Tick Population Explosion
Updated: Apr 8, 2022
Ticks have been around for millions of years but why does it seem like the tick population has exploded over the last few years?
Does it seem to you like ticks are suddenly everywhere? Why and how is this happening?
“Imagine a bird drops one female tick in an empty field. That lone female tick lays 2000 eggs and say half of those are females. Then those females lay 2000 eggs each...etc. etc. etc.”
Ticks are not new to the earth and have been around for millions of years. The oldest preserved tick to date was discovered encased in amber, attached to a prehistoric bird feather. It dates to near 90 million years old (from the Cretaceous Period).
Blood analysis of Otzi, a 5,300 year old ice mummy recently discovered in the Eastern Alps of Italy , showed that the man carried borrelia burgdorferi, marking the first known case of Lyme disease in a human.
In the last decade, we’ve seen a significant increase in reported cases of Lyme and other tick borne diseases across the continent. This massive jump in tick populations and tick-borne diseases has occurred in part due to changing climate conditions, and human encroachment on natural tick habitats. Ticks are now no longer found only in rural forested areas, but in urban areas and city centres as well.
Ticks require multiple blood meals to sustain them through each phase of their life cycle, and it’s through this series of feedings that they acquire and spread disease. Ticks can pick up Lyme and a multitude of other diseases from each meal source, then pass those pathogens along to their next hosts, including larger wildlife, humans and our animal companions.
One of the most common sources of the ticks’ first blood meal is the white footed mouse, 40-90% of which carry the bacteria responsible for Lyme disease. Rising temperatures and urban developments constructed within previously forested areas help support the sustained growth of white footed mouse populations, which in turn allow tick populations to thrive year round.
Today, as birds migrate they collect and drop off their nefarious travel companions into all sorts of landscapes. As each female tick is capable of laying up to 8000 eggs in a lifetime, it is no wonder tick populations are exploding and quickly becoming the largest vector for diseases in humans.
Imagine a bird drops one female tick in an empty field. That lone female tick lays 2000 eggs and say half of those are females. Then those females lay 2000 eggs each...etc. etc. etc.
Check out this 25 second video:
TICK LIFE CYCLE
Ticks Emerge Late Winter/Early Spring
The female ticks usually lay their eggs in the spring or summer, as they release thousands of eggs, tucked away in layers of moist vegetation until ready to hatch.
Eggs hatch into pin tip-sized larvae, then seek their first blood meal, typically from disease-ridden rodents such as white footed deer mice, and the pathogenic cascade begins. During each of their remaining feedings, ticks are capable of transmitting a variety of diseases to each successive host.
It is extremely important to remember that ticks can and will emerge any time temperatures rise above approximately 4C or 39-45F, whether winter is over or not. They won’t be emerging to bask in the sun, they’ll be on the hunt for blood.
Ticks in Summer
Peak season for ticks seems to be spring and fall, however, tick activity continues in the hot periods of summer, toward the end of June and into July. After feeding a second time, the nymphs develop into adults during late summer of the second year.
Can Ticks Survive Cold Winters?
Ticks are still busy well into late fall, first seeking their final pre-winter blood meal, and then securing a suitable protective habitat to get them through to spring. Some ticks won’t bother to hibernate, and instead will survive frigid winters on the literal backs (or ears, scalps, groins, etc.) of hosts mammals. However, when temperatures drop significantly most ticks will have already found refuge in moist layers of leaf litter or other organic ground cover.
In addition to the protection of ground cover, certain tick species including the black-legged tick have antifreeze proteins in their bodies, further helping to protect them from freezing to death. Interestingly and unfortunately, these proteins can be enhanced by certain pathogens, making some infected ticks particularly cold hardy. Meaning that ticks that have the ability to pass along infections are more likely to survive cold winters.
Are ticks 100% resilient to cold winters?
If winter arrived with sudden onset but sustained subzero temperatures, in areas with little to no organic ground cover or snow, then yes, some exposed ticks would likely die. But if winter has waltzed in and laid out a lovely layer of the white stuff, ticks will easily survive even in what we would consider the ‘coldest winter yet.’
Also, Tick borne diseases acquired in the winter may prove harder to diagnose as the symptoms of these illnesses so closely mimic those of the colds and flus typically caught at this time of year.
Please don’t let your guard down. Keep up with your tick checks and make sure you and your pets are tick free before you come back in from the cold.