Conserve Wildlife Blog

Posts Tagged ‘Survey’

Shorebird Expedition Brazil: Going to the heart of the mangroves

Wednesday, February 15th, 2017

Hundreds of red knots found to cap long day’s journey

By Larry Niles, LJ Niles Associates LLC

It took us long into the night to reach our next port.  We went from the relatively populated area of Braganza to the dark heart of this coastal region of Viseu. In three trucks, we caravanned through a maze of remnant tropical rainforests, cattle pastures, and impenetrable second-growth woodlands. Along the rain-slicked, red clay road, small and desperate looking towns popped out of nowhere always looking like the past was a better day. The road cut through countless mangrove forests that define this region.  We reached Viseu too late to do anything but find a place to stay the night.

A bridge across the many rivers from Braganca to Visiu, Brazil. Photo by Christophe Buiden.

By noon the next day, we boarded a Lancha boat named Garota Viseu (Viseu Girl). Local shipwrights craft these two-decker boats of about 50 feet in length, primarily to carry cargo and people from port to port.  Today it will carry us into one of the most remote estuaries in the 250-mile coastline of this enormous mangrove and beach landscape.  Our captain, 78-year-old Benedicto, with one crew navigated the coffee- colored Gurupi, a long river that cuts deep into the tropical coastline.

A nearly completed boat in a ship yard in Viseu.

Bene took his craft down the Gurupi within sight of the wind-tossed Atlantic Ocean.  The trade winds blow constantly here, almost always at near gale levels.  But then he turned into a small channel directly into the steamy mangrove forest.  At first the path was wide, lined with a dense tangle of mangrove on either side.  Whimbrels, scarlet ibis, semi-palmated sandpipers clung to tangles of roots as the high tide flooded the soft mud.

Captain Benedicto piloting his Lacho boat, the Garota Viseu.

Then he took the boat in a channel so narrow, the crew had to duck the whipsaw of mangrove branches.  We slowly snaked our way through a tunnel of green until we reached another wide channel.  Within a few minutes, we entered another narrow channel ultimately reaching the next bay.  Here we felt the full force of the stiff winds and deep rolling swell of the Atlantic.  An hour later we weighed anchor at the small community of Apiu Salvadore.

The Garota Viseu weaves its way through the narrow mangrove passage. Stephanie Feigin, Danille Paluto, Christophe Buiden and Yann Rochepault watch from the top deck of the boat.

 

 

Few people from the outside world come to this community of about 50 ramshackle huts and cabins and about 150 people. As the boat neared the shore with most of the team standing on the roof of the boat, scattered groups of the town’s people stood on the sandy bluffs overlooking the harbor as though we just landed from space.  Ultimately, we found them welcoming but wary.  Little good comes from the outside to these communities.

 

 

Over the next two days, we plied our craft of field biology. We needed to find small boats to take teams to the various shorebird habitats previously determined on our maps. Local craftsmen build these boats. Running about 20 feet in length, they use 10 to 20 horse power engines meant for something like a lawn tractor. Instead of driving a blade, the craftsmen power a long shaft that ends in a 8-inch propeller. The skipper can lift the engine and propeller according to the water’s depth. They suited our needs perfectly.

 

We fielded five teams in three in boats while Mandy, David Santos, Carmem and I surveyed Lombo Branco Island, about two miles from the Apiu Salvador. The sea shapes this island into a crescent, the inside protected from the restless waves.  Nestled within, one could see in miniature, the whole ecological system that creates resources for shorebirds.

 

At the heart of the island grows a small and stunted mangrove forest and an apicum, or wetland that only floods during lunar tides or spring tides. These are the highest of the monthly cycle of tides but only occur on the full and new moon. Every day the tide moves in and out of this small system. Twice a month the tide floods the apicum for several days at a time.

We arrived on the day of a waxing moon, near full. The very high-high tides reached well within the small drainage flooding habitats that have not been flooded in a few weeks. Shorebirds carpeted the wet mud, searching for all the invertebrate life that flourishes in this habitat. But the productivity only starts there. Here the tidal flow is gentle because the island shields it from the wind tossed Atlantic from all sides except the leeward quarter of the island. This gentle tidal flow flushes sediments from the mangrove swamp, the nutrients of the apicum and the normal productivity of a sediment-rich sandy substrate, forming the base layer of a productive food chain that nurtures small clams and other invertebrate – all prey for shorebirds.

