The Invasive Deer of Sidney Island

I got lucky enough this summer to get out to Sidney Island, helping a friend Cora Skaien with her PhD. Sidney is far south in the Georgia Strait, near Victoria and looking across at America’s San Juan Island. Sidney is remote, intensely beautiful, and having a big problem with deer.

Settlers introduced English fallow deer onto Sidney in the 1950’s, intending to hunt them. Without hunting pressure from Saanich peoples (pushed off these lands in 1852, a hurt that is still felt), and without wolves and cougars, the deer herds have grown to 5000 strong.

They act differently in the ecosystem than the native blacktail deer – the fallows move in much larger groups, and eat many things the blacktail won’t.They eat everything tasty they can reach. This tall oceanspray (Viccicus icus) has been hollowed out from the chest down.

The deer stood on their hind legs to get every leaf they could from this oceanspray (Viccicus icus).

Soft plants hide in the grass to avoid the brown plague. With changes wrought by settlement, logging and deer, many species have disappeared, and many have been forced to adapt. The overall effect is that the meadows are now largely grassland.

Geraniums and little hop-clovers can’t outgrow the grass without becoming fodder.

Much of Sidney Island was once a now-endangered “Garry oak meadow” ecosystem, with hundreds of beautiful species co-existing. We’re blessed with the contrast of nearby Shell Island – native Garry oak meadow without fallow deer:

Shell Island-1
Garry oak meadow on nearby Shell Island – free from fallow deer.

Photo credit: Cora Skaien

These meadows were maintained by Coast Salish peoples as thousand-year-old wild gardens. Edible blue camas and wild onion roots were harvested, Garry oak acorns were collected, forests were burned back, and too-small bulbs were replanted.

The fallow deer are intense. Even the trees need protection! These two Douglas Fir are around the same age – only one was coned off as a seedling:

Two Douglas firs around the same age. Residents and the island’s timber company have to cone off young trees until they are taller than the deer.


Julia and Ross Hedley, two islanders with a cabin overlooking Sidney’s beautiful south bluffs, became curious about whether removing the deer would allow a massive regeneration. They took it upon themselves to create fenced, deer-free recovery areas in their meadow.

Cora Skaien and UBC’s Arcese conservation ecology lab have taken advantage of this. They’ve done several years of detailed surveys, charting what’s growing inside and beyond these fences. They’re trying to paint a picture of the regeneration that would occur if the deer populations were lowered.

Cora Skaien (left, with Ash Nino Torres) is examining the impact these huge concentrations of deer are having on Sidney’s rare and endangered Garry Oak meadows.

Islanders have banded together to manage the population. A number are hunting deer for their families. I’ve heard the meat compared to ahi tuna. Beyond this, they’ve organized large culls – inviting staff from hunting stores on Vancouver Island to lure in, kill, butcher and pack out the meat of as many as 500 at a time.

The community has also pushed for a deeper ecological understanding of their island. While I was there, they held their 2nd annual BioBlitz. With help from bird, plant and insect experts, community members identified and cataloged as many wild species as they could in an afternoon. Their work gives us a great tool for monitoring the wildlands of Sidney as they change.

Organize a BioBlitz near you

As the deer disappear, what will change? These systems are complicated, and without  maintenance by Saanich peoples, perhaps many of the original species won’t return.

But perhaps they will! Even since the recent culls, islanders have seen native blue camas, harvest brodiaea, chocolate lily and monkey flower numbers growing.


Finishing my days by the ocean, gazing north to see Vancouver’s mountains small in the distance, I reflected on the beauty of this landscape and ecosystem. Spending time here, I’m surprised to quickly feel a connection to the health of these wild systems. It feels good to see the people of Sidney Island taking on strong responsibility for the land they live in, and the life they share it with.


Photo credit: Cora Skaien

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