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Grizzly bears, black bears, wolves, coyotes, cougars/ mountain lions,bobcats, wolverines, lynx, foxes, fishers and martens are the suite of carnivores that originally inhabited North America after the Pleistocene extinctions. This site invites research, commentary, point/counterpoint on that suite of native animals (predator and prey) that inhabited The Americas circa 1500-at the initial point of European exploration and subsequent colonization. Landscape ecology, journal accounts of explorers and frontiersmen, genetic evaluations of museum animals, peer reviewed 20th and 21st century research on various aspects of our "Wild America" as well as subjective commentary from expert and layman alike. All of the above being revealed and discussed with the underlying goal of one day seeing our Continent rewilded.....Where big enough swaths of open space exist with connective corridors to other large forest, meadow, mountain, valley, prairie, desert and chaparral wildlands.....Thereby enabling all of our historic fauna, including man, to live in a sustainable and healthy environment. - Blogger Rick

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Saturday, November 28, 2015

Fishers are much like Pumas isofar as males allowing several females to share their territory..........As males defend their territory against other male Fishers, the females are afforded a more favorable habitat to hunt prey and care for their kits............Unlike Wolves and Coyotes that have about a 60 day gestation period prior to pup birth, female martens carry for 10 or 11 months before birthing..........Both males and females are promiscuous during a roughly 45 day period mid March through the end of April..........Strictly carnivorous, Fishers are the one sure predator of porcupines and have been purposely reintroduced into many forest habitats to create a rough equilibrium with Porkies so that various tree regeneration can take place..............Kits disperse in late Summer and Fall through a process called squabbling, aggression that takes place am among the kits and perhaps their mother as well---In essence,a behaviour paradigm kicks into Fisher families with the theme being: "we have supported you ling enough, go make it on your own"................Note that while eastern fishers are on the rebound, the western fisher has yet to recover from forest removal and other human land altering activity..........Re-introductions of the Western Marten will likely be needed to ensure long term persistence of the species

Fisher Families Fall Out In Fall
Illustration by Adelaide Tyrol
Along with the crisp mornings and crimson colors that signal summer’s slide into fall, there are changes occurring in the forests that go mostly unnoticed.  Among them is the dispersal of fisher kits from their mother’s territory into their own. Little is known about the process of fisher families breaking apart, except that it generally starts in late summer or early autumn and unfolds gradually.
What is known is that fishers (Martes pennanti) are born in March, blind, helpless, and dependent on their mothers. It takes nearly three weeks for fisher kits to grow fur and nearly two months for their eyes to open. Despite the burden of caring for her helpless kits, the mother will wander off for short periods within a week or two of giving birth in search of new mates.
From late March through April, the female will mate with several males – ovulation is induced by copulation – and then carry the fertilized zygotes-turned-blastocysts  for the next 10 or 11 months. The change of day length in late winter acts as a trigger for the embryos to implant in the uterus. Thus the female is technically pregnant for all but maybe 10 days of the year, even though her active pregnancy is only around 50 days.
Males do not play a direct role in the rearing of the young, but they do allow adult females to overlap onto their territory, said Chris Bernier, Furbearer Project Leader for the Vermont Department of Fish and Wildlife. This sharing of space can have a positive effect on litters. “Because males exclude other adult males from their territory, but not adult females, the foraging opportunities for the females [are increased], and hence, their kits’ survival is likely enhanced,” said Bernier.
Young fishers spend the spring and summer under their mother’s care, learning to hunt and forage. They are primarily carnivorous, eating a variety of animals, including mice, moles, snowshoe hares, and woodchucks. Fishers are one of the few animals to successfully prey on porcupines.
Sometime in late summer or early autumn, the family dynamic starts to shift. “During this period, kits and their mothers start to squabble,” said Roger Powell, a professor of applied ecology at North Carolina State University and author of a book on fishers. “They stop sharing resting sites and start doing more foraging on their own.”
Exactly how the squabbling, known as inter-familial aggression, starts and what it looks like is not well understood. Rebecca Green, a doctoral student studying fishers at the University of California, Davis said that photos taken with remote cameras suggest that the fighting may occur more often between kits, as opposed to between a mother and her kits. While the interactions are “rough and tumble,” they don’t seem to be overly aggressive. “It looks largely playful and is probably good practice for interacting with other fishers and prey,” said Green.
Bernier, however, noted that studies done on fishers taken by trappers in the fall show that adult females and juveniles of both sexes tend to have more injuries than adult males. This suggests that inter-familial aggression may include mothers. Bernier agreed with Green that the dynamic is not well documented, and noted that he has never observed it firsthand.
The size of fisher territories can vary, depending, in part, on the abundance of food. Females tend to have smaller territories, around five square miles on average, while males may occupy a space twice that size. According to Powell, most kits travel less than 12 miles before finding a space unclaimed by another fisher, though some have been known to travel up to 30 miles before settling down.
While the distances traveled and the particulars of inter-familial aggression may vary, the results do not. By the time autumn winds down, fisher kits have struck out on their own and are no longer under the protective watch of their mothers

by: Carolyn LoriƩ , Thetford, Vermont.

Center for biological diversity statement on eastern versus western fishers as it relates to potential for long-term persistence

 In the eastern United States, the fisher recovered much of its range, as a result of strict trapping regulations, return of forest from abandoned farmlands and reintroductions.

 In the western United States, however, the fisher has not successfully re-inhabited the majority of its range, despite cessation of trapping (Aubry and Houston 1992, Zielinski et al. 1995a and 1997). The fisher is reduced to two native populations on the West Coast—one in northern California and another in the southern Sierra Nevada (Zielinski et al. 1995a and 1997)—and a reintroduced population in the southern Oregon Cascades (Aubry et al. 1996, Aubry and Lewis in litt.)  All three populations are threatened by continued habitat loss to logging, development and other anthropogenic factors, and population isolation and demographic stochasticity (Lamberson et al. 2000, Truex et al. 1998).

 Reestablishing the fisher in a larger portion of its range, including the central and northern Sierra Nevada and portions of Oregon and Washington, may be necessary to ensure the long-term survival of the fisher on the West Coast. 

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