 

We found whimbrels, semi-palmated sandpipers, ruddy turnstones, short-billed dowitchers, black belly plovers, willets, semi-palmated plovers, sanderlings and collared plovers.  In the lower reaches, we found 337 knots, a glorious find that will help our mapping model enormously.

Red knots, sanderlings, short billed dowitchers and other shorebird forage in the inter-tidal estuary of Morro Branco.

The following day we surveyed a second island, Coroa Criminosa. Why the sinister name we cannot say, but it supported a very similar esturary giving us another successful day. When the tide went out the small island of about 6 kilometers grew to over 20 kilometers. Intertidal sand flats spread out of sight in nearly all directions.

 

 

We left the island that night and arrived in Viseu just before dark. Once again we suffered the sway of the Atlantic. After weaving our way back through the mangrove and up the Gurupi River, we landed too late to go on.  We were thankful for the modest rooms with showers, a good meal and beer!

 


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


Shorebird Expedition Brazil: Conducting a scientific investigation in a tropical wilderness

Thursday, February 9th, 2017

By Larry Niles, LJ Niles Associates LLC

It’s hard to imagine the difficulties of people living here at Latitude 37 Degrees North when arriving at the equator in northern Brazil. It challenges even the hardiest of biologists. However, after three days our team has not only acclimated but we accomplished surveys in two separate estuaries.

 

Ruddy turnstone multiyear flight recorded by a geolocator caught in Maranhoa, Brazil.

 

Low tide was cut short on our first day in the field, while high tide persisted longer than we expected which challenged our surveying since it must take place when birds forage. Shorebirds typically forage until 1 to 2 hours before high tide and start again 1 to 2 hours after high tide, usually resting and digesting the food consumed at the lower tides. Because we intend to understand the foraging habitats of shorebirds in the wintering area, we must focus on the lower tides. This is always difficult due to logistical issues such as renting boats, equipment failures, and long distance from the ports present an array of complications. Still, we were able to go out in the field and collect some data.

 

The next day we did marginally better, each team member faced different problems. Our boat engine failed and we had to paddle back to port, another boat took so long to get to the shoal we intended to survey that it had already been covered by the tide.  But this is the nature of field work anywhere.

 

Yann and Christophe paddle our boat back to port after the engine failed.

 

No matter the complication, it is important to stick to our rigid protocols.  Our goal is to determine the best places for shorebirds in this area. We must work with the shorebird’s behavior because each tidal stage creates different value.  In a wild place such as this, they will choose to roost as close to the foraging areas as possible. In fact most will just roost then feed as the tide recedes then feed as the tide rises and then roost again.  So locating the feeding areas will usually indicate the roosting areas.

 

But things can go awry. In human dominate habitats like New Jersey, birds find it hard to roost near foraging areas. Most often the high tide forces them into people jogging, dog walking or enjoying flushing shorebirds.  So the shorebirds must leave, unnecessarily burning valuable fuel and suffering greater danger from avian predators.

 

The night-time roost creates the real threat here in Brazil and everywhere. At night many dangers lurk.  Ground predators, such as owls, feral cats, raccoons, and even people will take advantage of any unwary or sickened bird.  It is worse when birds are forced to use areas that are less secure than others. This can happen naturally at spring tides, for example, when the very highest high tides force them closer to the dangers lurking in the dunes or mangrove forests.  In places like Hereford, New Jersey, people often force birds to use more dangerous areas.

 

Larry Niles surveying.

 

So our goal here is to map all the areas of importance – foraging, day-time roosts and night-time roosts.  But we hope to do it with remote sensing; satellite maps that are trained by a mathematical model, that are, in turn, trained by our field data.  We count birds, photograph the surrounding habitats, precisely locate the sites, and even look at the substrate.  Is it mud, sand, muddy sand, sandy mud and so on?

 

Doing this in New Jersey is difficult.  Doing it in the northern coast of Brazil presents untold challenges.  One cannot easily access the coast here.  We have to rent boats to take us out to the birds, conduct surveys then get back before dark.  Sometimes we go out for days and stay in remote fishing villages, sometimes with only a floor to sleep and no facilities or power. Imagine unrelenting heat, mosquitoes, persistent blowing sand, copious sweat, and trying to conduct a scientific investigation. That would be demanding in any environment.

