Information

What would it take to recognize a deer by its photo?


I am trying to recognize a deer by its antlers or any other means. Elaborating: I was hoping to use their antlers to recognize them but I have heard that most deers shed their antlers every year so it would be difficult to recognize it from the last year's photo unless these antlers retain the same pattern every year.

If not the antlers, what other characteristics should I be looking for?

Is there any software that can help me in recognizing a deer?


There is a lot of variation in how and when deer shed their antlers. In most arctic and temperate-zone species, antler growth and shedding is annual, and is controlled by the length of daylight. In tropical species, antlers may be shed at any time of year, and in some species such as the sambar, antlers last several years. Some equatorial deer never shed their antlers.

The horns change every year and, especially, increase the number of branches (and consequently, change their shape). You can't recognize them by antlers, but by other features, such as color of the hair or the lineaments. Like us, animals have individual morphological differences that are recognizable and listable.

Biologists specializing in studies of particular animal species not only take photos, but also make drawings and write descriptions of behavior, to identify individuals within herds.

An optical examination, however, of the subject through drawings and photos (and if possible, direct observation), is more useful than a PC program. This involves identifying particular similarities and equalities that are not "identical". This is possible to do visually on a large (but limited) number of specimens. The human eye is the best computer.


The Open Source Computer Vision library OpenCV is pretty popular. I'm a Python guy, but it also has C, C++, and Java interfaces. The O'Reilly book Programming Computer Vision with Python was pretty good, and their C-oriented Learning OpenCV from 2008 is coming out with a new C++ edition in July, supposedly. There are also the OpenCV online docs, linking to the reference manual, user guide, tutorial, and Java API for each release.


Deer, fragmented forests, ticks, a Lyme-like disease … and a little praise for possums

Ticks were evidently so rare in Samuel Clemens’ Hannibal that a single live specimen had value enough to tempt Tom Sawyer to part with his newly shed tooth. Matthias Leu says it was the same in the Switzerland of his more recent youth.

“When I was a boy, I spent all my time in the forest,” Leu said. “I never saw one tick. And in Switzerland now, you should not leave the trails because there are so many ticks. So, it's not just in North America it's global.”

Leu and his colleague Oliver Kerscher are associate professors in the Department of Biology at William & Mary. They are among the co-authors on a new paper in the journal Landscape Ecology. The other authors are Brent Kaup, associate professor in the university’s Department of Sociology Dylan T. Simpson, a former graduate student now in a Ph.D. program at Rutgers University and two former undergraduate students, Molly Teague, 󈧓 and Joanna Weeks 󈧑.

Their paper in the journal Landscape Ecology is titled “Habitat amount, quality, and fragmentation associated with prevalence of the tick-borne pathogen Ehrlichia chaffeensis and occupancy dynamics of its vector, Amblyomma americanum.” It looks at the relationship among deer, a single species of tick and a single tick-borne disease.

The tick, Amblyomma americanum, is commonly known as the lone star tick and the disease it carries is ehrlichiosis. Leu said little is known about the ecology of the Ehrlichia chaffeensis bacterium. Most of the research that has been conducted focuses on the black-legged tick, the vector of Lyme disease. Lyme is better known than ehrlichiosis, and they have similar symptoms, but Leu says it may or may not be more common.

“A decade or so back, the medical world was not in tune with these tick-borne diseases,” he said. “There probably has been a lot of ehrlichiosis that was misdiagnosed as Lyme.”

Diagnosis is a clinical question, though, and Leu and his colleagues are more interested in similarities and differences of the ecological relationships that drive Ehrlichia chaffeensis and those of the more-studied Lyme pathogen. It starts with habitat.

In general, fragmented habitat means more deer. More deer means more ticks. More ticks means more tick-borne disease. But the equation is more complicated. It all begins with the habitat, Leu said, especially the concepts of fragmentation and the forest edge.

“Fragmentation occurs when a contiguous patch of forest is subdivided into smaller patches” he explained. Fragmentation can occur naturally, through forest fires or other disturbances, but most forest fragmentation today is done by humans. Some of the patches are cleared for farmland, or low-density housing. Other patches remain forested.

“And with fragmentation we increase the length of the edge,” Leu continued. “What once was a contiguous forest with an edge along the boundary, but now by subdividing that large patch of forest into smaller forest patches and mixing that area up with farmlands you now are creating lots of edges.”

He went on to explain that in ecological terms, the “edge” of a forest extends 250 to 300 yards in, at which point the habitat is known as the forest core or interior. Leu said researchers have found that microclimates often develop in forest interiors. And as originally vast forests become increasingly fragmented, there are many areas that have a great deal of forest, but those wooded areas are in patches, each less than 250 across. “So, it’s all edge,” Leu said.

And forest edges are prime deer habitat, he explained. “Deer love edges,” he continued. “If you think about it, there is more light, which means there is less competition among plants for sunlight and so the total plant biomass increases.”

Plus, there is a handy forest to jump into when a predator shows up. “It’s a combination of feeling safe and having food available,” Leu said.

Habitat that is attractive to deer makes for easy living for ticks. The lone star tick’s life cycle goes like this: Hatch out of the forest leaf litter as a larva. Find something to feed on. Have a blood meal for a few days. Drop off into some vegetation and start molting, emerging from your larval skin as a nymph. Find another something to feed on. Feed for a few weeks. Drop off and have a little rest. Molt into an adult, find another host, feed until full, drop off and make more ticks.

