Guest essay by Eric Worrall
Zoonotic disease researcher Katharine Walter has claimed that climate is causing a massive rise in human cases of potentially debilitating Lyme Disease. But there are a few problems with this theory.
…
Deer tick invasion
Encounters with ticks didn’t always cast a dark shadow over North American summers. Cases of Lyme disease first appeared in 1976 in the woodsy suburb of Lyme, Connecticut. At that time, deer ticks were found only in a hotbed encircling Long Island Sound, along with a small area in Wisconsin.
Since the 1970s, deer ticks have rapidly extended their reach north, west, and south. The most recent map shows that deer ticks now roam throughout the eastern coastal states, from Maine to Florida, and across the Midwest. They are now established in 45 percent of US counties. That means the deer tick has more than doubled its reach in the 20 years since the previous map was published.
The spread of Lyme disease has closely followed the spread of the forest nymphs. Lyme disease is now the most common disease transmitted by a vector — a mosquito, tick, or other bug — in United States. More than 30,000 cases are reported each year, and the Centers for Disease Control and Prevention estimates that 10 times as many Americans develop the disease.
…
Ticks spend the majority of their lives on the forest floor. They are vulnerable to changing local climates and death by freezing, drowning, or desiccation. Warmer winters and longer summers let more ticks survive and thrive further north each year. Warmer temperatures quicken the tick life cycle, too. Tick eggs hatch sooner and ticks spend more time questing for blood, and so are increasingly likely to feast on a human and pass on a disease-causing pathogen. Because more ticks survive and mature more quickly, diseases can be transmitted faster.
…
Read more: https://www.statnews.com/2016/07/01/lyme-disease-climate-change/
What happened in the early 1970s, which might have caused a sudden rise in the rate of dangerous insect borne disease infections?
In 1962, Rachel Carson published the book Silent Spring. It cataloged the environmental impacts of widespread DDT spraying in the United States and questioned the logic of releasing large amounts of potentially dangerous chemicals into the environment without understanding their effects on the environment or human health. The book claimed that DDT and other pesticides had been shown to cause cancer and that their agricultural use was a threat to wildlife, particularly birds. Its publication was a seminal event for the environmental movement and resulted in a large public outcry that eventually led, in 1972, to a ban on DDT’s agricultural use in the United States. A worldwide ban on agricultural use was formalized under the Stockholm Convention on Persistent Organic Pollutants, but its limited and still-controversial use in disease vector control continues, because of its effectiveness in reducing malarial infections, balanced by environmental and other health concerns.
Read more: https://en.wikipedia.org/wiki/DDT#United_States_ban
The timing fits. DDT was banned because of fears about its long term persistence in the environment – its ability to spread and continue killing insects, well beyond the location where it was originally sprayed.
But there are other issues which might have contributed to the “rise” in Lyme disease rates.
Nobody actually knows how many people are infected every year with Lyme disease. Estimates are statistical models, based on the number of people who are diagnosed, which the CDC admits are only a tiny fraction of the number of people they believe are actually infected. The bacterium which causes Lyme wasn’t identified until 1982, when it was described by Willy Burgdorfer. Given the variability of Lyme disease symptoms, any diagnosis prior to 1982 must be considered circumstantial at best. Changes to the quality of diagnosis, of which there have been a number in recent years, could potentially have a significant impact on the number of reported cases.
Each year, approximately 30,000 cases of Lyme disease are reported to CDC by state health departments and the District of Columbia. However, this number does not reflect every case of Lyme disease that is diagnosed in the United States every year.
Surveillance systems provide vital information but they do not capture every illness. Because only a fraction of illnesses are reported, researchers need to estimate the total burden of illness to set public health goals, allocate resources, and measure the economic impact of disease. CDC uses the best data available and makes reasonable adjustments—based on related data, previous study results, and common assumptions—to account for missing pieces of information.
… the number of people diagnosed with Lyme disease based on medical claims information from a large insurance database. In this study, researchers estimated that 329,000 (range 296,000–376,000) cases of Lyme disease occur annually in the United States.
Read more: http://www.cdc.gov/lyme/stats/humancases.html
Changes to land management may have also contributed. The ticks which transmit Lyme disease to humans hide in leaf litter. During much of the 20th century, controlled burning was unfashionable – fire departments sought to suppress fires, rather than burn off excess fuel. Policies have varied in different places at different times, so it is difficult to match management policies to tick prevalence, but controlled burning when it occurred likely had a massive impact on the tick lifecycle, by burning the leaf litter in which they hide.
