One Health

Hi Cailyn;

 Thank you for your post.  With regards to that 2.4 billion figure for community cats impacts on birds.  I think we need to be careful about making these types of statements without context.  Here is an interesting link to a blog that Peter Wolfe wrote on this topic that might be helpful: Cats Vs. Birds: Researching The Research - Faunalytics

   It is also interesting to note that in the UK(a leader in spay/neuter and tnr for cat programs) has a culture of indoor/outdoor cats and it is at times hard to adopt cats when you want them to be indoor only.

    Switzerland is known for their "cat ladders" on the outside of buildings to enable cats to come and go as they please.  

I think the word invasive species is interesting- I prefer the terms over-populated and under-populated for our species management puzzles that we currently have.

      I heard a presentation about how forests out west are going to cut down and hundreds of thousands of bard owls may be culled to help benefit the spotted owl.  Here is the interesting story. 

     Those of us in the animal welfare space need to think very carefully about our actions impacting wildlife and animal populations and how we can keep a balanced level of them all. 

Anyway, I just wanted to share with the group my thoughts on this very challenging topic because we are always going to have imbalances. 

Hello Stacy, 

Thank you for your response! I appreciate hearing other people's perspective on the topic. 

The blog post you linked is very interesting. Unfortunately, since it was posted in 2014 the subject of research surrounding cats as predators of birds has grown immensely. Many journals have published on the topic that agree birds are being harmed by free range cat communities, though I acknowledge that there is debate surrounding the exact number of birds killed. Here are a few papers for reference:

• Pavisse, Roman, Didier Vangeluwe, and Philippe Clergeau. "Domestic cat predation on garden birds: an analysis from European ringing programmes." Ardea 107.1 (2019): 103-109.
• Chu, Jonathan J., et al. "An updated estimate of the number of birds killed by outdoor cats in Canada." Avian Conservation and Ecology 20.2 (2025).
• Loss, Scott R., et al. "Review and synthesis of the global literature on domestic cat impacts on wildlife." Journal of Animal Ecology 91.7 (2022): 1361-1372.

I also understand that it is unpleasant to add a negative label such as "invasive" to a beloved pet species, but this term is the standard for scientists and habitat managers. Cats do fit all of the requirements to be labeled as such: 1) They aren't native to the area. 2) They repopulate freely in the wild. and 3) They harm native species and ecosystems. 

In the end, I understand that this topic is very sensitive and should be handled carefully. This is exactly why I thought it was a great topic for a forum like this one. I love cats and would never advocate for doing harm, rather I advocate for humane ways of lowering free range cat numbers like TNR and keeping pet cats indoors when possible. 

Hi Cailyn;

 Thank you for your post.  With regards to that 2.4 billion figure for community cats impacts on birds.  I think we need to be careful about making these types of statements without context.  Here is an interesting link to a blog that Peter Wolfe wrote on this topic that might be helpful: Cats Vs. Birds: Researching The Research - Faunalytics

   It is also interesting to note that in the UK(a leader in spay/neuter and tnr for cat programs) has a culture of indoor/outdoor cats and it is at times hard to adopt cats when you want them to be indoor only.

    Switzerland is known for their "cat ladders" on the outside of buildings to enable cats to come and go as they please.  

I think the word invasive species is interesting- I prefer the terms over-populated and under-populated for our species management puzzles that we currently have.

      I heard a presentation about how forests out west are going to cut down and hundreds of thousands of bard owls may be culled to help benefit the spotted owl.  Here is the interesting story. 

     Those of us in the animal welfare space need to think very carefully about our actions impacting wildlife and animal populations and how we can keep a balanced level of them all. 

Anyway, I just wanted to share with the group my thoughts on this very challenging topic because we are always going to have imbalances. 

Hi Cailyn;

 Thanks for your response.  One thing is for sure that I think all parties(bird and cat) agree that reducing cat overpopulation is the best end result.  In Newburyport(the heart of Piping Plover's with an Audobon center and fish and wildlife center), MA we successfully reduced the cat population through the use of TNR and affordable and accessible owned cat s/n so we no longer have cats in vulnerable areas. 