That something to feed on is usually a whitetail deer, although Leu says rabbits and raccoons are possible tick targets. But deer, Leu said, are, in ecological terms, “competent hosts,” serving not only as a meal for the tick, but also a reservoir for ehrlichiosis, capable of infecting the next feasting tick with Ehrlichia chaffeensis. He added that they believe that fawns and yearling deer are especially important in transmission of the bacterium.

“The older deer have antibodies,” Leu explained. “So they were infected at one point, but they no longer have the bacterium in their bloodstream.”

If whitetail deer are on the competent end of the tick-hosting spectrum, the other end is anchored by the possum, Leu said.

“They actually are kind of a dead end for ticks,” he said. “First of all, possums are very clean. They actually groom themselves so well that they have hardly any ticks on them. And secondly, they’re not a competent host. If they get infected, they can shed the bacteria.”

The William & Mary researchers monitored 16 study sites comprising a total of 130 plots in southeastern Virginia over a five-year period. Tick selection is done in the hot, humid summer. It’s tedious, it’s boring and, well, there are ticks. Leu says it’s sometimes hard to find a student willing to do it. But at least it’s easy to collect ticks.

“We drag a meter-square cloth across the forest floor,” Leu said. “And every three meters we pick the ticks off of the cloth.”

The picking off isn’t so easy. The researchers use tweezers and resort to pulling the larvae and nymphs off the cloth with duct tape.

The ticks go into a 75 percent ethanol solution. “We ‘pickle’ the ticks,” Kerscher likes to say.

Kerscher and his team take the pickled ticks to the lab. The ticks are “disrupted,” he says. They go into an instrument called a bead ruptor that shakes the ticks with tiny glass beads, cracking open the tough tickly exoskeleton. The cracked ticks are placed in a denaturant that gets rid of the proteins and the RNA.

“The goal,” Kerscher said, “is to get out the tick DNA. We want to make sure we have the type of tick in the vial that we think we have. You can tell the adults, but when you have the small nymph, it’s very hard to tell the species.”

DNA analysis showed that around 90 percent of the ticks harvested for the program were members of the target species, the lone star tick. Leu said that such figures don’t necessarily indicate an absence of other tick species in the collection areas. He suggested that there might be a physiological effect at work.

“The black legged ticks, they really don’t like hot weather,” he said. “In the heat of summer, when we’re collecting, they’re going under. The lone star tick doesn’t like cold weather, so they come out later.”

They ran additional tests to identify the DNA of the Ehrlichia chaffeensis bacterium and the lab team found it in .8 to 2.9 percent of the ticks sampled across all sites. But Leu points out that the prevalence of the bacterium varied greatly over the years, one year going up to 3.7 percent, then dropping down again.

The paper comes to some conclusions. For instance, deciduous forests are better incubators of Ehrlichia chaffeensis than coniferous ones.

“This means that forests managed for timber may be relatively safe, but areas like suburban parks may have a higher risk of disease,” the paper notes.

The research also raises some questions, such as the mysterious “turnover” or annual variance of the bacterium. The team is seeking funding to continue the studies. There are a number of new questions posed by work described in the paper. Kerscher says sequencing has shown evidence of endosymbionts and other related organisms living in the ticks.

“There is a lot of things going on inside these ticks,” he said. “And, remember, we were only looking for one single bacterium.”

Another question to be addressed is turnover, or the mysterious way Ehrlichia chaffeensis has of disappearing from a study site, only to pop up the next year.

“In two of the sixteen study sites, we never found the bacterium,” Leu said. “Those sites were out in the New Kent area where there is a lot of deer hunting. And you know, it’s a rare occasion to see deer out there. If you’re just looking for droppings, they’re hard to find, because there are very few deer out there.”


Identifying deer ticks and how to avoid them

Deer ticks, or blacklegged ticks, are very small, blood sucking insects. They prefer to feed on larger animals, such as deer, but they will also bite humans.

Deer ticks can spread the bacteria that cause Lyme disease, though they may also carry other bacteria. They are small and can be difficult to spot, as they tend to favor hidden areas of the body, such as the armpit or groin.

To prevent serious complications from the bite of a deer tick, it is essential to identify and remove the insect as soon as possible.

In this article, learn more about how to identify and remove deer ticks.

Deer ticks, scientifically known as Ixodes scapularis , exist primarily in the eastern and north-central parts of the United States.

A similar species called the western blacklegged tick, or Ixodes pacificus, exists mainly in the western parts of the U.S.

Blacklegged ticks are only about the size of a sesame seed . Immature ticks, or nymphs, can also bite. These are only about the size of a poppy seed.

Both adults and nymphs have eight long, black legs that extend from a round, bulb shaped abdomen.

Males are darker and generally have a uniform brown color, with a whitish strip around the outside of the abdomen. Females have a two-tone, lighter brown torso. A female’s torso may also become more rust colored after ingesting blood.

Although the body of a blacklegged tick tends to be flat, after eating, it fills up and expands.

Deer ticks will partially burrow into the skin and latch onto their host to feed. The body of a feeding tick will stick out of the skin. Afterward, there may be some irritation around the site of the bite.

Deer ticks excrete a form of anesthetic onto their host through their saliva. This allows them to attach to the host and feed without the host feeling pain from the bite. That said, some people may experience irritation at the site of the bite.

Since ticks attach to the host, they may remain on the site of a bite for some time. Regularly checking the body for ticks is the easiest way to identify a tick bite.

Ticks prefer to feed from places where the host will not notice their presence. For example, they may opt to feed in hidden areas near the groin, underarms, or other skin folds.

