doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Declining ruffed grouse population studies?

A few years ago, the topic of declining grouse populations was bandied about here. I know a study by Pennsylvania's DNR was cited as ongoing, as was perhaps another funded by the Ruffed Grouse Society(?). Were there any conclusions from those studies? Anything published?

If I remember correctly, corvis species (specifically crows) had been found to be highly susceptible to bird flu and, accordingly, that connection to grouse was being studied in-depth. Lots of ideas were mentioned at that time, including the predation by wild turkeys and skunks of the chicks, and even increasing coyote populations (when I was much younger, feral cats would often get blamed). I have also heard (more-recently) discussions about certain types of pesticides being suspected in declining bird populations world-wide, specifically nicotine-base pesticides.

Considering the technical depth and breadth of the readership here, can anyone speak to this?

Hi Lloyd,
Most game departments agree on the one thing that has the most effect on grouse, cover aging out. A reduction in the use of paper causing less cutting for pulp, soft lumber markets, a population that adores mature forests to the point of lawsuits. Jury is out on west Nile, turkeys and vermin being smaller contributors.
Chief

The cause of the 11-yr cycle in Ruffed Grouse populations remains unanswered. Last research report I read showed weaknesses in Gordy Gullion's "male aspen bud theory" from the 1950's and tended toward the existence of a complex predation cycle. Maybe another hundred years of data gathering will provide the answer. While all this was happening, the RGS and state agencies have learned a lot about how to create good breeding habitat for the species. I suggest all Ruffed Grouse and Woodcock hunters join the combined RGS-American Woodcock Society now called the RGS-AWS.

Lloyd could tell you that logging and timber harvesting is alive and well in his native state of Pennsylvania. There is no shortage of large tracts of mature forest that gets selective cutting or clear cutting. Yet ruffed grouse numbers have declined significantly over the last 20 -30 years.

It has gotten bad enough that the late grouse season was cancelled a couple years ago. I personally think that the introduction of the Eastern Coyote into Pennsylvania has had the greatest effect on reducing the population of grouse and other small game species. It would be hard to blame herbicides for lower grouse numbers since grouse do not live in areas that are sprayed. Our Game Commission has done a good job of implementing things that have contributed to reducing the overall number of active hunters, so we sure can't blame the decline on over-harvesting. But our illustrious Game Commission also is flush with cash from timbering, gas, and oil drilling, etc., on State Game Lands. So they don't seem to be at all responsive to the hunters who still purchase licenses.

Usually, the predators that have the greatest impact on ground-nesting birds (like all of our upland species) are nest predators. Raccoons often top the list. One reason is that as fur prices have dropped and trapping pressure has declined (and the animal rights crowd has done their best to make it politically incorrect to wear fur), numbers of furbearers have increased. Another negative impact on trapping has resulted from the decreasing number of farmers. A lot of farm kids used to make their spending money by running a trap line. Not nearly as many farm kids these days, not as popular to run a trap line, and easier money to go into town and work in a fast food restaurant. The Iowa DNR used to sell something over 5,000 youth trapping licenses annually. These days it's more like 500.

Definitely more concern about West Nile Virus these days. Even in years with good drumming counts when improved grouse numbers are anticipated, the expected population bump doesn't seem to happen. Although studies have shown that quite a few adult grouse shot by hunters have been exposed to WNV (contain antibodies) but have survived, science seems to indicate that it's more lethal on chicks. If that's accurate, that would explain why--even when drumming counts are high and nesting conditions are good--grouse numbers don't show much of an increase, if any.

In studies of dead birds that died from West Nile Virus, about 80% of the dead birds were corvids, i.e., crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. Yet these avian species do not seem to be in the same steep decline as ruffed grouse.

Nest predation has always been a factor in the survival of ground nesting birds, and trapping may have helped to limit the numbers of nest predators. But it is almost a certainty that the reduced numbers of young kids running traplines has been more than offset by a vastly increased number of Eastern Coyotes that also eat young racoons, feral cats, foxes, etc. Trappers run their traplines for a limited number of weeks each winter. But coyotes hunt and kill every day of the year.

Larry, we had a lot of pheasants in the 90s and we had about the same amount of trapping (close to nothing) and probably even more predators, especially foxes. The loss of farmsteads and old barns and other outbuildings has dramatically reduced some predators like raccoons, skunks, and opossums. I don't know what the status of foxes are statewide, but around here they seem to be just coming back however slightly from a long hiatus.

Most people that study these things put a lot more emphasis on winter kill hens and especially spring nesting conditions.

Coyotes have a unique ability to control litter size based on population levels. When they sing at night females sense population numbers by responses to the singing. When low, their litters can have 20 pups. When high, as few as 4. A federal study at the Savannah River Plant, aka "Bomb Plant" inserted vaginal transmitters into pregnant does. When the fawn dropped, the transmitters activated which allowed the biologists to quickly go to the drop site. More often than not the remains of the fawns were found and DNA testing confirmed coyote presence. 500 coyotes were exterminated in the study site over the course of a year. The following year there was no significant reduction in fawn kills by coyotes. Coyotes survive regardless of efforts to control their population.

here is a typical study report...

https://www.kinseysoutdoors.com/ruffed-grouse-decline-and-their-future-in-the-keystone-state/

problem is blamed on the usual:

-weather
-habitat
-disease

all factors which have no practical solution...how convenient for the self serving taxpayer funded state game managers...

have read a lot of these taxpayer funded studies...none of them address the real problem, which is predation...

put bounties on coyotes, turkeys and owls...then observe an increase in grouse numbers...and bunny rabbits...

When coyotes returned to eastern North Dakota, we had a big reduction in numbers of the three worst predators of ground nesting birds, striped skunks, raccoons, and red fox. Don't know about pheasants, but nest success of ducks seems to have improved even with the big decrease in traditional nesting cover. My friend who runs a Rogator sees good numbers of duck broods in ponds totally surrounded by soybeans. I think no-till and minimum-till have helped in this regard.

Bounties were a real waste of taxpayer dollars in the past and would be even worse today with so few bounty hunters.