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Coyotes-Wolves-Cougars.blogspot.com

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, January 20, 2018

"To assess the role of human disturbances in species' extinction requires an understanding of the species population history before human impact". ..........."The passenger pigeon was once the most abundant bird in the world, with a North American population size estimated at 3-5 billion in the 1800s"............."Its abrupt extinction in 1914 raises the question of how such an abundant bird could have been driven to extinction in mere decades"............ "Although European colonist and subsequent generation exploitation is often blamed, the role of natural population dynamics in the passenger pigeon's extinction is now coming to the fore".............. "Applying high-throughput sequencing technologies to obtain sequences from most of the genome, it has been calculated that the passenger pigeon's effective population size throughout the last million years was persistently about 1/10,000 of the 1800's estimated number of individuals, a ratio 1,000-times lower than typically found"............... "This result suggests that the passenger pigeon was not always super abundant but experienced dramatic population fluctuations, resembling those of an "outbreak" species"............. "Ecological niche models supported inference of drastic changes in the extent of its breeding range over the last glacial-interglacial cycle".............. "An estimate of acorn-based carrying capacity during the past 21,000 years showed great year-to-year variations"............ "Ecological conditions that dramatically reduced population size under natural conditions interacted with human exploitation in causing the passenger pigeon's rapid demise"..........."In addition, the genetic diversity in the passenger pigeon population was surprisingly low in relation to the number of individuals. This may have made the species more vulnerable to the land altering and removal of the mast-rich eastern forests that took place rapidly during the 19th century"

https://earthsky.us1.list-manage.com/track/click?u=e56e7a92b1c5790f7343ef95a&id=6014a23315&e=05988a1072

Why did passenger pigeons die out?

In the 19th century, passenger pigeons were so numerous that hunters competed to shoot as many as possible. But the last passenger pigeon died in the Cincinnati Zoo over 100 years ago. How did it all go so wrong?





This article is republished with permission from Gemini. This post was written by Steinar Brandslet.
Why do species die out? This is the overarching question being asked by many leading researchers. Knowing more about what leads to a species’ becoming extinct could enable us to do something about it. The passenger pigeon is a famous example and the species has been studied extensively.
The passenger pigeon (Ectopistes migratorius) was once found in huge numbers in North America. Records tell of passing flocks that darkened the skies for several days at a time. The species may have peaked at five billion individuals. A more conservative estimate is three billion.
Within a short time, the species disappeared completely.
Tom Gilbert is a professor at the University of Copenhagen’s Centre for GeoGenetics, but he also has a part-time position as an adjunct professor at the Norwegian University of Science and Technology (NTNU). Gilbert said: Given the huge size of the population, it’s simply amazing that the species disappeared so quickly.





 The human role
The history of the passenger pigeon is interesting, partly because it can tell us something about how and why species become extinct.
Native Americans also relied on passenger pigeons for food. But at least in parts of the passenger pigeons’ range, people had learned to harvest the species at a sustainable level that didn’t threaten to eradicate it.
It was common in some parts of North America to only eat young pigeons that were hunted at night, since this did not seem to scare away the adult birds or prevent them from re-nesting.
But starting around 1500, a more aggressive variant of humans came to the continent with the arrival of Europeans. The hunt for passenger pigeons grew and culminated in a massive hunt for the species throughout the 1800s, before the species finally collapsed and disappeared.









So were the Europeans then really the ones to blame for the collapse?
Already headed to oblivion?
In 2014, a study in published in the scientific journal PNAS strongly suggested that humans were simply the final straw in destroying a species that was already vulnerable and headed to oblivion.
The researchers asserted that despite their enormous numbers, the passenger pigeons were already in trouble. The species’ population numbers varied greatly, similar to lemmings, but over a longer period of time.
When the Europeans arrived, the species was already in a strong decline. The population was plummeting long before Europeans arrived, and perhaps Europeans even contributed to a short-term increase in numbers.



