Corvids
There are many bird species that can be classified as a corvid. In Edmonton, these include American crows, common ravens, blue jays, and black-billed magpies. These birds are commonly found in and around human settlements, such as playgrounds, parks, and urban and suburban neighbourhoods, though they may inhabit rural areas, such as farms. They are attracted to these areas due to the food scraps people leave as litter or in their garbages. Corvids are able to survive and reproduce in these areas due to the amount of food and shelter available to them. Common ravens and American crows are both black, but American crows are smaller. Blue jays have a white chest with blue, white, and black plumage. Lastly, black-billed magpies have white and black plumage with blue-green iridescent feathers in the wing and tail.
Each corvid species will have different social behaviours, with some preferring to reside in large groups and others preferring to be alone or in pairs. Black-billed magpies are one of the more social species of corvid and prefer to live in groups. They will often be seen in pairs in backyards. During the breeding season, corvids are more social with conspecifics; however, they will not interact with other animals unless they are being preyed upon or finding food for themselves.
Further information:
The Canadian Encyclopedia - American Crow
Living with corvids
All about birds
Each corvid species will have different social behaviours, with some preferring to reside in large groups and others preferring to be alone or in pairs. Black-billed magpies are one of the more social species of corvid and prefer to live in groups. They will often be seen in pairs in backyards. During the breeding season, corvids are more social with conspecifics; however, they will not interact with other animals unless they are being preyed upon or finding food for themselves.
Further information:
The Canadian Encyclopedia - American Crow
Living with corvids
All about birds
Corvids in Urban Areas
Edmonton is a continually growing urban city with a diverse river valley running through it. Wildlife have used the river valley as a way into and out of the city, thus increasing the urban wildlife population in Edmonton. Corvids are one of the species that have moved into the city and have adapted to live in human settlements. They seek out areas where humans live in order to find readily available food sources and shelter. Corvids are opportunistic omnivores, meaning that they scavenge for food and are able to eat a wide range of foods to sustain themselves. Their diet consists of worms, fruits, berries, insects, young chicks of other bird species, and leftover food from garbages. If a corvid comes upon a defenceless nest of baby chicks, it will take the opportunity to prey upon them.
Corvids are intelligent birds and have good memories, enabling them to remember where they are able to find food and return to those areas again and again. This is especially beneficial to them in cold weather when food is scarce.
Further information:
The American Crow
Corvids are intelligent birds and have good memories, enabling them to remember where they are able to find food and return to those areas again and again. This is especially beneficial to them in cold weather when food is scarce.
Further information:
The American Crow
Encountering Corvids
As the city grows, so does the likelihood of interacting with wildlife. Corvids are common in urban areas so it is important to know how to interact with them and what to do when encountering them. Many people do not have encounters with corvids; however, they are commonly seen throughout Edmonton. With these limited encounters, citizens may not know how to interact with them. The best thing to do when seeing a corvid is to give it space. They are territorial of their feeding grounds and protective of their nests. If people get too close to these areas, corvids will dive towards them but will not intentionally contact or harm them. This is a defence mechanism to scare off intruders. If this occurs, it is recommended to walk away from the area.
Further information: American crows and black-billed magpies Blue jays |
Creating a Healthy Backyard
It is common to see corvids in people's backyards. A healthy backyard can provide urban wildlife species with a safe area where they can exhibit their natural behaviour. There are many ways to encourage corvids into a yard and ways to create a healthy backyard for these birds. Corvids are attracted to areas that offer protection, food, and shelter. Trees can provide corvids with both shelter and protection. Corvids perch, nest, and hide from potential predators, such as neighbourhood cats, in trees. If there are more trees in the yard then there will likely be more corvid inhabitants. Corvids will also be attracted to yards with bird baths where they can cool off and will avoid new or shiny objects. Another way to attract these birds to the yard is by providing sufficient amounts of food. This can be through feeding pets outside, leaving the lids off of garbage cans, or keeping a flower bed or compost where worms and insects will likely be found.
A healthy backyard can be designed to attract or deter certain species of wildlife. If an individual does not want to attract corvids to their yard, there are certain measures that can be followed. These include the following:
Further information:
Radio Recording of "The Thieving Magpie"
Crows in urban areas
A healthy backyard can be designed to attract or deter certain species of wildlife. If an individual does not want to attract corvids to their yard, there are certain measures that can be followed. These include the following:
- Secure garbage bags in sealed containers
- Limit the amount of nesting areas in trees
- Feed pets indoors
- Place new or shiny objects in the backyard
- Ensure the compost is not readily available to wildlife
Further information:
Radio Recording of "The Thieving Magpie"
Crows in urban areas
Zoonotic Diseases
Zoonotic diseases are infectious diseases that can be transmitted between animals and humans. West Nile Virus (WNV) is one of these diseases. It was first observed in Africa before being discovered in New York and Canada. WNV is a prominent zoonotic disease that affects corvids more than other bird species. It is a fatal virus for corvids. The virus travels in the blood of the bird as it multiplies. WNV is transmitted from corvids to humans when a mosquito, which acts as a vector, bites the bird and transfers the virus to a human. It can not be transferred between humans except from mother to child through breast milk. Unfortunately, there is no treatment or vaccine against WNV; luckily, most people who become infected with WNV will not show any clinical symptoms and will be unaware of their infection.
