Conserving Purple Martins and Studying Natal Dispersal

The Lehigh Valley Audubon Society, The Acopian Center for Ornithology at Muhlenberg College, and Northampton County Parks and Recreation have worked hard to bring Purple Martins back to the Lehigh Valley over the past few years in places like Lake Minsi. With these colonies now boasting large numbers of breeding martins, the question arises: where will the newly hatched Purple Martin chicks nest? Some will return to the colony where they were born, if there are empty nesting gourds. Many of these birds, once they return to the Lehigh Valley for their first breeding season, will have to find somewhere else to nest. Where will these martins go?

This phenomenon is called natal dispersal. It is the permanent relocation of a Purple Martin during the breeding season, and it is an important part of how the birds find new nesting colonies. Natal dispersal remains a mystery for martin enthusiasts and researchers alike, and we’re trying to answer this question.

In conjunction with the University of Delaware and the Purple Martin Conservation Association, we are studying how far and frequently Purple Martins disperse from their breeding site. This information will be critical in the establishment of new colonies.

Purple Martin chicks are being color banded in the Lehigh Valley to track this natal dispersal. Each martin chick gets a color band that ties it to the colony where it hatched. Then, we can “resight” this bird in the field the next year, and see how far the bird has dispersed, based on where that bird is re-found. More banding from our collaborators is starting in southeastern and northwestern Pennsylvania. All of the martins across the state are color banded with a unique combination of colors, so we’ll know exactly where each banded bird we find originated.

Because Purple Martins can disperse so widely, we need your help looking for dispersed birds! Whether you have Purple Martins nesting on your property or in a local park, you can participate in this research project by looking for small, colored bands on the legs of Purple Martins. If you see a color banded bird at your colony, please let us know! First, record what color band or bands you see, the relative position of each band, and which leg the bands were on. If you have a camera, take some pictures! The easiest way to submit your sightings is with this web form: https://bit.ly/PA_Martin_Study. If you have pictures of a color banded bird at your colony, you can send them to Will Krohn, the graduate student at the University of Delaware helping conduct this research, at wkrohn@udel.edu. If you can’t complete the online form, you can also call Will at 484-702-1276.

Read more about recent LVAS Purple Martin towers.

Support our conservation efforts in the Lehigh Valley by becoming a member of our chapter, volunteering with us &/or donating.

LVAS Birding Packpack Program Continues

Carla Derck

Originally Published in January - March 2025 Quarterly Newsletter of The Lehigh Valley Audubon Society

The success of the LVAS birding backpack program continued this past fall with four kids’ backpacks presented to the Bethlehem Public Library on December 9, 2024. A collaborative grant from the National Audubon Society helped fund the expanding program.

At the suggestion of the library, a new item was added this time – a journal in which borrowers can record what, where and when they see birds. The journal remains with the backpack for future borrowers to reference and add their own sightings. The program has been so well-received that we may be expanding it to more area libraries in the future.

Photo of LVAS Board Member, Carla Derck, delivering Birding Backpacks to Bethlehem Public Library

Engage with Lehigh Valley Audubon Society to be notified of future educational programs, guided walks, volunteer opportunities, and all of our latest activities.

If you’re not already a member of our Community Chapter of Audubon, please join, volunteer &/or donate to help with our ongoing Lehigh Valley educational and preservation efforts.

Read about more of our past activities in our newsletter archives.

Bluebird Nest Box Tips from LVAS Habitat Committee!

Spring thaw is right around the corner!!

Eastern Bluebird at entrance to nest box - photo provided by Lehigh Gap Nature Center

Provide Clean Nest Boxes for Bluebirds

Now is a great opportunity to finish up some winter projects and get ready for nicer weather and some great birding.

If you are thinking about adding a bluebird box to your property, now is a great time to get it installed. Birds are slowly moving around and starting to inspect locations for nests this season.

If you have nest boxes up already, now is the time to get them cleaned out and ready for the next generation of bluebirds! No need to add material, simply remove any old nesting material or caches that rodents may have left for winter.