The bite itself may appear red on light skin or purple or brown on dark skin. If the tick is carrying Lyme disease, the site of the bite may also have a distinctive bull’s-eye appearance.

Depending on the bacteria they harbor in their bodies when they latch onto a new host, deer ticks can spread multiple diseases.

The sections below will discuss these diseases in more detail.

Lyme disease

According to the Centers for Disease Control and Prevention (CDC) , “Lyme disease is the most common vector-borne disease in the U.S.”

The disease spreads predominantly through deer tick bites. Infected deer ticks can pass on the bacteria that cause it, such as Borrelia burgdorferi and Borrelia mayonii.

Some symptoms of Lyme disease include headaches, fever, and general fatigue. Lyme disease also causes a distinct rash called erythema migrans in about 70–80% of cases.

The rash is circular, expanding at the site of the bite around 3–30 days afterward. The rash may have a bull’s-eye or target-like appearance — that is, it may have a red, brown, or purple center with a ring around it.

Most cases of Lyme disease are treatable with a few weeks of antibiotics. Without treatment, the disease may spread to the person’s joints, heart, and nervous system.

Other infectious germs

Deer ticks may also spread other harmful germs, including:

Deer ticks are more active in the warmer months, from April to September. However, a person can sustain a bite at any time.

If possible, avoid areas in which deer ticks live, including:

  • forest regions
  • thick, tall grasses
  • areas known to have mammal wildlife
  • brush and overgrown areas with high humidity and moisture

When walking on trails in these regions, try to walk in the center of the trail and avoid brushing against foliage. Deer ticks will often wait on the tips of these plants to attach themselves to an animal or person walking by.

For personal protection, it is important to wear clothing that provides full coverage — such as long socks, long-sleeved shirts, and pants — while hiking, camping, or traveling in an area known to have deer ticks.

Treating all clothing with a spray or soak product containing 0.5% permethrin might help repel ticks and other pests. These products can treat clothing, boots, and camping gear, though it is important to apply the treatment in a well-ventilated area and allow it to dry completely before use.

Some insect repellents may also help repel ticks, including:

  • diethyltoluamide
  • oil of lemon eucalyptus
  • picaridin
  • para-menthane-diol
  • IR3535
  • 2-undecanone

Even after a trip, it is important to take precautions to avoid ticks. Ticks can attach themselves to camping gear, pets, and clothing and may not bite a person until later on. Check all gear, clothing, and pets regularly.

Taking a shower within 2 hours of being in a tick-infested area may help wash off unattached ticks and provides a good opportunity for a person to do a tick check of their body.

Using a mirror to inspect hard-to-reach areas, look over the entire body to check for ticks , paying special attention to the following areas:

  • under the arms
  • inside the belly button
  • behind the knees
  • between the legs
  • around the groin
  • around the waist
  • on the scalp or near the hairline
  • around the ears

Many people interact with ticks in their yard or neighborhood. Anyone who lives in regions where deer ticks are common should try to make their property less friendly to deer ticks.


Bluetongue virus

Experts often compare bluetongue disease to EHD, as both share the same symptoms, affect the same species, and are not considered contagious. Bluetongue, however, has a reputation for causing affected animals to develop foot lesions. In animals like deer, elk, pronghorn, and cattle, it can be extremely painful and eventually causes death. The erratic movements caused by the foot lesions have led bluetongue to be known as the “dancing disease.”

“Both diseases are spread to animals by the bite of a certain type of midge,” said New Jersey Division of Fish and Wildlife Director Dave Chanda. “Neither disease can be transmitted to people. While EHD is only found in deer populations, the bites of the midge can transmit bluetongue to certain types of livestock.”

How to recognize bluetongue disease:

Bluetongue has the same symptoms as EHD, save for a high chance for animals to develop foot deformities. The lack of oxygen in the animal’s blood will also drain the color from certain parts of their body, especially the oral mucosa. This is what gives this disease its name, by turning the deer’s tongue blue. You can learn more about the disease in the video below.


Depth Perception and Visual Acuity

The eyes of deer are not as close together as ours so their depth perception is not good. They can spot a hunter moving, but may not readily know how far away you are. Compare that to humans or predators. Our eyes, and the eyes of predators, are close together giving better binocular vision. Really important for predators out their searching for a meal.

Though having eyes further apart reduces depth perception, it does have an advantage for deer. Having eyes further apart gives deer the ability to cover a lot of ground with their eyes. The added rods also give deer an extraordinary ability to detect movement. What hunters need to take away from all this is that movement is what does us in. So, don’t make unnecessary movements on stand. If you have to move, do so very slowly. And wear gloves.

This whole movement issue centers around visual acuity. Turns out that humans have sharp central vision, good visual acuity, whereas deer do not. When you focus on one spot, as you are right now in reading this, going from one word to the next, things in the periphery are not clear. They are blurred. When you focus on one spot, the further away from that spot, the blurrier it gets. Try it. Being able to see that word clearly is called visual acuity. In fact, when you go to the eye doctor and look at those “[email protected]” charts, your visual acuity is being tested.

What about a deer’s visual acuity? University of Georgia research showed that deer have 80 percent less acuity than we do. The reason ours is good is because we have an optic fovea that is located in the center of the retina and it is packed with many, many cones. That means that when we focus on one spot, we can see it clearly. On the other hand, deer have a band of photo receptors across the retina, rather than one central spot. This allows a deer to scan a wide field of view all at once, without moving their eyes, but they do not have as many cones in this narrow band as we do. Thus, the acuity to focus on one spot is not great. If you have a deer standing at 80 yards facing in your direction, looking at you, they will have difficulty seeing you if you do not move. But, if they are not looking directly at you, because they have those photo receptors all across the eye, they can see you. However, not clearly. Move, and your busted. Even when they aren’t looking directly at you.

