fact they are one of the finest game birds around; fun to hunt and the best eating bird in the woods. I’ll take grouse over domestic chicken or turkey any day.

I can’t bring myself to shoot one because they have become so scarce in areas where I go. I figure every one I leave alive might help grouse populations get back to where they once were.

I saw a decline in my hunting area in the early 2000s. The small flocks I used to encounter were rarely seen. Then sightings of pairs and singles became less frequent.

Any wildlife decline in one area can be the result of localized conditions, so I assumed it was me just having poor luck. About the same time, however, hunters in Pennsylvania, where the ruffed grouse is the state bird, began noticing population declines. Then other northeastern U.S. states reported falling numbers.

Wildlife biologists always talked about eight- to 10-year cycles in which grouse populations waxed and waned. Population declines were attributed to periods of heavy predation, parasitic infestations or severe weather. As these periods passed, populations bounced back.

However, grouse populations have not bounced back in many areas. What is happening to ruffed grouse is more than regular up and down cycles.

Last year a U.S. game bird report said grouse populations in the northeastern states have declined at least 30 per cent in the last 30 years. It predicted continuing declines unless the causes are clearly identified and addressed.

The causes are the subject of much study and debate in the U.S. One of the main theories of cause has been habitat loss.

These birds survive mainly on buds, berries, catkins, soft leaves and seeds. They love clover when they can get it.

These succulent foods are abundant in new growth forests. Mature forests with large canopied trees have less ground cover growth and therefore fewer food choices for grouse.   

Logging and forest fires allow for new forest growth in many areas, so habitat loss as a main factor in general population declines is questionable.

A recent theory is that ruffed grouse are being hit hard by mosquito-borne West Nile disease. Some research has shown that 80 per cent of grouse exposed to West Nile die or are left sick enough to be unable to survive harsh weather and predators.

There has been little to no research to determine if West Nile is a major factor in Ontario’s ruffed grouse decline.

No one is able to say definitively what is killing Ontario’s grouse. It might be habitat loss, West Nile, parasites, or unusually heavy predation or combination of all these factors.

We need a definite answer to be able to do whatever is necessary to stop the decline and help grouse populations get back to previous levels.

The ruffed grouse is more than just a game bird. It is an important link in forest biodiversity.

As Aldo Leopold, the American environmentalist, wrote in his A Sand County Almanac:

“ . . . the grouse represents only a millionth of either the mass or the energy of an acre. Yet subtract the grouse and the whole thing is dead.”

Email: shaman@vianet.ca
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