The sightings have been noted since early in the pandemic — critters everywhere, including here in Connecticut. It’s not quite deer roaming through Japanese subway stations or monkeys hanging out in Thai cities, but there’s enough bear, deer, chipmunks, rabbits, raccoons and more to make life a little, well, wilder than usual.
But a good bit of what’s going on in nature this summer is nothing close to cute. Climate change — which was responsible for this past winter’s warmth, the recent heat wave, repetitive windstorms and other weather events, including the many early-season hurricanes this year like Isaias — has brought a host of flying, crawling, hopping, buzzing, burrowing and otherwise mobile creatures, many of which can cause serious and even deadly diseases.
Layer COVID-19 on top and the folks who sound the alarms on these things are sounding them louder than usual.
“It certainly – at least anecdotally — seems like we’re seeing more of these species come in,” said Jason White, who took over as director of the Connecticut Agricultural Experiment Station on April 1 as COVID was exploding here. “Obviously the thing we’re eyeing right now is all the tick-borne diseases and mosquito viruses.”
The Experiment Station, a state agency with a wide portfolio of research and monitoring, is best known for tracking Lyme disease, West Nile virus and Eastern Equine Encephalitis – EEE, referred to as triple-E. These are normally the summer’s most worrisome health issues.
White and other researchers are worried about the coronavirus’ impact on other diseases, however.
“People are getting kind of disease weary,” White said. “This is all they’ve been hearing about for months and months and months. You get somebody who has flu-like symptoms and what are you going to do this year? You’re going to get a COVID test. Well, your COVID test comes back negative so you don’t think about it anymore. What if it’s Lyme? What if it’s one of those mosquito-borne illnesses? If it were any summer other than this one, those are the things you’d be thinking about.”
But there is way more than usual to think about out in nature this summer – for both people and plants. Mosquitoes are at the top of the list.
Threats from mosquitoes
Nine months ago, municipalities in Connecticut were frantically cancelling evening activities – obviously not for COVID – but for EEE. It has a human mortality rate of about 35%, and the fact that there were four human cases in the state — all but one fatal –- made it an off-the-charts year.
The first mosquitoes to test positive for EEE this season were found in Stonington on Aug. 5. That’s early. If they show up at all it’s usually not until late August. “I don’t think it will be as big as last year,” said Phil Armstrong, director of the mosquito surveillance program at the Experiment Station. “Last year was a record.” He said EEE usually lingers for a couple of years after a big outbreak like last year’s. A second positive mosquito was identified this week in Hampton.
It’s been in Massachusetts since early July and mosquito spraying is planned for more than two-dozen communities. Last year that state had 12 human cases, six of them fatal.
On the other hand, the recent stretch of hot, dry weather does not allow mosquitoes to thrive.
“Wet conditions are the best setup for mosquitoes,” Armstrong said. But he cautioned: “We have 50 different mosquito species and they all have different relationships to water.”
Increased rainfall and temperatures will accelerate mosquito development and they’ll bite more when it’s humid.
Mosquitoes that carry EEE tend to turn up in freshwater swamps and areas with a high water table – like those found in eastern Connecticut, which is where EEE tends to surface. Long periods of sustained rainfall like those in early spring – not periodic extreme rains like the state has had lately – are what help them proliferate.
But there’s another big factor – the birds that carry EEE in their blood. That’s what the mosquitoes feed on before they bite humans – or horses, another mammal in which EEE can be fatal.
EEE can kill birds, but there’s some evidence they’re developing immunity. And if they’re able to stay alive, the disease can be transmitted more easily to mosquitoes. Not only that, one of the most prolific carriers is that most common of birds – the robin.
The other major disease concern from mosquitoes remains West Nile Virus. But it’s generally from a different mosquito – Culex pipiens. It prefers torrential downpours and dirty standing water. It primarily develops in catch basins and storm drains, so heavy rain will flush them out.
But spring/early summer rain followed by drought like Connecticut had this year is a set-up for West Nile, and indeed the first mosquitoes that tested positive for West Nile were found on July 8 in Newington and have been increasing in number since. A human case was identified this week.
To keep track of all these tiny vectors, the state has added 16 new mosquito trapping stations — all in eastern Connecticut — bringing the total number of testing sites to 108. Each site has at least two traps that are cleared every 10 days. If West Nile or EEE is found, clearing changes to twice a week.
At some sites there’s a third trap to catch Asian Tiger mosquitoes, a species that has been creeping northward and, as climate change has made winters warmer, has overwintered in southern Connecticut. It can transmit the dangerous Zika and Chikungunya viruses.
Armstrong said the data the lab has collected provide a picture of how mosquitoes here are changing over time. Climate change seems to be playing a role. “We’ve seen a lot of other species that are new arrivals into the state that likely resulted from northward range expansion from the south,” he said. He said that’s different from some of the climate change-induced insect trends that are reducing diversity. “If you just look at overall mosquito abundance and mosquito diversity in the state – it’s going up.”