Since deer have poor visual acuity, slow movements are harder for them to detect, and of course, wearing camo helps. OK, not totally. Movement even when wearing camo, will get the attention of deer. We all know that. If you flip up your arm, even in camo, you enhance the chance of being seen by a deer, even one that is not looking directly at you. Truth is, it’s movement that does the hunter in, and it is camo that allows you to move and sometimes get away with it.

Consider this question. Do you think a deer has a better chance of seeing you move your hands if you are wearing camo gloves or if you are not wearing gloves? The defense rests its case.

The key then, relative to deer vision, isn’t so much color, but rather their ability to see really well in low light, and their ability to detect movement. If on stand you flip your arm up, even in camo, you enhance the chance of being seen by a deer, even one that is not looking directly at you. Combine that with their ability to see better at dawn and dusk, and you start to understand that when it comes to a deer’s vision, there’s more than meets the eye.

Featured Photo: Fran Rand (iStock)

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Finders Keepers

Everyone knows the secrets to deer hunting is reading sign and outsmarting him. right? Well that does little good if you can't see your quarry. Think you have good eyes? Test your skills! A little practice never hurt.

#1
Can You See the Deer?
Find the deer in this brushy picture.
(Can you find the deer? How many are there? )

#2
Can You See the Deer?
Not really a hard deer to spot but it is a really cool picture and will serve to get the ball rolling.
(Can you find the deer? How many are there?)

#3
Can You See the Deer?
This deer is completely in the open. Not the most difficult. but we are getting there.
(Can you find the deer? How many are there?)

#4
Can You See the Deer?
The most productive part of the day is fast approaching. Yet here you sit without a deer in sight. or is there?
(Can you find the deer? How many are there?)

#5
Can You See the Deer?
Well let's test your night vision. Is it a good time to climb out of your stand or should you wait a few more minutes so as not to disturb any deer present?

#6
Can You See the Deer?
Oh you think you are so good. You found the easy ones and even zeroed right in on the night-time buck. Well how good is your vision with the sun in your eyes?

#7
Can You See the Deer?
Anxiously awaiting the pics from your trail-cam. What's this? Yet another picture with nothing in it or is there more to this picture than meets the eye?

#8
Can You See the Deer?
What do you see in this picture? Too easy for ya! Click on the answer page and you might be surprised.
(Can you find the deer? How many are there?)

#9
Can You See the Deer?
Maybe I can stump you with another night-time shot! Ever heard of ghost deer? You're about to see one. maybe.
(Can you find the deer? How many are there?)

#10
Can You See the Deer?
Oh, you have got to be kidding me! This one is too easy. Maybe too easy.
(Can you find the deer? How many are there?)

#11
Can You See the Deer?
What do you see here? Can you find the deer? How many? Let's not be hasty.
(Can you find the deer? How many are there?)

#12
Can You See the Deer?
Another addition! Can you find the deer? How many?
(Can you find the deer? How many are there?)

#13
Can You See the Deer?
How good are your eyes? Can you find the deer? How many?
(Can you find the deer? How many are there?)

#14
Can You See the Deer?
How good are your eyes? Can you find the deer? How many?
(Can you find the deer? How many are there?)

#15
Can You See the Deer?
How good are your eyes? Can you find the deer? How many?
(Can you find the deer? How many are there?)

#16
Can You See the Deer?
Don't Go to Sleep on this one!
(Can you find the deer? How many are there?)

#17
Can You See the Deer?
Stop looking at the squirrels! They don't count.
(Can you find the deer? How many are there?)

#18
Can You See the Deer?
Just as real. but not as brightly lit!
(Can you find the deer? How many are there?)

#19
Can You See the Deer?
Don't Get Vertigo.
(Can you find the deer? How many are there?)

#20
Can You See the Deer?
OK, Geez other than the obvious one!
(Can you find the deer? How many are there?)

#21
Can You See the Deer?
Look Closer.
(Can you find the deer? How many are there?)

#22
Can You See the Deer?
More than you think!
(Can you find the deer? How many are there?)

#23
Can You See the Deer?
Don't Get Bogged Down!
(Can you find the deer? How many are there?)

#24
Can You See the Deer?
Don't Turn Your Back On Me!
(Can you find the deer? How many are there?)

#25
Can You See the Deer?
Come Lets Not Lay Down On The Job!
(Can you find the deer? How many are there?)

#26
Can You See the Deer?
This One is Head and Shoulders Better Than The Rest


#27
Can You See the Deer?
Ninja Deer!
(Can you find the deer? How many are there?)

#28
Can You See the Deer?
Don't fall out of the deer stand looking for this one!
(Can you find the deer? How many are there?)

#29
Can You See the Deer?
Tie off before proceeding.
(Can you find the deer? How many are there?)

#30
Can You See the Deer?
What do you do after you eat a big meal.
(Can you find the deer? How many are there?)

#31
Can You See the Deer?
Find this Louisiana marsh deer!
(Can you find the deer? How many are there?)

#32
Can You Find All The Elk?
Come on elk are big.
(Can you find the deer? How many are there?)

#33
Can You Find All The Elk?
You better stick to hunting antelope or bison.
(Can you find the deer? How many are there?)

#34
Can You Find Any Deer?
Look Where Deer Always Seem To Be!
(Can you find the deer? How many are there?)

