The poison, called bufotoxin, contains several different chemicals, such as bufagin, which affects the heart, and bufotenine, a hallucinogen. Cane toads in amplexus, a form of mating in which eggs are fertilized externally, photographed in Limón, Ecuador. The high-altitude forests that gird Africa are unsung carbon sinks. The inaccessibility of African montane forests has hindered efforts to quantify the carbon stored by these ecosystems. Now, a survey of mature mountainside forest plots in 12 African countries fills this knowledge gap, and highlights the need to preserve such forests. “Anyone who has conducted field inventories in tropical mountains knows that measuring and identifying 72,336 trees, often just a few steps away from the void, is an amazing feat,” writes tropical ecologist Nicolas Barbier in his analysis of the research.

Fencing the thousands of dams that exist across Australia to exclude cane toads is a daunting and prohibitively expensive prospect. However, using simulations we have shown that a practical and cost-effective approach to control cane toads would be to strategically create “toad breaks” to disrupt the network of refuge habitats available for toads. Control of toads at invasion hubs could be conducted reactively to control established populations or prevent the spread of toads by rendering invasion hubs unsuitable for colonization ahead of the invasion front.

Toads can be excluded from the areas shaded in red by restricting their access to artificial water. Cane toads cannot survive for more than three days during periods of dry conditions that normally prevail in arid Australia without access to water. However, dams created by pastoralists that serve as reservoirs for bore-water, have dramatically increased the availability of water in naturally parched semi-arid landscapes. Dams, therefore, provide a network of refuge habitats or “invasion hubs” in which toads congregate during dry seasons and visit on an almost daily basis. The poisonous toads kill both pets and native species when animals bite, lick, or eat them, and they outcompete native species for resources like food and breeding habitat. We thank Hayes Maclure for his help during field trials, Team Bufo, Melanie Elphick and Jorge Toledano for support, Camila Both for comments on the manuscript, and Bob MacDonald at Beatrice Hill Farm for sharing with us “good toad sites”.

Richard Shine

Dendrobatidis, although they have higher survival rates and better ability to clear an infection than other amphibians (e.g., 1). Dendrobatidis–inhibitory capacity on adult cane toads in Queensland suggests that the skin microbiome might confer some of the resistance to disease in this host species. Although amphibian skin microbiome communities change across ontogeny, host species is a strong predictor of skin communities across life stages a complete guide to ketamine withdrawal & addiction (8). Thus, the communities found on these adult toads may predict those found on juvenile toads. We used ANOVA to assess whether the presence of a conspecific (social facilitation) affected the rate at which toads were recruited to feeding stations. The dependent variable was the time elapsed from the time we turned on the light of the feeding station until the first free-ranging toad entered and commenced feeding (‘approach time’).

Here we exploit one of the best‐known biological invaders to discriminate between the two competing hypotheses of empty niche and niche competition. Besides strong morphological differences with native species, we also found variability within cane toads, especially in size of both males and females. Cane toad populations from their native range also reflect this morphological variability, potentially reflecting differential local adaptation (Hudson, McCurry, Lundgren, McHenry, & Shine, 2016).

“There’s a lot more work to be done. However, this research is the first – but most important – step in finding an effective way to control the cane toad,” Prof White said. Prof White said they had also discovered three new viruses within the DNA which could be used as “bio-controls”. Such methods have been successful in controlling rabbit populations. The study used advanced computers to sequence 360 billion DNA pairs and construct the “genome jigsaw”. In the world’s first field trials of marine cloud brightening, scientists have demonstrated a system designed to artificially brighten clouds to protect Australia’s Great Barrier Reef. On the back of a repurposed ferry boat, 320 nozzles spewed a mist of nano-sized salty droplets.

Excluding cane toads from water by using an alternative type of reservoir to dams is a practical approach to reduce cane toad populations. Dams could be fenced to exclude toads, or different types of reservoirs such as closed tanks which do not allow toads to access water could be used as alternative types of reservoirs to dams. Although each of the approaches to control cane toads we have demonstrated has its pros and cons, both the fencing of dams or the using of tanks as an alternative to dams have the potential to be used in landscape-scale programs to control cane toads.