It is not impossible that climate has influenced the distribution of Lyme disease. However, concluding that climate has caused a rise in Lyme disease infections in US and Canadian forests seems dubious, without considering the likely significant impact of other contributing factors, or the very real possibility that much of the apparent rise is a statistical artefact, caused by poor historical diagnosis and reporting.
Update (EW) – Katharine also mentions the rapid rise in deer population as a contributing factor
In part, ticks are following the spread of one of their favorite sources of blood: deer. As deer populations exploded over the last sixty years, thanks to strict hunting laws and the largely predator-free and deer-friendly landscapes in New England and the Midwest, deer ticks followed. However, the steady crawl of ticks north into Canada can’t be explained by deer alone.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
I contracted Lyme in 2012, from a tick in central France, where I live. I never saw it, but the bite was behind my right knee, and although painful and blistered, I couldn’t see a characteristic “bull’s eye” rash, and dismissed it. Later I developed flu-like symptoms, and took myself off to bed for a couple of days, after which the effects subsided. Some weeks later I developed an awful pain in my left shoulder, couldn’t sleep, and went to the doctor. When I happened to mention the episode, he sent me off for a blood test immediately, and the result showed Lyme. I had a course of fourteen daily antibiotic injections, and the pain went away. Since then I have developed an unexplained heart arrhythmia, and was hospitalised on three occasions last year, when after an angiogram, I had two stents inserted in my heart, but the arrhythmia persists, and leaves me fatigued and breathless after the slightest exercise. I am saddled with various drugs for the rest of my life, it seems.
At least here in France, they are aware of Lyme, and the relationship with ticks, but I have to say that although I mention it to my cardiologists at every opportunity, they tend not to link the heart failure with Lyme, which is surprising. Personally I think all my problems stem from this one tick bite.
We are in a rural area, with long grass prevalent, and plenty of deer, and other wildlife, and likewise, ticks. The cats I have owned, and now a new puppy were/are always collecting the buggers, like tick-magnets.
I can’t see, for the life of me, how climate has any effect. I’ve lived here for ten years, or so, and the climate (or weather) has been reasonably gentle throughout, with cold and mild winters, and hot and lukewarm summers. The ticks are still around, every year.
I do hope you persist in seeking treatment. Carditis and subsequent heart failure is a common late symptom of disseminated Lyme.
Climate isn’t the problem, unless it is the “social/political” climate.
Have you read the book by Dr. Neil Spector “Gone in a Heartbeat”? This guy , a cancer researcher for 25 years, ended up with a heart transplant due to undiagnosed Lyme. Heart complications of Lyme appear to affect males more than females.
There is another vector for Lyme besides deer ticks. I contracted Lyme in Baltimore, without ever leaving the city. Recently, Maryland has put out advice to doctors saying that there isn’t a second vector and to stop treating so many people for Lyme. Apparently, there are a lot of cases like mine, and the droids in the medical establishment want to enforce the “one vector” policy, without doing any additional research.
So, it could very well be increasing its range, and in about 20 years, you might see some research to that effect. Remember, Lyme isn’t really the disease, it’s the place where the disease was first discovered. It’s actually a spirochete infestation, and it’s complete hubris to think that there’s only one spriochete that mimics Lyme syndrome and that we’ve already found it.
OMG!!!! You are not suggesting the Zika mosquito, are you?
JDN Black-legged ticks (both eastern and western) can have multiple hosts-the white footed deer mouse is one of them in the East .
Tick nymphs will also attach to the skin around bird’s eyes, and be transported that way.
http://vetmed.tamu.edu/news/press-releases/study-shows-migratory-songbirds-can-carry-ticks-into-the-united-states.
Again, nothing at all to do with climate.
Leptospirosis is another commonly misdiagnosed disease caused by a spirochete.
Climate vs Lyme vs Deer vs Grain. Which the Cause and which the Correlation?
After plummeting >90% in 1900, deer populations have rebounded to >70% of ~1450 levels.
See article on deer populations.
Decline of Deer Populations
http://www.deerfriendly.com/_/rsrc/1446518535456/decline-of-deer-populations/1450Pop.jpg?height=318&width=400
Compare rapid legislation/fear driven increase in corn production to prevent “climate change”.
