#invasive species

[rebeccathenaturalist]

A quick video I made to show the difference between the two invasive and one native blackberry species in the Pacific Northwest. All three have edible berries and leaves and grow abundantly west of the Cascades. (Plus every berry you eat of the invasive species is one less load of seeds getting deposited with fertilizer by a bird later on!)

[typhlonectes]

[ikkihuikki]

Borshevik

[reasonsforhope]

"Two wild kiwi chicks were born near Wellington, New Zealand, about a year after a reintroduction program began in the city, the Capital Kiwi Project announced last week. The fluffy, brown babies are the first to be born near the country’s capital in at least 150 years. 

“This is very special for the team, which has been working hard for the last few years,” project founder Paul Ward tells the Agence France-Presse. The chicks are a “massive milestone for our goal of building a wild population of kiwi on Wellington’s back doorstep.”

These flightless, chicken-sized birds were once abundant across New Zealand, with the nation’s five species numbering an estimated 12 million individuals in total. But nonnative predators and habitat loss caused their populations to plummet. Today, approximately 68,000 kiwis remain....

Conservation and reintroduction programs, including the Capital Kiwi Project, have been working to restore a large-scale wild kiwi population for years. In 2022, the organization released 11 kiwis into the wild in Makara, a suburb about seven miles west of Wellington. Between February and May of 2023, another 52 birds were released, and 200 more are slated to be released over the next five years, reports Eva Corlett for the Guardian.

Along with reintroduction efforts, the project aimed to reduce threats from European stoats, also known as ermines. The mammals were brought to New Zealand in the 19th century in an attempt to eradicate another introduced creature: rabbits. But these weasel-like stoats are voracious predators and kill many of New Zealand’s native species, including kiwi chicks. Only about 5 percent of kiwi chicks survive to reach breeding age in areas where predators are not controlled, largely thanks to stoats. In areas under management, however, 50 to 60 percent survive. Knowing this, conservationists worked with 100 landowners across the bird’s 60,000-acre habitat to install 4,600 stoat traps.

Of the 63 adult kiwis now roaming the hilly farmlands of Makara, only about a quarter are being monitored—meaning more chicks will likely hatch in the near future. Conservationists will continue monitoring the two new chicks, though Ward tells the Guardian they still have a long way to go before they’re fully grown...

Over the years, the long-beaked birds have become a national symbol of New Zealand, with people who hail from the country often referred to as kiwis. The animals also hold special importance to the Māori people of New Zealand, who have cultural, spiritual and historic associations with the birds. Even the New Zealand dollar is sometimes referred to as the kiwi, and the bird is featured on the country’s dollar coin."

-via Smithsonian Magazine, December 6, 2023

[wachinyeya]

Tiny Indian Ocean Island Shows How Quickly Seabirds Recover When Invasive Predators Are Removed https://www.goodnewsnetwork.org/tiny-indian-ocean-island-shows-how-quickly-seabirds-recover-when-invasive-predators-are-removed/

18 years after rats were eradicated, Tromelin Island off the coast of Madagascar is a thriving colony of seabirds once again.

The same story happened over and over during the age of exploration: Europeans brought rats or rabbits on board their ships and dumped them on delicate, pristine island ecosystems.

Hundreds of islands became desolate wastelands this way, damage that has for the most part been reversed, as GNN has reported, in one of the greatest conservation stories ever told.

Now, this small teardrop of sand, rock, and palm trees in the southern Indian Ocean, is the most recent example of conservationists being able to completely rewild a landscape back to a period before European contact.

Spanning just 1 square kilometer, Tromelin Island is now home to thousands of breeding pairs of 7 seabird species like the masked and red-footed boobies.

By 2013, these two species had doubled in number from the precarious, rat oppressed lows of just a handful in 2004. In the subsequent 9 years, white terns, brown noddies, sooty terns, wedge-tailed shearwaters, and lesser noddies all came back on their own initiative.

