Gone, but not forgotten

Slap!!!

That is the sound of my hand crushing the life out of the last mosquito of 2019.

The mosquitoes stayed late this year, possibly because of the wetness and lack of frost. I can’t ever recall being bitten in October before, but this year I had several late October stings.  

Now the mosquitoes finally are gone, out of sight, out of mind, until May.

It is a mistake to put them out of mind. We need to think seriously about mosquitoes and the growing health threats they present.

Our planet is warming, encouraging bugs and plants once confined to warmer southern areas to move north.  Ticks carrying Lyme disease are moving beyond their normal ranges of southwestern Ontario and have reached on the edges of Haliburton County.

Mosquitoes carrying viruses not known in northern climates also are moving north. In the past 10 years or so nine previously unknown species have been added to the list of mosquitoes found in Ontario. That list has grown to 67 different species.

West Nile virus, not seen in North America until 20 years ago, is here now. Aedes aegypti, the mosquito capable of carrying the Zika virus, was found in southwestern Ontario two years ago.

That mosquito also has been known to carry other tropical diseases such as dengue fever, chikungunya, and yellow fever.

There also has been an increase in North America of eastern equine encephalitis, Triple E, as it is sometimes called,  a once rare but deadly mosquito-borne virus. There were three confirmed Triple E deaths in Michigan this past September.

At the end of October the U.S. Centres for Disease Control reported 35 confirmed cases of Triple E this year, 10 0f them in Michigan. Thirteen of those 35 infected people died.

To northerners, mosquitoes always have been just a summer annoyance. Different species moving north are a health threat not to be taken lightly.

Just ask Timothy Winegard, a professor at Colorado Mesa University and a Canadian, originally from Sarnia. His new book, The Mosquito, documents how mosquitoes and the diseases they carry have changed world history.

He writes that mosquitoes have killed more people than any other cause of death in human history. He estimates that mosquitoes carrying disease have killed almost one half of the 108 billion humans who have lived over the past 200,000 years.

His book documents how mosquito–borne diseases such as malaria changed war outcomes, decided the fates of empires and altered human history.

“The mosquito remains the destroyer of worlds and the preeminent and globally distinguished killer of humankind,” Winegard writes in the introduction to his book.

Last year the mosquito and her diseases killed 830,000 people worldwide.

I wrote her because only female mosquitoes bite. They do so to get blood needed to grow and mature their eggs.

Female mosquitoes will bite anyone with blood, but they do have some preferences. Research shows they have a special taste for Type O blood. People with Type O are bitten more often than folks with Type A or Type B.

Also, mosquitoes have an affinity for beer drinkers, although no one seems to know why.

Pregnant women get bitten twice as often as other people. Scientists say that is because pregnant women give off 20 per cent more carbon dioxide (CO2) than the average person. CO2 and the body chemicals that are mixed with it attract mosquitoes.

These are mild preferences that science still does not completely understand. What we do know as fact is that anyone with blood in their veins is a potential victim.

Being a victim once meant simply being irritated by an itchy bump on the skin. But that is changing as more mosquitoes carrying serious disease find their way farther north.

Many people bitten and infected with West Nile or Zika might not show any symptoms, or might temporarily feel feverish with muscle weakness.

However, West Nile and Zika can have serious consequences for some people. West Nile can infect the nervous system resulting in meningitis or encephalitis and bring on long lasting paralysis similar to polio. Zika has been linked to a serious birth defect and to Guillain-Barré syndrome.

So although they are gone, we should be thinking about being more careful about mosquito protection for when they return.

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And no birds sang

Fifty-seven years ago last week – September 27, 1962 –  Rachel Carson published Silent Spring, the book that really got us thinking about what we are doing to the environment.

Silent Spring predicted more future consequences from indiscriminate use of pesticides and other ways that we are abusing our world. Those predications are coming true.

A dramatic new analysis published in the journal Science says the U.S.-Canada bird population is almost three billion birds smaller than it was 50 years ago. The analysis is based on a study by seven research institutions in Canada and the United States.

The number – 2.9 billion fewer birds - is shocking, but not totally surprising. That fits with my observations at the cottage, where songbirds once provided an abundance of  joy.

A few finches and grosbeaks, once a daily feature at our place, showed up a couple of months ago, bringing a spark of hope. But this fall there is little birdsong around our place and walks in the woods have not flushed one ruffed grouse.

Almost six decades after Silent Spring, I am witnessing Silent Autumn.

Habitat loss and pesticides are two proven causes of bird decline. There are fears now, however, that changing climate is a contributing factor.

Scientists says there is no evidence that climate change is directly killing birds. Changing climate is, however, having indirect effects.

Recent studies have reported huge declines in insect populations. Insects and birds are hugely important to each other. Many birds eat insects for food. So fewer insects to eat means more birds searching for food to stay alive.

More importantly, rising world temperatures are bringing insects, and diseases they carry, to places they have never been before. For instance, mosquitoes carrying malaria, West Nile Virus (WNV) and other diseases are populating areas beyond their historical range.

There is a ton of Americans research on the impact of mosquito-borne disease on birds. U.S. studies have detected the presence of the West Nile Virus in more than 300 species of birds, including ruffed grouse.

Little research has been done in Canada, possibly because nasty bugs and the nasty things they transmit have been limited to warmer areas south of us.

That is changing. Our temperatures are rising and bugs and viruses are moving north. Ticks carrying Lyme Disease are one example. Mosquitoes transmitting the WNV are another.

Canadian research, especially into the impact of West Nile on birds, is urgently needed,

Thankfully we are getting some, from Dr. Amanda MacDonald, a University of Guelph researcher specializing in wildlife disease.

Her study is building data on wild turkeys and ruffed grouse exposed to West Nile in Ontario and Quebec. She is encouraging turkey and grouse hunters to help by submitting blood samples from birds they have shot. The study supplies filter strips for blood collection and postage-paid envelopes for submitting the samples.

Birds can be infected with West Nile when bitten by a mosquito which has bitten and drawn blood from an infected bird or animal.

Not all birds exposed to the virus become ill, or die. However, it does seem to hit hardest the corvid family of birds, of which crows and jays are members.

American research indicates that West Nile is reducing ruffed grouse populations. MacDonald’s study will provide information about levels and locations of exposure and could be a start to determining whether West Nile is a factor in shrinking grouse populations.

It also will be important for wild turkeys. Governments and private organizations spent much time and money on reviving wild turkey populations in Ontario. Any threat to that revival needs quick and thorough research.

We must learn everything about what is killing the birds so we can do more to prevent the losses. Not just because they are lovely to look at and wonderful to listen to.

West Nile, Lyme and other insect-borne diseases are becoming more common in our world. So far this year the U.S. Centers for Disease Control has reported well over 300 human cases of WNV, with 45 states and the District of Columbia reporting exposure in mosquitoes, birds or humans.

Silent Spring warned us 57 years ago. Now things that can hurt us are moving our way and we need to be better informed, better prepared.

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