The Northeastern Coyote: A Morphometric Survey of Canis latrans variant in Northeastern Maine

 

 

Abstract

The ecological role of the wild canids in the Laurentian Hills Ecoregion of Maine

PREDATOR OR SCAVENGER ADAPTATIONS?

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The coyotes of the Laurentian Hills Ecoregion of Maine are a part of the northeastern coyote (Canis latrans variant) population, known to be the largest extant version in of the coyote in North America. Biologists and geneticists commonly attributed their size to their hybridization with eastern wolves in Ontario during their eastern immigration. Much debate surounds the ecological and environmental effect that this species has had on the region since they immigrated into the region nearly 70 years ago.

In this morphometric study, 26 coyotes were collected from this specific ecoregion. Multiple data sets were created from the specimens to determine the ecological role they are playing in the region. Results suggest that the local wild canid population is scavenging large prey species (such as the moose and deer) more than other coyote populations. No evidence was found, however, to suggest that they have adapted to prey upon deer or moose more than other populations.

 

 

 

 

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Introduction

The Natural History and Hybridization of Canis latrans NATURAL HISTORY

Toward the end of earth’s most recent period of glaciations, known as the Pleistocene age, the grey wolf (Canis lupus) invaded the North American continent by way of the Bering Land Bridge after a long sojourn in Eurasia. What they discovered when they arrived was that their North American canid cousins had diverged into two separate species, the eastern timber or red wolf (Canis lycaon) and the western coyote (Canis latrans) (Hansen, Mallory, Vanderwolf, 2007). As that particular ice age lost its grip on the continent, the native canids (or New World Canids) started moving northward on the continent, while their larger grey cousins (or Old World canids) moved east and south from present day Alaska (Pacquet and Carbyn 2003).

In more recent history, there has been a ‘power sharing agreement’ between these canid families. Very generally speaking, the small coyotes were confined to the Southwest. Their native cousins, the eastern or red wolf (these are now believed to be conspecific species separated by European colonization of the east coast of North America) governed the East, using the Appalachian Mountain Range as their corridor; ranging from what is now the southeastern U.S. to northeastern Canada. The larger grey wolf took the northwestern two-thirds of the continent and what ever else suited its fancy (Moore and Parker 1992).

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This uneasy truce was upset only a few hundred years ago when Europeans came to the “New World,” bringing with them a cultural detestation of wolves. By the early part of the last century, wolves (both New World and Old World) had been extirpated from most of the continental United States (Busch 2007).

It has been said that, ‘nature abhors a vacuum’ and so the coyote-a smaller, more adaptable messo-carnivore, seized the opportunity to expand its range and began moving north and east (Russo 2008).

Moving first northward into Canada, the coyote’s range then traveled eastward, above the Great Lakes before migrating into their modern New England range (Moore and Parker 1992). The first coyotes took up residence here in the Laurentian Hills Ecoregion in the 1940s, just a few decades after the last recorded wolf was killed.

North America’s Largest Coyote

The eastern coyote(Canis latrans variant) is the largest extant variety of the coyote in all of North America. Even larger than those in Alaska (Way 2007).

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

In the coyote family, as in all canids, the males are typically larger than females. The size difference between western and eastern coyotes is so great, however, that the female eastern coyote, outweighs male western coyotes by 21% (Way 2005).

There is a biological rule, known as Bergman’s rule, which states that individuals within a species tend to be larger the further north they live, due to the colder climate. This adaptation aids in heat retention by decreasing the surface to mass ratio. In carnivores there is an added reason: If their prey is larger, they must become larger to bring them down.

Recent studies, however, show that longitude (west to east) accounts for approximately four times the amount of size variation in the coyote species than does latitude (Way 2007). Theories as to why this is true include ecological adaptation (evolution), hybridization with dogs, and hybridization with wolves.

Dr. Way (2007) discounts the ecological adaptation theory by pointing out that the available prey ( from rodents to whitetail deer) are relatively the same size across the longitudinal spectrum. Therefore there is no predator/prey paradigm that would favor a greater size from the coyote.

The “coy-dog” theory is discredited by many biologists on the premise that the breeding cycles of coy-dogs and coyotes are not the same. In particular, coyotes breed in the winter and have pups in the spring, while coy-dogs breed in the fall and have pups in the winter-the most inopportune time for wild canids in the frigid north to be tending to offspring.

The recent consensus is that the large size of the northeastern coyote is the result of hybridization with their ancestral cousins, the eastern/red wolf (Way 2008). This hybridization is, itself, an adaptation of the coyote to become the top predator in a region where their larger cousin has been extirpated by man.

Scientist believe that the eastern wolf and the coyote evolved here in the New World while the grey wolf evolved in the Old World. This also explains why these New World canids have shown a great propensity to hybridize when breeding options were limited while hybridization does not occur between coyotes and the larger, old world, grey wolf (Canis lupus) in other parts of North America.

 

Jonathan Hayes • email: hayes@missionwilderness.org 

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This specific interbreeding has been both documented and actively discouraged by biologists involved in restoring the critically endangered red wolf to the wilds of the Southeast. Hybridization with coyotes is currently considered the greatest threat to red wolf recovery in the southeastern United States (Busch 2007).

Research shows that coyotes generally avoid inbreeding when possible (Meir 1995). It is not a stretch then, to postulate the cross breeding opportunities for pioneering coyotes and lone wolves as they crossed through eastern wolf habitat in Canada making their way to northern New England.

