Is climate change to blame for the slow arrival of snow geese?

The News Journal

Snow geese fly over a farm field near Prime Hook National Wildlife Refuge near Milton.

A crescendo of honking from above was once a clear sign that winter was coming.

But for the past few years, the first cold snaps of winter largely have come in silence because of the absence of snow geese.

Sussex County farmer Jay Baxter said he’s thrilled his fields are quietly devoid of the squawking birds, which used to take over Delmarva farm fields by the tens of thousands come late October.

“They’re here; there’s just not as many,” the Georgetown-area farmer said. “I don’t understand why they’re not in the numbers they used to be.”

Birders have reported recent sightings of snow geese flocks – some estimating tens of thousands of birds – in Delaware through ebird.org. The website, launched by the Cornell Lab of Ornithology and National Audubon Society, lets people document real-time bird sightings.

But locals are seeing noticeably fewer flocks, said Christopher Williams, a University of Delaware wildlife ecology professor.

“It’s possible the answer could simply be that maybe it’s a warm year,” Williams said.

He said birds will save their energy and delay migration if their northern breeding grounds are still providing plenty of food.

“We’re not seeing as many on Delmarva as we used to, so I’d expect to see them in New York or somewhere else," he said. "But I’m not.”

So if they’re not congregating up north and waiting to migrate south, then where are all the snow geese?

To answer that question, it’s best to ask someone whose livelihood depends on their arrival.

“It’s a good thing for the Delaware farmers, but it’s a bad thing for the hunters,” said Andy Dively, who hosts guided waterfowl hunting trips in Sussex County through his Lewes-based business A&A Outdoors.

Dively says a shift in the birds’ fall migration began nearly a decade ago, but it didn’t have anything to do with the weather.

In 2009 and 2010, environmentalists filed federal lawsuits challenging U.S. Fish & Wildlife Service's yearslong practice of planting genetically engineered crops on public land in Bombay Hook and Prime Hook national wildlife refuges. They won that case, meaning those crops could no longer be planted at the refuges where the geese would land on their early trip south.

Shortly after, the agency agreed to stop planting genetically engineered crops on all of its refuges by 2016.

“They stopped migrating down the coast early when that planting stopped,” Dively said. “That is, in my opinion, the biggest reason they’re showing up later.”

Instead of hanging out in the marshes while waiting for the inland harvests, the geese are finding other places to chow down before they land on Delmarva fields, he said.

Farmers like Baxter are happy the birds are showing up late because they’re known to wreak havoc wherever they feed.

Snow geese rip plants out by their roots, instead of clipping the tops like their Canadian counterparts. That could mean bad news for marsh grasses and winter wheat crops, which Baxter said he stopped planting a few years ago because of the destructive geese.

“It used to be that you couldn’t leave home because you’d have to stay in the field and protect the crops from the snow geese,” Baxter said. “They’re an absolute annoyance.”

Farmers are pleased snow geese are taking their time getting to Delmarva.

A winter wonder

Snow geese weren’t always a winter staple in Delaware. It wasn’t until the mid-1980s that the birds turned the First State into a major pit stop on their journey south.

“Then they stopped in the hundreds of thousands,” said Jim White, who coordinates the annual Christmas bird counts for the Delaware Ornithological Society. “At Bombay Hook, you could see entire pools covered in white.”

Since the start of the 20th century, the species’ population exploded from about 10,000 birds to an all-time high of more than 1 million in the 1990s. The population boom was supported by federal protections for waterfowl as well as a new food source in waste grain on farm fields.

An increase in development and a change in farming practices also may be playing a role in the migratory shift of snow geese.

Dively recalled seeing a flock of about 3,000 geese trying to squeeze into a new development’s small retention pond. The birds thought they were returning to a good spot – it was an open field just the year before.

“They get confused when there’s 60 houses on that field instead of 60 acres of corn,” he said. If their go-to spots no longer exist, snow geese will remember that next time. “There’s no reason for them to want to come here first.”

Local farmers also are not leaving as much waste grain for the birds to feed on, as more winter cover crops like radishes are planted. Snow geese aren’t big fans of radishes, Dively said.

