Nature On The Move

By: Mary Richmond

Spring is such a busy time. Everywhere I go, I am reminded that much of our local nature is on the move. Some are leaving, some are arriving, and some are just moving about cleaning up, clearing out and settling in. 

Most notable are the migrating birds and fish, but we, being part of nature, are also on the move. Snowbirds have been returning in droves, filling our roads and shops once again. The quiet days of winter and early spring are officially over. One could even say they’ve moved on.

Our winter ducks have been flying north and west over the ocean and bay for a few weeks, crossing paths with returning cormorants flying in the opposite directions. Gannets are passing through, feeding on herring and other fish with the returning humpback whales.

Horseshoe crabs are making their way to shore to lay eggs for the next generation and the birds that feed on those eggs will be in close pursuit.

Many adult mammals, including ones we think of as nocturnal, can be seen any time of day right now, foraging for food for hungry young ones. They will travel as far as they need to. It’s not uncommon to see some of these hunters with multiple small rodents crammed together in their mouths as they return to their dens.

Perhaps the most monumental and stunning event each spring is the “run” of the alewives that occurs at this time each year. If you’ve never been witness to the mass movement of the alewives and herring from salt water to fresh to spawn and lay their eggs, you’ve missed out on a true wonder of nature. There’s probably still time to get to the closest run to see this most amazing movement of fish, but don’t wait too long. Check with your town to see where the closest run is but the runs on Stony Brook Road in Brewster and Bells Neck in Harwich are well known and easy to get to. You’ll want to watch the tides. The fish often come in on a high tide or a just falling tide. Thousands of fish force their way upstream on some days while fewer fish travel on others. Once they’ve spawned, the fish will return to the ocean.

The journey of the alewives is fraught with danger. If you’ve watched any nature shows about balls of bait fish, and herring are a favorite bait fish, you know that thousands of fish can be wiped out in one feeding frenzy. We can assume the ones that make it to the rivers here have escaped such a fate, but they are far from being home free. All along their ways up the rivers they are watched over by gulls. When the time is right, the gulls will descend onto and into the water to feast. If you’ve ever wondered how herring gulls earned that particular moniker, you won’t wonder for long if you witness one of their group assaults on the hapless herring caught in a pool waiting to swim and leap up the falls in a herring run.

Those fish that make it through the gull gauntlet swim into the ponds as if released from a nightmare. Their trials are not over, though. Ospreys, herons, egrets and more gulls await them on the other side. Eagles have joined the hungry throngs these days as well.

Even the eggs are under attack as other fish gobble them up almost as soon as they are laid, but thankfully, many still survive. The exhausted fish must swim back the way they came, avoiding the gulls and all the rest to once again swim in the sea, where, oops, they can join in another big bait fish ball. It’s tough being an alewife. This is good to remember when we’re having a bad day in traffic. Our likelihood of survival is much higher than theirs.

We are entering one of the best weeks of the year to watch for and identify migrating birds. Get up early to enjoy the dawn chorus, grab your binoculars, guide books and coffee and go see the beauty that is the morning fallout of bird migration. We never know what we’ll see until we get out there and look, but we do know that birds are on the move.