Matthieu Le Corre, an ecologist at the University of Reunion Island, told Hakkai Magazine how, in some cases, restoring seabird populations can be a tricky thing based on the particular species’ nesting habits.

On other islands where Le Corre has worked, they’ve had to install robotic bird calls and life-size replicas to convince the birds the island is a safe place to nest again. But Tromelin Island needed no such help, since these terns, noddies, and boobies are much more dispersed in their nesting patterns.

“In terms of conservation, it’s a wonderful success,” Le Corre says.

[justawanderingfan]

The Hidden Problem of Outdoor Cats: Ecology of Fear

As a huge cat lover who grew up with cats and adores every part of them, outdoor cats are a problem. You’ve probably already heard this, but domestic outdoor cats are responsible for a staggering number of extinctions in local bird populations, even if someone thinks their “sweet little baby would never hunt” because the cat definitely has. But that’s old news, and I’m here to present another (probably already done) theory on why these cats cause problems, and that is a concept called “The ecology of fear.”

Ecology of Fear is a semi-recent concept coined by ecologists that talks about the indirect impact predators have on prey species. Basically, besides directly influencing prey populations by killing prey, there is a broader impact caused by just the presence of a predator that causes defensive changes in behavior. This change usually involves being much more cautious, meaning there’s more energy devoted to being alert and weary and less energy spent on growth and reproduction. There’s also less food consumed because the prey cannot spent large amounts of time in the open. So what does this mean for cats?

It means that even if your cat has less than one brain cell and doesn’t know how to hunt and is scared of grass like mine is, it doesn’t matter. Just the existence of a cat in the area causes local animals to chance their behavior, often with negative impacts for themselves. Birds and other prey species already have to deal with natural local predators, and adding the pressure of cats into the system tips the natural balance too far against the prey.

So please keep your cats indoors, both for their safety and the safety of local animals.

Sincerely,

An aspiring ecologist

(Also: if you’re interested in more details on the ecology of fear, a good documentary to watch is “Nature’s Fear Factor” on PBS. It’s about the reintroduction of wild dogs to Gorongosa Natural Park)

[snototter]

A muscovy duck (Cairina moschata) and ducklings swimming near Pompano Beach, Florida, USA

by Lee J. Sanders Photography

[dandelionsresilience]

Good News - June 8-14

Like these weekly compilations? Tip me at $Kaybarr1735! And if you tip me and give me a way to contact you, at the end of the month I'll send you a link to all of the articles I found but didn't use each week!

1. Rare foal born on estate for first time in 100 years

“The Food Museum at Abbot's Hall in Stowmarket, Suffolk, is home to a small number of Suffolk Punch horses - a breed considered critically endangered by the Rare Breeds Survival Trust. A female foal was born on Saturday and has been named Abbots Juno to honour the last horse born at the museum in 1924. [...] Juno is just one of 12 fillies born so far this year in the country and she could potentially help produce more of the breed in the future.”

2. The cement that could turn your house into a giant battery

“[Scientists] at Massachusetts Institute of Technology (MIT) have found a way of creating an energy storage device known as a supercapacitor from three basic, cheap materials – water, cement and a soot-like substance called carbon black. [... Supercapacitators] can charge much more quickly than a lithium ion battery and don't suffer from the same levels of degradation in performance. [... Future applications of this concrete might include] roads that store solar energy and then release it to recharge electric cars wirelessly as they drive along a road [... and] energy-storing foundations of houses.”

3. New road lights, fewer dead insects—insect-friendly lighting successfully tested

“Tailored and shielded road lights make the light source almost invisible outside the illuminated area and significantly reduces the lethal attraction for flying insects in different environments. [...] The new LED luminaires deliver more focused light, reduce spill light, and are shielded above and to the side to minimize light pollution. [... In contrast,] dimming the conventional lights by a factor of 5 had no significant effect on insect attraction.”