Behavioral studies of the eastern coyote show that morphology is not the only thing that distinguishes them from their western counterparts. Their prey selection, hunting ranges and social behavior strikes a balance between the western coyotes and the eastern/red wolves (Way 2007, Suburban Howls)

For example, when alpha breeding pairs are allowed to establish themselves in a region (without being hunted or trapped) pack sizes are typically between three to five adults. While they may hunt alone for small prey, they reconnoiter at rendezvous sites in early morning and evening for playful socialization within clearly defined pack roles. Massachusetts coyote biologist Dr. John Way says that the eastern coyote “has ecological and physical characteristics that can be seen on a continuum of coyote-like to wolflike. (Way 2008)”

 

Jonathan Hayes • email: hayes@missionwilderness.org

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Dr. Brian White of Trent College in Ontario Canada has done a genetic survey of the coyote species and has found strong evidence of hybridization between eastern wolf and coyote in New England. In fact, of the 75 coyotes sampled in Massachusetts alone Dr. White found that all had eastern wolf genetic influence (Way 2008). According to Way, their research has found “variability within (White’s) study areas with some coyotes having nearly pure red/eastern wolf… DNA.”

This genetic contribution to Maine coyotes from their eastern wolf cousins may be ongoing. Eastern wolves have been trying to reestablish themselves in Maine for the past few decades. This is evidenced by the fact that they have been inadvertently killed by coyote hunters in Maine on a number of occasions in recent years (Way 2008). Indeed, eastern wolves range just 100 miles from the Maine border in Canada … not far considering wolves have been known to travel distances of over 500 miles in a matter of a few weeks (Busch 2007). Despite these genetic samplings of coyotes and hunted wolves within the state, current literature and governmental pronouncements declare that no wolves and only coyotes exist in Maine.

A New Species?

There is mounting evidence that the coyotes of Maine have hybridized with wolves to adapt to an environment in need of a top predator. It is obvious to biologists and laypersons alike that the eastern coyote is distinct from the rest of the species morphologically. Dr. White and others believe the eastern coyote should be given individual species status because they are more closely grouped to each other than with the western coyotes (Way 2008).

Before distinct breed status is attained, more research needs to be done to determine whether the morphological adaptations of the eastern coyote has stabilized to a somewhat uniform and distinct conformation. As Dr. Way explained, we will “most likely not be able to call the eastern coyote a new species until we sample throughout the Northeast to determine where they become less “eastern coyote” (Way 2008). Canadian biologists have already begun referring to this cross of Canis latrans and Canis lycaon (found prolifically in Ontario’s Algonquin National Park) as “tweed wolves.”

The laurentian plains and hills ecoregion of Maine, in the northernmost portion of New England is near to the epicenter of the wolf/coyote hybridization which likely occurred in the Algonquin

 

Jonathan Hayes • email: hayes@missionwilderness.org

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Park region of Ontario ( Wilson et. al 2009) but it is separated from the same by the northern reach of the Appalachian Mountain Range. This isolated proximity makes it an ideal region to look for a stabilized conformation.

My Purpose

It is beyond the scope of this study to definitively determine the taxonomic identity of the wild canids in the Laurentian Hills Ecoregion. They are herein referred to as coyotes because that is what they are commonly referred to locally.

The purpose of this study was to survey the Canis latrans variant population in the Laurentian Hills Ecoregion to determine if there is a consistent and unique morphometric conformation within the population. My data was compared to standard Canis latrans and Canis lycaon morphometrics to determine whether the local coyotes fall within either of their species morphological parameters. Then, I explored those unique distinctions to determine what ecological role these wild canids are playing in the regional ecology.

 

Jonathan Hayes • email: hayes@missionwilderness.org

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Materials and Methods

Specimen Collection and Comparison

COLLECTING SPECIMENS

Due to advances in technology, electronic tracking systems and laboratory genetics have come to play major roles in the study of animal behavior and relatedness in recent years. This has made the older, more traditional methods of morphology and the necropsy seem comparatively crass and antiquated (because they often require a dead specimen). This shift is regrettable, for as Dr. Frank Mallory of Laurentian University points out, “Necropsies can literally provide researchers with thousands of data points on hundreds of different parameters including; genetics, physiology, pathology, reproduction, condition, morphology, taxonomy, foraging, parasitology, ecology, behavior, demography, population dynamics and trophic relationships. (Mallory, 2000).” I have found this to be true in my study as this approach has provided me with more data than I would be able to address in multiple papers. Many of these data points will only be mentioned in this paper, without discussion, to provide a comparison for future studies.

In 2000, Trent and Laurentian Universities in Canada collected eastern coyote specimens from New England for a genetic study of the hybridization between Canis lycaon and Canis latrans. My intention was to compare available morphometric data from these coyotes with similar data from other coyotes outside the region. Regrettably, morphometrics were not done in these genetic studies. It has since come to my attention that in-depth morphological data on coyotes has not been gathered in other regions, which means that this current investigation must serve as a touchstone for similar projects in the future.

While morphometric data is available for wolves (one of the most studied animals in the world) little data exists for coyotes. In fact, many of the measurements included in this study have not been reported elsewhere. In a recent correspondence with Doctor John Way, a leading coyote biologist, I was told that, “No I don’t know anyone in particular that has done specific msmts (measurements) like you describe. You may be the first? ( J. Way, PHD, personal communication, July 2, 2010)” This is both exciting and frustrating.

