Conserve Wildlife Blog

Archive for the ‘Outdoor Recreation’ Category

The Importance of water temperatures, windstorms and shoals on the Delaware Bay

Friday, May 19th, 2017

By Dr. Larry Niles, LJ Niles Associates LLC

As we begin our field work on Delaware Bay shorebirds, our 21st season, oddly enough we are once again faced with extraordinary circumstances. As usual, the birds, after various flight of up to 6 days of nonstop flying, arrive in emaciated conditions. For example, in one catch this week we caught several red knots at around 86 grams far lower than normal weight of 130 grams. Putting that into perspective, a woman of 145 pounds would tip the scale at 93 pounds while a male of 175 pounds at 113 pounds! In other words, these birds are desperate to feed on the only prey on which they can build weight fast, the eggs of Delaware Bay horseshoe crabs.

But the various impacts of climate change and destructive forces of sea level rise, storm surge and out of normal weather patterns can wreak havoc on the timing of the horseshoe crab spawn. It messes with the heating and cooling of the bay and when combined with the normal variation one expects in an estuarine system, it creates almost unpredictable consequences.

Adding more uncertainty to this mix is the ongoing harvest of crabs for bait and the irresponsible bleeding by international medical companies. Both kill hundreds of thousands of crabs every year while doing nothing to create new crabs. Their combined impact has put the brakes on any recovery of the population after they both nearly mortally wounded the Bay population in the 1990’s and early 2000’s. Higher numbers of crabs would overcome a lot of early season uncertainty; lower numbers exacerbate them.

And thus, the story of this early part of the shorebird stopover. It starts with the odd weather this April and May. Can everyone remember how warm the weather of this winter? The map below is a reminder that it was one of the warmest on record. The figure below that shows how the Bay’s water warmed early reaching the threshold temperature for horseshoe crab breeding by early May. We trapped sanderling in the first week and were surprised to see a truly great crab spawn on May 4. Thank God for that.

The bays water temperature as measured at the Lewis DE buoy, increased earlier than normal until the first week of May. By that time it reached the threshold for horseshoe crab spawning. But by the second week it plunged as a consequence of the cooler than normal weather.

By the second week of May and yesterday (May 16) temperatures plunged in horseshoe crab world. We generally consider water temperature of near 59 degrees necessary for crabs to spawn in great numbers. We reached 62 degrees on May 4, then it went down to 58 degrees, lingering there for five crucial days.

At the same time, we suffered brutal westerly winds. Wind from this direction gins up waves on Delaware Bay that crash against many of the important crab spawning beaches. Crabs don’t spawn in waves.

Westerly winds turn the Delaware Bay into a tumult of breaking waves because of its relative shallow depth. Horseshoe crabs won’t breed in breaking waves

And just as the first flush of shorebirds came to the Bay, over 5,000 red knots on the New Jersey side, all the spawning shut down. All tried desperately to find enough horseshoe crab eggs to regain lost weight and begin the process of doubling their body weight.

Fortunately, breaking waves and cold water will prevent crabs from spawning on the beaches but not in the intertidal creeks. One of the key features of the New Jersey bayshore are its abundant tidal creeks. Most drain only tidal watersheds, draining and filling marshes twice every day. Naturally they build sand shoals because sand moves around the Bay generally in a south to north direction along the Cape May peninsula. When sand encounters the currents of the creeks, it settles forming shoals.

A small creek just north of Dennis Creek on Delaware Bay. The tidal creek mostly drain tidal marsh, the daily ebb and flow warming the waters making crab spawning possible when the bay waters are too cold

These shoals support most shorebirds during these early days. This is so because the intertidal flow of water into the marsh and out again warms the water that flows over the shoals. The shoals themselves are practically paradise for breeding crabs because of the loosely consolidated and large grain sand. They breed with abandon laying eggs in the shifting sands that brings many of the eggs to the surface where shorebirds can prey upon them. And they do.