4. When LGBTQ health is at stake, patient navigators are ready to help

“[S]ome health care systems have begun to offer guides, or navigators, to get people the help they need. [... W]hether they're just looking for a new doctor or taking the first step toward getting gender-affirming care, "a lot of our patients really benefit from having someone like me who is there to make sure that they are getting connected with a person who is immediately going to provide a safe environment for them." [... A navigator] also connects people with LGBTQ community organizations, social groups and peer support groups.”

5. Tech company to help tackle invasive plant species

“Himalayan balsam has very sugary nectar which tempts bees and other pollinators away from native plants, thereby preventing them from producing seed. It outcompetes native plant species for resources such as sunlight, space and nutrients. [...] The volunteer scheme is open to all GWT WilderGlos users who have a smartphone and can download the Crowdorsa app, where they can then earn up to 25p per square meter of Balsam removed.”

6. [Fish & Wildlife] Service Provides Over $14 Million to Benefit Local Communities, Clean Waterways and Recreational Boaters

“The U.S. Fish and Wildlife Service is distributing more than $14 million in Clean Vessel Act grants to improve water quality and increase opportunities for fishing, shellfish harvests and safe swimming in the nation’s waterways. By helping recreational boaters properly dispose of sewage, this year’s grants will improve conditions for local communities, wildlife and recreational boaters in 18 states and Guam.”

7. Bornean clouded leopard family filmed in wild for first time ever

“Camera traps in Tanjung Puting National Park in Indonesian Borneo have captured a Bornean clouded leopard mother and her two cubs wandering through a forest. It's the first time a family of these endangered leopards has been caught on camera in the wild, according [to] staff from the Orangutan Foundation who placed camera traps throughout the forest to learn more about the elusive species.”

8. Toy library helps parents save money 'and the planet'

“Started in 2015 by Annie Berry, South Bristol's toy library aims to reduce waste and allow more children access to more - and sometimes expensive - toys. [...] Ms Berry partnered with the St Philips recycling centre on a pilot project to rescue items back from landfill, bringing more toys into the library. [...] [P]eople use it to support the environment, take out toys that they might not have the space for at home or be able to afford, and allow children to pick non-gender specific toys.”

9. Chicago Receives $3M Grant to Inventory Its Trees and Create Plan to Manage City’s Urban Forest

“The Chicago Park District received a $1.48 million grant [“made available through the federal Inflation Reduction Act”] to complete a 100% inventory of its estimated 250,000 trees, develop an urban forestry management plan and plant 200 trees in disadvantaged areas with the highest need. As with the city, development of the management plan is expected to involve significant community input.”

10. Strong Public Support for Indigenous Co-Stewardship Plan for Bears Ears National Monument

“[The NFW has a] plan to collaboratively steward Bears Ears National Monument to safeguard wildlife, protect cultural resources, and better manage outdoor recreation. The plan was the result of a two-year collaboration among the five Tribes of the Bears Ears Inter-Tribal Coalition and upholds Tribal sovereignty, incorporates Traditional Ecological Knowledge, and responsibly manages the monument for hunting, fishing, and other outdoor recreation while ensuring the continued health of the ecosystem.”

June 1-7 news here | (all credit for images and written material can be found at the source linked; I don’t claim credit for anything but curating.)

[melgillman]

Another sample page from my new fruit-foraging zine, Fruit For Free! If you live in the eastern US, these trees are almost certainly growing down the block from you somewhere.

If you'd like to read the whole comic, covering this and many other types of easily-foraged fruit, you can get it as a free or pay-what-you-want PDF here!

[sourisverte]

Dahlonega, North Georgia.

[rebeccathenaturalist]

Are Cowbirds Invasive?

