White-nose disease is caused by the cold-adapted fungus Pseudogymnoascus destructans, which infects bats during hibernation and can survive for several years in cave substrates. Its spores can attach to caving equipment and remain viable at room temperature for at least 25 days, allowing contaminated clothing and gear to transport the pathogen even after a pause between trips. The introduction of the fungus from Europe to North America and its movement from the East Coast to the West Coast of the United States are considered human-mediated, making cavers’ travel and hygiene practices relevant to long-distance pathogen spread.

The researchers designed a 23-question questionnaire covering caving and hygiene habits, knowledge of white-nose disease, willingness to change behaviour for conservation, and demographics. It was available in English, Spanish, French, Russian, Slovenian and Bulgarian; no responses were received in Chinese. Recruitment used mailing lists from national and international speleological federations, international bat research groups, social media and the authors’ personal networks. Only respondents who completed every question were analysed, and two respondents from Africa were excluded because the sample was too small for analysis.

Participants were divided geographically into North America, where the fungus had been introduced and continued to cause significant bat mortality; Australia and South and Central America, where it had not been reported but was considered capable of causing mortality if introduced; and Europe and Asia, where it was native without an associated pattern of bat mortality. The primary analysis examined biosecurity scores for trips of 101–1,000 kilometres, the most frequently reported travel distance beyond that considered to present a low natural-spread risk. The researchers used hierarchical linear regression and automatic model selection based on the Akaike information criterion.

North American respondents knew the most about white-nose disease and most often followed specific mitigation or decontamination instructions. Respondents from Australia and South and Central America also showed relatively good awareness, and approximately half reported adhering preventively to disease-related instructions. In contrast, European and Asian respondents were less informed and rarely took steps intended to prevent further spread. Water-only cleaning was most common among respondents from Europe and Asia, water and soap or another detergent was more common in Australia and South and Central America, and adherence to white-nose disease decontamination procedures was most frequent in North America.

Among all respondents, the model selected continent of origin, white-nose disease knowledge and age, with age adding little explanatory power. Continent alone accounted for an R-squared of 0.13; adding knowledge increased it to 0.15, an incremental value of 0.02, and adding age raised it to 0.16. Among 350 respondents who had heard of the disease, the selected model included continent, adherence to disease-related instructions and participation in disease-related studies, producing an R-squared of 0.22. The researchers therefore found only weak support for their hypothesis that knowledge alone would strongly influence hygiene habits; the study’s cross-sectional design did not establish a causal effect.

Knowledge was not absent from reported behaviour, but other factors were associated with it. Personal responsibility was the most common reason for following disease-related instructions, while lack of awareness was the most common reason for not following them. Most respondents who had received information about human impacts on cave ecosystems reported changing their behaviour, and most of those already familiar with white-nose disease agreed that limiting anthropogenic spread of the fungus was necessary and possible. The authors interpreted these results through the Theory of Planned Behaviour, under which attitudes, perceived social norms and perceived practical control can shape behaviour beyond knowledge alone.

Travel history highlighted the remaining prevention problem. Respondents reported 387 trips between continents during the preceding 10 years, although the questionnaire allowed each person to select no more than 10 locations, so the list was not exhaustive. Of those trips, 137 were made by cavers whose biosecurity scores indicated that they cleaned equipment only with water or did not clean it. Some of these respondents were unaware that the fungus could be carried on used equipment or believed it was absent from their country of residence. Thirty-five percent of the low-biosecurity transcontinental travellers reported involvement in scientific activities. Although scientific cavers had higher disease knowledge, hygiene did not differ significantly by respondents’ stated purpose for caving.

The authors proposed distance-based hygiene guidance: washing equipment with water when changing sites within 100 kilometres, using water and soap for distances up to 1,000 kilometres, and using local equipment or established decontamination protocols for longer journeys, particularly between continents. They also called for updated, standardised guidance in Europe and Asia, translation into national languages and more time for researchers to clean equipment between sites. These are the study authors’ recommendations, not interventions tested by the survey. Limitations included unequal continental sample sizes, possible recruitment bias toward the authors’ contacts and countries with research networks, reliance on self-reported knowledge and behaviour, unmeasured factors such as participant sex and formal training, and the sensitivity of knowledge–behaviour relationships to question wording.

Subject of Research: A global online survey of cavers’ white-nose disease knowledge, travel and equipment-hygiene practices

Article Title: Cavers’ knowledge of biosecurity and its influence on the prevention of white-nose disease

Article References: Zhelyazkova, V., Tičar, J., Deleva, S., Ivanov, A., Toshkova, N., & Puechmaille, S. (2025). Cavers’ knowledge of biosecurity and its influence on the prevention of white-nose disease. Subterranean Biology, 52, 45-68. https://doi.org/10.3897/subtbiol.52.140425

Image Credits: AI Generated

DOI: 10.3897/subtbiol.52.140425

Keywords: white-nose disease, cavers, biosecurity, bat conservation, pathogen pollution, Pseudogymnoascus destructans, equipment decontamination, caving hygiene, global survey, knowledge, influence, prevention

The macadamia is not an ordinary crop. Labour-intensive harvesting and complex post-harvest processing make it one of the costliest nuts in the global market, which means that every percentage point of yield lost to insects translates into substantial economic damage. Protecting the trees from pests is therefore a central concern for growers, and the conventional response has often been intensive chemical or mechanical intervention. The new research suggests that an alternative, ecologically grounded strategy may already be flying overhead every night. By examining how natural vegetation in and around plantations shapes the communities of birds and bats that forage among the trees, the team set out to quantify the pest control services these animals provide and to identify the landscape features that sustain them.