This diagram by Joe Smith shows how the creeks of Delaware Bay create superior spawning and shorebird foraging habitat. Sand movement on the Cape May section of the bay moves northward because of tidal currents. This moves sand from south to north. When the American Littoral Society and CWF placed sand on Pierces, Kimbles and Cooks beaches, some part moved northward to the adjacent beaches. Ultimately it ended up on south Reeds making it a great spawning site. But on the way the sand falls out of the current and settles on the creek shoals. These shoals are large grain sand, loosely consolidated, making them perfect for crab spawning. At the same time the shoals shift exposing eggs to the sea, thus making them available to the birds. This is why the shoals are among the most important habitat on the bay.

This is what happens in the early days of this season. It was nip and tuck for most of the scientists, not knowing if the shoal resources would hold up to an ever-growing number of shorebirds arriving in desperate condition.

But today (May 19) we enjoyed warmth with the promise of the season back on track.

In the last 5 days, we were able capture enough knots, turnstones and sanderlings to track conditions and add new flags to the population for a later determination of population size. Despite adversity, so far so good. The data for each species is below.

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


LEARN MORE


 

20 Years of Shorebird Conservation and Research on Delaware Bay

Wednesday, May 17th, 2017

By Dr. Larry Niles, LJ Niles Associates LLC

A Monumental Work of Conservation

This year marks the 21st year of the Delaware Bay Shorebird Project. As one of the longest running shorebird projects in the world, the only one of its kind in the US, we wanted to memorialize this monumental work. To do so we convened a daylong series of presentations by scientists and managers from all over the world who have worked on the bay. Here are the abstracts. They are worth a look by nearly anyone interested in shorebirds and Delaware Bay.

The participants of the workshop on 20 years of conservation and research on Delaware Bay.

The presentations ranged widely. We heard talks diving deep into the science of shorebird ecology, like Phil Atkinson’s talk on the use of isotopes of carbon and nitrogen locked in feather samples and what they tell us about where knots spend the winter. Or Paul Smith’s talk on how modeled estimates of shorebird numbers compare to numbers counted from an airplane. On the other side of our scientific work were talks like Laura Chamberlin’s describing the role volunteers play in saving stranded horseshoe crabs rolled over by heavy seas or impinged in concrete rubble and derelict wooden bulkheads. In between were talks like those by David Stallneckt on the role of shorebirds in the transmission of flu viruses and how that knowledge might prevent the next pandemic of flu in people.

I liked Joe Smith’s talk on the restoration of Delaware Bay beaches and Ron Porter’s talk on the movement of shorebird tracked by tiny devices called geolocators.

Altogether they spoke loudly of the 20 years of intense study and conservation by our devoted team of scientists, managers and volunteers. In those 20 years of conservation of Delaware Bay we learned basics of protecting any place loved by people who love wildlife.

Dollars on the Beach

As with many places in this divided country of ours, and in many places in the world, we have witnessed on Delaware Bay a sad and wholly preventable natural resource tragedy. It’s now 20 years since the Atlantic Coast fishing industry nearly decimated the horseshoe crabs of Delaware Bay. They didn’t aim to do this of course, but as with any tragedy of the commons, once the crabs gained value as a bait, everyone wanted their share before it was lost. They hauled away millions of crabs, no one really caring about the consequence to the bay or the wildlife that depended on the crabs. It was a race to the bottom, that would not have been stopped if it weren’t for the scientists and managers that stood up to the industry, many of which gave presentations in our workshop.

Shorebirds feeding on eggs while crabs spawn.

The battle gave us several important lessons.

The first revolves around the value of the bay, the crabs and the shorebirds. We biologists, managers and public outreach people often see the natural value of this ecosystem in terms of its meaning to us. We are inspired by the knot’s magnificent journey covering 10,000 miles, often flying 6 days continuously.  We are awed by the natural system that responds to change much as our own body fights for life against all the many abuses we cause or suffer.  But we often miss the real value. During my time on the bay we have defended this valuable natural resource from many assaults, the winner take all crab harvest, the greedy exploitation of crab blood by medical companies, the overreach of aquaculturists plotting out the use of intertidal zones without regard to impact. Underpinning each of these threats is not esoteric value, but real wealth.

I once had a conversation with Rob Winkle, before he retired as Chief of Law Enforcement for NJ Division of Fish and Wildlife. He said “Larry you’ll never be able to protect these crabs, because to many people, they are dollars on the beach”.  In other words, natural wealth is wealth, pure and simple. The question is – do we protect this wealth for our children and grandchildren to make up their own minds about how to spend it?

