Tag Archives: extinction

Rethinking Extinction

Sudan, the last male northern white rhino, 3 years before he passed away, rendering the species functionally extinct. But should species like this be the focus of our conservation efforts?

Sudan, the last male northern white rhino, 3 years before he passed away, rendering the species functionally extinct. But should species like this be the focus of our conservation efforts? (Image Credit: Make it Kenya, CC0 Creative Commons)

Last year saw the death of Sudan, the last known northern white rhinoceros in the world. The story went viral, with the usual bemoaning of the way humans treat our planet, followed shortly by the normal rush back into anonymity for the world’s biodiversity. We are currently part of the most dramatic mass extinction event that the planet has ever seen, and more of these stories crop up every year. But is it a problem that the alarm bells are only raised when a creature hits the critically endangered level? Do we need to start paying more attention to population declines before hey hit such low numbers? And how do we even prioritise conservation efforts?

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Quantifying the Effect of an Invader

The Raccoon Dog, an alien species, has made its way to Sweden recently. But what sort of effect does it have on the native fauna?

The Raccoon Dog, an alien species, has made its way to Sweden recently. But what sort of effect does it have on the native fauna? (Image Credit: Prue Simmons, CC BY 2.0)

Nest predation by raccoon dog Nyctereutes procyonoides in the archipelago of Northern Sweden (2018) Dahl & Åhlen, Biological Invasions, https://doi.org/10.1007/s10530-018-1855-4

The Crux

We’ve spoken about biological invasions at length on EcolMass, and the detrimental effects that the arrival of a new species can have on native populations. Yet eradication is often impossible, and management expensive, so before taking extensive action, it’s always important to ensure that an alien species IS having a negative effect.

The raccoon dog is an Asian species, closely related to foxes, that was introduced to Europe in the early 20th century and has since spread into Scandinavia. Voracious predators that could spread further north due to climate change, our paper this week looks at the extent of their impact on the ecosystems they’ve spread to.

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Biological Annihilation

The sumatran orangutan, one of many species facing extinction in the earth's sixth mass extinction event

The sumatran orangutan, one of many species facing extinction in the earth’s sixth mass extinction event (Image Credit: Mike Pennington, CC BY SA 2.0)

Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines (2017) Ceballos et al., Proceedings of the National Academy of Sciences of the USA, DOI: https://doi.org/10.1073/pnas.1704949114

Guest Post by Jonatan Marquez

The Crux

The rate at which species and populations have been going extinct in the last couple of centuries has well and truly earned the title of the planet’s sixth mass extinction event. However, most people rarely realize the severity of the situation. Hearing about the loss of two vertebrate species a year or having the last of some far-off species die out doesn’t see to cause much concern in the general public.

A species extinction is always preceded by population declines and extinctions. Perhaps highlighting the state of natural communities at this level might put the severity of the situation in better context. For example, the Living Planet Index (LPI) estimates that between 1970 and 2012, wildlife abundance has decreased by 58%. This paper focuses on the state and trends of populations of vertebrates by analysing i) the proportion undergoing declines or shrinkages, ii) the global distribution of population reduction events and iii) the general scale of population declines among mammal populations.

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Trout Restoration in the Great Lakes: A Success Story

A Lake Trout, the species which was almost driven to extinction by overfishing and Sea Lamprey invasion, has now been restored in the Great Lakes

The Lake Trout, the species which was almost driven to extinction by overfishing and Sea Lamprey invasion, has now been restored in the Great Lakes (Image Credit: Cory Goldsworthy, MDNR)

Back in June this year, I was fortunate enough to attend the 9th International Charr Symposium, a conference which takes place every three to four years focusing on fish in the genus Salvelinus. The conference took place on Lake Superior, a site where the local Lake Trout population had previously been greatly reduced by overfishing and the invasion of the Sea Lamprey in the first half of the 20th century.