 

So this is the challenge of our crew – and they do it aplomb!  Last year one of the boats sank in 55 feet of water 8 miles out to sea. We all made it to land safely but we lost much of our equipment. The day after was grim, wondering if we should we go on or go home?  Without hesitation, not only did the crew go on to complete the survey but we ended up capturing twenty-two geolocators from ruddy turnstones tagged two years earlier. A good crew is hard to put together and stay productive in these conditions. A good spirit is the most important thing.

 

Our team chooses areas for the next day’s surveys. Beer is essential!

 

So we completed two days of surveys at the western end of our 150 miles long study area. Today we prepare for three days out to a remote area, accessible by boat only.  As I write, the team prepares for food, water and all the necessities of spending three days with minimum comfort.  We hope to camp in a fishing village, maybe a house, but we won’t know until we get there. We must prepare for all possibilities.

 

Our understanding of the inner workings of the Brazilian Extractavista reserve system grows every day. This system I believe holds great hope for us in the United States because it serves both the wildlife and fish and the people living in the landscape.  Pretend, for example, on Delaware Bay, the rural towns and the residents get first crack at the sustainable management of resources, not the companies exploiting them without regard to the future, as it is now. Instead of few people earning a good living off Delaware Bay resources, many would. Rural American would be transformed. This is what ICMBio hopes to achieve in this much poorer area.

 

Two members of our team are managers of the seven reserves in Para, our study site. They told us, for example, ICMBio (Chico Mendes institute), the federal agency in charge of the extractive reserves, pays a subsidy for local fishermen in exchange for helping manage the fishery resources. But the subsidy is limited to existing residents, not people within new reserves because of the new conservative government. One can see right away the challenges of two people managing seven reserves covering a coastline the size of New Jersey. Budget cuts have taken away all equipment funds. They must even clean their own offices as most nonessential staff has been cut under the new conservative government, a government accused of unfairly deposing the most popular liberal party.

 

This should resonate in the United States because it could be coming soon to a wildlife reserve near you.

 

Wintering knots in roost.


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


 

Emergency Osprey Nest Surveys in Cape May, Wildwood and Stone Harbor

Wednesday, June 22nd, 2016

What you won’t hear on the news!!

by Ben Wurst, Habitat Program Manager

Matt Tribulski places a young osprey back in its nest.

Matt Tribulski places a young osprey back in its nest.

It’s osprey season. Osprey Survey Season, that is. However, we never like to start the season off with these types of emergency surveys, but with the increase of strong storms and extreme straight line wind events, they are becoming an annual event. Ospreys nest on platforms in open areas near water, so their young can easily become victims during these types of storms. After receiving a text message from my colleague Kathy Clark yesterday evening about the intensity of the storms, she said we should try to do a survey of the affected areas. I had other plans but I knew that those could wait. (more…)

Black Rails: Secretive Denizens of our Coastal Marshes

Thursday, July 23rd, 2015
Searching for a Small, Dark Bird at Night, in the Dark

By: Alfred Breed, Field Technician

What you can see at night while listening for Black Rail. Shown are the datasheet and speaker that plays the various calls. Photo courtesy of Tom Reed.

The nighttime view while listening for black rails in the marsh. Shown are the datasheet and speaker that plays the various calls. Photo courtesy of Tom Reed.

Shhhhhhhh. Be very, very quiet. Sit perfectly still. Listen. When you are searching at night in the dark for the black rail, the rarest and MOST secretive of the secretive marsh birds, your best sense to use for detection is hearing.

 

The black rail is a small, darkly-colored marsh bird whose numbers are believed to have declined precipitously in the past few decades, primarily due to habitat loss (when their preferred high marsh habitat was filled and developed), as well as sea-level rise and the loss of salt hay farms (in New Jersey). The breeding population is likely extirpated from both Connecticut and New York, while its continued stability here in New Jersey is in question. Its conservation status varies by state, with full protection as an endangered species in New Jersey and some other states, and only the cursory protection of the Migratory Bird Treaty Act of 1918 in other, mostly southern states. Even in states where they are not listed as threatened or endangered, black rails are rarely seen because of low abundance, their secretive habits, and the inaccessibility of their preferred habitat.

 

Because of both its rarity and extremely secretive nature, the detailed habits of black rails are little known. Furthermore, historic and current population numbers critical to establishing its conservation status are not well understood. It is thought that they mostly feed during daylight hours, quietly traversing the marsh mud in search of seeds and invertebrate prey, thus remaining largely undetected beneath the dense grass mat. But during the breeding season they call, quite loudly, to each other at night.