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Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

Comparisons in morphology was made where they could and where the comparative coyote data is nonexistent, I will simply present my data for the future use of others.

As a precaution, I underwent a series of rabies shots at the beginning of this study, not only to protect myself from infection while working with these canids, but also to make me a more suitable candidate for future studies of this kind.

In the winter of 2009-2010, I collected 26 fully intact Canis latrans variant specimens from the Laurentian Hills Ecoregion of Maine. This was accomplished by trapping them myself, as well as

diligent networking with the local game wardens and hunting clubs.

I began soliciting the help of game wardens and hunters in the fall of 2009. I printed business cards and posters and distributed them throughout the region. Though there seemed to be little tangible immediate results from these efforts, it did familiarize the local hunters with my purpose.

I had recently become certified as a Maine trapper and set about trapping coyotes during the November-December, 2009 trapping season. This was my first year trapping, however. When trapping for canids in particular, great skill is required as they are the most cautious of all the fur bearers. By the time I had honed my trapping skills enough to start trapping coyotes, the two month trapping season was over.

Trapping: Making a “Standard Dirt Hole Set”

I began the trapping season using what is termed “the standard dirt hole set” and a variation known as “the mouse whole set.” The first step to this is to find a well traveled coyote corridor.

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

This can prove most difficult as the ground is frozen and coyotes have large ranges; often only visiting the same spot once in a week’s time. Then I looked for an appropriate embankment to dig a visible hole at such an angle as to require the coyote to stand right over it to see down inside. Next I dug a bed for my padded trap, about 9-12 inches away from the bait hole, in the direction I felt the coyote would approach. I drove my trap stake into the ground inside the bed and set the trap inside. After placing a screen cover of the trigger to prevent the dirt from causing it to fire, I gently sifted the dirt back over the bedded trap with a sifter. Finally, I placed lure on an overhanging branch and placed a bit of bait (I used cooked hotdog pieces) into the hole. This standard dirt hole set proved very effective for fox, which in this case was not my target species, but nonetheless appropriate game for the set type and the trapping season. Coyotes began stealing my bait almost daily without being captured. Often, the dirt that I had sifted over the trap got wet during the day and froze over at night, making it so that even I had trouble setting it off the following morning.

While most online trapping resources addressed the “problems associated with deep snow trapping” I discovered a technique that proved very effective for the eastern coyote. When snow gets deep coyotes use the same trails day after day, particularly when there is an easy meal nearby. A local farmer had dumped his butchered cow carcasses in a field and the coyotes were coming out of the cedar swamps at night to feed. Digging the trap bed was much easier in snow than in frozen dirt. I had to wrap the traps in crumpled white wax paper to keep them from freezing up. I placed one directly in the most heavily traveled path leading from the cedars (a trail set), and placed another on a clump of brush protruding from the snow that the coyotes were using to mark the territory by urinating (using their natural urine post rather than creating an artificial “post set”).

We only had deep snow the last two weeks of the trapping season. I caught two coyotes in both of these traps. I also felt these to be much more humane sets than the sets in dirt because you attached your trap to a grappling hook by a long chain rather than to a stake in the ground by a short chain. When foxes were trapped using the dirt hole sets they were exposed in the field with no sense of security from concealment. They also had little to no range of motion when I arrived the following morning. The coyotes trapped in deep snow ran to the concealment of the swamp and had almost a full range of motion even after the grappling hook anchored onto the brush. When I approached the coyotes they were trying to hide from me rather than wrestling with the trap. I could then dispatch the coyote from a distance before he knew he had been discovered.

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

The only drawback to this method is that it requires both tracking and snowshoe skills and would not be advisable in wide open farming or prairie country where a coyote might run a mile or more before getting snagged on brush.

If I had been able to continue trapping in deep snow I am certain my success would have continued. While there is a year round open hunting season on coyotes with no bag limit (i.e. no limit to how many a hunter can harvest) here in the state of Maine, I could not persuade the state warden to allow me to continue trapping throughout the winter for my project.

It took me the whole of the 2009-2010 winter to develop rapport with the local hunters. They had contributed willingly to an earlier University of Maine study that had, ultimately, shown that snaring causes to great duress to coyotes. They were, therefore, extremely weary of assisting another study. The fact that I was trapping coyotes myself proved to them that I was not against trapping in principle. I sought trapping advise regularly from the president of the Aroostook County Conservation Association, a hunting club that seeks to better the white-tailed deer population in Aroostook county by harvesting large numbers of coyotes. This friendship proved crucial. At the end of the winter coyote hunting season, he allowed me to come to the organization’s annual tournament and collect coyotes from the competitors. Twenty-four coyotes were collected in this one afternoon.

I was offered guided coyote hunts by registered guides to add to the number of specimens I had, but these hunts were in areas that were already well represented in this study. I would have hunted in poorly represented districts, for the sake of this study, but I saw no need to harvest in areas already well represented in this study, as there was already heavy hunting pressure on the coyote population in those areas.

Analysis

The coyotes were placed in freezers at the University of Maine at Fort Kent and kept at a consistent temperature of minus 22 Celsius until the spring semester ended. I then spent my summer collecting data on these coyotes, spending a day on each specimen.

I kept a single data sheet with general information on all the coyotes for quick reference which included the sex, mass, harvest location, hunter name, and tag number (see appendix).

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

Individual data sheets were also created for each specimen to record the more in depth morphometric data and observations (see appendix).

