Kanata's Blanding's turtles headed for extinction as development breaks up their habitat
"They play an important role in the ecosystem, and for that reason alone it’s important not to let them die off.”
Author of the article: Bruce Deachman
Publishing date: May 02, 2022 •
Publishing date: May 02, 2022 •
Between 2010 and 2020, the adult population of Blanding's turtles in and around the South March Highlands Conservation Area fell from 81 to 25, with computer models suggesting that they will become functionally extinct in the area by 2030.
PHOTO BY PROVIDED /Courtesy of Anni Auge
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Every year for four years, Anni Auge would come across Sparkles, an adult female Blanding’s turtle who lived — and perhaps still resides — in and around the South March Conservation Area in Kanata.
It’s nearly impossible to accurately determine Sparkles’ age. Blanding’s turtles stop growing when they’re about 20 years old and, unlike readers of this story, don’t show the typical signs of aging brought on by cellular deterioration, making them valuable for research into longevity. Named for 19th-century American naturalist William Blanding, the turtles can produce offspring into their 80s.
“They’re one of the longest-lived freshwater turtles,” says Auge, “so there’s some knowledge in them.”
Beyond simply their research value, Auge says the turtles significantly contribute to the biodiversity of the region. “That, by itself, is important. They’re predators, while their eggs and hatchlings are eaten by other predators. They play an important role in the ecosystem, and for that reason alone it’s important not to let them die off.”
Unfortunately, that’s precisely what’s happening.
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Every year for four years, Anni Auge would come across Sparkles, an adult female Blanding’s turtle who lived — and perhaps still resides — in and around the South March Conservation Area in Kanata.
It’s nearly impossible to accurately determine Sparkles’ age. Blanding’s turtles stop growing when they’re about 20 years old and, unlike readers of this story, don’t show the typical signs of aging brought on by cellular deterioration, making them valuable for research into longevity. Named for 19th-century American naturalist William Blanding, the turtles can produce offspring into their 80s.
“They’re one of the longest-lived freshwater turtles,” says Auge, “so there’s some knowledge in them.”
Beyond simply their research value, Auge says the turtles significantly contribute to the biodiversity of the region. “That, by itself, is important. They’re predators, while their eggs and hatchlings are eaten by other predators. They play an important role in the ecosystem, and for that reason alone it’s important not to let them die off.”
Unfortunately, that’s precisely what’s happening.
Anni Auge is a PhD student at Trent University who studied the decline of the population of the already threatened Blanding’s turtles due to urban development along Terry Fox Drive in Kanata. Her research suggests the animals will be ‘functionally’ extinct by 2030.
PHOTO BY JEAN LEVAC /Postmedia
Using GPS tags, Auge, an Ottawa resident and a PhD candidate in Trent University’s Environmental Life Sciences department, tracked and studied Kanata’s Blanding’s turtles from 2017 to 2020 as part of a requirement that land developers hire biologists to study the effects of urban growth. Auge’s findings, coupled with those of a similar study conducted through the City of Ottawa from 2010-13, paint a grim picture for the region’s Blanding’s population: over the past decade, the adult Blanding’s population fell from 81 to 25, a nearly 70 per cent decline, as the wetland area shrunk by 13.6 per cent and suitable habitat for the turtles was cut by almost 10 per cent.
Worse, however, is the expected trajectory for the yellow-necked animals that always appear to be smiling. Already listed as threatened in Ontario and endangered elsewhere, Auge says that computer models indicate that, at the present rate, Blanding’s turtles will become functionally extinct in the Kanata area by 2030, meaning that the female adult population will have dwindled to four or fewer individuals, ensuring an unavoidable path to extinction.
“There just won’t be enough to sustain a population in the area. The road mortality rate is so high, and we’re already at such a low population. It’s inevitable.”
She hopes to have her 48-page report published in Biological Conservation, a peer-reviewed journal.
Loss of habitat is the largest threat to the freshwater turtles, with increasing road mortality, especially of females in search of or returning from nesting grounds, the leading cause of death. About four adult females are killed each year by vehicles, she says, with devastating consequences for such a small population.
Auge points to recent development, both commercial and residential, along Terry Fox Drive as an example. Developers’ efforts at mitigation, she says, while good in theory — fences to keep the turtles off roads, for example, culverts to allow them subterranean road passage, and the creation of artificial wetlands — aren’t doing enough. Human-made wetlands, often little more than a large puddle when they’re created, take time to grow into a viable ecosystem, while fencing damaged by storms or removed due to development, as well as other hard-to-isolate features such as railroad tracks, make it difficult to keep the turtles, who may travel more than 20 km. in a year, safe.