Cat overpopulation's root cause is access to s/n for community cats.(those that are outdoors and unsterilized).  As our sterilization rates have decreased since 2019(Shelter Animals Counts), I am not surprised that the population statistics have shifted.    

You might find this video of interest as this is the organization that really helped me understand the challenges that cat owners face. I have been involved with them since 1994(board president for 16 years). So many of our MRFRS volunteers are also "Plover Wardens" at Plum Island- I think we have found a nice balance in the community.  

Also the work of Bob Sallinger at the Portland Audubon and the Cats Safe at Home is another successful resource understanding that there is a way for co-existance.  

The more information and perspective we can have the better.

I think we are all in agreement that there are more cats outside than there need to be, the question is how do we unify to create a plan to reduce the number of cats?

Stacy

Hello Stacy, 

Thank you for your response! I appreciate hearing other people's perspective on the topic. 

The blog post you linked is very interesting. Unfortunately, since it was posted in 2014 the subject of research surrounding cats as predators of birds has grown immensely. Many journals have published on the topic that agree birds are being harmed by free range cat communities, though I acknowledge that there is debate surrounding the exact number of birds killed. Here are a few papers for reference:

• Pavisse, Roman, Didier Vangeluwe, and Philippe Clergeau. "Domestic cat predation on garden birds: an analysis from European ringing programmes." Ardea 107.1 (2019): 103-109.
• Chu, Jonathan J., et al. "An updated estimate of the number of birds killed by outdoor cats in Canada." Avian Conservation and Ecology 20.2 (2025).
• Loss, Scott R., et al. "Review and synthesis of the global literature on domestic cat impacts on wildlife." Journal of Animal Ecology 91.7 (2022): 1361-1372.

I also understand that it is unpleasant to add a negative label such as "invasive" to a beloved pet species, but this term is the standard for scientists and habitat managers. Cats do fit all of the requirements to be labeled as such: 1) They aren't native to the area. 2) They repopulate freely in the wild. and 3) They harm native species and ecosystems. 

In the end, I understand that this topic is very sensitive and should be handled carefully. This is exactly why I thought it was a great topic for a forum like this one. I love cats and would never advocate for doing harm, rather I advocate for humane ways of lowering free range cat numbers like TNR and keeping pet cats indoors when possible. 

Hi Cailyn;

 Thank you for your post.  With regards to that 2.4 billion figure for community cats impacts on birds.  I think we need to be careful about making these types of statements without context.  Here is an interesting link to a blog that Peter Wolfe wrote on this topic that might be helpful: Cats Vs. Birds: Researching The Research - Faunalytics

   It is also interesting to note that in the UK(a leader in spay/neuter and tnr for cat programs) has a culture of indoor/outdoor cats and it is at times hard to adopt cats when you want them to be indoor only.

    Switzerland is known for their "cat ladders" on the outside of buildings to enable cats to come and go as they please.  

I think the word invasive species is interesting- I prefer the terms over-populated and under-populated for our species management puzzles that we currently have.

      I heard a presentation about how forests out west are going to cut down and hundreds of thousands of bard owls may be culled to help benefit the spotted owl.  Here is the interesting story. 

     Those of us in the animal welfare space need to think very carefully about our actions impacting wildlife and animal populations and how we can keep a balanced level of them all. 

Anyway, I just wanted to share with the group my thoughts on this very challenging topic because we are always going to have imbalances. 

Hello everyone! My name is Cailyn Haubein and I am a graduate student in the Ecology and Evolutionary Biology Department at UTK. I'm posting today for Invasive Species Awareness Week. Below, I've compiled some info about invasive species and how they relate to pets. I'm happy to chat with anyone or answer any questions.

What is an invasive species?

An invasive species is any organism (plant, animal, bacteria, or fungus) living outside its native range and causing harm to other species or the environment. Human travel and trade have increased the spread of these organisms, both accidentally (e.g., insects transported with food and wood) and intentionally (e.g., plants and animals introduced for gardens or the pet trade).