See USDA Background
http://www.ers.usda.gov/media/521847/cornuse.jpg
Compare the strong ‘correlation” between pirates and global warming
Another increase since the 70s is the number of people, particularly urban dwellers rambling and camping in remote spots. Deer are also less wary of humans and probably come closer to human habitation than they used to, not to mention all those tasty plants the humans cultivate.
I have a 6′ deer fence around my city property.
Highest and best use for Deer are gloves and venison chili..
+100!
Here in Rockwood, Ontario we’ve had plenty of ticks and some local dogs have come down with Lyme disease. From 2007 – 2014 we were finding lots of ticks on the dogs ears, especially when they ventured into the tall wet grass near the creek. We always wear long pants and hiking shoes when hiking into the woods. Last 2 years, not a single tick. Go figure.
The hunting laws for deer are likely a major contributing factor to the increase in Lyme disease. More severe hunting restrictions, more deer, more ticks, more Lyme disease. I don’t hunt but according to a local hunter (76 years old) they used to hunt deer years ago, in part, because there was no one around. Now the country side is full of subdivisions and paved roads and they have to go further up north to hunt. There are many deer around here but they don’t get a chance to get very big – maybe coyotes.
I suggest that the northern movement of Lyme disease in Ontario has a lot to do with the increase use of rural land for non-farm use and the corresponding increase in interaction between people, pets and tick-rich grasslands.
Back in the 1980s we hiked around Long Point, Ontario, near the southernmost point of the province. They had signs warning against Lyme disease back then. I live about 100-150 km north of Long Point today and had never seen a tick until about 10 years ago. Since that time the land between Long Point and where I live has changed dramatically. The main difference is the loss of greenspace – treed forest that is left natural. This forces the deer into smaller and smaller areas. This is also where humans like to come into contact with nature. Any study that does not look at changing land use and/or hunting just isn’t worth a read. There is more to an answer than just temperature.
I would love to see a study done on the prevalence of ticks, Lyme, and other tick-borne diseases in areas where hunting is common and areas where hunting is prohibited/rare. One survey in the Shenandoah Valley found that there were many more deer in Shenandoah National Park than in the surrounding area. Guess where hunting is common and where it is prohibited.
I don’t know if an official study has been done here in California, but in the endemic areas like Mendocino and Lake Counties where there is a lot of hunting and outdoor activities, the dogs (many of hunting type breeds) test positive for Lyme with alarming frequency. In Mendocino County 1 in 15 dogs tested + (and that is only dogs actually tested) and in Lake County (where most dogs don’t ever get tested) 1 in 40. That alone gives an alarming indication of just how prevalent Borrellia pathogens are, even with a vigorous and robust deer hunting season and far too many poachers.
Forgot to say that dogs are considered a sentinel species for Lyme prevalence.
Amazing how adjusting past temperatures….can adjust a disease that wasn’t even discovered then
Not diagnosed, but I’m sure it was around. Probably attributed to “rheumatism,” the flu, “declines,” knee sprains, old age, migraines, and encephalitis. Only recently have we even acquired the means to detect something like this, and even so the misdiagnosis rate as others have noted is astronomical.
“Otzi the Iceman” whom they found under ice in the Alps, actually had evidence of Lyme disease too. Global warming ..yeah, right under the ice. http://www.livescience.com/18704-oldest-case-lyme-disease-spotted-iceman-mummy.html
rats = rats
squirrels = bushy tailed tree rats
pigeons = sky rats
deer = rats on stilts
…Moose = rats on steroids !
sea gulls = sea pigeons, per my marine biologist sister.
“Altlered rats” too
In the 80s and 90s, I was a Girl Scout and went to day camp almost every year from about 6 to 14-15. We always had to wear pulled up knee socks, longer shorts, and a hat or bandana. Included in the camp paperwork was information about ticks and instructions on how to do a tick check. Bug spray was almost required, though I think you were not supposed to bring aerosol cans TO camp. My parents were both scouts, my mom was a camp leader for many years, and we did tick checks every time we came home from camping, hiking, or spending time in the woods. I did not know ticks were more present in meadows than woods until I was an adult. I really thought they dropped from the trees since the hat rule was enforced so strictly.