(Originally published on my website at https://rebeccalexa.com/are-cowbirds-invasive/)

When discussing invasive species, we often think of species that evolved far away on other continents. Here in the United States, thousands of non-native species have been brought here since the dawn of colonization; while not all became established, a significant number have since become aggressively integrated into local habitats, much to the detriment of native species they displace or otherwise harm. But sometimes a species will simply encroach upon an ecosystem adjacent to its native home, and then spreads from there, having the same negative impact as other relatively new arrivals. Which begs the question: are birds on the move like barred owls (Strix varia) and cowbirds invasive?

I want to especially look at the brown-headed cowbird (Molothrus ater). Like the barred owl, these chunky songbirds have expanded their range in North America in recent decades due to the extensive damage we’ve done to habitats across the continent. Both were particularly affected by the destruction of the Great Plains. Settlers tore up the ancient grasslands with plows, suppressed fires that had kept forests from encroaching, and started a trend of afforestation–planting trees where they aren’t supposed to be–that continues today. In the latter half of the 19th century, the plains bison (Bison bison bison) was slaughtered almost to extinction to make money off the sale of their remains, and to disempower indigenous communities throughout the region who were reliant on this keystone species for their very existence.

The owls hopscotched across the growing number of tree plantations that dotted first settlements, then towns, then sprawling suburbs and cities, and thus were able to reach all the way to the west coast, where they have put serious competitive pressure on the northern spotted owl. The cowbirds, on the other hand, became refugees as all but the last few hundred bison disappeared from the landscape. They instead turned to domestic livestock like cattle for their survival.

(Read the rest under the cut.)

Same Habits, Different Hosts

Brown-headed cowbirds are unusual in that they evolved to migrate with the bison, rather than waiting for new herds to arrive. The birds feed on insects stirred up by the herd’s hooves, along with seeds of grasses and other plants along the way. Cowbirds perching on the backs of these enormous mammals would have been a common sight prior to the bison’s near-extermination, and today they may still be seen watching for prey from on top of cattle, horses and other domestic livestock.

Because cowbirds have spent thousands of years migrating with their bison hosts, they couldn’t afford to settle in one place for months at a time to raise a nest of chicks, particularly as spring and summer would be prime time for finding insects to eat. It might be weeks or even months before a herd would return to a given area, and without the help of the bison the cowbirds would have had a difficult time finding enough insects on their own, let alone for a hungry nest of babies.

So the cowbirds evolved a rather controversial strategy: brood parasitism. Instead of building their own nest, they find someone else’s and leave a few eggs there for the unwitting owners to raise. Some people anthropomorphize the cowbirds as being “bad”, “lazy”, “evil”, and so forth. And, of course, it’s easy to call cowbirds invasive, too, since they literally invade the nests of other animals.

But nature is amoral; there are no inherently good or evil animals. While we may project our distaste for the cowbirds’ practices onto their value as a species, brood parasitism is simply one of a plethora of strategies animals have evolved in order to pass their genes on to the next generation. If it gets the job done, then it is an evolutionary success. Like the mate cannibalism of some mantids and spiders or animal infanticide practiced by male lions, baboons, and dolphins, brood parasitism may be vicious by our standards, but it is a legitimate survival tactic in the sometimes-cutthroat world of nature.

Are Cowbirds Invasive?

We can certainly call cowbirds invasive when they hop into a nest they didn’t build just to drop off an egg. But are they invasive on a more widespread level? Arguably yes. Not all invasive species were physically transported by humans, but the impact is the same: they have a deleterious effect on one or more other species in their habitat. And unlike coyotes, which only spread to new horizons when their competitors were extirpated by human hunters, brown-headed cowbirds are not filling a niche that was previously taken by another species. they are, instead, an often-unwanted addition to local ecology.

In addition to tearing up the Great Plains and then planting trees there, we also cut down massive numbers of trees in historically forested areas across the continent, leaving patches of fields in which cattle and other livestock graze. This has led to the spread of the cowbird beyond its normal range in the prairies. Other bird species that evolved alongside the cowbirds have developed ways to respond to brood parasitism, from throwing cowbird eggs out of the nest, to building a new nest entirely.