Studies of the genetic variation of the species using an investigative method called PSMC formed the background for these assertions. And now we have to concentrate a bit.
From one to many
All of an individual’s genes are called a genome. You have a genome, your mom has her own genome, your dog has one and the neighbour’s cat has yet another. These can be broken down into chromosomes and genes and base pairs, but you only have a single genome.
So, all of your chromosomes and genes are found in this one genome, but at the same time this genome is unique to just you and only you. Unless, that is, you have an identical twin or are a termite or belong to another species where the individuals are largely identical clones. (In the last case, it’s remarkable that you can read this.)









Here is the crux of the matter:
The PSMC method can use the information in the genes of a single individual of a species to map the history of the species.
You should therefore be able to see how the species developed over many generations, and estimate how many individuals there were at any given time, all based on a single genome.
Humans partially off the hook
Using this method, researchers found that the number of passenger pigeons was in free fall even before the arrival of the Europeans.







Although the species might not have become extinct, it would have shrunk significantly in any case, maybe to only a few hundred thousand individuals.
People were just the final factor in their demise. We may have pushed the passenger pigeons off the cliff, but the species was already on its way there.
So – according to the researchers behind the study in PNAS – it wasn’t just the Europeans’ fault.
It sounds almost too good to be true that you can come up with something so definitive based on information from just one or a few individuals. And in this case it is – at least if we’re to believe a new study published November 17, 2017 in the journal Science.
Ineffective for passenger pigeons
The problem is that the PSMC method can’t be used on passenger pigeons. The new research in Science provides completely different results.



Leading molecular biologist Beth Shapiro is the main author of the Science article, and Tom Gilbert is one of the study’s contributors. (Heads up – you can skip to the next section if you don’t want to know a little more about why PSMC doesn’t work for the passenger pigeon in particular.)
PSMC is based on the assumption that genetic variations occur relatively evenly all along the chromosomes that constitute the genome. That is, genetic changes are equally likely to occur at the ends of a chromosome as in the middle. But this turns out not to be the case for this species. Gilbert said:
Passenger pigeons don’t have the variation patterns that we’d expect, because of the strong selection on genes that appear to have been important throughout the species’ history. So it doesn’t work to use PSMC in this case.








In passenger pigeons, most of the genetic diversity was found at the ends of the chromosome. The middle of the chromosome showed little variation from one generation to the next as a result of the selection on these genes.
his fact may not sound revolutionary, but it yields completely different results if you try to read the history of the species based on the genome of a single individual.
You have to take into account that variations are greatest in certain parts of the chromosome rather than evenly distributed throughout. This makes the PSMC method unusable in this context.
Used another method
The researchers behind the article in Science didn’t use the PSMC method. Instead, they used mitochondrial DNA from 41 passenger pigeons as their starting point. Now we have to concentrate again.









Your DNA is not your only inheritance. Mitochondrial DNA is a distinct, separate inheritance found in certain cells called mitochondria.
Regular DNA is a combination of the inheritance from your father and mother. But mitochondrial DNA is only transmitted from your mother. Variations in mitochondrial DNA also occur due to mutations, and happen relatively consistently over time.
This is a different point of departure for understanding how a species develops over time, and the results can be quite different from those generated using the PSMC method.
In addition, the study presented in Science analyzed the entire genomes from four passenger pigeons and compared them with two genomes from band-tailed pigeons (Patagioenas fasciata), one of the closest relatives of the passenger pigeon.










The final result was that the new study ended up with completely different answers about the passenger pigeons and why the species met its demise.
Genetic diversity
The new study is interesting for several reasons. It tells us about the genetic diversity of the passenger pigeon, but also supports an entirely different explanation for the species’ extinction.
Scientists previously believed that the larger the population of a species is, the more genetically diverse it will be. But this theory has turned out to be wrong, as the recent passenger pigeon research has shown.




According to the article in Science, the large population size appears to have enabled passenger pigeons to adapt and evolve more quickly and thus remove harmful mutations.
In species with fewer individuals, chance can cause a less beneficial mutation to persist, but chance plays less of a role in species with greater numbers of individuals. Gilbert said:
Mutations that provide a major evolutionary benefit would spread rapidly.
The fact that beneficial mutations became incredibly dominant so quickly simply led to the disappearance of other genetic variants.