Despite all the precautions, and never once finding an attached tick, on July 4 of 1993 I suddenly had the bulls eye rash on the back of my calf. I got thrown in the car and taken to the doctor within an hour. The doctor did not bother doing a test (I do not know if they even had one) in part because the test(s) were not reliable, and because SOP was to give the initial treatment regardless of results. I was sent home with a prescription for horse pill sized antibiotics, but not before getting a massive shot in the butt. I threw the biggest fit of my life, and my dad had to hold me down while the nurse injected me. Fortunately, I never showed any other symptoms. I have no idea if I actually had Lyme, but I am glad I was treated. Still a bit peeved about the shot.
The problem is the mice and the deer. It is probably not helped by people running around in the woods without bug spray or leg protection, and then not checking for ticks. People do not always check their dogs unless they see a tick, and the “worse” ticks are hard to see unless they attach and really swell. I suspect that most of the uptick (ha!) in cases is due to the vector species’ population increases, lifestyle changes, and a lack of spraying insecticides. I do not think we necessarily need to return to the great spray clouds of the past, but I do think that judicious spraying in populated and frequented areas would make a difference in all kinds of disease.
We also should have banned all the Yankees from traveling. 😉
http://www.deerfriendly.com/_/rsrc/1446518535456/decline-of-deer-populations/1450Pop.jpg?height=318&width=400
Also at DeerFriendly, Lyme Disease with comments on the ineffective control through deer populations and the benefits of foxes. http://www.deerfriendly.com/lyme-disease
“Erythema migrans is the only manifestation of Lyme disease in the United States that is sufficiently distinctive to allow clinical diagnosis in the absence of laboratory confirmation.”
Wormser GP, Dattwyler RJ, Shapiro ED, et al. (November 2006). “The clinical assessment, treatment, and prevention of Lyme disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America”. Clin. Infect. Dis. 43 (9): 1089–134. doi:10.1086/508667. PMID 17029130. “pp. 1101–2 Background and Diagnosis of Erythema Migrans
“Shapiro” is the Borrelliosis “science” equivalent of Michael Mann or Kevin Trenberth, et al.
The statement is correct, the bulls eye rash alone can be used to diagnose lyme, with no other tests required.
Since AllyKat had a bulls eye rash, she would be diagnosed today, and they would probably forgo any additional testing.
BugsAway clothing by ExOfficio has a relatively permanent Permethrin acaricide component. The military specification was to last through 100 launderings.
There are also Permethrin spray clothing treatments with considerable remanence.
As the most acute tick stressor is dehydration/desiccation, a good anti-tick treatment for clothing AFTER exposure is to hang the clothing in bright sunlight for eight hours. A clothes dryer is not considered effective for the high humidity maintained through all but the last moments of the drying cycle.
“s the most acute tick stressor is dehydration/desiccation, a good anti-tick treatment for clothing AFTER exposure is to hang the clothing in bright sunlight for eight hours.”
Interesting. I noticed back in 2010, when we had a huge heatwave and drought, and it was about 110 degrees every day, I was wandering around on my overgrown acreage watering the 100-year-old trees, and I didn’t get any ticks on me at all. During a normal year, walking in those areas would bring out a lot of them.
I guess I’m lucky, I usually always feel the little critters crawling on me before they bite, and if not, then I will feel it when they bite, so they don’t stay attached too long.
People should always check themselves after a walk in the wilderness. Lyme disease is no joke.
Personally, I’d attribute any uptick to too many vodka & limes. Just hold the lime and replace with more vodka. Sorted innit?
Pointman
This is a FWIW posting pertaining to New Brunswick (the province east of Maine, not the city in NJ). When I was young, around the middle of the 1900s, you were allowed a licence to kill two male deer. Now licences are for only one animal.
I believe that I have read that that the number of deer is smaller in the woods, party because there is less food for them in areas where they used to flourish, probably as a result of changed forestry practices. In the past you often went to the north of the province to find deer; now I hear that northerners are coming to the south because the number of deer is smaller in the north due to the changes in forestry practices. (I have no interest in hunting so my knowledge is from newspaper articles rather than first-hand experience.) However, if you go to populated areas where the number of houses has increased in the past decades you will find more deer, and they are much like those described by other posters here, i.e., that they are found in large numbers and have largely lost their fear of man.
Doctors here are largely ignorant of Lyme disease and have to be hit over the head to recognize that the disease exists here (and in neighboring NS and perhaps PEI). In fairness to the doctors, they may be being misled by government spokespeople. I am not sure.
It seems that NB is slowly warming, for animal species not seen here before are becoming established, like cardinals, turkey vultures, and others. Even deer are not native here and replaced the elk(?) that were wiped out by man’s hunting.
