Wednesday, March 15, 2017

A Winter of Extremes; Its Impact Upon Wildlife Uncertain

A young girl offers nourishment to Jody yesterday at Harlem Meer in Central Park. At no time is such support more needed than now.
The geese and ducks survived the bitter snow storm of mid-March. But long range impacts of late winter storms and frigid temperatures upon wildlife breeding successes are likely to be impacted.
Harlem Meer was half covered in ice yesterday and is likely to be 90% or entirely frozen over today. Bad news in terms of food supplies for struggling water birds so late in the season.
New York City dodged a blizzard bullet yesterday.

Instead of the 18 inches of snow predicted, we merely got 8. But areas north and west of the city were slammed with as much as 32 inches of snow. And bitter, below freezing temperatures all along the north east for most of March make it seem more like the deep of winter, rather than one week before spring.

But it has been that kind of winter -- one of extremes, rather than easy predictions and normal pattern. 

Both, January and February were unusually warm with temperatures sometimes bursting up to the 60's. In most cases, the spring-like days were immediately followed by plunges in temperatures of more than 30 degrees (which also occurred this month). One day people literally walked around in light sweaters and shorts; the next in heavy parkas, hats and gloves.

One wonders of course, about this bizarre winter's impact upon wildlife.

As earlier reported, migratory Canada geese wintering at the Central Park Reservoir left unusually early this year to return to their breeding areas in the far north. They were gone by the end of February, whereas usually they don't depart until mid March.

Meanwhile, one of the pairs of breeding Reservoir geese (Hansel and Greta) returned early in March only to leave almost two weeks later when temperatures suddenly plunged and snow began to fall again.

Early spring blooms of flowers in Central Park have since been obliterated by freezing temperatures and snow.
And it is only now that the Central Park lakes are again icing over when they are typically thawing in March. Yesterday, Harlem Meer was more than half covered in ice. It is anticipated that today it will be more than 90% frozen or perhaps even entirely iced.

Temperatures are to remain at freezing levels in NYC for at least the next ten days.

Considering that many species of birds were already in preparations for nesting (or even already on nests in some cases), a late winter freeze like this is likely to have negative impact upon successful hatchlings.

When, for example, New York City experienced unusually frigid winters two and three years ago, few Canada geese eggs hatched in Central Park. In two cases, nesting hens at the Reservoir actually died soon after laying their eggs. At the time, I speculated that the bitter winters of 2014 and 2015 (lasting well into March) had taken so much out of the nesting geese, they simply lacked the nutritional weight and strength to withstand the rigors of nesting.

By contrast, last winter was mild in NYC and successful goose hatchings occurred at the Boat Lake and the Reservoir.  We also saw squirrel populations rebound in Central Park last year after a couple of years of low sightings.

But, the fact that most of this winter's frigid temperatures and snow have been crammed into the month of March is troubling for their potential impact and disruption upon breeding cycles of wildlife. Spring is usually devoted to rejuvenating strength and preparation for nesting and reproduction -- not having to withstand the challenges of late seasonal blizzards, icy lakes, scant food resources and January temperatures.

In short, while it appears our Central Park ducks and geese survived the bitter snow storm yesterday (and yes, NYC dodged a bullet in terms of the higher snow predictions), it might be the storm's aftermath that is actually far more nefarious.

This is especially true if Central Park ponds and lakes ice over (thereby restricting food sources) and we remain in a deep freeze until the end of the month.

"It might as well be spring" might (sadly) just be a song this year. -- PCA


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