Keep an eye out for more bird/habitat tips!

If you’re not a member of our Community Chapter of Audubon, please join and/or volunteer to help with our ongoing Lehigh Valley habitat preservation efforts.

You can read summaries of some of our efforts to Preserve habitat in the Lehigh Valley, like our multi-species Nest Box Trail System, or read related, more detailed stories by clicking a tag or category to filter this page.

Additional Bluebird Nest Box Construction and Maintenance Information:

https://nestwatch.org/learn/all-about-birdhouses/birds/eastern-bluebird/

https://www.audubon.org/news/how-build-bluebird-nest-box

Engage with LVAS, Help Maintain and Monitor Purple Martin Condos

We’ll need more help this year with installation labor, monitoring, maintenance, winter storage, and, of course, all the banding and data collection done each nesting season.

There were NO Purple Martins nesting at Minsi Lake before 2020. Thanks to Lehigh Valley Audubon Society (LVAS) volunteers, a large and growing Purple Martin colony can now be seen at Minsi Lake.

In 2024, the Northampton County Parks and Recreation and LVAS partnership managed 108 condos in six nesting towers—five at Minsi Lake Park and one at Louise Moore Park. Occupancy during nesting season in the Minsi Lake condos was over 90% with nesting pairs in 80 of the 90 condo units, including 36 new units.

Interested in volunteering? Email James Wilson, Recreation & Conservation Specialist for Northampton County Parks, at jwilson@norcop.gov to help with this Purple Martin project.

Complete the LVAS Volunteering Form to let us know what other volunteer opportunities might interest you.

Read more about Purple Martins at Minsi Lake.

The Impacts of Road Salt on Birds and Other Wildlife

Jennifer Latzgo, Pennsylvania Master Watershed Steward and Member of Little Lehigh Watershed Stewards

Originally Published in October - December 2023 Quarterly Newsletter of The Lehigh Valley Audubon Society

It won’t be long before winter weather is upon us again, and the salt trucks are rumbling along Lehigh Valley roads. Road salting and brining are very effective at preventing accidents, but unfortunately, the application of sodium chloride and other similar chemicals can have a significant environmental impact which affects birds and other wildlife.

As more and more land is built up into warehouses, factories, and housing developments, the amount of roads, parking lots and other impervious surfaces increases too. This results in greater amounts of salt being applied by both local road crews and private contractors. Added to that, over the past 20 years, there has been an increasing expectation of completely clear roads and zero accidents due to icy conditions. This has led to fears of litigation, which have resulted in greater and greater amounts of road salt being applied. This increase has been exponential; rising from about 5,000 tons in the 1940’s to about 25 million metric tons today.

Graph courtesy of Stroud Water Research Center and Carey Institute of Ecosystem Studies. Data from USGS.

Once it is applied to roads and parking lots, this road salt enters the environment in various ways . Subsequent rain events will produce salty runoff which can flow across the land directly into streams, ponds, lakes, and wetlands, or it can seep down through the soil into the ground water. Even though the period of applying salt is just a few months of the year, this salt stays in the environment year-round. A recent study by the Little Lehigh Watershed Stewards showed elevated salt levels in local streams flowing at base level in August. This was done at a time when there had been no recent rainfall and the streams were being primarily fed by groundwater. Other studies from around the country show that the level of salt in streams, ponds, lakes, wetlands, groundwater, and drinking water is increasing.

For our birds, the application of road salt can be dangerous in various ways. Birds have kidneys that are less efficient than mammalian kidneys at removing sodium, and if they take in too much, they need to increase their water intake. This means that directly ingesting salt particles can be lethal . Sadly, dead birds have been observed on roadsides after salt has been applied in winter. Other birds have also been seen exhibiting strange behavior such as fearlessness or appearing to be weak, sick, or slow . These are all signs of having ingested too much salt.

Why are birds attracted to road salt?