How pets become invasive:

Many pets escape captivity and establish invasive populations. Examples include goldfish, Burmese pythons, and European starlings. One of the most impactful examples is cats; feral and free-roaming pet cats kill an estimated 2.4 billion birds annually in the U.S. and significantly contribute to bird decline.

How you can make a difference (pets):

Keep cats indoors and support Trap-Neuter-Return programs to help stabilize feral cat populations. Never release pets into the wild-surrender unwanted animals to shelters to prevent ecological harm.

How invasives impact pet health:

Invasive plants can reshape ecosystems by forming dense growth that supports pests such as ticks. In Tennessee, species like Bush Honeysuckle, Oriental Bittersweet, and Japanese Barberry create ideal tick habitat, increasing risks of diseases such as Lyme disease for both pets and humans.

How you can make a difference (plants):

Stay aware of invasive plants on your property using state conservation resources. Here is a link for Tennessee: Link. When planting, choose locally sourced native species that support healthy ecosystems and natural pest predators. Native plant guides can help you identify suitable options for your area. Here is a link for the US: Link

References:

American Bird Conservancy

National Invasive Species Information Center

Invasive Plants Harbor Vectors

I agree with Stacy. I am more concerned about overbuilding and pollution as a massive contributor to the destruction of wildlife and their habitat. I would want to look at some well-balanced research showing accurate numbers. Some of these are from bird societies that depend on donations to exist and have been known to inflate those numbers significantly. This is dangerous to show feral cats and strays now as "invasive." These animals face enough challenges not to mention hate and cruelty for this to become another reason to want to exterminate them.

Hello everyone! My name is Cailyn Haubein and I am a graduate student in the Ecology and Evolutionary Biology Department at UTK. I'm posting today for Invasive Species Awareness Week. Below, I've compiled some info about invasive species and how they relate to pets. I'm happy to chat with anyone or answer any questions.

What is an invasive species?

An invasive species is any organism (plant, animal, bacteria, or fungus) living outside its native range and causing harm to other species or the environment. Human travel and trade have increased the spread of these organisms, both accidentally (e.g., insects transported with food and wood) and intentionally (e.g., plants and animals introduced for gardens or the pet trade).

How pets become invasive:

Many pets escape captivity and establish invasive populations. Examples include goldfish, Burmese pythons, and European starlings. One of the most impactful examples is cats; feral and free-roaming pet cats kill an estimated 2.4 billion birds annually in the U.S. and significantly contribute to bird decline.

How you can make a difference (pets):

Keep cats indoors and support Trap-Neuter-Return programs to help stabilize feral cat populations. Never release pets into the wild-surrender unwanted animals to shelters to prevent ecological harm.

How invasives impact pet health:

Invasive plants can reshape ecosystems by forming dense growth that supports pests such as ticks. In Tennessee, species like Bush Honeysuckle, Oriental Bittersweet, and Japanese Barberry create ideal tick habitat, increasing risks of diseases such as Lyme disease for both pets and humans.

How you can make a difference (plants):

Stay aware of invasive plants on your property using state conservation resources. Here is a link for Tennessee: Link. When planting, choose locally sourced native species that support healthy ecosystems and natural pest predators. Native plant guides can help you identify suitable options for your area. Here is a link for the US: Link

References:

American Bird Conservancy

National Invasive Species Information Center

Invasive Plants Harbor Vectors

Hello Adriana, 

I understand completely and I agree that urbanization and pollution are big treats to wildlife, but as conservation scientists we have to concern ourselves with all of the threats to biodiversity. One of the biggest threats to the world's biodiversity are invasive species as they are a major cause of species extinction (World Health Organization).

As previously stated, it is unfortunate that we have to label cats as invasive, but there is a long history of cats harming wildlife (the main qualification for this label). This is especially apparent in islands. In Hawaii, the Hawaiian Invasive Species Council have linked the introduction of cats as a major contributor to the extinction of 33 native bird species. There are numerous other examples of this on islands in Mexico, New Zealand, Japan, etc. 