Under the empty niche hypothesis, we would expect cane toads to fill a unique morphological niche not occupied by Australian native frog species. Thus, cane toads are expected to be morphologically distinct from endemic Australian species, most likely also occupying a different environmental or trophic niche than native frogs. The competitive exclusion hypothesis predicts the invaders’ morphological niche would overlap with native species’ phenotypic traits.

Personality Trials

Both individual personality and level of sociality may influence the decisions that an organism takes, and thus also affect its foraging strategy. For example, when testing the effect of personality type and its role on the producer-scrounger game in barnacle geese (Branta leucopsis), shy individuals tended to join bold individuals in a foraging situation, showing that personality affects scrounging behaviour. In this case, bold geese led while shy geese, by using social information, followed [42].

The map on the right shows the predicted range of toads in semi-arid and arid Australia based on their physiological limits (grey). Toads can only live in the grey area if they have regular access to water. The coloured areas represent the areas made available to toads by natural sources of water (blue) and artificial sources of water (red).

1. The first step in evaluating this scenario is to see if a newly-established population does indeed contain individuals of varying behavioural proclivities.
2. Thus, due to this taxonomic discordance, Australia might offer lower resistance to alien invasive species than continental regions, by providing the opportunity to invaders to fill an empty niche (Le Breton, Jourdan, Chazeau, Orivel, & Dejean, 2005; Shea & Chesson, 2002; Simberloff, 1995).
3. They are not protected by state, federal or local laws because they are invasive and unwanted.
4. That is, introduced species may spread more quickly when the population comprises a mixture of individuals with different personalities rather than being behaviourally monomorphic.

Individual variation in behavioural traits (including responses to social cues) may influence the success of invasive populations. We studied the relationship between sociality and personality in invasive cane toads (Rhinella marina) from a recently established population in tropical Australia. In our field experiments, we manipulated social cues (the 15+ pro tips on how to pass a marijuana drug test asap presence of a feeding conspecific) near a food source. We captured and compared toads that only approached feeding sites where another toad was already present, with conspecifics that approached unoccupied feeding sites. Subsequent laboratory trials showed correlated personality differences (behavioural syndromes) between these two groups of toads.

Cane toad DNA breakthrough ‘may help stop’ toxic pest

Only 39 of the 44 toads for which we recorded “time to approach” were included in the analysis, because five animals took longer than 90 min to approach. To quantify body condition (mass relative to length) of toads, we used residual scores from the general linear regression of ln body mass against ln SUL. Dung beetles were introduced to Australia to improve nutrient cycling in rangeland ecosystems and disrupt the life cycles of livestock parasites. However, predation by cane toads has reduced the important ecosystem services that dung beetles provide for the environment and pastoral industry. Cane toads have been nothing short of disastrous for the Australian environment. To provide a ‘social’ stimulus, we trained 32 adult female toads (98–120 mm snout-urostyle length [SUL]) to feed in the experimental apparatus (i.e., within a mesh enclosure on top of a white rubber mat, under a fluorescent light).

Laboratory Experiments

Feeding trials were carried out between 2000–2230 h under dim illumination. The two experiments were run on different nights, with 55% of the toads tested in Experiment 1 also tested in Experiment alcoholic eyes 2. Only the first toad that approached and began feeding on the mat was collected, individually marked with non-toxic paint and retained overnight in a clean, moist cloth bag.

Control hopes

We then performed a phylogenetic PCA, on all morphological variables, with phytools (Revell, 2012). Phylogenetic ANOVAs and phylogenetic PCA were also ran on the size‐corrected data set (Appendix S2). We also used PCA to reduce the dimensionality of the environmental data set. We performed ANOVAs and post hoc pairwise comparisons using Dunnett’s tests as well as for the first two environmental PCs, in order to assess which clades were significantly different to the cane toad.

Thus, ‘bold’ toads appeared to rapidly lose interest in feeding, and shift their attention to escaping. In contrast, the more sedentary ‘shy’ toads emerged later, but then settled into feeding without attempting to escape. This pattern may reflect the less active behaviour of shy toads, which allowed them (under our experimental settings) to focus on stimuli from the prey and as a consequence consume more prey.