 This in turn led to the genetic diversity in the passenger pigeon being surprisingly low in relation to the number of individuals. This may have made the species more vulnerable to changes.
But that was not why the passenger pigeon died out.
Our mistake
Here is Gilbert’s short version:
The passenger pigeon died out because of people.
The passenger pigeon wasn’t in trouble prior to Europeans arrival in North America. Nothing suggests that the species was struggling in any way.
Perhaps this isn’t that surprising. In the 19th century, passenger pigeons were so numerous that there were contests to shoot as many of them as possible during a certain period of time. In one competition, the winner had shot 30,000 birds.








If nothing else, the story of the passenger pigeon has contributed to a greater understanding that even prolific species can become extinct.
Something to learn
The large grasshopper Melanoplus spretus from the western United States suffered the same fate. It went from a population of several trillion to zero in a few decades, possibly because farmers destroyed its breeding grounds. In Norway and across the whole of the North Atlantic, the great auk (Pinguinus impennis) died out after people harvested them in large numbers.
People ate passenger pigeons in huge amounts, but they were also killed because they were perceived as a threat to agriculture. As Europeans migrated across North America, they thinned out and eliminated the large forests that the pigeons depended on. The pigeons lived primarily on acorns.









As the species was already dying out, 250,000 birds – the last big flock – were shot on a single day in 1896. That same year, the last passenger pigeon was observed in Louisiana. It was also shot.
The pigeons were probably dependent on a large flock size to reproduce. Their instincts didn’t work when only a few individuals remained here and there.
The last passenger pigeon died in the Cincinnati Zoo in 1914.

Friday, January 19, 2018

While a magic bullet to kill off the lyme disease carrying deer tick would be cheered, alas, the answer isn't that simple...................While extremely prolonged cold temperatures(zero and below) can have a debilitating impact on some % of the tick population, snow and leaf litter will moderate below ground temperatures to as high as 32 degrees, protecting ticks.............."A 2012 study at the Cary Institute of Ecosystem Studies in Millbrook, NY (Dutchess County), examined the probability of tick mortality in winter conditions in both Millbrook and Syracuse, NY"................. "The study found that exposure to subzero temperatures increased mortality “only at super-cold temperatures"................ "And it wasn’t a clear die-off; just an increased probability of dying".............”Regardless of winter conditions, more than 80 percent of the ticks survived at both sites"

https://adirondackexplorer.us5.list-manage.com/track/click?u=f2786fbb7862339a0b90113d7&id=95c18a3397&e=46b8d98c61

http://r20.rs6.net/tn.jsp?f=0016Lycf7JB7XHiQ485xbiOh80oAwWU7wuKKLFDNebhkdNzmTZnrdvXMSA9bDyn0A2FFaR8004x0Xzz92Px_OzyftYlu_HZAF9xnUkJ8Tb_cMyJVpLACtyTadLUi9baZGcSD6ZAaz269wuIIJXx8su24p5T6A6B5MnQLjIjnfgAyvAWfq5c-Cftd1aWo2U4ASsRDZeVhGCiesyw2JMWn_sOrOOW-SFRAJKtwD6Uuqd6Xnt0UGnzpuRtz8g6k7zi9kjTq6ElT_laIMu3y7PTUiOZvQ==&c=6NYCCb88lwXOFeK4f286HJkA42MNxtt7kHDjLIhwZ0oPbPBDtD4hZw==&ch=g5ToLdcQGcbO-NdScJXAUMHEROp-sydbvrF02UY8AHLcSfWJI-66Og==

WEDNESDAY, JANUARY 17, 2018

Will Our Extreme Winter Cold Wipe Out Ticks?