“They also want to nest on the side of the road,” Auge adds. “The gravel is good material. It’s warm, which is good for the nest, and so they think that’s a good place to lay their eggs. And if they lay their eggs there and they hatch, the hatchlings often go onto the road.”
Auge would like to see more and better mitigation measures. The artificial habitats, she says, have been built close to roads and railway lines, when they would be more effective farther from human activity. Additionally, there’s less new habitat being created than what’s being developed. Fences, she adds, could also be better maintained.
“The theory is good, but the implementation could have been better.”
She also feels that monitoring the effectiveness of mitigation measures is a vital but under-utilized tool to study the turtle population. “We monitored the turtles for four years, but that was really only when the development began. Who know what’s happening now? It should be monitored long term, to get an idea of how well these measures work.”
Ultimately, though, she feels urban development and natural ecosystems will always clash. “The results weren’t surprising. We know that development always contributes to habitat destruction and population extinction. And in this case it’s terrible for the (Blanding’s) population. And this is happening everywhere else, too.
“My data ended in 2020 and it’s now two years later,” she adds, “so who knows what the population is down to. I wonder what happened to Sprinkles.”
bdeachman@postmedia.com
Using GPS tags, Auge, an Ottawa resident and a PhD candidate in Trent University’s Environmental Life Sciences department, tracked and studied Kanata’s Blanding’s turtles from 2017 to 2020 as part of a requirement that land developers hire biologists to study the effects of urban growth. Auge’s findings, coupled with those of a similar study conducted through the City of Ottawa from 2010-13, paint a grim picture for the region’s Blanding’s population: over the past decade, the adult Blanding’s population fell from 81 to 25, a nearly 70 per cent decline, as the wetland area shrunk by 13.6 per cent and suitable habitat for the turtles was cut by almost 10 per cent.
Worse, however, is the expected trajectory for the yellow-necked animals that always appear to be smiling. Already listed as threatened in Ontario and endangered elsewhere, Auge says that computer models indicate that, at the present rate, Blanding’s turtles will become functionally extinct in the Kanata area by 2030, meaning that the female adult population will have dwindled to four or fewer individuals, ensuring an unavoidable path to extinction.
“There just won’t be enough to sustain a population in the area. The road mortality rate is so high, and we’re already at such a low population. It’s inevitable.”
She hopes to have her 48-page report published in Biological Conservation, a peer-reviewed journal.
Loss of habitat is the largest threat to the freshwater turtles, with increasing road mortality, especially of females in search of or returning from nesting grounds, the leading cause of death. About four adult females are killed each year by vehicles, she says, with devastating consequences for such a small population.
Auge points to recent development, both commercial and residential, along Terry Fox Drive as an example. Developers’ efforts at mitigation, she says, while good in theory — fences to keep the turtles off roads, for example, culverts to allow them subterranean road passage, and the creation of artificial wetlands — aren’t doing enough. Human-made wetlands, often little more than a large puddle when they’re created, take time to grow into a viable ecosystem, while fencing damaged by storms or removed due to development, as well as other hard-to-isolate features such as railroad tracks, make it difficult to keep the turtles, who may travel more than 20 km. in a year, safe.
“They also want to nest on the side of the road,” Auge adds. “The gravel is good material. It’s warm, which is good for the nest, and so they think that’s a good place to lay their eggs. And if they lay their eggs there and they hatch, the hatchlings often go onto the road.”
Auge would like to see more and better mitigation measures. The artificial habitats, she says, have been built close to roads and railway lines, when they would be more effective farther from human activity. Additionally, there’s less new habitat being created than what’s being developed. Fences, she adds, could also be better maintained.
“The theory is good, but the implementation could have been better.”
She also feels that monitoring the effectiveness of mitigation measures is a vital but under-utilized tool to study the turtle population. “We monitored the turtles for four years, but that was really only when the development began. Who know what’s happening now? It should be monitored long term, to get an idea of how well these measures work.”
Ultimately, though, she feels urban development and natural ecosystems will always clash. “The results weren’t surprising. We know that development always contributes to habitat destruction and population extinction. And in this case it’s terrible for the (Blanding’s) population. And this is happening everywhere else, too.
“My data ended in 2020 and it’s now two years later,” she adds, “so who knows what the population is down to. I wonder what happened to Sprinkles.”
bdeachman@postmedia.com
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