Using the University of Maine’s certified scale (Salter Scale, model 235 10X) I weighed and recorded the mass of each coyote. It is worth noting that there was almost a one pound loss in weight over the months spent in the freezers on both of the two coyotes I weighed both before and after freezing.

Photo identification was also made of each specimen, for an accurate record of markings, pelage consistency and variation, and other particulars. Multiple angels were taken for most specimens.

Guard hair samples were taken from the withers of each coyote; where the mane of the neck tapers to the shoulder blades, for future genetic studies.

A cast was made of the front left paw of each coyote, using plaster of paris, for long-term proof of paw size.

Each specimen was measured with a cloth measuring tape. The following measurements were taken:

•Contour length (from tip of nose to base of tail)

•Tail length (from base of tale to tip of the actual tail, i.e., not to the end of the hairs of the tail, which would have added inches but would not have been comparable to wolf necropsies which record tail lengths without the pelt on the carcass)

•Overall length (the sum of the contour and tail lengths)

 

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•Neck Width (taken in the middle of the neck)

•Girth (“chest” measurements taken just posterior to the forlegs)

•Height at Withers (from the center of the main paw pad to the top of the shoulder blade. This is difficult to measure but I pulled the leg straight and kept the measuring tape straight so that I could measure their height as though standing on all four paws)

•Shoulder to elbow •Elbow to wrist •Thigh to knee •Knee to ankle

Using a digital caliper that was certified to two significant digits beyond the decimal point (General Ultratech, stainless steel), the following measurements were taken on the dentition of each specimen:

•Upper canine width (at the gum-line from front to back)

•Upper canine length (from the gums)

•Upper Intercanine distance (the canine puncture holes on prey are often used to determin whether the predator was a wolf, coyote, or dog)

•Premolar Palate (distance between the first two premolars)

•Maxillary toothrow (from the front of the first premolar to the back of the last molar)

•Palate to toothrow ratio (a common ratio for determining whether the specimen is a coyote)

•Canine length compared to the mandibular foramina (a measurement that is used to discriminate between wolves and coyotes)

•Carnassial Tooth Width (from front to back along the gum-line. This is another common measurement for determining whether the specimen is a coyote or not).

•Dentition was also checked for wear to determine whether the coyote was a juvenile or an adult

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

Comments were recorded on the individual data sheets of any distinguishing features.

Each specimen was “field dressed” or disemboweled. Hearts were pulled and frozen to test for signs of heart-worm in the future.

Finally, each specimen was enclosed in a wire mesh cocoon that allowed flies, maggots, beetles and other decomposers to break down the carcasses while protecting the skeleton from being separated and strewn by scavengers. These skeletons (particularly the skulls) will be retrieved from their cocoons on my property and stored for future studies.

Pulling the hearts from the coyotes to test for heart-worm.

 

Jonathan Hayes • email: hayes@missionwilderness.org

Timeline

 

 

From Inception to Presentation

FORESIGHT

I began gathering scientific source material and collecting coyote specimens a year in advance, in anticipation of my undergraduate thesis.

Making a Log of each Coyote’s Gender and Hunting Tag Number Before Moving them into the University Freezers in February, 2010

Inception to Presentation

March, 2009- I began discussing possible canid related undergraduate projects with my faculty counselor, Dr. Stephen Hansen.

June, 2009- I completed Maine State Trappers Certification.
November and December, 2009- I began trapping and promoting the research with local

hunters and trappers by means of flyers, business cards, and conversation.

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Jonathan Hayes • email: hayes@missionwilderness.org

February, 2010- I was invited to the Aroostook County Conservation Association’s predator tournament to collect coyotes from participants.

 

 

March and April, 2010- I received a series of rabies vaccine shots as a precaution.

August, 2010- I spent a day on each specimen until each coyote was photographed, measured, paw casted, and dissected. Heart samples were also be taken on each specimen. Samples were labeled and put in deep freeze for future studies.

Fall Semester, 2010- I compiled and interpreted all research data under the auspices of the biology department faculty. I published the results and presented them to faculty and peers in a powerpoint presentation. I also produced a scientific poster for a poster presentation.

 

Jonathan Hayes • email: hayes@missionwilderness.org

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Results

Touchstone measurements for the Canis latrans species UNCHARTERED WATERS

Wild Canids of the Laurentian Hills Ecoregion.

The Laurentian Hills Ecoregion is located in the northeastern most portion of the United States. The borders of the geological region are comprised by the St. John River to the North, New Brunswick Canada to the East, The Northeastern Highlands Ecoregion to the West, and the Laurentian Plains to the South. Three quarters of the region is forested, with many wetlands and lakes as well. The primary forest type is boreal spruce. Annual precipitation is approximately 1041mm per year. July temperatures are, on average, 60F and January temperatures are, on average -10F.

Until human alteration, the region was home to more boreal ungulates, such as the moose and caribou and the regional canid was the eastern wolf.

Now that the region has been altered by extensive logging and agriculture, the caribou, eastern wolf and cougar have been lost. The white-tailed deer immigrated into the region in the latter half of the 19th century and coyotes arrived on the scene in the 1940’s.

The eastern coyote has adapted morphologically to fill a void left by the loss of apex predators. With such large ungulates as the moose, something needed to fill the ecological gap as the regions apex scavenger.

Presented here are the mean, maximum, and minimum measurements for each data set as well as how they compare to other available data sets. The included appendix will serve researchers further with individual specimen data.