A young cowbird sits in a sparrow’s nest. Note the sparrow egg in the lower left corner that has been pushed out of the nest.

But birds in the cowbird’s expanded territory aren’t always so savvy. That includes species that have seen declining numbers in recent decades due to habitat loss, lead and other toxins, and predation by another invasive species, the domestic cat (Felis catus). Since cowbirds and their chicks will both remove their hosts’ eggs from a parasitized nest, and cowbird chicks may toss their host’s young out or steal all their food, this means fewer numbers of the host species being successfully hatched and fledged. All of which means cowbirds are becoming a serious conservation concern.

That being said, we shouldn’t be too quick to dismiss an entire species by calling all cowbirds invasive. Within their native range in the Great Plains, they are an important part of local ecology. And–unlike certain members of our own species–they are not intentionally cruel animals that want to see other living beings suffer. They are simply doing what their ancestors have done for thousands upon thousands of years, and unlike humans they have no capacity to consider the impact on their hosts.

One last note: if you are tempted to remove cowbird eggs from a nest, please don’t. First, it’s an activity best carried out by professionals who have a better sense of what nests should be attended to and when. Moreover, egg removal can not only cause the host birds to abandon their nest and their own eggs, but cowbirds are more likely to attack hosts who remove the offending eggs, and you could be setting the nesting pair up for retaliation from the cowbirds. And brown-headed cowbirds, like almost all native birds in the United States, are protected by the Migratory Bird Treaty Act, which makes it a federal offense to disturb or harm the birds themselves, as well as their eggs or nests. If you are in an area where cowbirds are considered to be invasive, and you are concerned about another species’ nests, contact your state wildlife department or the closest Audubon Society (some of these societies have changed their names in recent years, but fulfills the same roles as before.)

Did you enjoy this post? Consider taking one of my online foraging and natural history classes or hiring me for a guided nature tour, checking out my other articles, or picking up a paperback or ebook I’ve written! You can even buy me a coffee here!

[headspace-hotel]

My opinions on invasive species are so complicated that no matter what opinion you have about them I will want to argue.

If you say "invasive species are a constructed category and not inherently evil" you unlock the part of me that rages about the impact of Bradford pears and honeysuckle bushes on my ecosystem.

If you say "Invasive species are bad and we have to get rid of them" you unlock the part of me that has a glowing admiration for Nature's ability to adapt and survive.

I don't really agree with "a species transported outside of its native environment is changing the ecosystem and that's bad" as a principle, because nature is constantly changing and there is no original unspoiled state of the ecosystem. However I don't trust this argument coming from somebody that hasn't spent hours and hours pulling wintercreeper or seen a forest understory sterilized by bush honeysuckle.

Oftentimes I believe that invasive species take over because a keystone species has been removed from the ecosystem. For example my hypothesis is that the destruction of the Canebrakes in the Southeastern USA made the region vulnerable to invasion.

I also think that the way the ecosystem is interacted with and managed by humans causes invasive species to invade

However ultimately I think each species and each individual region of Earth is its own unique case.

Kudzu for example is a food and fiber plant used and cultivated since ancient times in China. It is a mutualistic symbiont with humans, with both of our species strongly contributing to the survival and thriving of the other. Kudzu must be controlled by harvest and use by humans; since using it for food, medicine, and clothes has declined, it has begun to show invasive behavior IN CHINA, WHERE IT IS NATIVE

Dandelion is a weed that is mostly confined to ecosystems very heavily disturbed by humans, and it has strongly positive effects on those ecosystems. It is also a mutualistic symbiont with humans.

Amur honeysuckle, Lonicera maackii is an incredibly virulent invasive species in Southeastern USA forests, virtually destroying all other plant biodiversity in the understory where it grows. The cause of this is pretty simple, Arundinaria gigantea a keystone species was removed, and regular controlled burns were stopped when Native Americans were forced off their land. Thus there was a niche left gaping wide open in the ecosystem.

