Sharing the Shoreline

Each year, Piping Plovers (Charadrius melodus) and Interior Least Terns (Sterna antillarum athalassos) arrive at John Martin Reservoir to raise their chicks. They stay at John Martin through spring and summer, leaving for their wintering grounds in August.

Because both species of birds have declined in recent decades, they are protected by federal and state laws. The populations of these birds that spend their summers at John Martin are special because they are small and isolated.

The U.S. Army Corps of Engineers (USACE) works with Colorado Parks and Wildlife (CPW), the U.S. Fish and Wildlife Service, and the U.S. Geological Survey to run a management project for them.

Piping Plovers

                            Adult Piping Plover                                                                    Juvenile Piping Plover

Identifying features of an adult Piping Plover are highlighted. Photo by USFWS.

Identifying features of a juvenile Piping Plover are highlighted. Photo by Victor W. Fazio III.









  • Small migratory shorebirds
  • Eat small insects and crustaceans
  • Run along the shoreline looking for prey


Interior Least Terns

                           Adult Interior Least Tern                                                     Juvenile Interior Least Tern

Identifying features of the adult least tern are highlighted. Photo by Florida Fish & Wildlife.Identifying features of a juvenile Least Tern are highlighted. Photo by









  • ​Small migratory shorebirds
  • Unique subspecies of Least Terns
  • Eat small fishes
  • Hunt by diving into shallow water

Management Project

  • Began in 1990
  • Joint effort between USACE, Colorado Parks and Wildlife (CPW), and U.S. Fish and Wildlife Service
  • Biologists and park rangers work together to protect the birds and educate visitors

Image of a piping plover.Management Activities

Habitat improvement

  • Invasive tamarisk (also known as saltcedar or tamarack) removal
  • Tamarisk is a large shrubby tree introduced to the U.S. in the 1800s to help with river erosion
  • It has spread throughout the western U.S.
  • Crowds out native species, ruins beachy shorelines, and destroys shorebird habitat
  • USACE rangers regularly remove tamarisk and prevent new plants from establishing

Plover and tern monitoring

  • USACE rangers and CPW biologists monitor nest sites and collect data
  • Data collected include number of breeding pairs, number of eggs laid, and number of chicks hatched
  • This helps USACE and CPW determine the status of the populations

Image of a sign informing the public that the area is closed because of the presence of nesting piping plovers and least terns.Temporary nest site closures

  • Parts of the shoreline are closed in nesting areas to protect nesting birds from human disturbance
  • When people enter nesting areas, plovers and terns are forced to flee and leave their eggs and chicks unprotected
  • Additionally, eggs and chicks are very hard to see and can be accidentally stepped on
  • Closure sites are marked with signs and twine
  • Current closures are posted on our Facebook page, and at the South Shore kiosk 

Bird banding

  • The U.S. Geological Survey bands adults and chicks
  • This allows researchers to estimate survival and track migration

Public outreach

  • John Martin rangers offer educational talks and activities for schools, clubs, and other groups interested in learning about plover and tern conservation
  • If interested, email us at

Ways You Can Help

  • Avoid nesting sites and closed areas - an updated list of closures can be found on our Facebook page and at the South Shore kiosk 
  • These are marked with signs and twine
  • Do not walk, fish, or let your dogs run in these areas
  • Avoid landing your boat in closure areas. Buoys are placed along the shore to mark these areas
  • If you see a plover acting injured, it means you are too close to a nest and should leave the area
  • An updated list of closures can be found here, on our Facebook page, and at the CPW Visitor Center and kiosk
  • If you see someone in a closed area, please contact USACE (719-336-3476) or CPW (719-829-1801)

Image of trash in the back of a truck.

Pick up all litter and throw it away in a trash can

  • Garbage attracts predators to nesting birds, harms wildlife, and can injure visitors
  • Dispose of trash in a designated bin

Bring all hooks and line home with you

  • Leftover lines and hooks can tangle and kill wildlife

Keep dogs leashed while at the Reservoir

  • Off-leash dogs can crush eggs and chicks
  • Learn more about how your pet can have a safe and fun visit by checking out the National Park Service’s B.A.R.K. Rangers page

Report any unusual activity

  • If you find a dead plover or tern, contact us immediately (719-336-3476)
  • Do not touch it; take a picture and let us know where the bird is
  • Contact us if you find a plover or tern nest outside closed areas

Plover/tern eggs are labeled in this image.






Spread the word

  • Tell other visitors about the plovers and terns at John Martin
  • Follow us on Facebook for updates

Nesting Season Newsletter

USACE created a newsletter with highlights from last year’s nesting season and information about individual birds nesting at John Martin.

** Download the 2024 newsletter here. **

Click here to sign up to receive our annual newsletter in your inbox and to view previous year's newsletters.

Eastern Black Rails

The Arkansas River Valley, including John Martin Reservoir, is also home to the federally threatened Eastern Black Rails. These marsh birds are a migratory wetland species, the smallest of the rails, and populations are rapidly declining. Little is known about this species because they are very secretive and notoriously difficult to study, which makes conservation efforts very difficult.

An Eastern Black Rail parent with chicks at John Martin Reservoir. Photo courtesy of CPW.









We do know that they require wetlands with dense plant cover and extremely shallow waters. Rails use these wetlands to breed and raise their chicks, during which time adults are flightless and vulnerable to predators and extreme weather.

The wetlands throughout the Arkansas Valley and around John Martin provide important habitat for the rails, as well as other species such as waterfowl, amphibians, and fish. Wetlands are also beneficial to people because they:

  • Improve water quality
  • Prevent shoreline erosion
  • Reduce flooding damage
  • Store carbon
  • Provide recreation opportunities

The most important thing we can do for rails and other wetlands species is to protect their habitat. To learn about wetlands in your area, click here to visit the National Wetlands Inventory. 

Sunset on the wetlands at John Martin Reservoir. Photo courtesy of USACE.

Bald Eagles

A Bald Eagle prepares to take flight. Photo courtesy of CPW. Once on the brink of extinction, protection by the Endangered Species Act helped bald eagle populations rebound. These majestic birds spend the winter at John Martin Reservoir, arriving in the fall and staying until late spring. Bald eagles hunt for fish in the reservoir and as many as 100 birds may congregate in the same area! Since 2007, they are no longer listed as endangered, though they are still protected by the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act.

If you’d like to see the bald eagles at John Martin, use the following tips:


  • Look for eagles roosting in cottonwood and elm trees along the reservoir and Lake Hasty.
  • Dawn and dusk are the best times to view them.
  • Use binoculars or a spotting scope to admire them from a distance and do not get too close. Eagles are very sensitive to human disturbance and well-meaning visitors can scare them off their roost.
  • Pick up all trash and food scraps. Human food is bad for the birds and can harm them.