Before the morphological data is provided, it should be pointed out that the studies we will be comparing our population to generally excluded coyotes under the age of two. Our study includes coyotes of all ages but, based on harvest dates, we can assume that none of them are

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Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

under the age of 8 months. While a large portion of our study is comprised of coyotes that have not reached the age of physical maturity. Therefore, the measurements presented here should be considered as a minimum standard.

20100717_129.JPGAuthor measuring the Upper Intercanine Distance (or “bite mark”)

External Morphology

The mean total body mass for the 26 coyotes in our study was 14.8 kg. Males weighed on average 15.75kg while females weighed on average 13.52kg. This is compared to an average western male coyote weight of 12.1kg and average western female weight of 10.6kg. Mean eastern coyote weights from other studies seem to put our coyotes on the low end of the eastern scale, with males weighing on average 16.4kg and eastern females weighing an average 14.7kg. This seeming lack of mass in our study is doubtless due to the fact that we are including juveniles in our study while the other studies excluded all non mature specimens.

Total mean body length for the coyotes in our study, from tip of nose to the last vertebrae of the tail, was 127.77cm. The male average was 131.57cm while the female average was 122.59cm. In comparison, the coyotes of the San Joaquin Valley Study in California (Cypher 1995) were on average 110.15cm long, with male length being 112.8cm and female length being 107.5cm.

Many other external measurements were taken on each coyote but will not be included in this section because there is no other studies available to compare our measurements to. Individual

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

data sheets, as well as the mean, maximum and minimum for each of these external measurements are included in the appendix of this thesis to serve as a reference for future studies.

Dentition

The standard morphometric for upper canine tooth width at the gums of coyotes (eastern coyotes included) is less than 11mm. Wolf canine width is typically 12mm or more (Elbroch 2006). The coyotes of our study area had a mean upper canine width of 9.65mm, with a minimum width of 8.12mm and a maximum of 11.24mm. The average male canine width was 10.13 and the average female width was 8.99mm.

The average intercanine distance (bite mark) of a western coyote is 28.45mm. The average eastern coyote intercanine distance is 31.81mm, with an overall mean of 30.12. The coyotes in our region had an intercanine distance larger than even the eastern coyote average, measuring in at a mean of 31.23mm. The minimum was the western coyote average (28.08mm) and the maximum in our study was 33.88mm. Our male average was 31.92mm and our female average was 30.28.mm.

Another common method of distinguishing coyotes from other canids is to determine whether the upper canine teeth reach the imaginary line formed by the two mandibular foramina pits in the lower jaw. The majority of canids’ canines do not reach this line although coyote canines do reach the line (Elbroch 2006). Of the coyotes in our study, the canines reached the line of the mandibular foramina in 23 of the 26 specimens.

Coyotes have longer, more narrow muzzle than do other canids. A coyotes maxillary toothrow is 3.1 times longer than the first premolar inter-palatial distance. This holds true with a 95% accuracy across the species range (Elbroch 2006). Dogs and other canids have a muzzle with a width to length ration closer to 2.7. The coyotes in our study were predicted to have a ration between 2.7 and 3.1 but the mean for our population was actually 3.21, meaning that their muzzle is proportionately longer and more narrow than the average coyote. This dramatic find made us question our measurements. The only mistake we could have made was not to have measured any molars that had not yet penetrated the gum, because we were working with fresh, rather than fleshed, specimens. If this were the case, however, it would have made our finding even more dramatic, rather than diminish it.

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

Finally, coyote morphometric study consensus is that the upper carnassial teeth at the gum line should be less than 20mm wide (this includes eastern coyotes). A width of 20mm is not the mean of carnassial width but the maximum (Elbroch 2006). The coyotes in the Laurentian Hills ecoregion of Maine have a mean carnassial width of 20.59, which is greater than the maximum for the species. The minimum width in our study was 19.05mm and the maximum was 22.26mm. Average male carnassial width in our study was 20.79mm with the females coming in a little smaller at 20.35mm. Statistically there is no difference in the male and female carnassial measurements.

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

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Discussion and Conclusion

SCAVENGER ADAPTATIONS

The morphometric data collected from the 26 coyotes harvested in the Laurentian Hills ecoregion of Maine, suggest that we do indeed have the largest representatives of the Canis latrans species in North America.

Note how the front end seems disproportionately large when compared to the rest of the body. Not ideal for running down large prey, but for establishing dominance on a carcass.

It has been beyond the scope of this study to determine the genetic origin of the wild canids of this region. Indeed, these wild canids are referred to locally as coyotes, but even the most ardent of anti wolf groups in the region acknowledge the eastern/red wolf genetic contribution to our resident coyote population. Many genetic surveys have been done to determine the ancestry of New England’s wild canids. Our research has concerned itself more with what the morphometric data can tell us about the ecological role these wild canids are playing in the Laurentian Hills Region.

The eastern coyote has adapted, morphologically to fill a void left by the loss of apex predators. With such large ungulates as the moose. Something needed to fill the ecological gap as the regions apex scavenger.

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Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

The dentition of a predator is much like a Swiss Army Knife. Each tooth is a tool for different functions. Canine teeth are the killing tools in the mouth of the coyote. The carnassial teeth are the meat processors of the mouth. They are used to hack off large portions of meat and to crush large bones.

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The carnassial teeth are placed further back in the mouth to take advantage of musculature leverage. Carnassial teeth are used for hacking off slabs of carcass meat and crushing large bones.

