(Feature photo © Spirit of Suffolk)
In their latest research, Service and colleagues map the distribution and frequency of the ‘Spirit bear’ allele to support conservation planning of these culturally important phenotypic variants. Author Christina Service shares her team’s findings below.
I stared in disbelief the first time I (finally) saw one. It was a black bear, frantically chasing salmon in a shallow creek as black bears often do in the fall. But it was pure white, from tip to tail. That was eight years ago. I now know a little more about how rare such a sighting can be.
They are known as ‘Spirit bears’ – a rare white-coated variant of black bears that occur only in limited areas in coastal British Columbia, Canada. They carry enormous cultural, ecological, and economic importance. Given these multiple values, the Gitga’at and Kitasoo/Xai’xais First Nations – who have shared their territories with Spirit bears since time immemorial – have invested in applied research to better understand the distribution and protection of Spirit bears in their territories.
As my PhD was co-developed with the Kitasoo/Xai’xais First Nation, Spirit bears were rightfully given a focal position in my research program.
Early in my program, we set out to use non-invasive hair snags to sample the DNA from bear hair across the coastal temperate rainforests in the archipelago and deep mainland fjords that make up British Columbia’s central coast. But much to my surprise (but less so for Gitga’at and Kitasoo/Xai’xais Nation members), we detected the elusive Spirit bears in very low numbers compared to their black counterparts (making for frustratingly low samples sizes for statistical analyses).
The rarity of Spirit bear detections defied my expectations based on previous estimates of their frequency in the literature. I wrote this observation off as a fluke for the first year, and then the second… but by the sixth year with remarkably low detections, it was much harder to interpret these low numbers as anomalies. These observations led us to ask: are Spirit bears rarer than the data currently used to manage them suggest? How adequate is their current protection through existing parks and protected areas?
In response to these objectives, our team analysed DNA from non-invasively sampled hair from 385 black bears across 18,000 km2 in the heart of the “Great Bear Rainforest”. We identified – then mapped – where we detected the carriers of the Spirit bear version of the gene (i.e. allele), the ‘switch’ that – only when inherited from both parents – gives black bears a white Spirit bear coat.
Our results revealed that Spirit bears are more vulnerable than existing management processes recognise, with this vulnerability stemming from two sources.
First, we found that the frequency of the white version of the gene was as much as 50% lower than previous estimates. While ongoing work will estimate the number of Spirit bears in the area, such a finding hints that Spirit bears are rarer than previously believed.
Secondly, our work also revealed that existing parks and protected areas do not encompass the habitat where ~50% of the Spirit Bear ‘hotspots’ occur, regions where the Spirit bear version of the gene is especially prominent.
We hope these findings can inform current and future land use planning, which may include the potential for increased protection for Spirit bear gene ‘hotspots’ currently outside of parks and protected areas.
Finally, our work offers a unique example of conservation research targeted at the specific phenotype (or form) rather than a population or species as a whole. Though unique phenotypes are rarely explicitly considered in conservation planning, here in coastal British Columbia, this is the unit of diversity that underlies enormous cultural and economic values (the latter via ecotourism). We argue, therefore, that the phenotype in this case – and likely others globally – can provide a meaningful biological scale in which to target conservation action.
Though Spirit bears are geographically restricted to this region of Canada, we suggest that similar approaches could be applied across many different regions and taxa in response to the unique ways local communities value biodiversity.
Read the full research: “Spatial patterns and rarity of the white‐phased ‘Spirit bear’ allele reveal gaps in habitat protection” in Issue 1:2 of Ecological Solutions and Evidence.