#35
Can You Find Any Deer?
Skill Level Easy!
(Can you find the deer? How many are there?)

#36
Can You Find Any Deer?
Numbers Aren't Alway Intergers!
(Can you find the deer? How many are there?)

#37
Can You Find Any Deer?
Don't let this one become a two headed monster!
(Can you find the deer? How many are there?)

#38
Can You Find Any Deer?
Hmmmm! Anyone out there?
(Can you find the deer? How many are there?)

#39
Can You Find Any Deer?
Hmmmm! Anyone out there?
(Can you find the deer? How many are there?)

#40
Can You Find Any Deer?
Hmmmm! Anyone out there?
(Can you find the deer? How many are there?)


Morphology and behaviour

In all but one species of deer, males carry antlers in the reindeer (Rangifer tarandus), both sexes carry antlers. The single antlerless form, the Chinese water deer (Hydropotes inermis), reflects an earlier pre-antler condition, as is shown by the fossil record. In this primitive condition males have long, sharp upper canines, called tusks, that are used for slashing and stabbing in territorial contests. Some species carry both antlers and tusks and show a progression of increased antler size and complexity with decreased size and functional structure of the tusks. ( Musk deer resemble primitive deer in that males are armed with tusks.)

Deer have several other distinguishing characteristics. All deer lack the gall bladder. Females have four teats. Deer may have scent glands on their legs (metatarsal, tarsal, and pedal glands), but they do not have rectal, vulval, or preputal glands.

Deer are specialized herbivores, as is reflected in their large and anatomically complex digestive organs, their mobile lips, and the size and complexity of their teeth. However, deer rely little on coarse-fibred grasses, and they have not evolved grazing specializations comparable to those found in bovids. Instead, they are highly selective feeders on young grasses, herbs, lichens, foliage, buds, aquatic plants, woody shoots, fruit, and natural ensilage—that is, plant food characterized by low fibre but high protein content, toxicity, and digestibility.

The bias of deer toward high-quality food has its origin in the very high demands of antler growth for minerals, protein, and energy. Antlers are “bone horns” that are grown and shed annually. The growing antlers are encased in “velvet,” a highly vascularized, nerve-filled skin covered by short, soft hairs. The blood-engorged, growing antlers are warm to the touch and quite sensitive. Depending on the species, they take up to 150 days to grow, after which the velvet dies and is forcefully removed by rubbing the antlers against branches and small trees. Along with some blood residue, this imparts a brownish colour to the otherwise white antler bone. Antlers finish growing before the mating season and are used as weapons and shields in combat or as display organs in courtship. Normally shed after the mating season, antlers may be retained in some territorial tropical deer for more than a year. The relative demand for energy and nutrients declines with body size but increases exponentially for antler growth. Therefore, large-bodied species require more nutrients and energy to grow antlers than do small-bodied species. These requirements cannot be obtained from grasses but only from nutrient-rich dicotyledonous plants.

The requirement for nutrients and energy has severe repercussions on the ecology of deer. It confines deer to relatively productive habitats, excluding them from deserts, dry grasslands, and geologically old landscapes leached of nutrients. Moreover, it severely limits the abundance of Cervidae in mature, species-rich faunas in which many herbivore species compete for food. In order to meet their high nutrient demands, deer are specialized to exploit disturbed ecosystems. For instance, after a forest fire, an area normally passes through several ecological plant successions within a few decades before the original conditions are restored. Early plant successions normally contain an abundance of the type of plant food required by deer. Some disturbances, such as river flooding and the rise and fall of lake levels, occur annually and create local, perpetually immature, nutrient-rich ecosystems. Since disturbances such as wildfires, storm floods, avalanches, or wind-felled trees are unpredictable, deer have evolved great abilities to quickly find and colonize such transient habitats. For example, the severe ecological upheaval caused by the extreme climatic oscillations of the Ice Ages greatly favoured deer. Glaciers ground rock into highly fertile waterborne silt and wind-borne loess that refertilized landscapes and rejuvenated the soil. Extinctions swept away warm-climate competitors. From the tropics deer spread to colder and more seasonal landscapes, including the Alps and the Arctic. Like other families of large mammals that colonized extreme Ice Age environments, deer diversified and evolved into grotesque giants that had ornate coat patterns and large, bizarre antlers, which could grow only from nutrient-rich soils.

While deer tend to have broad, somewhat similar food habits, they are highly divergent in their antipredator strategies. This divergence segregates species ecologically and thus minimizes potential food competition between species sharing the same space. A deer species that hides and, if discovered, departs in rapid jumps to hide again requires forests and thickets, while a highly specialized runner needs flat, unobstructed terrain to outrun predators. Specialized jumpers may choose to stay close to steep slopes and rugged terrain and thus avoid areas frequented by species that run and jump, while cliff climbers may exploit gradients and altitudes closed to others.


Blacklegged "Deer" Tick

The Blacklegged “Deer” tick is a notorious biting arachnid named for its dark legs. Blacklegged ticks are sometimes called “Deer” ticks because their preferred adult host is the white-tailed deer. In the Midwest, blacklegged ticks are called the “Bear” ticks. Deer ticks are found primarily in the northeastern, mid-Atlantic, southeastern, and northern central United States but extend into Mexico. This tick is of significant medical and veterinary importance because of its ability to transmit Lyme disease , Anaplasmosis, human Babesiosis, Powassan virus, and more.