I hope that these disjointed observations are of some use.
Ian M
Climate change is probably only important in the northward expansion of the deer tick and the increase in deer populations likely explains much of the increase in ticks and hence Lyme. Two of the the other possible causes the author suggests for the expansion of Lyme are almost certainly not important. DDT was generally applied to agricultural crops (with very limited applications for controlling forest pests) and therefore the banning of DDT almost certainly was unrelated to the expansion of Lyme. In addition, the eastern forests where Lyme is prevalent (there also is a hot spot in northern coastal California) are not fire prone and therefore the suggestion that a reduction in prescribed burning lead to increases in ticks is far fetched.
Silent spring :
http://www.citylab.com/work/2016/01/rome-bird-poop-starling-guano/422634/
aka civil nitrate emergencies
how are they going to deal with the cold-
“U-Turn! Scientists At The PIK Potsdam Institute Now Warning Of A “Mini Ice Age”! “
“I’d shoot the deers at my backyard, ….”
If Hugs was my neighbor he would be hoping the police got to him before me. I do not have a problem with guns. I have a problem with idiots with guns.
My solution to ‘idiots with guns’ after getting out of the navy, was to move to the boondocks. Every fall the idiots would come from the city to shoot something. I was advised to put orange vests on the kids walking to bus stop so they would be mistaken for a deer.
One knuckle head bagged a deer while his car was being filled up in Pinegrove. The sheriff looked up from his morning coffee at his house to see a rifle being pointed in his direction.
Arrested, jailed, fined, weapons confiscated, deer meat given to charity. Sounds like justice to protect society from idiots not government overreach.
Seeing deer is one of the benefits of rural living.
It’s actually a spirochete infestation
=================
Leptospirosis is a water born spirochete that took a long time to diagnose in Hawaii in the 1980’s, after it started killing people. Made me sick for 2 years. Old joke, didn’t die but often wished I had.
What made it so hard to diagnose was no doctors had seen it in more than 50 years, so it wasn’t recognized. But at one time it was quite common among farm workers and such. Perhaps Lyme disease is similar. Perhaps it was simply making a come back.
Clearly it cannot have been climate that killed off Leptospirosis, only to see it return. Unless on accepts that climate actually changes in cycles, and we are simply returning to an earlier climate.
Interestingly, in western Colorado where I live, for the first twenty years I would get 3-5 ticks a week on my clothing until it dried out in mid-June and they would be gone for the season. However for 4-5 years now I haven’t seen a single tick. Seems strange since the past two years have been wet well into summer.
Infected ticks can have either a type if infective agent that lives on mouse blood or bird blood; these 2 different types of infective agent do not cross over to use the other kind of blood. We humans are vulnerable mostly when infected ticks move upward from vegetation/mulch where the tick had hung out for maximum air moisture to prevent loss of water.
CO2 does come into the equation. Ticks come upward on a blade of grass “seeking” a host & in the case of infected ticks this move generally occurs by ~ 1 in the afternoon to summer sundown (~8p.m.). This timed phase-in is when the cyclical morning CO2 inflow through leaf stomata (pores) has begun to wane at ~ noon; until then the leaf blade is creating a relatively lower ppm of CO2 at the leaf interface with the air.
Ticks that are developmentally ready to “seek” hosts are responding to the ratio of CO2; dry ice (gasses out CO2) tick traps are very effective. In the case of infected ticks, these do get a symbiotic benefit from being infected; the infection alters some of the levels of specific heat shock proteins (HSP) making infected ticks better adapted to the higher temperature a tick might encounter when leaves ground cover.
Human blood CO2 level (goes up with exertion) is also a factor in where the tick seems most likely to bite us. Red blood cells location is, in part, tied to blood plasma resistance at membranes & greater permiability occurs as internally carried CO2 goes up.
Furthermore, infected ticks aiming for blood, seem to preferentially bite us where instrumentation measures show ~168-176 kilo Ohms resistance & in living cells CO2 concentration responds to variations of reistance by altering perfusion. I do not know if ticks have any capability to register host electrical resistance, nor for that matter a potential host’s internal CO2 gradient – tick “seeking” may be just adapted to blood heat signature.
How about a citation please? I have read a lot on Ixodes ticks and recall nothing like what you write.
Hi D.H., – Which part interests you in particular? I am using a tablet & typing bit of a chore.