Protection Requires a Relationship

The real value of natural resources speaks to the second lesson. Protection is not only an action composed research, monitoring and management, it is also a long-term relationship with a place. Those of us working on the bay for 20 years know this very well. The abstracts speak to the relationship and our continuing efforts to understand and improve, to rebuild what was lost, to anticipate what comes next. If in 1997 we started work in the bay to publish a few papers and move on to the next interesting place, the battle to save this vital shorebird stopover and horseshoe crab spawning area would have been lost. The dollars crawling up on the bay beaches means protection doesn’t end with fighting one short-sighted greedy use, because there will be an inevitable successor. It takes a long-term relationship to develop protection and keep it vital and active.

I learned this many times in my career, most recently from my good friend David Santos now a professor at the University of Belem in northern Brazil. We have been doing work in the northern coast, a major wintering areas for Arctic nesting shorebirds. After a passionate discussion on how to best bring greater protection of the area he said “you come here for a few weeks and think you can save this place”. He was right, the truth is we can only help if we commit to work in northern Brazil for enough time to get it right.

And this is my final lesson. There is no easy way to develop a long-term effort to prevent the inevitable series of short sighted use of a natural resource without the help of the people who care.

Clive Minton on Delaware Bay.

When Clive Minton and Humphrey Sitters first came to the bay to start the project that is now 20 years old, I was awed by their experience, skill and knowledge. I thought why are they doing this? Neither were being paid only supported to do the work. I was employed as the Chief of NJ Fish and Wildlife’s Endangered Species Program. Now I know, it is only because they care. They are fascinated by the bird’s natural history, they publish scientific papers on the subject but they come year after year because they care.

There’s more to this than just tree-hugging emotionalism. In the US, we have gradually professionalized conservation, ensuring only paid staff do the work with only minor roles for users. It’s an entirely credible position in times of flush budgets. Its pitfall becomes obvious in the age of Trump, years of budget cuts and increasing influence of resource industries dismantle that achieved in the good years. Overall it ends with natural resources declining in nearly every section of the country.

Clive and Humphrey, come from England and Australia where conservation depends heavily on volunteers. It’s a pastime to research, monitor and conserve birds, not necessarily something that pays. For example, the Royal Society for the Protection of Birds (RSPB) has over a million members, but over 18000 volunteers working at 200 preserves and only 1300 staff. Remember this is in a country that has a population of 53 million. By contrast in the US with a population of over 300 million National Audubon Society half the number of members and staff and nearly the same budget.

In our experience these numbers don’t speak to the reality of how people actually feel in the US, or at least hear on the bay. We can say without reservation that the research, monitoring and conservation on the bay depends on the dedication of many volunteers taking part in our work. We literally could not do the work without their help.

John, upper right in red shirt, is a volunteer steward protecting beach important to Delaware Bay shorebirds. This is he first year. Next to him is Humphrey Sitters, the editor of Wader Study, an international technical journal on shorebirds and a highly trained expert on shorebirds. He has worked on Delaware Bay as a volunteer scientist for 20 years. It is the work of these two and many others that makes the protection of Delaware Bay a success.

And so, this is the final lesson. The best way to overcome this cycle caused by the relentless exploitation of the bay’s natural wealth is building a team of people devoted to it study and conservation. This involves the many professionals who care enough to maintain a focus through the ebb and flow and agency prerogatives, a team of retired professionals and young adults seeking experience for their nascent careers and just as importantly as many people who care enough to put time into the yearly care of this valuable natural systems.

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


LEARN MORE


 

NJTV: Osprey population continues to rebound in NJ

Tuesday, April 18th, 2017

NJTV News recently covered the continuing recovery of ospreys in the Garden State by visiting the nesting pair at Long Beach Island Foundation for the Arts & Sciences. CWF’s Ben Wurst and David Wheeler joined NJTV for this inspiring video and accompanying story.


LEARN MORE


What’s Happening at Waterloo?

