Status of Species
The proposed status for the Killdeer is Special Concern under COSEWIC assessment and criteria. Over the past 52 years the species population has shown a great decline (Killdeer Life History, 2017). The species meets some but not all criteria necessary for it to be listed as Threatened however, if factors posing a threat to the species are not fixed than the species may shortly demand a Threatened status.
Cause of Decline
The species is vulnerable to 20th century problems which seems to be its main cause for decline. The species enjoys living in human modified habitats which puts them at risk to a variety of factors such as pesticide poisoning, collisions with cars, lawnmowers, oil pollution and more (Jackson, 2000).
Recovery Summary
Action Summary
Background
Species Name and Classification
Scientific name: Charadrius vociferus
Common name: Killdeer
Taxonomic group: Birds
Family: Charadriidae
Distribution
The killdeer is among the most widespread of North America’s shorebirds. Their breeding range includes all provinces and territories with the exception of Nunavut and Newfoundland (Climate Change Canada, 2018). The species is mostly found in and breeds in Canada however, they can also be found in the United States, Mexico and parts of South America and Europe. Killdeer are resident or medium distance migrants as some northern birds spend their winters in Mexico. As seen in Figure 1, the birds tend to breed in the Northern Region and in the southern US, the birds live there year round (Killdeer Life History, 2017).
General biology & life-history
Habitat
Killdeers are plovers that inhabit flat areas with vegetation that is usually no taller than one inch. They primarily inhabit open spaces and are most familiar in urban areas where they live on lawns, driveways, open fields or in parking lots. While they can be found near water, unlike other shore birds, they also enjoy dry areas (Killdeer Life History, 2017). Though killdeer are not too picky with their environment, temperature is the main factor that determines where the species can or cannot live. They cannot live in temperatures lower than 10 degrees Celsius so when the temperatures drop, the bird must migrate (Chung, 2001).
Diet
Killdeer primarily feed on invertebrates such as snails, grasshoppers, earthworms and beetles. One hunting strategy that the killdeer practices is to follow farming plows with the hope of retrieving any insects or worms that are brought to the surface (Killdeer Life History, 2017).
Reproduction and Nests
Killdeer are monogamous as they remain together year round and may even breed together for several years. They usually begin breeding in early spring and nesting may begin anywhere from March, if they live in the southern United States to June, if they live in Canada. Killdeer may lay up to three broods per season but usually only raise one successfully. Eggs are incubated for 24 to 28 days and after hatching, the birds will remain with their parents for 20 to 31 days (Dewey, 2001). Killdeers nests are about 3-3.5 inches across making them very small as well as shallow. Killdeer make their nests out of scraps such as rocks, shells and even trash (Killdeer Life History, 2017). Both nest construction and incubation is the responsibility of both parents (Dewey, 2001).
Description
Adult killdeer range in size from about 9-10 inches (Dewey, 2001). They have a large head, large eyes and a short bill and they are slender with a long pointed tail and long wings. They are brown/tan in colour on top and white underneath. Their chest has two black bands while their face is marked with black and white patches (Killdeer Life History, 2017). Killdeer on average live to be about 3 to 5 years old however, they have been recorded to live as long as 10 years (Animal Spot, 2018).
Predators
Neither adult nor young killdeer have any specific predators, however, as most small birds, they are predators of bigger species such as birds of prey, coyotes, skunks, raccoons, etc. (Animal Spot, 2018). In order to defend themselves against a deliberate threat they will use their famous tactic, known as the “broken wing” act. They spread and hang one wing in hopes that it appears broken and they will cry out loud in order to lure their intruder away from their nest (Canadian Wildlife Federation).
Population Sizes and Trends
Global population trends of the species show a 47% decline since 1966 with majority of this decline occurring since 2012 (Killdeer Life History, 2017). Canadian population trends show a 30% decrease over three generations which is equal to a total of 76% decline since 1970 (Climate Change Canada, 2018). It is estimated that currently there are between 500,000 and 1 million breeding birds in Canada (Killdeer(Charadrius vociferus)).
Threats
Since the species enjoys living in urban and human modified areas, they are vulnerable to many 20th century problems such as collisions with cars and buildings, oil pollution, pesticides, lawnmowers and more thus making urbanization likely the greatest threat to the species (Killdeer Life History, 2017).
Special Significance
Although Killdeer inhabit a variety of areas, they are not a keystone species, they do not have any major effects on their ecosystem and even though some animals are predators to them, they are not the main source of food for any other species. However, killdeer are very useful to farmers as they have a large appetite for pests (Canadian Wildlife Federation).
Existing Protection
There is no existing protection for the killdeer and currently the species is listed as least concern by the IUCN (IUCN, 2016).
Proposed status with COSEWIC guidelines
After close consideration of the data available on the killdeer, it is believed that the killdeer should be listed as Special Concern by COSEWIC. As being given this listing, the killdeer meets criteria such as its abundance having declined due to being increasingly threatened by various demographic or environmental factors. If these factors are not reversed or managed than it is reasonable to assume that the killdeer may become threatened (Climate Change Canada, 2018).