Quick Overview:

  • Commonly found in deciduous forests and shrubs bordering forests.
  • Not typically found in open fields or in grassy areas.
  • Diseases transmitted:Lyme disease , Babesiosis , Anaplasmosis , Ehrlichiosis , and Powassan Virus .
  • Male ticks are not known for transmitting infections.
  • Females typically lay their eggs (

Adult Female

Adult Male

Nymph

Larvae

Identification

Unfed female Eastern blacklegged ticks, also known as deer ticks, are easily distinguished from other ticks by the orange-red body surrounding the black scutum. Males do not feed. A type of hard tick, deer tick populations tend to be higher in elevation, in wooded and grassy areas where the animals they feed on live and roam, particularly their reproductive host, the white-tailed deer.

Adult deer ticks have no white markings on the dorsal area nor do they have eyes or festoons. They are about 3 mm and dark brown to black in color. Adults exhibit sexual dimorphism. Females typically are an orange to red color behind the scutum.

Biology

Ixodes scapularis is a three-host tick each mobile stage feeds on a different host animal. In June and July, eggs deposited earlier in the spring hatch into tiny six-legged larvae. Peak larval activity occurs in August, when larvae attach and feed on a wide range of mammals and birds, primarily on white-footed mice (Peromyscus leucopus).

After feeding for three to five days, engorged larvae drop from the host to the ground where they overwinter. In May, larvae molt into nymphs, which feed on a number of hosts for three to four days. In a similar manner, engorged nymphs detach and drop to the forest floor where they molt into the adult stage, which becomes active in October.

Adult ticks remain active through the winter on days when the ground and ambient temperatures are above freezing. Adult female ticks feed for five to seven days while the male tick feeds only sparingly, if at all.

Adult ticks feed on large mammals, primarily upon white-tailed deer (Odocoileus virginianus). Beginning in May, engorged adult females typically lay between 1000 to 3000 eggs on the forest floor at the site where they detached from their hosts.

Mortality rates for ticks are high. Tick death is caused by density-dependent factors such as parasites, pathogens, and predators, all of which appear to have little impact on tick populations. Density-independent factors causing tick mortality include a range of adverse climatic and microclimate conditions, which can influence temperature and humidity and have the greatest impact on tick survival. Due to their low probability of finding a host, starvation is a major mortality factor of ticks. Host immunity and grooming activity may affect mortality.

Feeding and Blood Meals

Blacklegged Deer ticks feed on blood by inserting their mouth parts into the skin of a host animal such as a mouse, dog, bird, or even human. They are relatively slow feeders and will usually feed for 3-5 days at a time. In order to spread disease to a human or animal, first a tick needs to be infected with the pathogen and it needs to be attached and feeding for a certain amount of time.

If the tick is infected, on average it must be attached and feeding for 24-48 hours before it transmits Lyme disease. This timeframe is the average amount of time needed to transmit the Lyme spirochete however, there have been a number of studies that have presented different findings. The two most recent and largest studies done in the U.S. (2011 & 2017) presented two very different findings. The first concluded that Lyme could be transmitted in as little as 16 hours, while the later study’s findings showed that a tick must be attached and feeding for “at least 48 hours or more” to transmit Lyme. The bottom line is that the more time a tick is attached and feeding, the greater likelihood of disease transmission. On average, about 1 in 3 adult Blacklegged ticks and 1 in 5 Blacklegged Deer tick nymphs are infected with the bacteria that causes Lyme disease.

Less common tick-borne diseases, such as anaplasmosis, can be transmitted after just 24 hour Babesiosis, after 36 hour of feeding.

Diseases

Medical Importance

The Blacklegged Deer tick, Ixodes scapularis, is an important vector of the Lyme Disease spirochete, Borrelia burgdorferi, as well as the agents of Human Babesiosis, Babesia microti, and Human Granulocytic Ehrlichiosis (HGE).

A significant feature in the transmission dynamics of Borrelia burgdorferi is the importance of the nymphal stage’s activity preceding that of the larvae which allows for an efficient transmission cycle.

Before and during larval tick feeding, the naturally infected nymphs transmit Borrelia burgdorferi to reservoir hosts. The newly hatched spirochete-free larvae acquire the bacteria from the reservoir host and retain infection through the molting process. In the springtime, nymphs derived from infected larvae transmit infection to susceptible animals, which will serve as hosts for larvae later in the summer.

Human exposure to Blacklegged Deer ticks is greatest during the summer months when high nymphal Ixodes scapularis activity and human outdoor activity coincide. Their small size, their vastly greater abundance over the adult stages and the difficulty in recognizing their bites tends to make nymphs the most important stage to consider for reducing disease risk.

Veterinary Importance

Most commonly encountered in dogs, Lyme Disease is caused by Borrelia burgdorferi bacteria. Lyme disease is transmitted by the Blacklegged Deer tick and the Western Blacklegged Deer tick. Lyme disease has been found throughout the United States and Canada, but infections are most frequently diagnosed in the northeastern, mid-Atlantic and north-central states, as well as in California.

More serious complications include damage to the kidney, and rarely heart or nervous system disease symptoms may come and go and can mimic other health conditions. Cases vary from mild to severe with severe cases sometimes resulting in kidney failure and death.

Canine Anaplasmosis is caused by Anaplasma species of bacteria, specifically Anaplasma phagocytophilum and Anaplasma platys. Both forms of canine anaplasmosis are found throughout the United States and Canada. Areas where canine anaplasmosis is more common include the northeastern, mid-Atlantic and north-central states, as well as California. Anaplasma platys, specifically, is more common in Gulf Coast and southwestern states Anaplasma phagocytophilum is transmitted by the deer tick and the western black-legged tick. These are the same ticks that transmit Lyme disease which increases the risk of co-infection with multiple tick-borne diseases.