Tuesday, April 11th, 2017

By Allegra Mitchell, CWF Biologist

 

Waterloo Village in Byram Township, Sussex County is more than a tourist attraction and local gem, it is also home to the largest cross-road amphibian migration in New Jersey. Each spring, frogs, toads, and salamanders stir from their hibernation to make their way to their breeding sites. Some of these sites, like the one at Waterloo, are vernal pools – small, temporary bodies of water that appear in early spring as snow melts and rain and groundwater gathers, and disappear throughout the summer as they evaporate. The ephemeral nature of these pools can’t support fish, which would prey on amphibian eggs and larvae. Vernal pools therefore provide some protection for amphibian offspring, with many species such as wood frogs and spotted and Jefferson salamanders – both of which are listed as New Jersey species of Special Concern – relying exclusively on these vernal pools for breeding.

 

 

The greatest challenge for amphibians breeding at Waterloo Historic Village is crossing Waterloo Road. Living in the most densely population state takes a toll on many species of wildlife in the form of habitat loss, degradation, and fragmentation. Each year, many amphibians become victim to vehicular collision as they move from their hibernation sites across Waterloo Road to the vernal pool in which they reproduce. Amphibians may be disproportionately affected by vehicle-caused road mortalities compared to other wildlife because of their tendency to migrate en masse to breeding sites. These annual road mortalities can have devastating effects on amphibian population sizes, especially for the local at-risk salamander populations. In fact, as little as about 10% annual risk of road mortality in spotted salamanders can lead to the local extinction of an entire population.

 

Wood Frog eggs. Photo courtesy of MacKenzie Hall.

To address this problem, the Conserve Wildlife Foundation of New Jersey (CWF) and the New Jersey Endangered and Nongame Species Program (ENSP) organized amphibian rescue efforts. Since 2002, dedicated volunteers have assisted frogs, toads, and salamanders across Waterloo Road during the busiest migration nights. This aid has proven effective in reducing amphibian road mortalities, but it is not a permanent solution to the problem. Efforts are underway to construct under-road tunnels to help guide amphibians safely across Waterloo Road. These tunnels will provide safe passage for these critters throughout the breeding season, including on their migration back into the woods where they will hibernate. Since this return migration is more sporadic and less weather-dependent than migration to the vernal pool, it is much harder to protect amphibians as they make their way back to the forest.

 

 

This year, CWF scientists have begun the initial phases of research to understand current amphibian population sizes and the impact of vehicle traffic on these animals at Waterloo. Scientists and volunteers have been out 7 days a week since amphibian migrations began in late February to tally daily roadkill on Waterloo Road. This study will be used to evaluate changes to frog, toad, and salamander populations as the under-road amphibian tunnels are installed. CWF scientists have also conducted egg mass counts in the vernal pool at Waterloo Village to estimate the current population sizes of the different amphibian species in the area. Having this knowledge will allow CWF to improve on future projects to minimize road-related human-wildlife conflicts.

 

Spotted Salamander egg mass. Photo courtesy of MacKenzie Hall.

Along with improving conditions for amphibians in this location, CWF’s work at Waterloo Village will serve as an example of New Jersey statewide initiatives to reconnect wildlife habitat as a part of the Connecting Habitat Across New Jersey (CHANJ) program. The goal of CHANJ is to make our state landscapes more permeable to wildlife movement so that all of New Jersey’s residents – human and wildlife – will have the space they need to thrive.

 

In an effort to bring people and wildlife together in a positive way at Waterloo Village, CWF scientists are leading educational walks for the public and local schools. Through hands-on interaction, local residents can learn about and appreciate the remarkable wildlife right in their own back yards and what they can do to support conservation efforts.

 

All New Jerseyans can help wildlife this season by planting native plants for their gardens, building bat boxes where bats can roost, and, of course, by keeping an eye out on the roads, especially on warm, rainy nights when amphibians might be migrating.


LEARN MORE


Allegra Mitchell is a biologist for Conserve Wildlife Foundation of New Jersey.

 

Princeton Seventh-Graders Protect Bats through Hands-on Research Project

Thursday, January 12th, 2017

Students partner with nonprofit Conserve Wildlife Foundation to design better bat houses

By Stephanie Feigin

Although bats have a reputation of being dangerous and scary, these flying mammals are something to be coveted, and the students at Princeton Day School know why. Seventh grade students Albert Ming, Arjun Sen, Martin Sen, Dodge Martinson, Kai Shah, and Samuel Tang teamed up with Conserve Wildlife Foundation to design a better construction plan for bat houses. The students hope to promote better conditions for bats living in Central Jersey.

