Decay Detecting Dog
The UK’s First Tree Decay Detection Dog
Sika: A Pioneering Nose in British Arboriculture
Crown Tree Consultancy has built a reputation for expertise in arboriculture, combined with curiosity and a willingness to explore new ideas. That spirit is perhaps best embodied by Sika—the UK’s first tree decay detection dog.
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A Border Collie raised on the slopes of the South Pennines, Sika has been part of the team since 2013. Trained by Principal Consultant Ivan Button, she has the ability to detect multiple types of decay-inducing fungi in trees. From Kretzschmaria deusta to Meripilus giganteus and Ganoderma spp., her extraordinarily sensitive nose allows her to indicate potential decay, even when no fruiting bodies are visible.
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While Sika is not deployed routinely and is only used to identify where further investigation is warranted (and never to condemn trees), her presence reflects the consultancy’s ethos: blending traditional arboricultural practice with innovative approaches to improve understanding of trees. She occasionally assists with publicly accessible woodland or estate surveys, particularly where conditions make visual inspection more difficult, such as scenting beneath ivy or among dense epicormic growth.
A Pioneer, Not a Product
Sika’s abilities aren’t the result of a scientific training programme; they’re the outcome of Button’s curiosity. Could a dog be trained to detect signs of tree decay? Hidden within a dog’s shiny wet nose are up to 300 million olfactory receptors, compared to approximately 6 million in a human nose. They possess a brain area up to 40 times larger devoted to scent analysis and have a second olfactory system dedicated purely to chemical communication analysis, like pheromones and VOCs. This secondary system is called the vomeronasal organ. Some breeds can detect substances at concentrations as low as one part per trillion—the equivalent of half a teaspoon of salt dissolved in an Olympic-sized swimming pool.
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Drawing on publicly available dog training resources, online advice, and experimentation, Button began to train Sika using positive reinforcement (rewarding the desired behaviour). Positive reinforcement usually takes the form of a tennis ball, a game of tug, or a bit of cheddar, which (during formative training) she was given only when she successfully scented a target scent. Teaching her to indicate detection reliably via a trained bark took patience (and a harmonica!) but persistence paid off. Today, Sika can confidently alert to the presence of numerous fungi she’s been trained to recognise.
Roadshows and Resilience
The results of the training speak for themselves. Sika has demonstrated her skills live at major events, including the ARB Show and the Arboricultural Association’s Amenity Conference, where attendees have seen her track and identify hidden samples of decay fungi with remarkable accuracy – she can even find tiny pieces of paper that have been stored with the samples.
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Sika’s journey hasn’t been without challenges. In 2022, she suffered a serious injury that required complex surgery and a lengthy rehabilitation process. Thanks to a specialist sling, a patient recovery team, and a few extra cubes of cheese, she made a remarkable recovery. Her resilience reflects values upheld by the consultancy: compassion, adaptability, and perseverance.
While her novel work has always drawn a crowd, the purpose behind it is serious. Button noted, “We’re certainly not suggesting that detector dogs replace traditional decay assessment methods such as sonic tomography or the Resi Drill™, but in the right context, Sika’s nose offers a supplementary line of investigation and might one day inspire further innovation in tree health diagnostics or enhance biosecurity measures.”
Although Sika’s skills have never been studied scientifically, Forest Research and their partners have recently demonstrated an 89% successful first-time detection rate in a groundbreaking study showing that dogs can be used to detect the algae-like organism Phytophthora ramorum. As detector dogs gain recognition in conservation and biosecurity applications, Crown Tree Consultancy is proud to have been among the first in the UK to explore their potential use in tree care.
Meeting the Challenges of Biosecurity Threats
Biosecurity is increasingly critical in UK arboriculture, with new pests and pathogens continuing to arrive through global trade routes. Many host plants show no visible symptoms of these pests until long after the introduction of the new pest. Early detection is key, and this is where trained scent-detection animals could offer enormous promise.
Crown Tree Consultancy has shown interest in how scent-detection animals, including dogs, mice, and even insects, could contribute to early-warning systems. From screening at borders to woodland monitoring, animals offer the potential for faster, more targeted detection in support of the UK’s 2023 Biosecurity Strategy, which calls for more proactive approaches.
While detector dogs come with limitations (they need regular feeding and walking, often abscond from office duties and certainly can’t write reports), they also offer unique advantages and in the right context can help identify where further investigation is warranted.
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A Great Place to Grow
Sika isn’t just a clever working dog—she’s a reminder of what’s possible when expertise and exploration meet in a work environment where enthusiasm is encouraged, learning is ongoing, and the occasional bark is allowed. This same spirit guides all consultancy work at Crown Tree Consultancy, from bespoke advice on historic estates to practical, evidence-based tree risk assessments in urban settings.
Crown Tree Consultancy plans to keep doing what it does best: practical, evidence-based arboricultural advice for clients across the UK. By staying open to new approaches—whether high-tech, low-tech, or four-legged—the consultancy continues to strengthen the quality of service it offers. And from time to time, when the conditions are right, Sika might just come along for a sniff too.
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Some of Crown Tree Consultancy’s most commonly instructed services are BS5837 reports for planning and tree condition surveys for safety purposes. By investing in a professional arboricultural survey at the outset of a development project, stakeholders can ensure compliance with industry standards, safeguard important green infrastructure throughout the design phase and minimise the risk of costly delays. Likewise, regular tree condition surveys are an important part of responsible tree ownership.
If you require any type of arboricultural survey, the dedicated team of arboricultural experts here at Crown Tree Consultancy are on hand to help with your enquiry via email or phone. Their office is open Monday to Thursday 9 am - 5:00 pm and Friday 9 am - 4:30 pm.
Email: info@crowntrees.co.uk // Phone: 08000 141 330