Studies have found that they are looking for grit to digest their food, and the salt particles are the same size as grit. If birds do not have access to water, which may well be the case in wintertime, they can experience toxicological effects and die after ingesting as little as one particle of salt. Additionally, being attracted to roadside areas, and possibly having reduced fear on top of that, means that they are at high risk of being hit and killed by vehicles.

The other risk for birds is that increased salt levels interfere with the food webs that they depend on. If you go to any healthy creek and look among the rocks, you will find it teeming with all kinds of tiny creatures including insects, larvae, worms, and crayfish. Scientists call these animals macroinvertebrates, and their quantity and diversity are used as a very accurate indicator of stream health. Studies show that macroinvertebrates are negatively affected by increases in salt levels which cause stress and stunted development at low levels and mortality at high levels.

Other life in streams, lakes, and wetlands is also negatively impacted by salt . This includes zooplankton that live in ponds, lakes, and wetlands. They are important because they consume phytoplankton which can be the cause of algae blooms. Amphibians such as wood frogs and salamanders are vulnerable because they absorb salt through their skin. Also, wood frog tadpoles hatch in early spring when the salt levels are highest and can result in deformities as well as increased mortality.

So, as you can see, we have a big problem which is only going to get much worse if steps are not immediately taken.

What can you do?

First of all, be aware of the quantity of salt that you apply to your driveway and sidewalks in wintertime. You can reduce the amount you need by shoveling regularly. When you apply the salt, use about 12 ounces for a 20 foot driveway or 10 sidewalk paving squares. Always sweep up any leftover salt.

If you live in a controlled development that uses a private contractor, pay attention to how much road salt is being used, and if it appears to be excessive, bring it to the attention of your homeowners’ association.

Using liquid salt brine can result in as much as 70% less salt being used. Some municipalities such as the City of Allentown have switched to brining in recent years. If your municipality is still using salt crystals, encourage them to change to brine. There are also other measures that municipalities can take such as covering salt piles and using application regulators on their equipment. If you are interested in knowing more, check out the information at this link: https://www.iwla.org/water/stream-monitoring/salt-watch/road-salt-best-practices

Sources

Environmental Hazards of Road Salt https://extension.psu.edu/environmental-hazards-of-road-salt#:~:text=This%20exponential%20increase%2

A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales https://pubs.acs.org/doi/10.1021/es101333u

River chloride trends in snow-affected urban watersheds: increasing concentrations outpace urban growth rate and are common among all seasons https://www.sciencedirect.com/science/article/pii/S0048969714017148?via%3Dihub

Road Salts and Birds: An Assessment of the Risk with Particular Emphasis on Winter Finch Mortality https://www.jstor.org/stable/3785019#:~:text=The%20high%20attraction%20of%20salted,wildlife%20mmanag

Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica) https://pubmed.ncbi.nlm.nih.gov/16159689/

Muhlenberg Professor Daniel Klem, Jr. Honored with Walt Pomeroy Conservation Award

The Pennsylvania Audubon Council Eastern Chapter gathered at Muhlenberg College in Allentown, PA on November 2, 2024 to discuss challenges common to the three PA Council Chapters, to prioritize issues and to collaborate on solutions.

In the afternoon, Leigh Altadonna, President of the Pennsylvania Audubon Council, and Peter Saenger, President of the Lehigh Valley Audubon Society, presented the “Walt Pomeroy Conservation Award” to Muhlenberg Professor Dr. Daniel Klem, Jr. for his decades of avian research, including studies on bird deaths caused by window strikes.

Dr. Klem was nominated for this honor by the Lehigh Valley Audubon Society and the Presque Isle Audubon Society, and he was selected unanimously by the Council’s Executive Committee.

The award is a framed limited edition print of a Peregrine Falcon that was originally created to help fund the Lycoming Audubon Society's Peregrine reintroduction project in Williamsport, Pennsylvania.

Pictured with his family, Dr. Daniel Klem, Jr., author of Solid Air, accepts the “Walt Pomeroy Conservation Award” presented to him by the Pennsylvania Audubon Council