 

This habit, nocturnal vocalization, is what we hope to use to determine the continued presence of black rail here in our coastal marshes, and eventually their abundance and other critical biological information. As part of a cooperative effort by the Conserve Wildlife Foundation of New Jersey, the New Jersey Division of Fish and Wildlife, and New Jersey Audubon Society, staff and volunteers are conducting surveys at points throughout the black rail’s potential breeding range in New Jersey and other states. One purpose of such research is to collect and analyze data in order to establish sound, effective, science-based species management plans coordinated across the species’ entire range.

Underway during daylight hours to check-ride new field boat, and deploy an acoustic recording unit that also “listens” for Black Rail.

Underway during daylight hours to check-ride deploy an acoustic recording unit that also “listens” for black rails.

The current phase of the black rail project requires me to transport by boat four expert bird-by-ear surveyors, capable of identifying birds common to the coastal marsh habitat from their song alone, at night. I bring each “listener” to ten randomly selected points within suitable high marsh habitat at the proper tide and during the designated survey period between 10:30 PM and 3 AM. Each 10-point survey route is repeated three times across a six-week period from May-July. Surveyors record all of the identifiable species they hear as well as the direction and estimated distance of the calls from each survey point.

 

The survey consists of two minutes of passive listening followed by several recorded black rail vocalizations broadcast from a very loud speaker that are interspersed with short silences in order to listen for any response. The black rail calls are followed by calls from Virginia and clapper rails, as they will also sometimes elicit a response from our quarry. Surveys are conducted with winds below 12 mph and in little to no precipitation in order for the sound to carry to both human and bird ears. Absolute silence is critical in order not to miss any of the more distant calls that pierce the darkness. The scrape of a boot on the deck, the crinkle of a snack wrapper, or a sudden sneeze has the potential to drown out the sound of a distant call. Discussions about species, direction and distance are held in a quiet whisper.

 

CWF field technician Alfred Breed, the intrepid nocturnal boat pilot for the Black Rail survey project.  Photo courtesy of Tom Reed.

CWF field technician Alfred Breed, the intrepid nocturnal boat pilot for the Black Rail survey project. Photo courtesy of Tom Reed.

This season, our four survey routes encompassed appropriate habitat areas of several of the tributaries to the Great Egg Harbor Bay watershed. In our quiet and isolated marsh stream we are joined only by the birds we hear, many fireflies and less benign insects, spring peepers, croaking bullfrogs, and the occasional splash of a startled muskrat. Periodic traffic noise from the roads that encircle Great Egg Harbor Bay are a reminder that it is difficult to entirely escape civilization here in New Jersey. But listening to the marsh at night, while boating up a narrow isolated tributary that snakes its way toward the transition from marsh to upland, definitely allows for a sense of quiet communion with nature. Because of its extensive lighting, the BL England power plant in Beesley’s Point is truly a bejeweled wonder to behold at night from almost anywhere in the watershed, and the light pollution that emanates from the Atlantic City sky line can be actually quite helpful for nighttime navigation.

 

As far as this season is concerned, all of the hoped for data was successfully collected from each point during the survey periods, with only one survey transect interrupted by an un-forecast pop-up lightning storm that required a quick race back to the safety of the boat ramp. With the surveys now completed, we look forward to sharing the results when they are available for release.

 

This is the first of hopefully many seasons of data collection of this type. As each season’s final results are collected and analyzed, we hope to focus our survey efforts from geographically random points within appropriate habitat, to the areas of repeated detection, and to eventually be able to achieve our long term goal: namely a science-based understanding of the black rail population in our state that informs a viable and effective species management plan.

 

As a result of my participation in this study with four expert surveyors, for three survey nights each, at 10 points per night, and 10 minutes per point, I have had the privilege of intently listening for over 20 solid hours to our nighttime native secretive marsh bird songs in the presence of experts who can teach me what it is we’ve heard. Although I was only able to master a few of the calls with which I was not already familiar, it has truly been a pleasure and a valuable learning experience accompanying these experts into the field. I can’t wait to do it again next season!

 

The Conserve Wildlife Foundation and New Jersey Division of Fish and Wildlife wish to thank Alf for the excellent logistical, navigation, and boat handling skills he brought to this project. Just as we could not conduct the survey without our observer’s expert ears, we would be equally lost without Alf’s expertise on the water. Thank you, Alf!