Threats from ticks
“I always get asked ‘is it a bad tick year,’” said Kirby Stafford. He is the state entomologist and as chief entomologist at Experiment Station runs the Center for Vector Biology and Zoonotic Diseases. “Every year is a bad tick year. Some are just more so than others.”
This year’s degree of bad is yet to be determined. But at one of the state’s two tick testing labs – the one known as a passive lab because the public brings ticks in to be examined – ticks were coming in all winter at a heavy clip, according to its director Goudarz Molaei.
From November to mid-March, Molaei said, they used to receive 50-100 ticks. But that’s ballooned up to hundreds – some 800 in 2017.
Last year the station started active tick testing, collecting them from 40 sites across eight counties. But a tick’s two-year life cycle makes prediction complicated. Ticks in any given year reflect how many were born the previous year. And the ticks born in any given year will inform what happens the following year.
Among the other pieces of the tick puzzle is the number of hosts the ticks need — some for reproduction, some for transmitting the disease. And in the case of the rodents and large mammals that handle those duties, there are a lot more at the moment.
The changing climate is also starting to alter the profile of ticks appearing in the state, with southern species working their ways north as the climate warms. The Lone Star tick is “exhibit A,” Stafford said. It is an aggressive biter that can spread several dangerous diseases including ehrlichiosis, a bacterial infection that can produce flu-like symptoms; or cause Alpha-gal syndrome — a recently identified allergy to red meat.
“The Lone Star tick is probably responsible for about 90% of tick bites in the southeastern United States – but it’s been moving northward with our warmer winters,” Stafford said. “It began showing up on Long Island in the early 1990s and is now abundant there.”
In the past decade, Lone Star tick submissions to the passive tick lab have increased from about 2-3% to more than 4% this year. In 2017 Stafford discovered a large population of Lone Stars on the peninsula that is South Norwalk’s Manresa Island.
More ominously, Stafford and a colleague conducted overwintering survival studies with adult stage Lone Star ticks in Maine. While the survival rate was low, some nevertheless weathered the winter.
Stafford also has his eye on the Asian Longhorned tick, which infests deer and livestock and can transmit some nasty diseases including a hemorrhagic one. It’s not in Connecticut but has infested sheep in Hunterdon County, NJ since 2017 and is in Westchester County, N.Y. and on Staten Island. It is parthenogenic – which means females don’t need males to reproduce.
Overall his tick concerns are similar to Jason White’s – that folks fixated on COVID may ignore symptoms of Lyme disease, which Stafford said tends to be under-reported anyway. And with people using parks and outdoor areas more as a respite from being stuck home due to the pandemic, he worries more people will suffer tick bites.
Mosquitoes and ticks may be the most worrisome of summer visitors, but they are not the only changes in the critter world that Connecticut is experiencing.
Trees and just about anything else that grows
There is one bit of good news. Gypsy moths shouldn’t be too bad this year. (Of course there wasn’t much left for them to eat.)
Spring rains like the ones we had this year and last are good for proliferating a soil fungus that can keep the oak-munching critters in check. But the three years before that were absolute devastation.
“We’ve had drought before and we’ve had gypsy moths, but the two came together in three consecutive years and the trees just couldn’t take it,” said Chris Martin, director of the Division of Forestry at the Department of Energy and Environmental Protection and the state forester.
Well over hundreds of thousands of trees covering 90,000 acres have been defoliated, rendering many of them hazards to safety, not to mention utility lines in storms such as the recent tropical storm Isaias.
There won’t be aerial surveillance of trees this year. The Cessna aircraft used to do conduct it are too small to allow social distancing, but last year’s was brutal enough for both years. And there are plenty more insects causing trouble.
Emerald Ash Borer arrived less than a decade ago. Efforts to keep it from spreading largely failed and it has marched west to east to cover the entire state. It takes three to five years to kill a tree once it’s established.
“We’re going to lose most all of our ash on account of this,” Martin said. “The insidiousness of this insect is that it’s small, it spreads itself quickly, it’s hard to detect and by the time you notice it, it’s too late.”
While the ash borer was introduced through global trade, the arrival of Southern Pine Beetle is clearly climate change-driven. It’s been throughout the south for decades – hitting the New Jersey pine barrens as far back as the 1980s and turning up in Connecticut in 2016.
Another newcomer is Beech Leaf Disease – caused by a nematode. It was found in one tree in Stamford last year, but when scientists began monitoring, they discovered that wasn’t the only one by a long shot. It had come from Westchester and Dutchess Counties in New York and headed all the way through Rhode Island and into Massachusetts, said Bob Marra, a forest pathologist at the Experiment Station.