Additionally, cats are officially recognized as invasive by the world's leading conservation organizations including the International Union for Conservation of Nature (IUCN). Here is a quote from an analysis they completed in 2020, "In terms of impacts to threatened species, rats and cats are again the top 2 IAS (Invasive Alien Species) impacting 740 and 433 threatened species respectively."(IUCN). Labeling cats as such is important because it recognized that actions need to be taken to manage their populations, not extermination, but management through TNR and Socialization. I hope, like Stacey stated, we can all agree that we need to reduce feral cat populations.

In terms of well balanced research, I do acknowledge that research has inherent bias. I will say that I liked the results of a previously mentioned paper specifically because they clearly laid out a range of potential bird mortality estimates regardless of it being published in Avian Conservation and Ecology. Citation: Chu, Jonathan J., et al. "An updated estimate of the number of birds killed by outdoor cats in Canada." Avian Conservation and Ecology 20.2 (2025). 

I agree with Stacy. I am more concerned about overbuilding and pollution as a massive contributor to the destruction of wildlife and their habitat. I would want to look at some well-balanced research showing accurate numbers. Some of these are from bird societies that depend on donations to exist and have been known to inflate those numbers significantly. This is dangerous to show feral cats and strays now as "invasive." These animals face enough challenges not to mention hate and cruelty for this to become another reason to want to exterminate them.

Hello everyone! My name is Cailyn Haubein and I am a graduate student in the Ecology and Evolutionary Biology Department at UTK. I'm posting today for Invasive Species Awareness Week. Below, I've compiled some info about invasive species and how they relate to pets. I'm happy to chat with anyone or answer any questions.

What is an invasive species?

An invasive species is any organism (plant, animal, bacteria, or fungus) living outside its native range and causing harm to other species or the environment. Human travel and trade have increased the spread of these organisms, both accidentally (e.g., insects transported with food and wood) and intentionally (e.g., plants and animals introduced for gardens or the pet trade).

How pets become invasive:

Many pets escape captivity and establish invasive populations. Examples include goldfish, Burmese pythons, and European starlings. One of the most impactful examples is cats; feral and free-roaming pet cats kill an estimated 2.4 billion birds annually in the U.S. and significantly contribute to bird decline.

How you can make a difference (pets):

Keep cats indoors and support Trap-Neuter-Return programs to help stabilize feral cat populations. Never release pets into the wild-surrender unwanted animals to shelters to prevent ecological harm.

How invasives impact pet health:

Invasive plants can reshape ecosystems by forming dense growth that supports pests such as ticks. In Tennessee, species like Bush Honeysuckle, Oriental Bittersweet, and Japanese Barberry create ideal tick habitat, increasing risks of diseases such as Lyme disease for both pets and humans.

How you can make a difference (plants):

Stay aware of invasive plants on your property using state conservation resources. Here is a link for Tennessee: Link. When planting, choose locally sourced native species that support healthy ecosystems and natural pest predators. Native plant guides can help you identify suitable options for your area. Here is a link for the US: Link

References:

American Bird Conservancy

National Invasive Species Information Center

Invasive Plants Harbor Vectors

In this discourse I think we've decided that TNR is one of the great solutions to help cats and conservation.

We still have a debate about language. I do think that while cats may logically fit into that ["invasive species"] definition, we also must understand that words cause harm. This is true of all words; using the word "educate" instead of "sharing information". Both are doing the same by definition, but one takes a colonial or even confrontational stance. 

Cats may be, ecologically speaking, an "invasive species". But in forums like the public, or in animal welfare spheres we have to be careful of that language and choose different ones. 

As someone who works primarily in animal cruelty, Adriana is very correct. When we use the words "feral" or "invasive species" we unintentionally blocked a slew of protections for them. Ohio only THIS YEAR confirmed cruelty statutes apply to stray cats. Yay for Ohio, but the cats in Indiana are still facing legal issues because by demoting them to these terms we have or potentially will harm those cats.