Yet the concerted efforts of the State, Provincial and Federal governments’ Fisheries Departments from the U.S. and Canada worked to successfully control the invasive Sea Lamprey species, and the native Lake Trout population was restored. I spoke with Don Pereira, Don Schreiner and Cory Goldsworthy of the Minnesota Department of Natural Resources (MNDNR) and Minnesota Sea Grant (MNSG) about one of the rare success stories of invasion ecology.

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Costa Rica: Sustainability in an Animal Paradise

Costa Rica has taken huge steps forward in the last 30 years to save their ecosystem, with the tourism industry benefiting enormously

I’ve just returned from a two-week vacation in Cosa Rica. While ostensibly a holiday, if you’re an ecologist in a country where ecological conservation forms the basis of their tourism industry, it can be hard to switch off. So amongst a plethora of monkeys, iguanas, basilisks, hummingbirds and crocodiles, I noted a few things which are worth briefly discussing before we get back into our regular blogs next week.

A warning though. Whilst a fair bit of well-researched content appears on this website, the observations here are much more general, and by no means applicable to the whole country.

  1. The Plastic Addiction

I know this isn’t exactly a hot take. Plastic consumption is one of the world’s foremost environmental catastrophes, and if the enormous soup of plastic in the middle of the Pacific wasn’t enough to ram the point home, the four others forming around the world should be.

What surprised me here was that despite the emphasis the Costa Rican government places on the conservation of biodiversity, there appears to be no effort in the tourism industry to shy away from easily avoidable plastic use. Plastic straws and cups were in abundance, but the real mind-boggler was the use of small plastic bags to contain cutlery. Having knives and forks handed to me in new plastic casing at half the restaurants we visited was an odd experience, and one which seems easily avoidable.

However we encountered a few places which eschewed the plastic wrapping and provided cardboard straws. Hopefully this is a growing trend.

  1. Animal Sanctuaries

One thing Costa Rica was far from short on was recovery centers for injured animals. We visited one in Cahuita, and were impressed by the number of volunteers they had managed to attract, most seemingly without any background in zoology. Other centers had one-day volunteer programs advertised, which were often tailored to getting children involved. The centers require government permission to release any individuals back into the wild, which seems to be an effective communication pathway. Yet like all dialogues between organisations with different priorities, it produces disagreements. We heard many examples of rehabilitated animals that the government considers too used to human exposure to reintroduce.

The center we visited did seem to focus more on animal welfare than population conservation (though they certainly did not ignore the latter), and associates who have previously volunteered at these centers seem to agree. There were several examples of animals who, even with rehabilitation, were incapable of contributing to population viability, or whose injuries were not directly or indirectly caused by humans, some whose removal from the population could be considered important contributors to genetic and behavioural evolution. However staff made the excellent point that with the number of these species that receive injuries from human activity every year, the least they could do is try to treat a few injuries that weren’t.

Whilst iguanas used to be a food source for the locals, local hunting is now restricted

Whilst iguanas used to be a food source for the locals, local hunting is now restricted (Image Credit: Sam Perrin, NTNU)

  1. Conservation Laws

Costa Rica’s conservation laws prohibit the killing of many species found throughout the country. No complaints here. Many of these species are integral parts of the Costa Rican ecosystem and tourism industry. However a guide from the Caribbean side of the country was discussing his family’s traditions of hunting many of these animals, and how the government provided no alternatives to these traditional food sources when the laws were introduced. Whilst I am all for criminalising the killing of endangered species, having a government tell your family to change their lifestyle, whilst they continue practices that have a much larger impact on the native ecosystem (ongoing deforestation and commercial harvesting amongst them) must rankle somewhat.

Having said this, I live in a country where hunting quotas are strict and easy to monitor, and contact between hunters and the government is frequent. Commercial harvesting is potentially an easier way to manage sustainable population of harvested species, and a source of employment for families in need of new income.

 

In conclusion, I’ll reiterate that much of the above may be a product of observational bias. Bias also leads me to suggest that regardless of your thoughts on the above, you go and check out Costa Rica for yourself. It’s marvellous.