Migratory shorebirds

Pacific Rim National Park Reserve

Stressors | Monitoring | Findings


Migratory shorebirds use the Pacific coast as a flyway between their breeding grounds in Canada, the United States, and the Russian Arctic, and their wintering grounds in South, Central and southern North America. They migrate north in the spring, and back down south in the fall after breeding season. These birds are critically dependent on the beaches in and around Pacific Rim National Park Reserve to rest and replenish their energy stores.

Their timelines and energy reserves leave little room for unexpected setbacks. Delays in their journey and stressors such as human disturbance can compromise their survival and breeding success. This can lead to a long-term drop in their population numbers.

Pacific Rim National Park Reserve’s 20 kilometres of ocean beaches and in-land mudflats make great stopover locations for migratory shorebirds because these areas are home to the small insects, invertebrates, bloodworms and biofilm that make up a shorebird’s diet. 


Human disturbance

Volumes of research conducted to date demonstrate that sandy beaches, which are a primary habitat and foraging area for shorebird species, are a common place where human-wildlife conflict occurs.

Humans disturb critical shorebird activities, like foraging for food, by participating in fast-paced recreational activities, like running and cycling, and unlawful activities, such as letting dogs and pets roam the beaches off leash. When flushed by people or dogs, shorebirds are forced to expend extra energy to avoid potential predators. This stress interferes with their ability to refuel before continuing their migration.

Parks Canada staff on bicycles talking with a couple on the beach with three dogs on leash

Did you know?

Dogs are permitted in the Long Beach area of Pacific Rim National Park Reserve, with the exception of Combers Beach from April 14 to October 1. In areas where dogs are permitted, they must be on leash at all times. This includes beaches, trails, parking lots and in the water.

Learn more

How is Parks Canada monitoring shorebird populations?

The effect of human disturbance on migrant birds is a conservation issue of international importance as it can lead to population declines. Disruptions can occur during migration, wintering, breeding and foraging. To better understand how visitor use of beaches in Pacific Rim National Park Reserve impacts shorebirds, Parks Canada has been monitoring migratory shorebird habitat use. Researchers look at a 100m stretch of sandy beach during one hour of the day, tracking the total number of birds spotted. By monitoring the six key shorebird species present during spring and fall, we can better understand population trends.


  • Six key shorebird species present during spring and fall:
  • Dunlin
  • Least Sandpiper
  • Sanderling
  • Semipalmated Plover
  • Western Sandpiper
  • Whimbrel


Radio-telemetry project
In 2018, Parks Canada initiated a radio-telemetry project to determine how long individual shorebirds stay in Pacific Rim National Park Reserve during spring and fall migration and how they divide their time between ocean beaches and inland mudflats. Here, several dozen shorebirds of four species have been fitted with miniature VHF radio transmitters weighing less than 1g and tracked for the duration of their stay in Pacific Rim National Park Reserve.
33 shorebirds were tagged in Pacific Rim National Park Reserve as part of the radio-telemetry project. Data on the birds’ movements was collected through receivers at these locations: Kwisitis Visitor Centre on Wickaninnish Beach, Dinner Island in Browning Passage, The Wickaninnish Inn in Tofino.
Note: Data receivers are part of the Motus Wildlife Tracking System, which is an international collaborative research network. Learn more.
  • Environment and Climate Change Canada - Canadian Wildlife Service
  • Rainforest Education Society


Data from these receivers was downloaded in October of 2018. The number of detections per bird varied widely from 31 to 44,835. The tagged birds were primarily detected by the receiver at the Kwisitis Visitor Centre

Residence time


Birds stayed at the study area on average 5.1 days, with a minimum of one bird that was detected for 3.6 min to a maximum where the bird remained at the site for 13.1 days.  Western Sandpipers stayed an average of 1.6 days, whereas Semipalmated Plovers remained an average of 6.8 days. Sanderlings remained an average of 11.3 days. 

Long distance migrations



Most birds were only detected at the three sites in the Pacific Rim region (Kwistis Visitor Centre, Dinner Island, Wikaninnish Inn) however two birds that were tagged at Long Beach were detected elsewhere on the Motus Network. One Western Sandpiper tagged on August 24, 2018 was detected again in Florida on September 19th, 2018. The other bird - a Sanderling - tagged on September 6th, 2018, remained near Tofino for 13 days and then was detected again in Texas on Oct 1st and 2nd, 2018. 

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