Bats are in the midst of tragic declines as a consequence of habitat loss and a devastating fungal disease known as White-nose Syndrome. CWF works to preserve bats, which basically provide a free pest removal service. A single bat can consume up to 3,000 mosquito-sized insects in one night! Their value to agriculture is estimated at $53 billion annually in the United States alone. Not to mention they provide mosquito and biting insect control, which are not only a nuisance but also have disease spreading potential.

Many bats in New Jersey have come to depend on manmade bat houses, structures specifically designed and placed for the needs of the bats, and the Princeton Day School students stepped up to help.

First, the students researched the best, most economical type of wood to use for construction. Next, they used an infrared thermometer to see how well heat is absorbed and retained by the different wood types after they were painted and stained using three different colors.

Keeping the inside of a bat house within the right temperature range is vital to the survival of bats, especially the vulnerable young pups. If a bat house becomes too hot (above 95 degrees) or too cold (below 65 degrees), the health of the bats is threatened. Bats move their pups from house to house in search of the right temperatures.

The students used the results of their temperature experiment and high and low temperature readings for Central Jersey over the past three years to design a plan for a bat condo unit that would satisfy bats temperature requirements during their entire six month roosting period.

The x – axis is the number of hours passed during the day and the y- axis represents degrees Fahrenheit.
This graph displays the research for the best type of wood (cedar, pine or plywood) to use for constructing bat houses, along with different kinds of paint (adobe, slate or russet) to determine which combination could retain the most heat for the bat colonies. Heat retention was measured over a long period of time while exposed to the sun.
The research revealed that the bat houses are most successful if they are painted or stained and weather resistant wood like cedar would last much longer than softer wood like pine or plywood. When cedar wood was used the temperature changed the most as the air temperature changed and the least when sunset came. When plywood was used the temperature changed the least as the air temperature changed and the most when sunset came. When pine wood was used the temperature changed moderately as the air temperature and moderately when sunset came.
The conclusion made was that there are differences among wood and paint combinations. Adobe paint on plywood has the smallest average temperature change even though the difference is not statistically significant and adobe paint on cedar had the smallest temperature change between 4 and 6 degrees. They chose adobe paint on cedar or plywood as they are also the most cost effective.

With the results of their research and experiments, the students made informed decisions to design the bat boxes. The final product was three bat houses built using plywood. They painted one of the houses in a black slate color to provide maximum heat during the colder months, and painted a second house in an adobe beige color to provide air conditioning during the hot summer months. Lastly, they chose a russet color to for the moderate months.

CWF Wildlife ecologist Stephanie Feign who worked with the students on the project was happy to see how passionate these kids were to learn and be hands-on. “Their passion and enthusiasm were inspiring. Projects like these not only benefit wildlife, but also benefit surrounding communities and provide experiential learning for students.”

New Jersey is home to nine different species of bats, two of which are listed as endangered or threatened. Six species that do not migrate south for the winter remain in New Jersey to hibernate in a cave or another safe place. When they awake from hibernation in April, the females search for roosting spots to bear and raise their young pups. With so few intact forests in New Jersey, bats are struggling to find places to safely roost.

That is why projects like this one with Princeton Day School are essential for preserving bats. Not only did the projects help bats, but it also helped the students by requiring them to use problem solving and critical thinking skills to protect a creature that they came to value. Wildlife, which kids become excited and passionate about, is a valuable educational tool.

The team is currently working with Princeton Day School facilities to erect the bat condo unit on campus. Hopefully, by next spring, the school will be home to many new, very comfortable bats.


LEARN MORE:


Stephanie Feigin is a Wildlife Ecologist for Conserve Wildlife Foundation.

  • Subscribe!

    Enter your email address to subscribe to the Conserve Wildlife Blog and receive notifications of new posts by email.

  • Support Conserve Wildlife Foundation

    Support our efforts to protect New Jersey’s rarest animals, restore important habitat, and foster pride in New Jersey’s rich wildlife heritage.

    Join - Donate - Adopt a Species
  • Get Connected

  • Recent Comments