Import of Northern cardinal – risk to biodiversity in Norway


Report no: 2023: 18

Published: 30.06.2023

Key message:

The risk of negative impact on biodiversity in Norway from import and private keeping of the Northern Cardinal is low.

This is the main conclusion in the risk assessment of the Northern Cardinal that VKM has performed on behalf of the Norwegian Environmental Agency.


The Northern Cardinal (Cardinalis cardinalis) has for long been a popular bird to keep due to its striking colour, shape and beautiful song.

The Northern Cardinal is one of three species in the Cardinalis genus. It has a wide geographic distribution, from southeast Canada down to Mexico, Belize and north in Guatemala. The species is not migratory and spends it whole life in the same area. The species can tolerate a wide range of climatic conditions, including condition that resemble those on the coast of southern Norway. The species is bred in large numbers in Europe.

What VKM has done

VKM has combed the scientific literature and relevant websites for information on the causes and consequences based on the ecology and behaviour of the Northern Cardinal. VKM has also modelled which areas in Norway that would serve as suitable habitat under current climatic conditions and towards the year 2100.

VKM assessed that four mechanisms for potential negative effects on biodiversity were relevant to evaluate further and risk assess. These were:

  • competition with native birds for food and nesting sites
  • hybridization with native birds
  • transfer of pathogens and diseases
  • interactions with other alien species

VKM has also assessed the species using the Norwegian Biodiversity Information Centre risk assessment scheme.


VKM concludes that it is likely that the Northern Cardinal will compete for food, but unlikely that there will be competition for nesting sites or territories.

"Regardless of what the competition is about, the effects will be small. The risk is therefore low," says Lawrence Kirkendall, VKM's spokesperson for the project.

Hybridization is only possible with one species, the common chaffinch. VKM concluded that this is very unlikely to happen and that the risk it represents is low.

It is very likely that the Northern Cardinal can transmit diseased to Norwegian birds, should it establish here. However, there is a lack of data on which diseases that exist in the captive populations in Europe. VKM concludes that the potential effect of disease transmission would be small, and that the risk it poses is moderate to low.

VKM finds that there will likely be interactions between the Norther Cardinal and other alien species, especially in terms of spreading seeds from bushes and trees.

"We consider the negative effects of such spreading of seeds to be small, and therefore conclude that the Northern Cardinal poses a low risk to biodiversity through this mechanism," adds Kirkendall.

Can the Northern Cardinal establish in Norway?

Under the current climatic conditions will most of the coastal areas of Eastern- and Southern-Norway, up to about Trondheim, serve as suitable habitat for the Northern Cardinal. With increasing temperatures, it is likely that the species will also be able to thrive in further north, further in land and at higher elevations. However, in order to establish here it must first come here in sufficient numbers.

The species can escape from private keeping. It can potentially also spread from Europe if it should establish there first. This has, however, not happened in at least 30 years, despite it being a common bird to keep privately.

"As it takes quite many individuals, at the same place and time, to establish in a new area, we conclude that it is very unlikely that the Northern Cardinal will establish a viable population in Norway," explains Kirkendall.

The risk assessment is approved by VKM's Panel on Biodiversity.

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