Again D.H. – If the Ohms detail is new to you my source is Alekseev (& co-authors) who has been publishing related research since 1984. See (2006) ” Evidence the tick attatchment to the human body isn’t random”; originally published in journal Acarina, Vol.14, no.2 which gives the kiloOhms that I rounded off for brevity.
Recently in his career (2010) Alekseev proposed that Cadmium ( &/or maybe other heavy metals) in the tick’s exo-skeleton is sensitive to kiloOhm impedence & this influences why ticks may go for different sites on the same person. With ticks “seeking” they don’t always just get on us by our chance brushing against them; some can deliberately close the last gap on us. See “Influences of anthropogenic pressure on the system Tick-Tick-borne pathogens”; if stumps your browser it’s ISBN = 9789546425652 .
The Lyme Disease is clearly a product of a global cooling in the early 1970s.
I have a theory that there is a direct relationship between hysteria and the mysterious. IIRC, Cohen listed the 5 avoidable activities with the highest risk based on statistics as smoking, drinking, riding a motorcycle, owning a gun, and elective surgery. If Cohen was writing today, texting while driving he might make the list.
As tragic as it might be, a depressed teenage boy offing himself with a gun is not a mystery as to cause and effect.
Aliments that are hard to detect,treat, or identify a cause (lyme disease, cancer) are mysterious and generated disproportionate hysteria. They are ripe for fear mongering.
So what is the root cause of deer kills on highways? Human idiots driving too fast and not paying attention.
If there is a passenger and male driver, the passenger should be looking for deer entering the road and say ‘deer’. The driver should brake hard without losing control.
This does not work with women drivers. Women hear ‘dear’ and turn their head to make eye contact with sweetie pie and say ‘what honey’! My two sons in the back seat and I had ducked for cover because we knew a deer was coming through the windshield. We have no idea of how mom missed the deer.
One tenet of root cause analysis is that you can learn just as much from a non-fatal mistake. We practice yelling ‘moose’ when mom is driving.
For those who will use any excuse to shoot something, it is been my experience that deer are less predictable during hunting season. Hunting for food is fine. Killing something because you think is a pest is a slippery slope.
Your dog = rat named fluffy.
” If Cohen was writing today, texting while driving he might make the list. ”
Definitely. Using a phone while driving is one of the most dangerous, irresponsible things a person can do.
It has been touched upon in earlier comments but I think it bears repetition; the vast migration in North America and probably other European colonial expansion areas from small farms/villages/towns to large cities really became noticeable in the 1970s, at least in the areas of Canada and the USA that I have lived and travelled. All those settlement areas that are marginal for successful modern agriculture, went from cleared forest and grasslands under intensive management (annual clearing with fire being one of the main tools) by families living on the land year round to zero management lands used only for recreation, in the span of one generation in many cases.
In a way those lands are going through a similar transition to the aftermath of a large forest fire. Have average temperatures changed enough to move the range of deer further north or did they just expand into areas previously farmed, with virtually an unlimited food supply and very few predators? Does anyone doubt that subsistence level settlement farmers, paying their taxes with the egg money, did not harvest deer, elk and moose for food, regardless of hunting limits? After all, they came to settle colonial areas partly because they could own their land. They came from European countries where the land owner owned the wild game living on their property or was given management rights by their crown land patent.
Also, from my personal experience, small farmers are quick to eradicate predators. I am not condemning them in any way as livestock and poultry lost to predation was food taken from your family. Have you ever seen a picture of a settlement family that included an obviously overweight person? My grandmother had her own 22/410 over/under for poultry protection and though I don’t think she weighed more than 100 lbs with her gum boots on, if she needed more firepower than that and the men weren’t nearby she would go get the “hunting” rifle and take care of the problem.
The exodus from family farms here in Canada, along with increased regulation of firearms and hunting caused a dramatic drop in hunting pressure on deer at almost the same time. We now have primarily urban populations, who only visit those rural settlement areas that are no longer farmed, for seasonal recreational use. Around here, the boreal forest is slowly returning. Most of the old fields are open meadow and fast growing deciduous trees and undergrowth with the tertiary coniferous tree species spreading.
I suspect that the limitations of forage and larger predator populations in areas of the boreal forest that had no settlement period are a much greater barrier to the spread of deer populations northward than even several degrees of average temperature change. Some increase in food supply due to CO2 fertilization might be defensible but I also suspect that trying to “tease” that out of normal cycles of predator/prey/hunting population relationships may be beyond the precision of scarce data.
