A new friend of this blog, Biologist Shannon Barber-Meyer of the U.S. Geological Survey(USGS) forwarded to me the recent peer reviewed paper that biologists Ronald McRoberts and David Mech penned on the factors that limit Wolf populations............We also recently posted Dan MacNulty's(Biologist at Utah State) paper on related subject matter entitled: ("A Reappraisal of the Evidence for Regulation of Wolf Populations") which concluded that "wolf population regulation is goverened by density-dependence as much as limitation by prey availability"......... "The data suggested that wolf populations are self regulated rather than limited by prey biomass by at least a 3:1 margin"............ "In establishing goals for sustainable wolf population levels, managers of wolf re-introductions and species recovery efforts should account for the possibility that some regulatory mechanism plays an important role in wolf population dynamics"...........McRoberts and Mech enter into this discussion by postulating that "data do(es) not support the hypothesis that wolf densities are regulated by social factors"..........They go on to say that "social factors such as territoriality and intraspecific strife, age of first reproduction and dispersal do operate in wolf populations"......... "Ultimately, they might only fine tune basic wolf densities to biomass values at finer scales than have so far been measured"................."Our results also contradict the conclusion that an upper density bound of 69 wolves per 1000 square km2 exists in wolf populations"...........Instead, we found no evidence for a maximum wolf density except that dictated by biomass"............."Our analysis indicates that the question of whether wolf density is regulated by prey biomass or social factor as high prey densities should remain open"..............."The most important information that managers should consider is that regardless of what regulates wolf densities, such densities can fare exceed the 69/1000km2 proposed as an upper bound under the model of Cariappa et al.(2011; Table 2)"..............."Researchers however, should closely examine all possible regulating factors"......As Cubanynes et al.(2014) found, high wolf densities can increase intraspecific aggression"......"Although such aggression in itself may not regulate wolf populations because pup survival and dispersal are also critically important(Mech et al. 1998, Adams et al. 2008)......... "Aggression remains a factor to be considered and warrants further research on its role in wolf population regulation".........I truly enjoy the ongoing in-depth analysis of all things wolf and coyote in North America..............Always poignant "Point/Counter Point" theories put forward by so many qualified scientists------truly like a "battle of the titans" between Pro tennis standouts Rafael Nadal and Roger Federer-------120 mph "hard and true" serves back and forth,,,,,,,,,,,,back and forth...............David Mech stated in a recent INTERNATIONAL WOLF MAGAZINE article that the reason scientist disagree so much on these topics is that " that is the way science works".......Science is self-correcting".........One study concludes something; then the other scientists scrutinize the study and sometimes see problems with the first study's methods, analyses, results or interpretations"

Date: Fri, Aug 22, 2014 

To: Rick Meril

Fm: Shannon Barber-Meyer <shannonbarbermeyer@gmail.com>

Cc: "L. David Mech" <mechx002@umn.edu>

Hi Rick,

Have you seen the latest publication by McRoberts and Mech (2014) in The Journal of Wildlife Management that concludes that "data do not support the hypothesis that wolf densities are regulated by social factors"?

 Please post the abstract (below) to your blog for interested readers relative to your recent post on "Wolves will kill for more space" study in Yellowstone. I've also attached the entire manuscript.  Thank you!

Shannon Barber-Meyer, PhD

USGS, MN Wolf and Deer Project

FULL PEER REVIEWED ARTICLE BY MCROBERTS AND MECH:

http://www.scribd.com/doc/237566559/340-Wolf-Population-Regulation-Revisited-Again-1?secret_password=QVxbTwaipTA3su0uwuUC

Commentary 

 Wolf Population Regulation Revisited—Again

RONALD E. MCROBERTS,

 U.S. Forest Service, Northern Research Station, 1992 Folwell Ave., St. Paul, MN 55108, USA 

L. DAVID MECH,

1,2

U.S. Geological Survey, Northern Prairie Wildlife Research Center, 8711–37th St. SE, Jamestown, ND 58401, USA 

 ABSTRACT

 The long-accepted conclusion that wolf density is regulated by nutrition was recently challenged, and the conclusion was reached that, at greater levels of prey biomass, social factors such as intraspecific strife and territoriality tend to regulate wolf density. We reanalyzed the data used in that study or 2 reasons: 1) we disputed the use of 2 data points, and 2) because of recognized heteroscedasticity, we used weighted-regression analysis instead of the unweighted regressions used in the original study. We concluded that the data do not support the hypothesis that wolf densities are regulated by social factors.

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Is food and disease the only two limiting factors on a given Wolf population

within an ecosystem?..........Utah State researcher Dan MacNulty

has determined that family groups of wolves compete with each

other for space and resources, acting as self limiting agents on

the overall Wolf Population................."Wolves are ultimately

limited by is the amount of space they have to raise their pups in safety"

Posted: 18 Aug 2014 10:33 PM PDT READ BOTH THE KSL-TV NEWS REPORT AS WELL

AS THE PEER REVIEWED ARTICLE BY CLICKING ON BOTH LINKS BELOW http://www.ksl.com/?nid=148&sid=29873051#bswTwvzzjAoUI93l.03 https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CDEQFjAD&url=http%3A%2F%2Fwww.aphis.usda.gov%2Fwildlife_damage%2Fnwrc%2Fpublications%2F11pubs%2Fbreck113.pdf&ei=c93yU4nZHYThoATDmICABg&usg=AFQjCNFWs9217g17h2bWo61ZXBmWBj7Vvg Wolves will kill for

more  space, new USU

study finds By Amy Joi O'Donoghue May 17th, 2014 @ 8:16pm Dan Stahler, National Park Service