A. gigantea (river cane), our native bamboo, has the property of forming ridiculously dense clonal colonies in damp lowland areas. The Southeastern USA invasives that are majorly problematic seem to have similar habits. A. gigantea is also disturbance dependent, particularly loving fire, but these days you mostly find it in vacant lots and along fence rows. Similarly most of our invasives need a moderate disturbance level to take over. The trouble is that A. gigantea is nearly wiped out through much of its range, and rarely reproduces sexually, so it can't spread like the invasives can.

Each plant has to be understood as its own unique living creature with its own way.

I desperately want to learn about Pyrus calleryana in its native habitat and learn the ways of this plant, as I don't understand it yet...

[bloodborne-on-pc]

I've been trying to think of the best way to articulate this for a long time, but I think something that maybe influences many outdoor cat owners to be adamantly against the idea of the idea of their pet being an invasive species, is the way we talk and think about invasive species.

If you see any post on social media talking about an invasive species, people in the comments tend to talk about "destroying" them with a sort of gleeful malice. Essentially, invasives are acceptable targets for cruelty. They are considered "evil", making it okay to hate them and inflict violence upon them, and to revel in that violence.

So, if a person has this viewpoint, consciously or not, and sees someone claim their beloved pet is invasive, they will probably balk at the idea and reject it. Their cat isn't evil! That's absurd! How could you say that?

And that is completely true. The domestic cat isn't evil. Neither is the spotted lanternfly, common buckthorn, or any other invasive species. They are harmful to the environments they are introduced into, but they don't cause that harm because they are malevolent. They're doing the exact same things they would be in their original environment. Those things are just bad for their non-native one. In some situations, removing invasive species may involve killing the organism, but we shouldn't relish in the suffering this will cause them.

Obviously, there are lot of factors influencing why people refuse to keep their cats inside. But I can't help but wonder if this kind of attitude might exacerbate it - and if changing the way we talk about invasive species might help a little. Even if not, we should do it anyway - all living things deserve respect.

[great-and-small]

My grandmother is trying to get me on a python bowl trip as a birthday present but i don’t know if I’ve got the strength 😭

[petrii-dish]

Go, my bug warriors 🦂🪰

Scor-frin and Mir-aphid! Siffrin is a namib thicktail scorpion (so niche but the pattern works well…) and Mirabelle is a woolly aphid!

I haven’t worked on my bug au in a bit so I’m dropping these two here before they get buried in the wip timeloop forever

[joy-haver]

Note to new foragers;

while you are learning about the species you want to harvest, also learn what sustainable harvesting looks like. Learn about invasive species management, and agroecology. A lot of people start with the book Braiding Sweetgrass, by Dr Robin Wall Kimmerer. It is approachable, and covers the Honorable Harvest really well. The Poor Proles Almanac podcast and Substack are both incredible sources of information as well.

In general, tho, you should start by knowing this:

- If a species is native, and especially if it is rare on the landscape, do what you can to encourage it. Don’t over harvest, clear away invasives around it, save and spread its seeds. Maybe even hand pollinate it if needed.

- If a species is not native, feel free to harvest much more of it. Discourage its spread, but you don’t necessarily need to remove every single one you see. For a very small select few non native species, a little bit of spreading can even be okay. But be sure you know what you are doing. In general, it is better to remove a non native species than to let it stay. Keep native seeds on you to replace them with. I carry around little dime bags of seeds.

- if a species is Invasive (not native & choking out native species) remove as much as you can without damaging the local ecology. For foraging this might mean you harvest a ton of yellow charlock, even more than you need, because you see it choking out wild lettuce. This is a good thing to do (at least where I am). Because the charlock will overtake everything. But if you start managing in other ways, like tarping or tilling or spraying, keep in mind that oftentimes the medicine can be worse than the disease. If you spray a field of charlock you don’t get wild lettuce, you get more charlock.

Anyways, good luck!