Deer TickI’ve been asked on four different occasions, recently, how tick populations will be impacted by the December/January below-zero cold. Some of those asking had heard reports, apparently claiming that tick populations would be decimated, if not eradicated, by the prolonged period of extremely cold weather.
We’d all certainly welcome that. It’s probable that you or someone you know has been affected by ticks and/or by Lyme disease. And any downward pressure on tick populations is welcome. But, the answer isn’t that simple.
Extremely cold temperatures do have an impact on overwintering insects and insect-like critters. (Technically, ticks are not insects. They’re arachnids, like spiders.) But determining mortality rates based on winter weather conditions is anything but certain. The mechanisms that allow their survival are varied and complicated. So different groups will have different rates of survival.
Some ticks survive as eggs deposited before winter. Depending on the species, a single female tick may lay 3,000 – 8,000 eggs, after which she dies. Ticks in other stages of development also overwinter in the shelter and relative comfort of the soil or within leaf litter and ground clutter, where snow cover can actually provide additional protection from extremely cold temperatures and wind.












Even when the air temperature lingers in the double digits below zero F, things that are covered with an insulating blanket of snow will remain much nearer to 32°F. In fact, the temperature beneath the snow, in many cases, will keep the soil from freezing. I’ve been told that just one foot of snow cover will completely protect the soil, and any organisms living within the soil, from the subzero air temperatures above the snow surface. And many experts believe that, even without snow, it takes a long period of bitterly cold weather to even have a chance of knocking tick populations back.
The rate of mortality greatly increases, however, with the combination of extremely cold conditions and liquid water. Overwintering insects and non-insects alike (i.e. ticks), must remain dry; insulated by the surrounding ice and snow; but not touching it.


 ticks in leaf litter









A 2012 study co-authored by Rick Ostfeld; an ecologist at the Cary Institute of Ecosystem Studies in Millbrook, NY (Dutchess County), examined the probability of tick mortality in winter conditions in both Millbrook and Syracuse. The study found that exposure to subzero temperatures increased mortality “only at super-cold temperatures. And it wasn’t a clear die-off; just an increased probability of dying.” Regardless of winter conditions, more than 80 percent of the ticks survived at both sites.
According to Peter Jentsch, an entomologist and Senior Extension Associate with Cornell Cooperative Extension’s Hudson Valley Lab in Highland, NY, “most living things are able to survive environmental extremes if they have enough time to transition and acclimate to change.”
It’s interesting to note, too, that a 2010 study from the Journal of Clinical Investigation showed that some ticks developed a type of glycoprotein, a compound produced within their bodies, which works to help them survive the cold.
Some tick species overwinter on warm mammalian hosts; often moose or deer, but also black bears, dogs, and occasionally horses or cattle. They attach themselves to the animals’ fur. Then, during the winter months, to the hosts themselves; feeding and molting until spring arrives, at which time they drop to the ground, where the females lay their eggs.
NYS Integrated Pest Management (IPM) Program Extension Support Specialist, Joellen Lampman, first looks at how extremely harsh weather conditions may impact mammals; small mammals, like mice, when considering the question of the recent frigid weather and how it will impact tick populations.
In a recent IPM news article she writes, “Animals that have a harder time finding food are more likely to (in order of lessening consequences) die of starvation, succumb to other stresses such as disease or predation, fail to mate, give birth to fewer young, and give birth less often. In a nutshell, there should be fewer hosts, come spring. And fewer hosts eventually lead to fewer ticks.”
But there’s some bad news, too. Lampman writes, “During the time of high tick numbers and fewer small mammal hosts, each of us, and our companion animals, are at greater risk of coming into contact with questing (waiting on plants for a host) ticks. So, as soon as the temperatures rise into the mid-30s (and we know you will be out enjoying the veritable heat wave), ticks will be questing, and we need to steer clear of ticks and the diseases they carry – the IPM way.”
For more information, click here.

Does "killing frost" kill deer ticks?


