Nest Site Abandonment
Adult piping plovers remain wary of repetitive or intense disturbances in the immediate area of the nest. If adults are scared, they may abandon a nest for their own safety. These pairs will often re-nest somewhere else on the beach in the hopes that it will be a “safer” place. This extends the time that a pair is actively nesting, increases stress in the birds and gives the chicks a late start which decreases the chance of a successful migration. The intent of the Piping Plover Recovery Program is to give plovers the best shot at nesting successfully by reducing disturbance and threats.
How to tell if a plover is feeling threatened:
You have probably come across a piping plover during your time at on the beach. Generally people should try to give the birds space (aim for fifty metres, especially if you are observing them for a long period of time). There are a few situations where you should leave an area calmly but quickly:
Broken-Wing Display – If predators come close to a nest, the adult plover will attempt to distract them away from the nest location. The eggs in the nest are camouflaged, and because the nest is just a depression in the sand it is very difficult to locate on its own. Adult plovers will move quickly away from the nest, and distract potential predators by faking an injury — in this case, a broken wing. This can be very effective, as long as the disturbances are infrequent. If you see a plover dragging a wing near the ground, move away from the plover while watching the ground around you. It is very likely that you have come very close to a nest and you should be observant to avoid accidentally stepping on it! Please report this behaviour to the Volunteer Coordinator.
Piping – Piping plovers are named for their clear “pipe” call. If you hear a persistent ‘piping’ you may be getting too close to them. This call is used mainly when there are young chicks in the area. Your presence is stressful to the parent plover — so try your best to locate the family and move around them. Try not to come between the adults and the chicks. If you wish to observe a family of piping plovers, do so from a distance. Piping is also used if merlins, a predator, are in the area. Giving plovers space to get away from this fast predator is important.
Piping plovers can nest successfully even in areas of high use with a few helpful protection measures and the cooperation of beach goers. Legally, piping plovers, their nests, and the habitat necessary for their survival are protected by multiple pieces of federal and provincial legislation, including the Endangered Species Act (Ontario), Species at Risk Act (Canada) and the Migratory Birds Convention Act (Canada). The Ontario Endangered Species Act protects individuals from a variety of actions — including causing harm, harassment, or death. To help the piping plovers nest successfully, and to help beachgoers abide by these laws, a few protection measures used on the beach are described below:
Predator exclosures are cage-like structures that are placed around nests of piping plovers to exclude predators from the eggs. They are made so that adult plovers and their chicks can move freely in and out, keeping larger predators like merlins, crows, gulls, foxes, and domestic pets away from the eggs. Shortly after, there will be a roped off area of approximately fifty metre radius placed around the nest. This is called a perimeter fence and it has signs that prohibit entry, by anyone other than authorized personnel. The Ontario Ministry of Natural Resources & Forestry (OMNRF) and Canadian Wildlife Service (CWS), construct the exclosures to minimize the risk of plovers abandoning a nest site. These cages also protect the nest from accidental damage by people. To construct and place the cages, one must have specialized training and acquire permits from federal and provincial agencies.
After the final egg is laid, both the male and the female will take turns incubating the eggs. When the adult is relieved from its incubating duties by its partner, it spends time foraging or looking for food along the beach. Incubation shifts can be anywhere from thirty minutes to four hours! The chicks will hatch in 26–30 days. Once hatched, the chick is immediately mobile and active. At this point, each plover family may behave differently. Some will stay close to their original nest site, while others may venture along the beach. In all cases, the chicks are particularly vulnerable. Parents remain vigilant to protect their young from predators including gulls, merlins, and other predators. Disturbing parent plovers when the chicks are still young could allow a predator to have a successful hunt. Chicks are also vulnerable to the cold and rely heavily on their parents as a source of heat. Chicks will “brood” or huddle underneath one of their parents to stay warm. The parent may look like it has ten legs and be doubled in size.
As the chicks grow, they become more adventurous. Usually the mother plover will start her migration south when the chicks are two to three weeks old, and the father will remain to guard and teach the young. The chicks grow to be the size of adults in three to four weeks. The father plover will start his migration south when the chicks are four or five weeks old and have demonstrated an ability to fly. The chicks remain on the beach until they have eaten enough to fuel their flight south. They will continue to practice flying during this stage, and will use more areas of the beach. The young plovers will fly to overwintering areas on their own. It is still a mystery how they know where to go without following an adult plover. We won’t necessarily see these young back on our beach, as juveniles will usually disperse to avoid nesting on the same beach as their parents. Successful parents usually do return, and individuals are recognizable by the coloured bands placed on their legs. Most of the new or first year birds we see along Lake Huron’s shoreline were hatched from nests in Michigan, reinforcing that international cooperation and communication is essential for the survival of this species.