Habitat

Blacklegged Deer ticks live in wooded, brushy areas that provide food and cover for white-footed mice, deer and other mammals. This habitat also provides the humidity ticks need to survive. Exposure to ticks may be greatest in the woods (especially along trails) and the fringe area between the woods and border. Rarely, blacklegged ticks may be found in more open areas (such as yards) that are near wooded habitat so it is important to be on the lookout for ticks when in or near wooded areas.

Blacklegged Deer ticks search for a host from the tips of low-lying vegetation and shrubs, not from trees. Generally, ticks attach to a person or animal near ground level. In fact, they rarely ever climb trees, or go higher than 3 to 4 feet up. They do not fall out of trees. Blacklegged Deer ticks also crawl they do not jump or fly. They grab onto people or animals that brush against vegetation, and then they crawl upwards to find a place to bite. This action is called “questing.”

Distribution

These ticks are primarily distributed in the Northeastern and Upper Midwestern regions of the United States.


Ixodes scapularis
is found along the east coast of the United States. Florida westward into central Texas forms the lower boundary, although there are reports from Mexico. The upper boundary is located in Maine westward to Minnesota and Iowa.

The distribution of Ixodes scapularis is linked to the distribution and abundance of its primary reproductive host, white-tailed deer. Only deer or some other large mammal appears capable of supporting high populations of ticks. In the northeastern United States, much of the landscape has been altered. Forests were cleared for farming, but were abandoned in the late 1800s and 1900s causing succession of the fields to second-growth forests. These second-growth forests created “edge” habitats which provided appropriate habitat for deer resulting in increased populations and thus, may have increased populations of the blacklegged tick.

Over the last two decades, the distribution of blacklegged ticks has expanded. They are now found throughout the eastern U.S., large areas in the north and central U.S., and the South. The northern distributions of the blacklegged tick are continuing to spread in all directions from two major endemic areas in the Northeast and Upper Midwest. It’s important to note that adult ticks will search for a host any time when temperatures are above freezing, including winter.

Blacklegged ticks are found in a wide variety of habitat that are suitable for birds, large and small mammals such as mice, deer, squirrel, coyotes and livestock. All life stages can bite humans, but nymphs and adult females are most commonly found on people who are in contact with grass, brush, leaves, logs or pets that have been roaming the outdoors.

Comments

Blacklegged Deer ticks prefer to hide in grass and shrubs while waiting for a passing host . They prefer vegetation located in transitional areas such as where forest meets field, mowed lawn meets un-mowed fence line, or a foot trail through high grass or forest as these areas are where most animals travel sometime during each 24-hour period .

The other habitat most likely to harbor blacklegged ticks is the den, nest, or nesting area of its host such as that of skunks, raccoons, opossums, but especially the white-footed mouse. The white-footed mouse prefers woody or brushy areas. It nests in any place that gives shelter such as below ground, in stumps, logs, old bird or squirrel nests, woodpiles, buildings, etc.

During the winter, adult ticks feed primarily on the blood of white-tailed deer. In the spring, a female tick will drop off its host and will deposit about 3,000 eggs. Nymphs, or baby ticks, feed on mice, squirrels, raccoons, skunks, dogs, humans and birds.

A favorite feeding area for these ticks on humans is at the back of the neck, at the base of the skull long hair makes detection more difficult. However, the ticks will usually crawl about for up to 4 hours or so before they attach. Then, a tick has to be attached for a period of 6-8 hours before a successful transmission can take place.


Solar Dependence and Food Production

Some organisms can carry out photosynthesis, whereas others cannot. An autotroph is an organism that can produce its own food. The Greek roots of the word autotroph mean “self” (auto) “feeder” (troph). Plants are the best-known autotrophs, but others exist, including certain types of bacteria and algae (Figure 1). Oceanic algae contribute enormous quantities of food and oxygen to global food chains. Plants are also photoautotrophs, a type of autotroph that uses sunlight and carbon from carbon dioxide to synthesize chemical energy in the form of carbohydrates. All organisms carrying out photosynthesis require sunlight.

Figure 1. (a) Plants, (b) algae, and (c) certain bacteria, called cyanobacteria, are photoautotrophs that can carry out photosynthesis. Algae can grow over enormous areas in water, at times completely covering the surface. (credit a: Steve Hillebrand, U.S. Fish and Wildlife Service credit b: “eutrophication&hypoxia”/Flickr credit c: NASA scale-bar data from Matt Russell)

Figure 2. The energy stored in carbohydrate molecules from photosynthesis passes through the food chain. The predator that eats these deer is getting energy that originated in the photosynthetic vegetation that the deer consumed. (credit: Steve VanRiper, U.S. Fish and Wildlife Service)

Heterotrophs are organisms incapable of photosynthesis that must therefore obtain energy and carbon from food by consuming other organisms. The Greek roots of the word heterotroph mean “other” (hetero) “feeder” (troph), meaning that their food comes from other organisms. Even if the food organism is another animal, this food traces its origins back to autotrophs and the process of photosynthesis. Humans are heterotrophs, as are all animals. Heterotrophs depend on autotrophs, either directly or indirectly. Deer and wolves are heterotrophs. A deer obtains energy by eating plants. A wolf eating a deer obtains energy that originally came from the plants eaten by that deer. The energy in the plant came from photosynthesis, and therefore it is the only autotroph in this example (Figure 2). Using this reasoning, all food eaten by humans also links back to autotrophs that carry out photosynthesis.