SEA
In the 1970’s in Connecticut, it was Big News to see a deer. As in, “Come quick, kids . . .!” Hunters rarely if ever took the legal limit. Nowadays? The limit has been raised, over and over again, the season lengthened, the weaponry permitted expanded. Some towns even have professional “controlled hunts” to cull the population. I myself frequently see whole HERDS of up to 30 individuals, running like caribou! This is something no one EVER expected to see. Why did they expand? With zero forest management or cutting as cited above, everything’s filling up with underbrush which is their food. You see twin and even triplet fawns every spring now. Plus, surburbanites are not only planting tons of ornamentals which they also eat avidly, they FEED the buggers with “Deer Chow” from local feed stores, luring them in for oooh! aaah! PICTURES. Three-quarters of these ex-city-dwellers think Nature is Disney. Do the math . . .
Lyme is yet another disease ranchers deal with using anit-biotics.
ref:
Conventional ranchers must treat their animals with antibiotics because animals get a lot of horrible diseases. The organic activist movement may also be a factor in the spread of Lyme. Cattle need a varied diet and protection from heartworm, Lyme, and other diseases.
The animals mostly need strong immune systems, which is a function of proper management and feeding. In horses, there is much debate about whether, and how, Lyme actually manifests. What we DON’T know dwarfs what we think we “know.” But one thing I can tell you for sure, having lived here all my life–it is not NEARLY as big a problem as the hysteria-mongers want everyone to think. Most of the time, man or beast, 2 weeks on Doxy and you’re good to go. The symptoms are usually gone within 3 days on it. But as someone said above, “mysterious” is a great starting point for the exploiters of Fear.
There is some evidence that the blue-bellied lizard native to California has a natural immunity to the spirochete, and may even be able to kill it in the host ticks.
Very interesting. The Borrelia spirochete lives in the mid-gut of all stages of the tick at very low levels. The conventional wisdom is that it takes 24 hours and more of feeding for the spirochete to multiply to infectious levels and travel to the tick mouth parts.
Lane, R. S.; Mun, J.; Eisen, L.; Eisen, R. J. (2006). “Refractoriness of the Western Fence Lizard (Sceloporus occidentalis) to the Lyme Disease Group Spirochete Borrelia bissettii”. Journal of Parasitology 92 (4): 691–696. doi:10.1645/GE-738R1.1
It is important to distinguish between species of the Borrelia to know how long it takes for infective spirochaetes to get from tick mid-gut to mouth salivary glands. For specific species & their respective carrier see (2011) Rudenko, et al.
“Updates on Borellia burgdorferi sensu lato complex with respect to human health”.
Possibly the quickest (in time lapse) tick borne Borrelia to be infective to blood of new host is the species B. afzelii. Furthermore, the tick species I. ricinus seems to be more adapted to hosting the B. afzelii than other Borrelia versions.
Ticks I. scapularis & I. pacificus are relatively slow to pass on Borrelia (~40hrs?), while tick I.ricinus nymphs (adults not as rapidly) feeding on vertebrate blood transmit infection in less than 24 hours. At issue is not only how fast different Borelia get
to any kind of tick’s salivary glands, but also how long that species of Borrelia takes to re-orientate that any one kind of tick’s genes to start making the vector virulence proteins that must be passed into the bitten vertebrate’s blood in order to overcome early immune defenses. For orientation try (2008) Hovius, et al. “Salp15 binding to DC-SIGN inhibits cytokine expression by impairing both nucleosome and mRNA stabilizations”; free full text from PLOS Pathogens division
The deer in my northcentral Florida neighborhood have been decreasing for the past 8 years with the decline in the economy. Practically everyone shoots the deer on their property for food, and if you don’t want to, someone will volunteer to do it for you.
Definitely need to protect yourself from ticks, as they are plentiful. Tuck in your pants and shirt tails, spray clothes with deet, and apply an oil based spray to your skin to keep the little buggers from digging in too quickly. Bug checks immediately following forays into the wilds, which could be your front yard, is a necessity.
Most likely the decline in hunting has caused the deer tick explosion. If people are not going to hunt the deer, then local govts. should organize hunting parties several times per year. Overpopulation of deer is dangerous to people driving cars, so this problem should not be treated lightly..
Also, there is medicine you can give pets to kill fleas, ticks, heart worms, and other parasites. Not always pleasant, but outdoor animals need protection too.