Category: Get Involved

Delaware Bay Shorebird Project Team Finishes 2015 Banding Season

By: Dr. Larry Niles, LJ Niles Associates LLC

All our efforts to help shorebirds on Delaware Bay this year couldn’t have been better rewarded – nearly every red knot left the bay in good condition and in one of the earliest departures in the 19 years of the Project. We counted just over 24,000 knots in our aerial count of the entire Bayshore on May 26th. Just two days later, most had left and we could find only a few hundred, feeding on eggs like human shoppers feed on bargains at a half-price sale. By May 31st, virtually all were gone, along with the ruddy turnstones, sanderlings and semipalmated sandpipers. The beaches had an odd, deserted feel after the frenzy of the preceding days.

A good thing for birds and all those who love birds. The end of the shorebird stopover season also means the end of our shorebird team – at least for another year. All through the week, we lost team members—the North Americans left by car, those from other continents by air. Those who stayed shifted from research to manual labor: cleaning and storing equipment, closing up the rental houses, and reconnecting lost items to their owners.

Will our project continue? Now in our 19th year of work on the bay, one must recognize the realities of time’s passage. Clive Minton just cleared 80, and the rest of the original team will soon follow. This author, who started at relatively young 44, is now pushing his mid-sixties. Death visited our team this year with the passing of Allan Baker. Surely the rest of us will start “falling off the perch” as Clive is fond of saying.

And yet, all committed to return for a 20^th year. I worry over the fundamentals: our funding remains uncertain, the listing of knots as Threatened in the U.S. creates new regulatory hurdles, and N.J. politics seem to get more fractious every minute. Will there be a 20^th year of this project?

 

The answer starts and ends with the willingness of our team to do it again. It starts there because good ideas and projects always seem to find support; I know we will find a way. It ends there because this team provides the best chance of a strong scientific underpinning for protection. Our team includes some of the most important shorebird scientists in the world. At our dinner soirees (generously provided by Jane Galetto’s Citizens United team), Ph.D.’s are as common as empty beer bottles. It’s no surprise that conversation drills deep into conservation biology, behavioral ecology, migration physiology, stopover ecology, virology and many other subjects of interest to all our team, both scientists, old and young, and lovers of good science.

 

In many ways, the lives of our team members revolve around birds. The Delaware Bay Shorebird Project provides us a meaningful excuse to pull together once more. Our team members love birds, and do everything they can to help them. It’s been that way for 19 years, and it is this commitment that has led to this year’s results.

For the first time in 19 years, red knots left in a condition similar to the lucky ones migrating through before the fishing industry decimated horseshoe crabs in 1997. After that year, the populations of knots, turnstones, semipalmated sandpipers, and sanderlings fell off a cliff. For the last four years, however, the terribly reduced populations of shorebirds have been in rough balance with equally reduced number of horseshoe crabs breeding on the Bay. Consequently, the percentage of knots reaching the threshold weight of 180 g has climbed. (Knots need at least this weight to reach the Arctic and breed successfully.) From a low of just 5% making weight in 2003, they’ve clawed their way upward 30% in 2010, 50% in 2013 and now this year’s 90%.

One must be cautious about the interpretation of this number but the catch of red knots on which it was based were truly fat birds! One weighed 226 grams, nearly 100 grams higher than its fat free weight. Whatever the figure it was a good season for both birds and the people who love them.

Learn more:

• Delaware Bay Restoration – RestoreNJBayshore.org
• Conserve Wildlife Foundation’s Delaware Bay Shorebird Project

Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.

An Update from the 2015 Delaware Bay Shorebird Project Team

By: Dr. Larry Niles, LJ Niles Associates LLC

Clive Minton is fond of saying, “the knots vote with their wings” as a way of saying knots concentrate in the best places for knots. Of course it’s true, animals move to the habitats they find most suitable, nature leaves little room for anything but. Sometimes however, animals use a habitat only because they have little choice — in other words, they are making the best of a bad situation. The job of a good wildlife biologist is to understand the difference. Unfortunately, it’s often not obvious.

 

In all the places studied by this author — Tierra del Fuego, the Arctic, and many places in between — knots distinguish themselves as highly selective habitat specialists. There are many practical reasons for this: usually knots occur in flocks and thus require more space than many other species. More importantly, as they put on weight for their incredibly long-distance flights, they often push the limit of safe wing-loading (body weight to wing area). This makes them vulnerable to predators, both real and imagined. They need more flying space, more space for advance warning of a predator’s presence. They demand special roost habitats as well, especially night roosts that are free from disturbance and have good sight distances. Altogether they need more.

 

In Delaware Bay, they need all this, but above all they need good horseshoe crab egg densities. In the mid 2000’s when shorebird numbers were high, the demand for those eggs exceeded the production from the rapidly diminishing crab population. Knots wandered the bay like homeless refugees. Competition for eggs drew tens of thousands of birds to places unused by knots in healthier times.

 

Mispillion Harbor, Delaware, for example, in some years supported much of the knot population in the Bay because it acts like a funnel-trap for crabs. Crabs wandered into the harbor through long stone jetties finding themselves in crab breeding heaven, sandy shoals in a closed space, free from wind-generated waves that normally leave them upside down. The egg-laying frenzy caused eggs to reach epic densities, thus preparing many shorebirds for their onward journey to the Arctic. Tens of thousands of shorebird packed into Mispillion Harbor in densities so high that one could smell ammonia off-gassing from the amount of bird waste.

 

But for knots, Mispillion left a lot to be desired. The same jetties that protect the inner harbor from wind-driven waves also provide low-flying raptors the cover to pounce on flocks before they can easily react. Fat birds make easy prey for peregrine falcons, who themselves struggle to keep up with the insatiable hunger of rapidly growing chicks.

 

But even as shorebird numbers fell in response to the reduced crab numbers, egg densities improved in other places. Knots reassessed their choices and voted with their wings.

 

This is why this year’s high count of red knots on the New Jersey side of the Bay are so important.  Two days ago, Mark Peck, Joe Smith and I flew the entire Bay to count knots, ruddy turnstones and sanderlings. We counted over 24,000 knots, with 21,000 of these using the beaches managed by the many groups that take part in shorebird management on the New Jersey shore of Delaware Bay.

 

I am not saying this is a competition between two states — I’m saying the numbers serve as assurance that all our hard work is paying off. It’s a confirmation that the beach restoration projects, the Shorebird Stewards project, the reTURN the Favor crab rescue project, and more are bearing fruit. These coordinated strategies are led by Conserve Wildlife Foundation of New Jersey, American Littoral Society, Manomet Center for Conservation Sciences,  New Jersey Audubon Society, the Wetlands Institute, Citizens United to Protect the Maurice River, The Nature Conservancy, as well as Downe Township, Maurice River Township, Middle Township and the Division of Fish and Wildlife, New Jersey Department of Environmental Protection. This work is funded by the US Department of Interior, Fish and Wildlife Service, the National Fish and Wildlife Foundation and the Willliam Penn Foundation. Good work all!

We now near the end of the stopover season at Delaware Bay. Three days of southerly winds are proving irresistible for many birds. Nearly two-thirds have left and the rest will be gone in a few days. Thanks to the people who love birds and the residents of the Bay, they leave well-prepared for the next stage of their challenging and inspiring lives.

Learn more:

• Delaware Bay Restoration – RestoreNJBayshore.org
• Conserve Wildlife Foundation’s Delaware Bay Shorebird Project

Dr. Larry Niles has led efforts to protect red knots and horseshoe crabs for over 30 years.