If our goal is solutionary - both for the environment and the cats, we cannot harm the cats to help the ecology. "Most good and least harm" is the amazing premise of Zoe Weil's book which recognizes that it is rare that we have a solution that doesn't harm another party. If this then that - harm may happen somewhere. So instead, we look to do the most good, and least amount of harm.

In this case of this, lets not demote cats by giving them a name that may cause harm. Lets encourage TNR to help our ecological friends. Let's talk about not feeding wildlife (including birds!) so we can co-exist better with wildlife.. Let's talk about bells on outdoor cats, or humane deterrents ... We have a lot of options that we can explore. I think we can all agree on that!

I encourage you to change the language of 'invasive species' and instead advise that the cat overpopulation has caused harm; and here's some of the amazing things we can work together to do. It's very informative, and there are hard truths in this. I'm trying hard to not appear defensive, [or be defensive].

But please understand, our POV too... this label could potentially cause true, cruel, harm to cats. I know that's not your goal, you only hoped to inform us of the impacts of the overpopulation of cats. We are also trying to share that as you share this message; but careful how it's labelled.

Hello Adriana, 

I understand completely and I agree that urbanization and pollution are big treats to wildlife, but as conservation scientists we have to concern ourselves with all of the threats to biodiversity. One of the biggest threats to the world's biodiversity are invasive species as they are a major cause of species extinction (World Health Organization).

As previously stated, it is unfortunate that we have to label cats as invasive, but there is a long history of cats harming wildlife (the main qualification for this label). This is especially apparent in islands. In Hawaii, the Hawaiian Invasive Species Council have linked the introduction of cats as a major contributor to the extinction of 33 native bird species. There are numerous other examples of this on islands in Mexico, New Zealand, Japan, etc. 

Additionally, cats are officially recognized as invasive by the world's leading conservation organizations including the International Union for Conservation of Nature (IUCN). Here is a quote from an analysis they completed in 2020, "In terms of impacts to threatened species, rats and cats are again the top 2 IAS (Invasive Alien Species) impacting 740 and 433 threatened species respectively."(IUCN). Labeling cats as such is important because it recognized that actions need to be taken to manage their populations, not extermination, but management through TNR and Socialization. I hope, like Stacey stated, we can all agree that we need to reduce feral cat populations.

In terms of well balanced research, I do acknowledge that research has inherent bias. I will say that I liked the results of a previously mentioned paper specifically because they clearly laid out a range of potential bird mortality estimates regardless of it being published in Avian Conservation and Ecology. Citation: Chu, Jonathan J., et al. "An updated estimate of the number of birds killed by outdoor cats in Canada." Avian Conservation and Ecology 20.2 (2025). 

I agree with Stacy. I am more concerned about overbuilding and pollution as a massive contributor to the destruction of wildlife and their habitat. I would want to look at some well-balanced research showing accurate numbers. Some of these are from bird societies that depend on donations to exist and have been known to inflate those numbers significantly. This is dangerous to show feral cats and strays now as "invasive." These animals face enough challenges not to mention hate and cruelty for this to become another reason to want to exterminate them.

Hello everyone! My name is Cailyn Haubein and I am a graduate student in the Ecology and Evolutionary Biology Department at UTK. I'm posting today for Invasive Species Awareness Week. Below, I've compiled some info about invasive species and how they relate to pets. I'm happy to chat with anyone or answer any questions.

What is an invasive species?

An invasive species is any organism (plant, animal, bacteria, or fungus) living outside its native range and causing harm to other species or the environment. Human travel and trade have increased the spread of these organisms, both accidentally (e.g., insects transported with food and wood) and intentionally (e.g., plants and animals introduced for gardens or the pet trade).

How pets become invasive:

Many pets escape captivity and establish invasive populations. Examples include goldfish, Burmese pythons, and European starlings. One of the most impactful examples is cats; feral and free-roaming pet cats kill an estimated 2.4 billion birds annually in the U.S. and significantly contribute to bird decline.