If you think that recent nighttime temperatures dropping into the 20's is going to kill off the adult deer ticks crawling just about everywhere these days... well, think again! The killing frost may finish off your garden and the pesky mosquitoes that have remained around, but not the deer ticks. These ticks just don't die from the cold.
Instead, they typically retreat daily into the leaf litter to stay hydrated. Then, they'll climb back onto knee-high vegetation any time temperatures are above freezing, hoping to latch on to a passing deer, dog, cat, or human. To some, these ticks seem tough; they'll be out there until the ground freezes. And they'll be back as soon as it thaws. You need to know this so you're not caught un-prepared.
You may be wondering what does kill these persistent creatures. Adult deer ticks die when they finally run out of energy reserves acquired back when they were nymphs. This typically happens in the following May. But May is when the poppy seed-sized nymphs become active, so there really are very few "tick free" breaks during the year.

Ticknado! Scarier than Sharknado!

Just when you thought that the bloodsuckers of summer should be gone, some come back. TICKS. That's right! Not all types ... but one type that's especially dangerous - adult blacklegged ticks. Rather than being killed off by cooler nighttime temperatures -- even a frost or a freeze -- adult blacklegged tick populations are just rev-ving up, and they can strike ... well, like a Ticknado! And similar to being prepared for any other natural disaster, NOW is when you should have your tick bite protection toolkit ready and implemented.

Brrrrr... Polar "Vorticks"!

Have you been wondering (hoping) if these brutal polar vortex episodes sweeping the eastern half of the nation are freezing the palps off of blacklegged (deer) ticks? It’d be nice, right? Read more about Polar Vortex temps and how they impact ticks in our Tick Note: Polar Vorticks!


Wednesday, January 17, 2018

While it is well documented that Wolf Packs will "go to war" and fight neighboring Wolf Packs to obtain additional territory, I have never seen or heard of a lone female Wolf invading a Wolf natal den to try and kill the pups of the year..............The video that you will view by clicking on the link below shows how fiercely the females of a given Arctic Wolf Pack will defend their newly born pups from an invading lone female wolf..................A must view!


A MUST-SEE VIDEO OF FEMALE WOLVES DEFENDING THEIR PUPS AGAINST
AN INTRUDING LONE FEMALE --CLICK ON LINK BELOW TO VIEW

https://www.google.com/url?rct=j&sa=t&url=https://www.livescience.com/61384-brutal-wolf-pack-fight-video.html&ct=ga&cd=CAEYASoUMTgxMjQ5NTgzNzAzMDQzOTE4MzIyGmRhOTdjZjk0NzgwNDY5OWE6Y29tOmVuOlVT&usg=AFQjCNHN9g7qk_XYfHzKb3R9PItN9nZTEQ

Pack of Female Wolves Destroys Enemy Intruder in Brutal Fight (Video)

  | 

A pack of female wolves defends its den from an intruder in a new PBS documentary.
Credit: Nature: Arctic Wolf Pack/WNET
Moms are fierce — especially when they're wolves.
In a dramatic new video from an upcoming PBS documentary on Arctic wolves, a pack of female wolves defends its den from a bedraggled, strange wolf who attempts to make a meal of the pack's defenseless cubs.
Well, defenseless except for their mother and her three female packmates.
In a snarling, brutal sequence, the pack drags, bites and pulls the invader away from the pups. Within moments, the pups are safe from danger, and the stranger is on the run.
he footage is part of a new episode in the series "Nature." The episode, "Arctic Wolf Pack," airs on PBS on Jan. 17. The documentary follows a pack of Arctic wolves (Canis lupus arctos) living only 500 miles (800 kilometers) from the North Pole. The snowy-furred canines birth their fuzzy, blind pups in dens burrowed into the Arctic tundra. Their mother, dubbed Snow White, isn't alone in caring for them. Her packmate, Black Spot, nurses Snow White's pups — a mysterious behavior never before captured on film. To make milk, Black Spot must have recently given birth herself, but the fate of her mate and her own litter is a mystery.
Arctic wolves are found in Greenland and the far northern reaches of Canada. It's the only subspecies of gray wolf that is not threatened by hunting or loss of habitat, according to the World Wide Fund (WWF) — an advantage it gains by living so far north that it rarely encounters humans.
Beyond its white fur, the Arctic wolf's short muzzle and small ears distinguish this subspecies from its more southerly gray cousins. These adaptations make it easier for the wolves to retain body heat, according to the WWF. The wolves live off of Arctic hares, caribou and musk ox, the latter of which grow to at least 10 times the wolves' weight. With such large prey, survival is a matter of cooperation between packmates — whether that means banding together to hunt or to protect the next generation.
The documentary "Nature: Arctic Wolf Pack" from THIRTEEN premieres Wednesday, Jan. 17, at 8 p.m. on PBS