“It’s definitely not climate change,” he said. “It’s a migration shift.”

White, who has been birding for 35 years, also said he doesn’t think climate change is the main culprit.

“Now they’re more scattered, and I can’t attribute that to weather,” he said. “Animals just fluctuate so much.”

Snow geese can be found in some parts of Delaware, including Prime Hook National Wildlife Refuge near Milton. But birders are reporting fewer sightings than in previous years.

Signs of climate change

While Dively, White and Williams were hesitant to cite climate change as a cause of the snow goose's late arrival, data show this fall wasn’t the usual sweater-weather of the past.

“This was an unusual year,” said State Climatologist Dan Leathers. “I think what people are really feeling this year is that summer never ended.”

It’s not that winter got a late start – recent snowfall begs to differ. Instead, it appears Mother Nature almost skipped right over fall.

September was about 1.9 degrees warmer than the usual average of 68 degrees. June and July also had above-normal temperatures.

“But October, where we often notice the seasons are changing, ended up being very warm,” Leathers said. That month was about 5.5 degrees above the normal mean temperature of 57.1 degrees, making it the second warmest October in Delaware since record-keeping began in 1895.

“The leaves didn’t change; flowers were still blooming,” Leathers said. “I think you can attribute that to the warmth in September and October.”

November was pretty normal temperature-wise, but the three-month average has earned fall 2017 the title as the state’s seventh warmest autumn in the last 122 years.

“All our seasons have been getting slightly warmer,” Leathers said. Records show that since 1895, autumn in Delaware has been getting warmer by about 0.2 degrees every decade. Overall, average temperatures have increased by more than 2 degrees in the last century.

“Once we got past October and into November, things have kind of come back to where you expect them to be,” he said.

While Delaware has already seen snow, that doesn’t mean the First State is in for a harsh winter. La Niña conditions, caused by cold water in the tropical Pacific Ocean, may mean less snow and above-average temperatures in the Mid-Atlantic this winter, Leathers said.

Climate change’s impact on First State critters

Leathers said it’s difficult to say whether warmer weather means winter is starting later or ending sooner, but he can say that a changing climate is impacting Delaware’s growing season.

Data show the last frost of spring has been arriving earlier, while the first frost has come much later in the year. Chris Bason , executive director of the Delaware Center for the Inland Bays, said that has translated to about 45 additional days for farmers to grow their crops.

“That’s where you see climate change, on the margins or the extremes of the seasons,” he said. When it comes to wildlife, plants are often the best indicator of a changing climate.

“The best one is plants blooming out of season,” he said, noting that he’s seen reports of forsythias blooming in December instead of waiting for spring.

Changing air and water temperatures also have impacted marine life. Fish species like striped bass are driven to migrate according to water temperature and have been arriving much later than previous years. Southern species like trigger fish and red drum are passing the northern tip of their range and showing up off the coast of Delaware, he said.

Suzanne Thurman, executive director of the Lewes-based Marine Education, Research and Rehabilitation Institute, said dolphins and seals are showing up earlier and staying later.

This seal was photographed on Middlesex Beach a few years ago. Wildlife rescuers say seals are showing up on Delaware beaches later and are lingering longer.

Seeing seals resting on the beach at the same time lifeguards are on duty is a new phenomenon, she said. Their timing has shifted slightly, by maybe a few weeks, but dolphins are becoming less transitory and more full-time residents.

“Dolphins are extending their stay from being a summer visitor to being here 10 months out of the year,” she said. “Nobody’s going to object to seeing dolphins for a lengthier period of the year. The concern would be if they’re unhealthy dolphins. It’s something we’ll be keeping an eye on.”

Warmer temperatures are just one piece of the puzzle, as evidenced by the story of Delmarva’s snow geese sightings.

“In all of these things, there’s a number of different factors at play,” Bason said. “But certainly, climate is playing an increasingly large role in the distribution of species. Any non-scientist can see that it’s happening.”

Contact reporter Maddy Lauria at (302) 345-0608, mlauria@delawareonline.com or on Twitter @MaddyinMilford.