The fact that the canines of the local wild canid population remain within the perimeters of coyote measurements, suggests that their killing habits are not that different from coyotes in other regions (i.e. feeding primarily on rodents, mesocarnivores, and, opportunistically, on larger prey in poor condition).

The enhancement of an elongated muzzle, rather than a broader, more wolf like muzzle, also suggests that their predatory habits have not changed, and perhaps in the non-winter months, our population is relying on these small prey species even more than in other regions. Elongated muzzles are a benefit to snatching small rodents and digging into prey holes. The broader muzzle of a wolf gives more bite pressure for grabbing larger prey and pulling them down. Our coyotes, for their body size, have even less mass to their muzzles than coyotes of other regions. This detracts from their ability to bring down larger prey.

The fact that the mean carnassial tooth measurement of our population is higher than the maximum carnassial tooth measurements for other coyote populations suggests that these coyotes are eating larger animals on a regular basis than other populations. This adaptation is so extreme that the skull mass has not yet caught up with the carnassial hardware. The skulls we

 

Jonathan Hayes • email: hayes@missionwilderness.org

have exhumed thus far are showing exposed carnassial and molar roots in the skull because the skull has not gotten thicker to accommodate such large teeth.

 

 

My hypothesis then, is that the coyotes of the Laurentian Hills ecoregion are likely eating more moose and deer than coyotes in other regions, but not necessarily preying on more moose and deer than other populations. When winter starved deer flounder, when gut shot moose or road- killed deer are discovered, these wily opportunistic feeders set up shop on the carcasses. With no wolves or cougar to run them off of the carcass, with the black bear in their winter slumber, these large coyotes stay within sight of their frozen meals, eating their fill for weeks without any need to expend energy hunting. They use their imposing size to intimidate and run off any messo- carnivores/scavengers that attempt to steal a morsel. They are, therefore, providing a service to the ecoregion by cleaning up the carcasses of our forests and killing winter starved deer so that there is more available food for the stronger surviving population. 

 

 

 

Carnassial Tooth Width
“Coyote Upper Carnassial tooth UP TO 20 mm? (Skulls)

 

 

ID

 

 

Carnassial mm

 

 

1M

 

 

22.17

 

 

2F

 

 

20.77

 

 

3F

 

 

19.05

 

 

4M

 

 

19.76

 

 

5M

 

 

19.92

 

 

6M

 

 

20.39

 

 

7F

 

 

22.22

 

 

8F

 

 

20.39

 

 

9F

 

 

20.21

 

 

10F

 

 

20.05

 

 

11M

 

 

20.83

 

 

12M

 

 

19.61

 

 

13M

 

 

19.88

 

 

14M

 

 

19.83

 

 

15F

 

 

21.08

 

 

16M

 

 

22.26

 

 

17F

 

 

19.34

 

 

18F

 

 

20.08

 

 

19M

 

 

20.8

 

 

20M

 

 

21.01

 

 

21M

 

 

21.7

 

 

22M

 

 

20.06

 

 

23M

 

 

21.15

 

 

24F

 

 

20.92

 

 

25F

 

 

19.82

 

 

26M

 

 

22.02

 

 

Average

 

 

20.59

 

 

Minimum

 

 

19.05

 

 

Maximum

 

 

22.26

 

 

Carnassial Male

 

 

Carnassial Female

 

 

22.17

 

 

20.77

 

 

19.76

 

 

19.05

 

 

19.92

 

 

22.22

 

 

20.39

 

 

20.39

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

page59image1944

page59image2216

 

 

Carnassial Male

 

 

Carnassial Female

 

 

20.83

 

 

20.21

 

 

19.61

 

 

20.05

 

 

19.88

 

 

21.08

 

 

19.83

 

 

19.34

 

 

22.26

 

 

20.08

 

 

20.8

 

 

20.92

 

 

21.01

 

 

19.82

 

 

21.7

 

 

20.6

 

 

21.15

 

 

22.02

 

 

20.795333333

 

 

20.357272727

 

 

19.61

 

 

19.05

 

 

22.26

 

 

22.22

 

 

Body Mass

Because Yearlings were included in this study, measurements should be treated as minimums (Way comparison excluded those under 2yo) Western avg male 12.1, female 10.6, Eastern male16.4 female 14.7 … Total avg male 14.25 female 12.42. Total avg. 13.33

 

 

ID

 

 

Weight kg

 

 

1M

 

 

21.4

 

 

2F

 

 

13.2

 

 

3F

 

 

15

 

 

4M

 

 

19.6

 

 

5M

 

 

15.6

 

 

6M

 

 

16.8

 

 

7F

 

 

16

 

 

8F

 

 

11.8

 

 

9F

 

 

17.2

 

 

10F

 

 

15.4

 

 

11M

 

 

16.2

 

 

12M

 

 

10.8

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

page59image50400

 

page60image2312

 

 

 

 

ID

 

 

Weight kg

 

 

13M

 

 

14.4

 

 

14M

 

 

13.2

 

 

15F

 

 

12.6

 

 

16M

 

 

19.2

 

 

17F

 

 

10

 

 

18F

 

 

12.5

 

 

19M

 

 

12

 

 

20M

 

 

13.6

 

 

21M

 

 

15

 

 

22M

 

 

19.4

 

 

23M

 

 

12.6

 

 

24F

 

 

12

 

 

25F

 

 

13

 

 

26M

 

 

16.4

 

 

AVERAGE

 

 

14.803846154

 

 

Minimum

 

 

10

 

 

Maximum

 

 

21.4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mass Male

 