Tuesday, January 16, 2018

In suburban Rockland County New York(suburb of NYC), so-called journalists are seeking to scare people about Eastern Coyotes(e.g. Coywolves), calling them "dangerous" and making them out to be "frankenstein-like"................I thought that the beginning of this new year of 2018 merited another review of what the Eastern Coyote is and what it is not---- and what it is doing in our woods, fields, towns and cities...........Just to reiterate, THE COYWOLF IS NOT A THING,,,,,,,AND IT IS NOT LOOKING TO EAT YOU!



You might rememberhaving seen this Eastern Coyote video from Queens, New York  a couple of years ago
 https://youtu.be/ezrUK3_2uQ0


 Yes, eastern coyotes are hybrids, but the ‘coywolf’ is not a thing

Talk of “coywolves” – a blend of coyote and wolf – is everywhere. There is a PBS specialcalled Meet the Coywolf, a recent article in the Economist, and it is now trending on Facebook. The media really love this new animal name.
There is no doubt that there is a hybrid canid living in the eastern US, and that it is the result of an amazing evolution story unfolding right underneath our noses.









However, this is not a new species – at least not yet – and I don’t think we should start calling it a “coywolf.”

Genetic swapping

What creature are we talking about? In the last century, a predator – I prefer the name “eastern coyote” – has colonized the forests of eastern North America, from Florida to Labrador.
New genetic tests show that all eastern coyotes are actually a mix of three species: coyote, wolf and dog. The percentages vary, dependent upon exactly which test is applied and the geographic location of the canine.
Coyotes in the Northeast are mostly (60%-84%) coyote, with lesser amounts of wolf (8%-25%) and dog (8%-11%). Start moving south or east and this mixture slowly changes. Virginia animals average more dog than wolf (85%:2%:13% coyote:wolf:dog) while coyotes from the Deep South had just a dash of wolf and dog genes mixed in (91%:4%:5% coyote:wolf:dog). Tests show that there are no animals that are just coyote and wolf (that is, a coywolf), and some eastern coyotes that have almost no wolf at all












In other words, there is no single new genetic entity that should be considered a unique species. Instead, we are finding a large intermixing population of coyotes across the continent, with a smattering of noncoyote DNA mixed in to varying degrees along the eastern edge. The coywolf is not a thing.
 All eastern coyotes show some evidence of past hybridization, but there is no sign that they are still actively mating with dogs or wolves. The coyote, wolf and dog are three separate species that would very much prefer not to breed with each other. However, biologically speaking, they are similar enough that interbreeding is possible.
This genetic swapping has happened more than once in their history; one study showed that the gene for black coat color found in North American wolves and coyotes today (but not in Old World wolves) originated in dogs brought to the continent by the earliest Native Americans. Some prehistoric hybridization event transferred the dog gene into wild wolves and coyotes.

The eastern coyote is born

We can estimate the date of the most recent hybridization events that created eastern coyotes by analyzing their genetic structure. Their DNA show that about 100 years ago, coyotes mated with wolves, and about 50 years ago with dogs. A century ago, wolf populations in the Great Lakes were at their nadir, living at such low density that some reproductive animals probably couldn’t find another wolf mate, and had to settle with a coyote.