The nematodes inside the leaves make the foliage look dark. And that’s where they breed. Tons and tons of eggs. “Anything we’re seeing now this year, had to have come from over-wintered buds that were already infected,” Marra said. “The leaves emerge fully symptomatic.”
Marra is also facing the potential of Oak Wilt arriving in Connecticut from where it’s currently holed up – in Brooklyn, N.Y. It’s a fungus but the vector is a native bark beetle. Oak Wilt operates similarly to Dutch Elm disease in that it blocks the tree’s vascular system, killing it within a season – even a large mature oak.
Marra hasn’t found Oak Wilt in the state, but he’s not saying it’s not here. “Probably is,” he said. “We just have not seen it yet.”
But if you’re looking for good critter news – try the Asian Long Horned Beetle, a pest that is happy to munch on any number of hardwood trees. Connecticut has managed for the better part of a decade to keep it from making the move from the Worcester, Mass. area across the border to this state.
“I think the lesson learned is we just don’t know what’s next,” DEEP’s Martin said.
Big animals, little animals
Gale Ridge, an associate scientist at the Experiment Station, isn’t entirely sure which category the Cicada Killer wasp is in – big or little. As wasps go, it’s big. More to the point, it is much the same size and look as the so-called “murder hornet” that’s become a media sensation. It is causing Ridge to take “call after call after call after call.”
“That’s probably one right now,” she said as one of her phones started ringing, as if on cue.
The murder hornet, officially the Asian giant hornet, was found in Washington state. “That’s 3,000 miles away,” she exclaims. And so she’s providing a handy how-to-tell-them-apart from the cicada killer diagram, since the cicada killer (which might have its name changed to the somewhat more benign cicada hunter) is around here.
Other than killing cicadas and dragging them off to a hole in the ground to feed her young, these wasps are harmless. In her 20 years at the Experiment Station, “I’ve never known anyone to get stung by them. Males don’t even have stingers,” Ridge said.
Of course you don’t have to be big to do damage, which home gardeners and even seasoned farmers are learning this year more than usual, the experts say.
Asiatic garden beetles are out there in huge numbers hiding in the dirt during the day and feeding at night on just about anything. (So if you’re wondering what has chewed up every leaf in your vegetable bed – this is a pretty good bet, Ridge said.)
Shuresh Ghimire, vegetable specialist with UConn Extension service, said squirrels, chipmunks and deer are what he’s hearing about. “I’m getting queries from growers and gardeners who have been farming for many years and have never encountered such a big problem with squirrels,” he said.
He’s also getting many more weekly calls about European corn borer problems than he has in previous years.
The fruit fly known as spotted wing drosophila continues its march begun about a decade ago through the state’s berry crops in particular. “We’re still in a situation that’s pretty dire for fruit growers,” said Richard Cowles, a scientist with the Experiment Station.
Weather patterns drive infestations, especially if it’s humid at ripening, a circumstance he called “pure hell for growers.” This summer he could see problems starting to increase during strawberry season. But now with the sustained hot and humid conditions, he said: “It’s going to be a wild ride for blueberry growers.”
But what really has him worried is a new arrival – the Spotted Lanternfly – after one was sighted in Southbury fall. It will eat pretty much anything, but has a special taste for vineyards, which growers in Pennsylvania learned the hard way. “It sucked the living daylights out of the vineyards and killed them outright,” Cowles said. “They don’t have a significant number of enemies to keep population in check.”
If they arrive in Connecticut, he worried, there would be “mind-boggling impacts.”
So far there have been no additional sightings, but he’s anticipating there will be. “We’re just waiting for other shoe to drop.”
Beyond all the hand-wringing over small but troublesome critters, it’s the big eye-popping animals that have gotten a lot of the public’s attention. Reports of bears, bobcats and coyotes in particular, along with smaller mammals have been nonstop.
“What’s actually different and what’s perceived to be different — those are two different things,” said Jenny Dickson, director of DEEP’s wildlife division. She attributes a good bit of it to people being at home more due to the pandemic. “They’re noticing more things than they do normally.”
There are definitely more bears.
Some of the wildlife activity has to do with people staying indoors, especially this spring when hibernating animals reappeared, giving them human-free spaces to roam in. Some of it has to do with active restoration efforts, such as with osprey. But a lot of it has to with climate change.
It was a warm winter, making it easier for species to survive and their food more plentiful. Ranges and seasons for animals have expanded generally due to the warming climate.
“I think there are populations that are just expanding, and it’s not necessarily tied entirely to mild climates or food availability, although both of those things help,” Dickson said.
But whatever the animal for whatever reason, Dickson is good with it.
“What has stood out for us are the number of calls we’ve gotten from folks who are sort of newly discovering the wildlife around them,” she said. “For them it’s a combination of new and scary and fascinating all at once.”