Field Notes Ep. 3: Why You Still See Threatened Species Everywhere

Conservation Conversations from Passel Estate

Seeing Wildlife Isn’t the Same as Understanding It

For many Margaret River locals, seeing a Western Ringtail Possum running along the top of your backyard fence after dark is a fairly common sight.  The unmistakable calls of Black Cockatoos returning to their evening roosts are equally familiar, while Quenda continue turning up in suburban gardens, bush reserves and roadside vegetation throughout the Southwest.

If these species are still seen so regularly, how can they possibly be threatened?

It’s one of the most common questions conservation scientists encounter, and one Dr Rochelle Steven said often leads to the same misconception.

“In Margaret River, people see Ringtails every day. Same goes for Black Cockatoos and Quenda,” she explained.  “People often don’t believe these species are threatened if they see them so regularly.”

It’s an understandable assumption almost all of us have made at one time or another. After all, it’s difficult to imagine an animal could be fighting for survival when we still encounter it so often in everyday life.

Most of us instinctively judge the health of the environment or a certain species by what we happen to see around us. But conservation rarely works that way.  What feels quite common at a local scale can tell a very different story across an entire landscape. It’s a question conservation scientist Dr Rochelle Steven spends a lot of time pondering.

As part of our ongoing Field Notes series, we’ve been sitting down with Rochelle in the lead-up to the biodiversity baseline surveys planned at Passel Estate later this year. While the surveys themselves will document the wildlife living across the property, many of our conversations surrounding the work involved reach far beyond the estate itself.

Today’s conversation challenged one of the biggest misconceptions surrounding threatened species.

The Hidden Story Behind Familiar Wildlife

Part of the reason Western Ringtail Possums can still appear surprisingly common is because they’ve adapted remarkably well to parts of the urban environment here in the Southwest.

Rochelle explained that many of their preferred food trees also happen to be widely planted throughout parks, streetscapes and home gardens across the region. As long as possums can find food and somewhere to shelter, they’ll often continue using these modified landscapes.

At first glance, that sounds like a conservation success story.

But it’s only part of the picture.

Why Breeding Habitat Matters

For all their adaptability, Western Ringtail Possums still depend on something our backyards can’t always provide.

“They may use gardens for food and movement, but they still need patches of bush to breed,” added Rochelle.

It’s an important distinction.

Gardens can provide feeding opportunities and safe passage through urban areas, but they don’t replace the larger, connected patches of native vegetation needed to sustain healthy breeding populations over the long term.

As more of those bushland connections are lost or fragmented, the pressure on wildlife doesn’t always become obvious straight away.  Sometimes, the consequences take years to emerge.

The Hidden Cost of Habitat Loss

One of the more fascinating ideas to emerge from our conversation with Rochelle was a concept few people outside conservation have ever heard of.  It’s called ‘extinction debt’.

The idea is surprisingly simple.  Habitat loss doesn’t always reveal its full impact immediately. A species can continue appearing stable long after important habitat has already been lost, creating the impression everything is fine until population declines begin to emerge some time later.

The concept of extinction debt has been documented across ecosystems around the world for decades. In simple terms, it recognises that wildlife populations often continue persisting long after habitat has been altered, with the full consequences only becoming apparent years or even decades later.

“You can do something in the environment and not see the full effect of it until years later,” explained Rochelle.  “You still have to pay that debt back…”

It’s a way of thinking that completely changes how we interpret the wildlife around us.

The animals we see today aren’t simply a reflection of today’s landscape. They’re also the legacy of decisions made years earlier.
Which also means the actions taken today may not reveal their full consequences until long into the future.

For Western Ringtail Possums, Rochelle believes that extinction debt is still accumulating. Habitat continues to be cleared and fragmented, roads further divide breeding populations, while vehicle strikes and introduced predators place additional pressure on a species already facing long-term challenges to its survival.

“I believe that for many of our species, including Ringtails, we have not fully paid the extinction debt that we’ve already signed ourselves up for.”

Why Private Land Matters

As breeding habitat is becoming increasingly fragmented, every remaining patch of native vegetation matters for species survival.
That’s one of the reasons conservation on privately managed land is becoming an increasingly important part of the broader conservation picture throughout the Southwest.

National parks and publicly funded conservation reserves remain essential, but they’re only one part of the landscape. Across Australia, the majority of land is privately managed, meaning long-term biodiversity conservation cannot rely on governmentally protected areas alone. Increasingly, conservation scientists recognise that working landscapes including farms, vineyards and privately managed bushland, must also form part of the long-term conservation solution by providing habitat, movement corridors and helping maintain connectivity between larger reserves.

For properties like ours here at Passel Estate, the upcoming biodiversity surveys will help provide a clearer understanding of how native species use the property today, creating a baseline against which our future conservation efforts can be measured.

Why Evidence Matters

One of the biggest takeaways from speaking with Rochelle is that biodiversity surveys aren’t simply about counting animals.
Each survey becomes another piece of a much larger picture, helping conservation scientists understand how species are using the wider landscape and how those patterns continue changing over time.

The recent work of Dr Roy Teale and his team which we discussed in our World Wildlife Day Blog is a good example. Large regional surveys help build a broader understanding of Western Ringtail Possum populations across the Southwest, allowing scientists to ask bigger questions about habitat, landscape connectivity and long-term population trends.

For Rochelle, however, those findings also come with an important reminder:  Better data shouldn’t be mistaken for the end of the conservation story.

As she cautioned earlier in Episode 2, the greatest risk is that encouraging population estimates are interpreted as a sign that the species no longer requires protection, when many of the pressures driving its decline still remain.

Property-level surveys also serve a more local, but equally important, purpose.  They document the species already using a landscape, identify important habitat features and establish a clearer understanding of how individual properties contribute to the broader conservation picture.

For Passel Estate, the upcoming biodiversity baseline survey represents an opportunity to better understand the biodiversity already sharing this landscape while contributing another piece to the growing body of knowledge surrounding conservation throughout the Southwest.

No single survey will ever provide every answer.  But every well-designed survey helps replace assumptions with evidence, creating a stronger foundation for the conservation decisions that follow.

Like any good field note, it’s not intended to be the final chapter.

It’s the beginning of a much longer story.

Next Up

With our conversations with Rochelle having set the groundwork, it is almost time to take Field Notes out into the field!

Animal ethics approval is in place; acoustic recorders and camera equipment have been readied; and, with Rochelle leading the survey, we’ll be heading out to see what conservation research actually looks like on the ground.

In the next Field Notes entry, we’ll take you with us on our Western Ringtail Possum field survey and put everything we’ve been discussing so far into practice.

Stay tuned…

Field Notes Ep.1: How Conservation Became Part of the Passel Estate Story
Field Notes Ep. 2: Catch-Ups with a Conservation Scientist
Field Notes Ep. 3: Why You Still See Threatened Species Everywhere
Field Notes Ep. 4: Inside a Western Ringtail Possum Survey