Conserve Wildlife Blog

Posts Tagged ‘Shorebirds’

CWF Scientists Follow At-Risk Migratory Shorebirds to Tierra del Fuego

Wednesday, February 7th, 2018

by Stephanie Feigin, Wildlife Ecologist

 

Over the past two years, our team, with the help of funding from the Neotropical Migratory Bird Conservation Act, has worked to create critical habitat maps and detailed threat maps for at-risk shorebird species in Northern Brazil and in Tierra Del Fuego, Chile. These projects have established the foundation for conservation planning in these important wintering areas for migratory shorebirds like red knots.

 

Brazil:

Two years ago, our team began working in Northern, Brazil covering the Atlantic coastline of both Pará and Maranhão state between Belém and São Luís. Our team conducted two successful excursions to Brazil taking point count surveys of wading shorebirds collecting approximately 44,700 individual bird sightings to add to the database our team created for the critical habitat maps (Figures 1 & 2).

Figure 2. Results from the 2017 point count survey

                    Figure 1. Results from the 2016 point count survey

 

David Santos and Larry Niles conduct point sampling surveys in Maranhão Brazil.

We conducted surveys using point count methods using fixed radius plots positioned along transects, with all wading birds counted within the 250m radius. Transects were conducted by either walking or while in a boat across various tidal stages and a variety of habitat types including mangrove creeks, sand flats, mudflats and beaches.

 

 

 

Brazil Team: Carla Meneguin,
Paulo Siqueira, Ana Paula Sousa, Larry Niles, Juliana Almeida, Carmem Fedrizzi Joe Smith, Stephanie Feigin, Yann Rochepault, Laura Reis and Christophe Buiden (photo by Juliana Almeida)

 

 

 

Our team then created threat maps of the region from coastal development, mining operations, offshore drilling, and shrimp farming to help inform future conservation planning and mitigate impacts of these activities to the critical shorebird habitat in the region.

 

Chile:

This year, with a second round of funding, our team conducted work in Tierra Del Fuego, Chile to create critical habitat and detailed threat maps for Bahia Lomas in Chile. Bahia Lomas is both a globally significant RAMSAR wetlands site and a Western Hemisphere shorebird site of hemispheric importance.  

 

Shorebirds in Bahia Lomas

Historically, Bahía Lomas and nearby Rio Grande supported wintering populations of 67,000 red knots –  the largest wintering area for knots in the Western Hemisphere. In the last 30 years, however, the population has declined to less than 15,000 knots in Bahía Lomas and the population in Rio Grande is functionally extinct (Morrison et al 1989).

 

 

Aerial Survey over Bahia Lomas

 

 

 

This January our team conducted surveys along the coast of Bahia Lomas to understand distribution of shorebird species within the region, using the same sampling methods, study key roosting and feeding habitats, and delineate critical habitat and threats to the region to inform future conservation and minimize impacts to shorebird populations.

 

Team in Chile including Ross Wood, Stu Mackenzie, Carmen Espoz, Larry Niles, Joe Smith, Yann Rochepault, Christophe Buidin, Antonio Larrea, Richard Lathrop, Stephanie Feigin and Amanda Dey.

Over two weeks our team of New Jerseyans and Canadians conducted point-count sampling surveys throughout the bay with large assistance from our partners from Universidad Santo Tomás in Chile to determine key habitats. Additionally, our team conducted four aerial surveys to get species distribution counts on a large scale of the whole bay at various tide stages, as well as a helicopter survey to continue the population counts of the region done by Dr. Guy Morrison. Finally, our partners with the Universidad Santo Tomás conducted marine invertebrate sampling surveys. These data will be combined to aid in the creation of a GIS mapping system that can identify the most important shorebird habitats in the region.

 

 

 

 

 

In the next few months our team will use these data and overlay them with threat mapping to determine the critical habitats undergoing the greatest threats.  This project is designed set the stage for proactive conservation planning that will mitigate future threats and will hopefully uncover the source of ongoing declines to the shorebirds in this region.

Citation:

 

Morrison R.I.G. & Ross R.K. (1989) Atlas of Nearctic shorebirds on the coast of South America. Canadian Wildlife Service Ottawa (Canada).

 

2017: Piping Plover Nesting Season

Thursday, November 16th, 2017
How did they do?

Emily Heiser, CWFNJ Wildlife Biologist

Statewide pair-nest success was down this year, but remains above the long-term average. photo by Northside Jim.

For the 12th year in a row, the Conserve Wildlife Foundation of New Jersey, in partnership with New Jersey Division of Fish & Wildlife’s Endangered and Nongame Species, assisted in monitoring and managing the state’s Beach Nesting Bird Project.  Four species are regularly monitored throughout the field season: piping plovers (federally threatened, state endangered), least terns (state endangered), black skimmers (state endangered), and American oystercatchers (state species of special concern). Statewide, piping plovers are of particular concern as their numbers continue to decline and federal recovery goals have not been achieved.  (more…)

onEarth Blog: Red knots in danger from all sides

Monday, July 3rd, 2017
This recent story highlights the threats facing red knots and the horseshoe crabs they depend on, as well as Conserve Wildlife Foundation’s role in protecting the species.
Read the article in full here: onEarth Species Watch

Photo by Hans Hillewaert

Newsworks: Why the Red Knot lives and dies by what happens in NJ

Wednesday, June 21st, 2017

NewsWorks ran a feature story on red knots and the incredible team of international volunteers who make Conserve Wildlife Foundation’s past two decades of scientific surveys possible.

