Shorebirds Too Late To Breed Successfully Delaware Bay 2007
We should not have gone out of the Gandy’s Beach Marina on Sunday. A small craft advisory was posted by the National Weather Service and even worse, over an inch of rain was being forecast. If we were to catch knots, then we had to go out of the barely- protected inlet at Gandy’s Creek and hug the bay shoreline for about a quarter mile in a 16 foot aluminum V-hull known un-affectionately as “the Pig”. But after three unsuccessful tries at catching knots over the previous two days, we had to make a go of it. There was a large group of knots on the beach and they really should have left a week ago. Now they were late and we had to find out why.
The team could walk to the catch site safely, only having to taken by boat across a small creek. Clive, Peter and I would take all the heavy equipment in the boat.
Clive and Larry in rough sea, calling the red knot catch. Peter Fullagar
We needed to get a good idea of the condition of the birds at the end of the season. Our last few catches had been as revealing as the big movement of knots from the bay beaches in New Jersey to Mispillion Harbor in Delaware. Reports from Kevin Kalasz, who leads the Delaware Fish and Wildlife’s team, suggested that the knots were building weight rapidly at Mispillion and lifting off to the Arctic in small groups. We had seen turnstones and sanderling doing something similar here in New Jersey.
But Kathy Clark’s flight last week revealed several thousand knots and many thousand turnstones, semipalmated sandpipers and sanderlings still remained along the northern bayshore of New Jersey. We tried to catch the birds several times but without luck. During the previous attempt Clive, operating from a boat, had found a group of about 600 knots just down-bay from Gandy’s Beach. They were only accessible by boat. Most likely the birds were waiting to leave at any moment so there was urgency to go out on this miserable day to catch them.
Greenish wind-rows of horseshoe crab eggs on Gandy’s Beach. Dick Veitch
It was important to make this catch because the late season catches are often the most revealing. If most of the shorebirds have left the bay then a late catch will show the weights of the birds that for one reason or another could not make sufficient weight in time and were therefore unlikely to breed successfully. The Arctic summer is so short that even if they did lay down the resources needed to fly to the breeding grounds they would be unable to rear their chicks before the cold weather returns in late summer. But in the last few days there have been a significant number of birds remaining in the bay, and so a late catch will help us to understand their plight. When the Delaware Bay knot population stood at 95,000 birds in 1989, a few thousand left behind at the beginning of June was unimportant, but with the current peak count at only 12,000, a few thousand represents a significant proportion of the whole population. As far as we could determine, at least 1,500-2,000 knots had been left behind, possibly more. We wouldn’t know for sure until Kathy’s flight.
I delivered Sue, Pablo, Victor, Alice, Philippa and Dick to the other side of the small creek so they could walk to the catch site. Clive, Peter and I motored out into a chaotic, choppy sea with Atlantic-coast-size waves crashing against the sod bands that are exposed by the low tide. Rain threatened at any moment. After a difficult landing and a relatively quick set of the three-cannon net, the team moved behind a patch of phragmites while Clive and I watched the danger zone and catch area from the pitching boat. Nearly all the birds left when we arrived but they were now slowly trickling back into the area.
Looking back, this was our lucky day; things went well from the start. A small group of knots walked up straight up the beach into the catch area. These acted as decoys and moments later a larger flock fell “like rain” into the catch area and we fired. We caught 171 knots and 37 turnstones. It was our best catch of the year. And it was the most important.
The three-cannon net firing over a flock of knots and laughing gulls. Peter Fullagar
We found that there were indeed birds with high weights, a few above 205 grams. And there were low weights as well, one poor soul weighing only 98 grams! The most interesting was the weight distribution; more than 80% of the knots were below the threshold weight of 185 g needed to go off to the Arctic. The turnstones had a similar weight profile. We had six retraps from Argentina and one from Chile that we had banded in 2003.
As often happens to us, we were unexpectedly treated to the hospitality of the people who live on the Delaware Bayshore. After we made the catch a cold drizzle threatened our team and the catch with a dismal day. We would have to erect makeshift shelter for the birds and the team, but the wind was driving the rain almost horizontal. We couldn’t allow the birds to get wet so it seemed that we had a difficult problem.
We decided to take everyone, team and birds, back to the landing in the hope of stretching out a tarp across some of the boats in the boatyard to form a makeshift shelter. I went into the Marina office to ask Pete Wagner, the owner of Gandy’s Beach Marina, for his permission to do this and without hesitation he told us to come inside his office and set up our equipment and band the birds indoors! We gratefully did so and processed over 200 birds in perfect comfort. Pete’s son Nick joined our team, which included Pablo and Victor, our visitors from Mexico. In conversation, Nick told us how his father, as part of his local church, helped to build homes for needy families in Mexico. Our group couldn’t thank Pete and Nick enough for their generosity.
The team processing a catch of red knots and ruddy turnstones in the Gandy’s Beach Marina Office. Larry Niles
Nick Wagner weighing a ruddy turnstone. Philippa Sitters