The study was conducted at ten intensively managed macadamia plantations in South Africa, a design that allowed the researchers to capture variation in both management intensity and surrounding land cover. At each site, the team compared trees growing at the edge of the plantation with trees in the centre, a comparison specifically chosen to analyse the influence of the surrounding vegetation on the animals visiting the crop. Edge trees sit closer to hedgerows, forest fragments and other natural features, while central trees are embedded more deeply within the monoculture, so any systematic differences in pest damage or animal communities between the two positions can reveal how strongly the wider landscape shapes what happens inside the orchard.

Surveying the fauna required two very different techniques. The researchers recorded 111 bird species through direct observation, walking the orchards and documenting the birds foraging among the trees. Bats, being nocturnal and difficult to observe visually, were detected through their echolocation calls, which were captured with acoustic recording equipment and used to identify 16 species. This acoustic monitoring allowed the team to build a detailed picture of which bat species were active over the plantations, how their activity varied between sites, and how that variation related to the structure of the surrounding landscape and the level of insect damage measured on the nuts.

The results pointed clearly to bats as the dominant pest control agents in the system. Bat activity was associated with reduced insect damage, and this effect was particularly pronounced in plantations that contained less natural habitat within their boundaries or were surrounded by natural habitat in the wider landscape. Natural habitat, in the sense used by the researchers, includes native forests, bushland and scrubland, the heterogeneous vegetation types that provide roosting sites, foraging grounds and refuge for insectivorous bats. In landscapes where these features persisted, the bats appeared to compensate for the scarcity of on-farm natural cover, patrolling the orchards and suppressing the insect populations that would otherwise feed on the developing nuts.

To test the contribution of flying vertebrates directly, the team conducted exclusion trials, a classic experimental approach in which nets are used to keep birds and bats away from the trees. The outcome was striking. When birds and bats were excluded, the proportion of nuts damaged by insects rose from 6.2 per cent to 10.7 per cent, an increase of roughly 70 per cent. This experiment provides some of the most direct evidence that these animals deliver a measurable, economically meaningful service to macadamia growers. Intriguingly, however, the researchers could not demonstrate a direct influence of bird numbers on pest infestation, suggesting that in this system the nocturnal bats, rather than the diurnal birds, carry the primary burden of biological pest control.

The landscape context proved to matter in more ways than one. As the proportion of natural habitats around the plantations increased, not only did the number of bats rise, but their diversity increased as well, indicating that intact vegetation supports a richer community of these aerial predators rather than merely a larger one dominated by a few generalist species. Even the yield of the macadamia trees was linked to the share of natural habitat in the landscape, reaching its highest level when natural habitats accounted for around 60 per cent of the surrounding area. This peak suggests a non-linear relationship in which a substantial but not exclusive share of natural cover best supports the ecological processes, from pest suppression to pollination, that underpin crop production.

Bird communities, by contrast, responded to fine-scale structure within the plantations rather than to the broader landscape. The researchers found that the species assemblages differed between the edges and the centres of the orchards: species that prefer dense and woody vegetation were more common at the plantation edges, while species of open habitats predominated in the interior. This edge-to-centre gradient shows that even within a single intensively managed plantation, the arrangement of vegetation creates distinct niches for different bird species, and it hints that the conservation value of an orchard depends not only on what surrounds it but also on how its own internal habitat mosaic is structured.

The implications extend well beyond macadamia. Lead author Dr Mina Anders of the Department of Functional Agrobiodiversity and Agroecology at the University of Göttingen emphasised the broader message of the findings. Natural habitats, she explained, are valuable refuges that support beneficial organisms providing pollination and pest control, which in turn benefits agricultural production and the farmers who depend on it. It is therefore essential, she argued, that natural habitats and their conservation are incorporated into the planning of agricultural land. In other words, the patches of native forest, bushland and scrubland that persist between and around fields should not be viewed as idle or expendable land, but as functional infrastructure that actively contributes to farm productivity.

For a crop as valuable as the macadamia, the economics of this ecological service are compelling. A 70 per cent increase in insect-damaged nuts when bats and birds are excluded illustrates how quickly quality, and with it market value, deteriorates without these natural allies. The study thus highlights a form of agriculture that combines biodiversity with production, in which conserving natural vegetation within and around farmland is not a concession to environmental ideals but a practical investment in yield and nut quality. As global demand for macadamias continues to grow, the research offers growers and land-use planners a concrete, evidence-based reason to protect the forests and scrublands that shelter the bats working the night shift over South Africa’s orchards, and it adds macadamia plantations to the growing list of cropping systems where the fate of the harvest is quietly tied to the health of the surrounding landscape.

Subject of Research: The role of bats, birds and natural habitat in biological pest control in macadamia orchards

Article Title: Bats as a form of biological pest control

Article References: Bats as a form of biological pest control. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: bats, biological pest control, macadamia, South Africa, agroecology, natural habitat, biodiversity, bird communities, echolocation, crop yield, landscape management, University of Göttingen