Read the full story here.

Firing the net so that the shorebirds can be tagged and released. Photo by Bill Barlow.

 

Dick Veitch (left) and Dr. Larry Niles (right)

 

Shorebirds lift off to an uncertain end from Delaware Bay

Thursday, June 8th, 2017

By Dr. Larry Niles, LJ Niles Associates, LLC

Red knot by James Fiorentino.

I am reviewing a new paper by Sjoerd Duijns, a student working on the benefits of being a fat shorebird. Still, a draft, the paper analyses data from radio-tagged red knots leaving the Bay in good condition (i.e. fat) and finds they may leave later from Delaware Bay than lighter birds but arrive earlier in the breeding grounds because they can pick the best time to leave. They are also more likely to breed successfully and survive the Arctic breeding season to the following fall. In other words, being a fat knot on Delaware Bay makes life good.

So, in light of this new information, how did the red knots and other shorebirds fare in this year’s Delaware Bay Stopover?  One must not be firm, with so many unknowns, but here’s a working biologist’s best guess.

By all accounts it was one of the worst years in recent memory, but with a twist that offers a glimmer of hope.

First, the Bay’s water reflected an unusually cool May and never really warmed to the levels necessary for a really good horseshoe crab spawn until the very end. This caused odd occurrences of crab spawning. For example, crabs bred in greater densities at the southern beaches this year, more than in previous years. The spawn at Norburys Landing, just south of the commercial oyster aquaculture development zone (ADZ), was one of the best this year, and knots and other shorebirds used the area in great number. One can only guess the water temperatures warmed over the wide inter-tidal flats provided just enough to elicit spawning. The same process was true of all the creeks on the Bay.

Laughing Gulls and shorebirds feast on horseshoe crab eggs at Norbury’s Landing just south of the Aquaculture Development Zone. (below)The southern portion of the bay was much more important this year because waters warmed faster on the large inter tidal shelf of this portion of the bay.

Second, the knot numbers never really climbed to the levels of the last three years. I’m guessing this was illusory, a consequence of the count being done on two days at the peak. It’s likely many more birds came to the Bay and seeing many birds for too few eggs, left for better resources elsewhere. Those that left were probably short distance winterers – those from relatively close in Florida and other nearby areas. The Bay’s horseshoe crab eggs would help them too, but they can get by on Atlantic Coast clams and mussels. The long-distance birds are the ones that need the Bay’s resources.

Third, when finally, the spawn got underway, a freak concurrence of wind and tide killed many thousands of crabs, potentially damaging the population and very likely ending any possibility of a really great spawn. The cobblestone road of crabs on the water’s edge. We saw none of that this year. Not once.

 

 

The upper graph compares predicted high tides ( in blue) with the actual high tide (in Red). On the night of 26 May. This occurred during the lunar spring tide, the highest in May. Finally, a brief burst of NW wind pushed the abnormally high tide into waves breaking across the beach berm, carrying with it tens of thousands of horseshoe crabs.

In a freak concurrence of wind and tide, waves pushed horseshoe crab over the beach into the marsh by the thousands.

Grim results, but here’s the twist. In good years, knots leave near the 27th of May. One day they jam the beach gobbling up eggs, the next day there gone. In bad years, they linger. In 2003, we caught birds on the June 10th.  There’s a cost to this of course, in lower survival and failing production. This year was a new in between. By the time of departure on May 27th, less than a quarter of the knots were prepared to leave. But they hung on until the 30th, blessed with a new flush of horseshoe crab eggs created by a middling spawn and a northwesterly wind churning up the beaches and exposing deeply buried eggs. Did the birds gain enough weight?

It’s hard to say, our last catch of just 33 knots suggests they might have, but an end-of-the-season catch makes a poor assessment. Once birds start leaving, the ones behind could be the light birds not ready to leave, or the heavy birds waiting for better weather. We won’t really know until the fall counts in the southbound stopover or the winter count in Tierra del Fuego.

This, our 21st season of intense research and conservation on Delaware Bay by all accounts will be like no other. Throughout all of it, the team of scientists and volunteers remained inspired, energetic and resourceful. In this one month, we conducted more scientific investigation and conservation than most projects do in an entire year. Whatever the outcome of this year’s stopover season, our team can look hopefully to the north and know that all that could be done for the birds was done.

Those of us that were paid for our time sincerely thank those who volunteered their time including; the stewards that manned the closed beaches helping hundreds of people understand why closures were needed; the volunteers in the banding team who endured long hours of preparing equipment, making bands, sewing nets and keeping cages and of course counting, catching and processing birds; the volunteers who doggedly pursue opportunities to resight flagged birds to estimate numbers and yearly survival; the volunteers that provided meals every single night, a welcome relief from a hard day’s work; and finally, the volunteers that went out all over the Bay to save horseshoe crabs in weather both good and bad. We all did our best. God help the birds and horseshoe crabs.

Our banding team on a catch at South Reeds.

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


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