The more recent date for the dog hybridization likely results from a cross-species breeding event at the very leading edge of the wave of colonizing coyotes in the east, possibly after a few females first spanned the St Lawrence seaway into upstate New York, where they would have encountered abundant feral dogs, but no other coyotes.
Nowadays, eastern coyotes have no problem finding a coyote mate. Their populations continue to grow throughout their new forested range, and they seem more likely to kill a dog than breed with it. Wolf populations in the Great Lakes have also recovered, and the wolf is once again the worst enemy of the coyote, rather than its last-chance prom date.
Coyotes have also expanded north into Alaska, although there is no sign of hybridization in that range extension. In Central America, they have expanded out of Mexico’s deserts, working their way south past the Panama Canal in the last decade, apparently bound for South America.
No genetic studies have looked at Central American coyotes, but photographs of doglike animals suggest that coyotes might be mixing it up across species lines along the leading edge of this southward expansion as well.

Coywolfdog evolution

Hybridization across species is a natural evolutionary phenomenon. The old notion that an inability to breed should define what a species is has been abandoned by zoologists (with a resounding “I told you so” from botanists). Even modern humans are hybrids, with traces of Neanderthal and Denisovan genes mixed into our genome.











The first requirement for evolution is variation, and mixing genes from two species creates all sorts of new variations for evolution to act on. Most of these probably die, being a compromise between two longstanding species that were already well-adapted to their own niches.
However, in today’s rapidly changing world, new variations might actually do better than the old types. Some of these genetic mixes will survive better than others – this is natural selection.
The coyote with a bit of wolf genes to make it slightly larger was probably better able to handle deer, which are overabundant in eastern forests, but still wily enough to live in a landscape full of people. These animals thrived, dispersed east and thrived again, becoming the eastern coyote.
Exactly which dog and wolf genes are surviving natural selection in today’s eastern coyote is an area of active research.
Coyotes with odd coat colors or hair types are probably the most conspicuous sign of dog genes in action, while their slightly larger size might come from wolf genes. Some of these genes will help an animal survive and breed; others will make them less fit. Natural selection is still sorting this out, and we are witnessing the evolution of a new type of coyote right under our noses, one that is very good at living there.











Western coyotes adapt locally to their environments, with limited gene flow between populations (called “ecotypes”) living in different habitats, presumably reflecting local specialization.
Will eastern coyotes specialize locally as well? How will dog and wolf genes sort out across cities and wildernesses of the east?
Expect some really cool science in the next few years as researchers use modern genetic tools to sniff out the details of this story.

Evolution still in progress

There are many examples of bad animal names that cause a lot of confusion.
The fisher is a large type of weasel that does not eat fish (it prefers porcupines). The mountain beaver of the Pacific Northwest is not a beaver and does not live in the mountains. And then there’s the sperm whale…
We don’t get many opportunities to name new animals in the 21st century. We shouldn’t let the media mess up this one by declaring it a new species called the coywolf. Yes, there are wolf genes in some populations, but there are also eastern coyotes with almost no wolf genes, and others that have as much dog mixed in as they do wolf. “Coywolf” is an inaccurate name that causes confusion.
















The coyote has not evolved into a new species over the last century. Hybridization and expansion have created a host of new coyote variations in the east, and evolution is still sorting these out. Gene flow continues in all directions, keeping things mixed up, and leading to continual variation over their range, with no discrete boundaries.
Could evolution eventually lead to a coyote so specialized for eastern forests that they would be considered a unique species? Yes, but for this to happen, they would have to cut off gene flow with nonhybrid animals, leading to distinct types of coyotes that (almost) never interbreed. I think we are a long way from this possibility.
For now, we have the eastern coyote, an exciting new type of coyote in the midst of an amazing evolutionary transition. Call it a distinct “subspecies,” call it an “ecomorph,” or call it by its scientific name Canis latrans var. But don’t call it a new species, and please, don’t call it the coywolf.