How you can make a difference (pets):

Keep cats indoors and support Trap-Neuter-Return programs to help stabilize feral cat populations. Never release pets into the wild-surrender unwanted animals to shelters to prevent ecological harm.

How invasives impact pet health:

Invasive plants can reshape ecosystems by forming dense growth that supports pests such as ticks. In Tennessee, species like Bush Honeysuckle, Oriental Bittersweet, and Japanese Barberry create ideal tick habitat, increasing risks of diseases such as Lyme disease for both pets and humans.

How you can make a difference (plants):

Stay aware of invasive plants on your property using state conservation resources. Here is a link for Tennessee: Link. When planting, choose locally sourced native species that support healthy ecosystems and natural pest predators. Native plant guides can help you identify suitable options for your area. Here is a link for the US: Link

References:

American Bird Conservancy

National Invasive Species Information Center

Invasive Plants Harbor Vectors

Hi Rachel, 

I appreciate your perspective on this topic. Your message doesn't come off as defensive at all. It's great to hear from another East Tennessean! I have heard nothing but praise for Young-Williams Animal Center. 

I completely understand that using the word invasive colloquially for cats would cause more harm than good and I apologize if my use of the term came off as assertive. My intent for the original post and any replies was only to bring an ecological and conservation perspective on the topic for Invasive Species Awareness Week and promote discussion around invasive species as they relate to pets.

I agree that it is important for terms such as invasive to stay within the context of their fields. While cats are formally recognized as invasive from a scientific perspective I agree that phrasing like "harm of wildlife due to cat overpopulation" is more appropriate for use outside of scientific contexts. 

Lastly, I want to highlight that just because I use the term invasive in reference to cats doesn't mean that I don't recognize the nuance of the situation and the protections that cats deserve (I really do love cats even if it doesn't come off that way). From talking with others in my department it seems we all share a similar sentiment on the topic.

Having this discussion with you, Adriana, and Stacy has been very informative and valuable for me as it shows how scientists and animal activists can have open conversations about sensitive topics. I think if conversations like this happened more often then we could make genuine progress towards solutions for important issues like cat overpopulation. 

A question for you or anyone else: Are bells on cats a good solution? I've heard in the past that it's dangerous to keep collars on outdoor cats since they can snag on debris and that breakaway collars fall off too easily. I'm curious of your opinion. 

In this discourse I think we've decided that TNR is one of the great solutions to help cats and conservation.

We still have a debate about language. I do think that while cats may logically fit into that ["invasive species"] definition, we also must understand that words cause harm. This is true of all words; using the word "educate" instead of "sharing information". Both are doing the same by definition, but one takes a colonial or even confrontational stance. 

Cats may be, ecologically speaking, an "invasive species". But in forums like the public, or in animal welfare spheres we have to be careful of that language and choose different ones. 

As someone who works primarily in animal cruelty, Adriana is very correct. When we use the words "feral" or "invasive species" we unintentionally blocked a slew of protections for them. Ohio only THIS YEAR confirmed cruelty statutes apply to stray cats. Yay for Ohio, but the cats in Indiana are still facing legal issues because by demoting them to these terms we have or potentially will harm those cats.

If our goal is solutionary - both for the environment and the cats, we cannot harm the cats to help the ecology. "Most good and least harm" is the amazing premise of Zoe Weil's book which recognizes that it is rare that we have a solution that doesn't harm another party. If this then that - harm may happen somewhere. So instead, we look to do the most good, and least amount of harm.

In this case of this, lets not demote cats by giving them a name that may cause harm. Lets encourage TNR to help our ecological friends. Let's talk about not feeding wildlife (including birds!) so we can co-exist better with wildlife.. Let's talk about bells on outdoor cats, or humane deterrents ... We have a lot of options that we can explore. I think we can all agree on that!

I encourage you to change the language of 'invasive species' and instead advise that the cat overpopulation has caused harm; and here's some of the amazing things we can work together to do. It's very informative, and there are hard truths in this. I'm trying hard to not appear defensive, [or be defensive].