 

Mass Female

 

 

21.4

 

 

13.2

 

 

19.6

 

 

15

 

 

15.6

 

 

16

 

 

16.8

 

 

11.8

 

 

16.2

 

 

17.2

 

 

10.8

 

 

15.4

 

 

14.4

 

 

12.6

 

 

13.2

 

 

10

 

 

19.2

 

 

12.5

 

 

12

 

 

12

 

 

13.6

 

 

13

 

 

15

 

 

19.4

 

 

12.6

 

 

16.4

 

 

34.7 lbs

 

 

29.7 lbs

 

 

15.746666667

 

 

13.518181818

 

 

10.8

 

 

10

 

 

21.4

 

 

17.2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

page61image1840

page61image2112

 

 

Total Body Length

 

 

 

 

Length Male

 

 

Length Female

 

 

139

 

 

125

 

 

143

 

 

125

 

 

133.5

 

 

128

 

 

131.5

 

 

117.5

 

 

132

 

 

125

 

 

127

 

 

116

 

 

129

 

 

121

 

 

126.5

 

 

121

 

 

140

 

 

121

 

 

121

 

 

123

 

 

133

 

 

126

 

 

130

 

 

135.5

 

 

124

 

 

128.5

 

 

131.56666667

 

 

122.59090909

 

 

121

 

 

116

 

 

143

 

 

128

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ID

 

 

Overall Length cm

 

 

1M

 

 

139

 

 

2F

 

 

125

 

 

3F

 

 

125

 

 

4M

 

 

143

 

 

5M

 

 

133.5

 

 

6M

 

 

131.5

 

 

7F

 

 

128

 

 

8F

 

 

117.5

 

 

9F

 

 

125

 

 

10F

 

 

116

 

 

11M

 

 

132

 

 

12M

 

 

127

 

 

13M

 

 

129

 

 

14M

 

 

126.5

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

ID

 

 

Overall Length cm

 

 

15F

 

 

121

 

 

16M

 

 

140

 

 

17F

 

 

121

 

 

18F

 

 

121

 

 

19M

 

 

121

 

 

20M

 

 

133

 

 

21M

 

 

130

 

 

22M

 

 

135.5

 

 

23M

 

 

124

 

 

24F

 

 

123

 

 

25F

 

 

126

 

 

26M

 

 

128.5

 

 

AVERAGE

 

 

127.76923077

 

 

Minimum

 

 

116

 

 

Maximum

 

 

143

 

 

Compare to an average of

Height @ Withers

 

 

ID

 

 

Height cm

 

 

1M

 

 

55.5

 

 

2F

 

 

49

 

 

3F

 

 

52

 

 

4M

 

 

56

 

 

5M

 

 

54

 

 

6M

 

 

57.5

 

 

7F

 

 

58

 

 

8F

 

 

51

 

 

9F

 

 

51

 

 

10F

 

 

52

 

 

11M

 

 

51.5

 

 

12M

 

 

56

 

 

13M

 

 

55.5

 

 

14M

 

 

54.5

 

 

15F

 

 

52

 

 

16M

 

 

56.5

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

page63image2144

 

 

ID

 

 

Height cm

 

 

17F

 

 

51

 

 

18F

 

 

53

 

 

19M

 

 

51

 

 

20M

 

 

52.2

 

 

21M

 

 

57.5

 

 

22M

 

 

57.5

 

 

23M

 

 

55

 

 

24F

 

 

54

 

 

25F

 

 

55

 

 

26M

 

 

52

 

 

AVERAGE

 

 

53.853846154

 

 

Minimum

 

 

49

 

 

Maximum

 

 

58

 

 

 

 

Male Height

 

 

Female Height

 

 

55.5

 

 

49

 

 

56

 

 

52

 

 

54

 

 

58

 

 

57.5

 

 

51

 

 

51.5

 

 

51

 

 

56

 

 

52

 

 

55.5

 

 

52

 

 

54.5

 

 

51

 

 

56.5

 

 

53

 

 

51

 

 

54

 

 

52.2

 

 

55

 

 

57.5

 

 

57.5

 

 

55

 

 

52

 

 

54.813333333

 

 

52.545454545

 

 

51

 

 

49

 

 

57.5

 

 

58

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

Premolar to Maxillary Toothrow

 

 

 

 

ID

 

 

PP to MT

 

 

1M

 

 

3.05

 

 

2F

 

 

2.98

 

 

3F

 

 

3.42

 

 

4M

 

 

3.27

 

 

5M

 

 

2.82

 

 

6M

 

 

3

 

 

7F

 

 

3.47

 

 

8F

 

 

3.27

 

 

9F

 

 

3.08

 

 

10F

 

 

2.99

 

 

11M

 

 

3.17

 

 

12M

 

 

2.99

 

 

13M

 

 

3.07

 

 

14M

 

 

3.62

 

 

15F

 

 

3.09

 

 

16M

 

 

3.26

 

 

17F

 

 

3.37

 

 

18F

 

 

3.15

 

 

19M

 

 

3.34

 

 

20M

 

 

3.12

 

 

21M

 

 

3.41

 

 

22M

 

 

3.14

 

 

23M

 

 

3.04

 

 

24F

 

 

3.46

 

 

25F

 

 

3.75

 

 

26M

 

 

3.13

 

 

AVERAGE

 

 

3.21

 

 

Minimum

 

 

2.82

 

 

Maximum

 

 

3.75

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Male

 

 

Female

 

 