Possible symptoms of WNV include:
There are a number of steps that can be taken to limit the spread of WNV. They are the following:
Further information:
Government of Canada - West Nile Virus
Alberta: Agriculture and Rural Development - West Nile Virus
Centers for Disease Control and Prevention - West Nile Virus
Health informatics - West Nile Virus
- Headache
- Meningitis
- Stiff muscles
- Fever
- Fatigue
There are a number of steps that can be taken to limit the spread of WNV. They are the following:
- Limit the amount of wet areas in the yard, including puddles and kiddie pools
- If the property has a pool, ensure that the water is constantly moving and being filtered
- Wear dark clothes that cover most of the skin's surface
- Do not go outside when it is dark as the mosquitoes are more likely to be active
- If handling dead birds, be sure to wear protective clothing, including gloves
Further information:
Government of Canada - West Nile Virus
Alberta: Agriculture and Rural Development - West Nile Virus
Centers for Disease Control and Prevention - West Nile Virus
Health informatics - West Nile Virus
Population Management
In Edmonton, there is no known population management protocol established for corvids; however, there are certain steps a person can take in order to minimize the prevalence of corvids on their land. It is illegal to harm or kill birds and other animals in parklands and public areas. Many birds are protected under Canadian law; however, the following corvids are not: American crows, black-billed magpies, and common ravens. However, common ravens are allowed to be hunted on private property by the owners of the land. Even though these birds are not protected under any laws or regulations, we do not advocate or advise shooting the birds. Many of the birds that are shot do not die instantly and are brought to the Wildlife Rehabilitation Society of Edmonton (WRSE). The birds that are brought in usually have irreversible damage of the nervous system, requiring them to be euthanized.
If a corvid population is being a nuisance in a crop or yard, the easiest method of control is to trap the birds. Traps can be obtained through the city or made by the individual. Once the birds are trapped, Animal Care and Control Officers will come to the residence and pick up the birds.
To ensure that unwanted corvids do not return to the residence or crop, preventative steps must be taken. If the corvids have disturbed a farmer's crop, a scarecrow can be placed in order to deter the corvids. More measures are outlined in the above section, "Creating a Healthy Backyard".
Further information:
Alberta Guide to Hunting Regulations
City of Edmonton - Wildlife
Bylaw 2202 - Animals Section 17 part 4
If a corvid population is being a nuisance in a crop or yard, the easiest method of control is to trap the birds. Traps can be obtained through the city or made by the individual. Once the birds are trapped, Animal Care and Control Officers will come to the residence and pick up the birds.
To ensure that unwanted corvids do not return to the residence or crop, preventative steps must be taken. If the corvids have disturbed a farmer's crop, a scarecrow can be placed in order to deter the corvids. More measures are outlined in the above section, "Creating a Healthy Backyard".
Further information:
Alberta Guide to Hunting Regulations
City of Edmonton - Wildlife
Bylaw 2202 - Animals Section 17 part 4
Research
Ellis, J., T. A. Langen, and E. C. Berg. 2009. Signalling for food and sex? begging by reproductive female white-throated magpie-jays. Anim. Behav. 78: 615-623.
Jokimaki, J., and J. Suhonen. 1998. Distribution and habitat selection of wintering birds in urban environments. Landscape Urban Plann. 39: 253-263.
Lindsey, K. J., and C. E. Adams. 2006. Public demand for information and assistance at the Human–Wildlife interface. Human Dimensions of Wildlife. 11: 267-283.
Marzluff, J. M., and E. Neatherlin. 2006. Corvid response to human settlements and campgrounds: Causes, consequences, and challenges for conservation. Biol. Conserv. 130: 301-314.
Shephard, T., S. Lea, and d. I. Hempel. 2015. 'The thieving magpie'? no evidence for attraction to shiny objects. Animal Cognition. 18: 393-397.
Ellis, J., T. A. Langen, and E. C. Berg. 2009. Signalling for food and sex? begging by reproductive female white-throated magpie-jays. Anim. Behav. 78: 615-623.
Jokimaki, J., and J. Suhonen. 1998. Distribution and habitat selection of wintering birds in urban environments. Landscape Urban Plann. 39: 253-263.
Lindsey, K. J., and C. E. Adams. 2006. Public demand for information and assistance at the Human–Wildlife interface. Human Dimensions of Wildlife. 11: 267-283.
Marzluff, J. M., and E. Neatherlin. 2006. Corvid response to human settlements and campgrounds: Causes, consequences, and challenges for conservation. Biol. Conserv. 130: 301-314.
Shephard, T., S. Lea, and d. I. Hempel. 2015. 'The thieving magpie'? no evidence for attraction to shiny objects. Animal Cognition. 18: 393-397.