The domestic cat found its way to the list of alien species in Poland. – Cats kill at least several hundred thousand vertebrates a year and it is difficult not to mention the lack of their negative impact. These are scientific facts – said Wojciech Solarz, professor at the Institute of Nature Conservation of the Polish Academy of Sciences in an interview with tvnmeteo.pl. What does this mean for purr owners? Do they have to worry about the future of their beloved pets?
According to the Institute of Nature Conservation of the Polish Academy of Sciences, one of the greatest threats facing nature protection is biological invasions of alien species. The huge scale of this problem results, inter alia, from the fact that it is one of the least predictable and most dynamic natural processes resulting from the development of civilization. At the same time, biological invasions remain one of the least explored and least recognized threats to biodiversity.
Invasive alien species are plants, animals, pathogens and various other organisms that are not native to ecosystems and can cause damage to the environment or the economy, says the Institute of Nature Conservation of the Polish Academy of Sciences. In addition, they can have a negative impact on human health. Such species have a negative effect, in particular, on biodiversity, including the reduction of populations or elimination of native species, through food competition, predation or the transmission of pathogens, and disruption of the functioning of ecosystems.
The domestic cat is an invasive alien species? What does it mean
At the end of June 2022, a domestic cat (Felis catus). It was described as invasive.
– There is no doubt that, firstly: the cat is an alien species in Poland, and secondly, there is no doubt that it has a negative impact on nature. I do not know any research results that would contradict this – said Wojciech Solarz, professor at the Institute of Nature Conservation of the Polish Academy of Sciences, in an interview with tvnmeteo.pl. – Cats kill at least several hundred thousand vertebrates annually in Poland and it is difficult not to mention the lack of their negative impact. These are scientific facts, he added.
The expert noted that the fact that a cat was included in the database does not change its legal status.
– The fact that we have granted this status to the cat, we have also granted many other invasive alien species such as aphids, bacteria and others – said Wojciech Solarz. He noted that the database of alien species includes over 1,800 species, while only some of them are directly subject to the provisions of the Act, the EU regulation. This is the regulation of the European Parliament and of the Council on the preventive and remedial actions against the introduction and spread of invasive alien species, which entered into force on 1 January 2015. – Remedial actions should be carried out in relation to those species that are listed in the regulation. This is a group of several dozen species, the cat is not on this list and probably never will be. It is difficult for me to imagine a situation that a cat will be included by the European Union or Poland as an invasive species that needs to be combated – said the expert.
The fact that our purrs hunt vertebrates when they go outside is certain. – It is difficult for me to accept any arguments that the cat is a non-invasive, harmless species. But on the other hand, it absolutely does not mean that they should now be massively exterminated, emphasized Solarz. – Cats simply murder millions of animals, it has always been so, it is nothing new. Eventually, cats were domesticated to catch mice and help humans, he noted.
The expert referred to an article published in 2019 in which researchers write how many cats kill birds and other vertebrates each year. – This article deals with individuals who are directly killed, but we also deal with individuals who are injured. Such individuals, for example, may not be able to reproduce, the scientist noted.
Solorz noticed that it would be good if we limited the number of cats outside during the breeding season, because the death of one parent means the death of the entire brood. – I think that this alone would be a great step to improve the situation – he said.
Cats kill millions of vertebrates each year
Scientists: Dagny Krauze-Gryz, Jakub Gryz and Michał Żmihorski wrote in an article published in 2019 that domestic cats kill millions of Polish vertebrates each year. Their calculations showed that rural purrs bring home about 48.1 million small mammals (their actual number ranges from 41.2-55.4 million) and 8.9 million birds (between 6.7 and 10, 9 million) each year.
Cats eat even more animals. Estimates of the number of their victims are 583.4 million mammals (their number is in the range 505.3-667 million) and 135.7 million birds (103.9-171.3 million) per year.
As for birds, the most common victims are popular species that nest near human settlements. These are, for example, sparrows, tree sparrows and starlings – species whose numbers are generally decreasing in Poland. Birds that nest on the ground, such as the yellow wagtail, lark or whip, are also vulnerable to cat attack.
Research in England has shown that cats may be responsible for up to 30 percent of deaths in the local sparrow population. Cats can also influence birds indirectly. American research shows, for example, that the stress caused by their presence may reduce fertility in birds.
A growing problem
The problem of invasive alien species is constantly increasing, mainly due to the development of global trade, transport and tourism, which allow the easy introduction and spread of alien species into the environment. If the alien species’ new environment is sufficiently similar to the native one, it can survive and reproduce easily. In addition, it may not encounter natural enemies or other constraints in its path, and it may become invasive anyway. Invasive alien species increase their range and displace native species. This process is driving socio-economic, health and environmental costs around the world.
Such species also pose a threat to development, through their impact on various areas of the economy, such as agriculture, forestry, fisheries, but also on natural ecosystems. This damage is further exacerbated by climate change, environmental pollution, habitat loss and human environmental transformation.
tvnmeteo.pl, iop.krakow.pl, gov.pl
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