Monday, January 15, 2018

"The impacts of hyperabundant white-tailed deer (Odocoileus virginianus) populations on understorey plant community structure and composition are well-established"................ However, few studies have examined how the recovery of wolves might moderate these effects"........... "Recent studies of species interactions in Yellowstone National Park (YNP) suggest that the recovery of wolf populations can naturally ameliorate ungulate-caused ecosystem simplification"............. "In this study, we examine whether a similar trophic cascade was triggered by the recovery of the Great Lakes wolf population in northern Wisconsin"........... "In addition, by assessing community-level responses as opposed to species-level responses and by measuring across several spatial scales of observation, we hope to inform future research by identifying the ideal response variable and spatial scale for detecting effects of top predators in similar terrestrial systems"............ "As predicted for a trophic cascade response, forb species richness at local scales (10 m2) was significantly higher in high wolf areas (high wolf areas: 10.7 ± 0.9, N = 16, low wolf areas: 7.5 ± 0.9, N = 16, P < 0.001), as was shrub species richness (high wolf areas: 4.4 ± 0.4, N = 16, low wolf areas: 3.2 ± 0.5, N = 16, P < 0.001)"................... "Also as predicted, percentage cover of ferns was lower in high wolf areas (high wolf areas: 6.2 ± 2.1, N = 16, low wolf areas: 11.6 ± 5.3, N = 16, P < 0.05)"






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Recolonizing wolves trigger a trophic cascade in Wisconsin (USA)

Authors

  • First published: 
  1. Summary

    1. We tested the hypothesis that wolves are reducing local browse intensity by white-tailed deer, thus indirectly mitigating the biotic impoverishment of understorey plant communities in northern Wisconsin.
    2. To assess the potential for such a top-down trophic cascade response, we developed a spatially and temporally explicit model of wolf territory occupancy based on three decades of wolf monitoring data. Using a nested multiscale vegetation survey protocol, we compared the understorey plant communities of northern white cedar wetlands found in high wolf areas with control sites found in low wolf areas.
    3. We fit species–area curves for plant species grouped by vegetation growth form (based on their predicted response to release from herbivory, i.e. tree, seedling, shrub, forb, grass, sedge or fern) and duration of wolf territory occupancy.
    4. As predicted for a trophic cascade response, forb species richness at local scales (10 m2) was significantly higher in high wolf areas (high wolf areas: 10.7 ± 0.9, N = 16, low wolf areas: 7.5 ± 0.9, N = 16, < 0.001), as was shrub species richness (high wolf areas: 4.4 ± 0.4, N = 16, low wolf areas: 3.2 ± 0.5, N = 16, < 0.001). Also as predicted, percentage cover of ferns was lower in high wolf areas (high wolf areas: 6.2 ± 2.1, N = 16, low wolf areas: 11.6 ± 5.3, N = 16, < 0.05).
    5. Beta richness was similar between high and low wolf areas, supporting earlier assumptions that deer herbivory impacts plant species richness primarily at local scales. Sampling at multiple spatial scales revealed that changes in species richness were not consistent across scales nor among vegetation growth forms: forbs showed a stronger response at finer scales (1–100 m2), while shrubs showed a response across relatively broader scales (10–1000 m2).
    6. Synthesis. Our results are consistent with hypothesized trophic effects on understorey plant communities triggered by a keystone predator recovering from regional extinction. In addition, we identified the response variables and spatial scales appropriate for detecting such differences in plant species composition. This study represents the first published evidence of a trophic cascade triggered by wolf recovery in the Great Lakes region.
    7. Photo pair of understorey vegetation within the Chequamegon-Nicolet National Forest, WI.( top picture below) Shows a high wolf area (within the Bootjack Lake pack territory) and (bottom pictue below) shows the paired low wolf area (in the buffer zone between the Bootjack Lake pack and the Miles Lake pack).




















































Diagram of hypothesized tri-trophic interactions in northern Wisconsin forests. Solid arrows represent direct positive and negative interactions. Dashed arrows represent hypothesized indirect interactions. Dotted line represents competitive interactions.










intensity of wolf impact based on 10 years (1998–2008) of wolf pack territory data (WiDNR). Years of occupancy represent the duration of wolf pack tenure. High wolf areas = 8–10 years of occupancy, low wolf areas = 0–3 years of occupancy