But please understand, our POV too... this label could potentially cause true, cruel, harm to cats. I know that's not your goal, you only hoped to inform us of the impacts of the overpopulation of cats. We are also trying to share that as you share this message; but careful how it's labelled.

Hello Adriana, 

I understand completely and I agree that urbanization and pollution are big treats to wildlife, but as conservation scientists we have to concern ourselves with all of the threats to biodiversity. One of the biggest threats to the world's biodiversity are invasive species as they are a major cause of species extinction (World Health Organization).

As previously stated, it is unfortunate that we have to label cats as invasive, but there is a long history of cats harming wildlife (the main qualification for this label). This is especially apparent in islands. In Hawaii, the Hawaiian Invasive Species Council have linked the introduction of cats as a major contributor to the extinction of 33 native bird species. There are numerous other examples of this on islands in Mexico, New Zealand, Japan, etc. 

Additionally, cats are officially recognized as invasive by the world's leading conservation organizations including the International Union for Conservation of Nature (IUCN). Here is a quote from an analysis they completed in 2020, "In terms of impacts to threatened species, rats and cats are again the top 2 IAS (Invasive Alien Species) impacting 740 and 433 threatened species respectively."(IUCN). Labeling cats as such is important because it recognized that actions need to be taken to manage their populations, not extermination, but management through TNR and Socialization. I hope, like Stacey stated, we can all agree that we need to reduce feral cat populations.

In terms of well balanced research, I do acknowledge that research has inherent bias. I will say that I liked the results of a previously mentioned paper specifically because they clearly laid out a range of potential bird mortality estimates regardless of it being published in Avian Conservation and Ecology. Citation: Chu, Jonathan J., et al. "An updated estimate of the number of birds killed by outdoor cats in Canada." Avian Conservation and Ecology 20.2 (2025). 

I agree with Stacy. I am more concerned about overbuilding and pollution as a massive contributor to the destruction of wildlife and their habitat. I would want to look at some well-balanced research showing accurate numbers. Some of these are from bird societies that depend on donations to exist and have been known to inflate those numbers significantly. This is dangerous to show feral cats and strays now as "invasive." These animals face enough challenges not to mention hate and cruelty for this to become another reason to want to exterminate them.

Hello everyone! My name is Cailyn Haubein and I am a graduate student in the Ecology and Evolutionary Biology Department at UTK. I'm posting today for Invasive Species Awareness Week. Below, I've compiled some info about invasive species and how they relate to pets. I'm happy to chat with anyone or answer any questions.

What is an invasive species?

An invasive species is any organism (plant, animal, bacteria, or fungus) living outside its native range and causing harm to other species or the environment. Human travel and trade have increased the spread of these organisms, both accidentally (e.g., insects transported with food and wood) and intentionally (e.g., plants and animals introduced for gardens or the pet trade).

How pets become invasive:

Many pets escape captivity and establish invasive populations. Examples include goldfish, Burmese pythons, and European starlings. One of the most impactful examples is cats; feral and free-roaming pet cats kill an estimated 2.4 billion birds annually in the U.S. and significantly contribute to bird decline.

How you can make a difference (pets):

Keep cats indoors and support Trap-Neuter-Return programs to help stabilize feral cat populations. Never release pets into the wild-surrender unwanted animals to shelters to prevent ecological harm.

How invasives impact pet health:

Invasive plants can reshape ecosystems by forming dense growth that supports pests such as ticks. In Tennessee, species like Bush Honeysuckle, Oriental Bittersweet, and Japanese Barberry create ideal tick habitat, increasing risks of diseases such as Lyme disease for both pets and humans.

How you can make a difference (plants):

Stay aware of invasive plants on your property using state conservation resources. Here is a link for Tennessee: Link. When planting, choose locally sourced native species that support healthy ecosystems and natural pest predators. Native plant guides can help you identify suitable options for your area. Here is a link for the US: Link

References:

American Bird Conservancy

National Invasive Species Information Center

Invasive Plants Harbor Vectors