Biology in Action

Photosynthesis at the Grocery Store

Figure 3. Photosynthesis is the origin of the products that comprise the main elements of the human diet. (credit: Associação Brasileira de Supermercados)

Major grocery stores in the United States are organized into departments, such as dairy, meats, produce, bread, cereals, and so forth. Each aisle contains hundreds, if not thousands, of different products for customers to buy and consume (Figure 3).

Although there is a large variety, each item links back to photosynthesis. Meats and dairy products link to photosynthesis because the animals were fed plant-based foods. The breads, cereals, and pastas come largely from grains, which are the seeds of photosynthetic plants. What about desserts and drinks? All of these products contain sugar—the basic carbohydrate molecule produced directly from photosynthesis. The photosynthesis connection applies to every meal and every food a person consumes.


Deer Anatomy | The Rest Of The Story

While we’ve covered various parts of a whitetail’s anatomy that can be aimed for during a hunt to result in a kill, it’s also good to be well-versed in the rest of a deer’s anatomy, so you can become a more well-rounded and knowledgeable hunter.

Wait, a deer has how many stomachs? Well, just one… sort of. Read on…

The Whitetail Digestive System

All deer species have a four-chamber stomach. The four chambers are called the rumen, reticulum, omasum and abomasum. Deer are able to consume large amounts of food in a relatively short period of time. That food is swallowed and passed to the first stomach, which is known as the rumen.

The digestive bacteria in the rumen begins to break down the cellulose found in the plant life that the deer has consumed. However, the rumen cannot completely break down and absorb all the necessary nutrients, so the deer will regurgitate the food later and chew it again. This is often referred to as the deer “chewing its cud.” This allows the deer to further break down the food, so it can absorb the nutrients it needs.

Once the food is chewed the second time, it moves to the reticulum, which serves as a strainer of sorts. Foods that are more difficult to digest will remain in the rumen and reticulum chambers for a longer period of time. This can cause a “roadblock” of sorts and can lead to malnutrition and sometimes even death, all while having a “full stomach.”

After a period of about 16 hours, the food will pass from the reticulum to the omasum. In the omasum, the water from the food is absorbed. The food then passes to the abomasum, which produces acid that further breaks down the food that the deer has eaten.

After leaving the abomasum, the remaining food particles and liquid are passed to the deer’s intestines, where it will eventually exit the body as feces and urine. Whitetail typically defacate an average of 13 times per day.

A deer has four different chambers of the stomach, each with a different role in food digestion.

It’s sometimes hard to believe how a whitetail’s skinny legs can produce so much speed and power.

While whitetail cannot maintain top speed for long distances, they can run up to 40 miles per hour in short bursts.

With the use of their hooves, they are able to make sharp turns and pivots, even at high speeds. Their hind legs provide the power for their speed and jumping ability. In fact, deer are also good swimmers.

Whitetail bucks have tarsal glands on the inside of their hind legs. These glands secrete a musky scent unique to that individual deer. The buck will urinate on the glands and leave the scent in areas that it paws out on the ground, called scrapes.

Other male and female deer visit these scrapes to check scent. During the breeding season, or “rut”, bucks will scent check scrapes to identify what female does may be in the area or what intruder buck might be in his territory.

A whitetail buck has tarsal glands on the inside of its hind legs.

Not all hunters are after antlers, but it’s certainly a nice bonus when you are able to harvest a trophy. So how fast can those antlers actually grow? Read on…

Antlers

Male deer have antlers on top of their head as part of their anatomy. Although rare, it is also possible for a doe to grow antlers occasionally. A whitetail’s antlers are actually live tissue that are composed of bone. A deer’s antlers hold the distinction of having the fastest growing tissue of all animals.

Whitetails begin growing their antlers in the Spring and they can grow at an average rate of up to two inches per week! During development, the antlers are covered with a spongy tissue called velvet. The velvet contains blood vessels that generate growth of the antlers.

Antler growth typically stops in late Summer to early Fall. Once growth stops, the deer will remove the velvet from their antlers by rubbing them on the bases of trees. After the breeding season ends, bucks will shed their antlers. Shed times can vary in different parts of the country, but typically take place between January and March.

A whitetail’s antlers can grow at an average of up to 2 inches per week!

Whitetail Ears And Hearing

A deer has hearing that is far superior to human hearing. This serves a whitetail well in identifying danger in the form of humans and other predators.

Muscles attached to the whitetail’s ears allow it to rotate them and hear in multiple directions without having to move its head.

This helps it to determine which direction the sound or is coming from and possibly even how far away the sound is. This part of a deer’s anatomy plays a critical role in its survival.

Eyesight… “All Around” Vision

You may have heard the saying that someone has “eyes in the back of their head.” A deer of course does not have those, but because its eyes’ location on the sides of its head, it does in fact, have a 310-degree field of vision. Almost as good as eyes in the back of the head!

Although it is hard for deer to focus on one object, their excellent vision helps them see clearly in the night-time hours.

Smell

A whitetail’s excellent sense of smell is one of its best defense mechanisms. A deer will lick its nose to make it moist. This allows it to “capture” odor particles that are carried by the wind and that stick to the deer’s nose. This not only helps a deer identify danger, but also plays a huge part in the breeding process.

Both male and female deer leave scent behind via urine and various scent glands. Among other things, a whitetail’s incredible sense of smell allows a buck to know when a doe is ready to breed, or when an intruder buck is in the area.

A deer’s nose is its best defense mechanism.


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