3.05

 

 

2.98

 

 

3.27

 

 

3.42

 

 

2.82

 

 

3.47

 

 

3

 

 

3.27

 

 

3.17

 

 

3.08

 

 

2.99

 

 

2.99

 

 

3.07

 

 

3.09

 

 

3.62

 

 

3.37

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

page65image1944

page65image2216

 

 

Male

 

 

Female

 

 

3.26

 

 

3.15

 

 

3.34

 

 

3.46

 

 

3.12

 

 

3.75

 

 

3.41

 

 

3.14

 

 

3.04

 

 

3.13

 

 

3.162

 

 

3.2754545455

 

 

2.82

 

 

2.98

 

 

3.62

 

 

3.75

 

 

“Coyote 3.1 Domestic Dogs 2.7 or less. Ratio proved 95% accurate. Skulls)”
Many specimens were improperly measured due to the fact that the last molars had not penetrated the gums. A few of these have been remeasured since the gums have been removed. It is certain that our ratio will be even more extreme (close to 3.3) when all fleshed skulls are remeasured

Canine Width
“Coyotes 11mm or less, Wolves 12mm or more (Skulls)”

 

 

Male

 

 

Female

 

 

9.96

 

 

9.06

 

 

9.81

 

 

10.24

 

 

10.19

 

 

8.86

 

 

9.58

 

 

8.12

 

 

10.56

 

 

9.04

 

 

9.76

 

 

8.95

 

 

10.11

 

 

9.5

 

 

10.01

 

 

8.18

 

 

9.51

 

 

9.17

 

 

10.23

 

 

8.66

 

 

10.96

 

 

9.13

 

 

10.27

 

 

10.77

 

 

9.13

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

Male

 

 

Female

 

 

11.24

 

 

10.139333333

 

 

8.9918181818

 

 

9.13

 

 

8.12

 

 

11.24

 

 

10.24

 

 

 

 

ID

 

 

Canine Width mm

 

 

1M

 

 

9.96

 

 

2F

 

 

9.06

 

 

3F

 

 

10.24

 

 

4M

 

 

9.81

 

 

5M

 

 

10.19

 

 

6M

 

 

9.58

 

 

7F

 

 

8.86

 

 

8F

 

 

8.12

 

 

9F

 

 

9.04

 

 

10F

 

 

8.95

 

 

11M

 

 

10.56

 

 

12M

 

 

9.76

 

 

13M

 

 

10.11

 

 

14M

 

 

10.01

 

 

15F

 

 

9.5

 

 

16M

 

 

9.51

 

 

17F

 

 

8.18

 

 

18F

 

 

9.17

 

 

19M

 

 

10.23

 

 

20M

 

 

10.96

 

 

21M

 

 

10.27

 

 

22M

 

 

10.77

 

 

23M

 

 

9.13

 

 

24F

 

 

8.66

 

 

25F

 

 

9.13

 

 

26M

 

 

11.24

 

 

AVERAGE

 

 

9.6538461538

 

 

Minimum

 

 

8.12

 

 

Maximum

 

 

11.24

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

page67image1904

page67image2176

 

 

Inter-Canine Distance

Average East and West Coyote 30.12 (Skulls) Western: 28.45 Eastern: 31.81

 

 

 

 

ID

 

 

Inter-canine Distance

 

 

1M

 

 

33.88

 

 

2F

 

 

30.04

 

 

3F

 

 

30.87

 

 

4M

 

 

31.02

 

 

5M

 

 

33.23

 

 

6M

 

 

32.32

 

 

7F

 

 

32.2

 

 

8F

 

 

28.08

 

 

9F

 

 

31.04

 

 

10F

 

 

31.87

 

 

11M

 

 

31.71

 

 

12M

 

 

29.64

 

 

13M

 

 

32.65

 

 

14M

 

 

30.17

 

 

15F

 

 

30.32

 

 

16M

 

 

32.1

 

 

17F

 

 

30.21

 

 

18F

 

 

30.77

 

 

19M

 

 

30.35

 

 

20M

 

 

31.44

 

 

21M

 

 

32.69

 

 

22M

 

 

33.46

 

 

23M

 

 

30.52

 

 

24F

 

 

28.42

 

 

25F

 

 

29.29

 

 

26M

 

 

33.69

 

 

AVERAGE

 

 

31.23

 

 

Minimum

 

 

28.08

 

 

Maximum

 

 

33.88

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Male

 

 

Female

 

 

33.88

 

 

30.04

 

 

31.02

 

 

30.87

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

 

 

 

 

page68image2144

 

 

 

 

Male

 

 

Female

 

 

33.23

 

 

32.2

 

 

32.32

 

 

28.08

 

 

31.71

 

 

31.04

 

 

29.64

 

 

31.87

 

 

32.65

 

 

30.32

 

 

30.17

 

 

30.21

 

 

32.1

 

 

30.77

 

 

30.35

 

 

28.42

 

 

31.44

 

 

29.29

 

 

32.69

 

 

33.46

 

 

30.52

 

 

33.69

 

 

31.924666667

 

 

30.282727273

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Do Canine teeth reach the “line” of the Mandibular Foramina?

Below the line: Likely Coyote
Above the line: majority of canids (although red wolf also reaches line)

 

 

Canine to Mandibular Foramina

 

 

Number of Specimens

 

 

Online

 

 

23

 

 

Short of line

 

 

3

 

 

Jonathan Hayes • email: hayes@missionwilderness.org

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