Abstract
An all-hands-on-deck rationality appears to characterize invasive alien species (IAS) eradication. Not only are citizens enrolled in their monitoring and management to extend authorities’ capabilities, but a recent trend in so-called nature-based solutions also outsources labor to non-human species. Within the realm of biocontrol initiatives, these non-human actors are strategically enlisted to counter invasive species through various methods such as predation, detection, sensing, niche occupation, and infiltration for internal destruction. This paper critically examines this conscription of non-humans, including sentient animals, to do the dirty work for us, by synthesizing ongoing cases from each of these categories or careers of non-human labor. These range from metabolic and ecological labor, performed with relatively little human intervention, to contrived schemes of capturing, sterilizing, tagging, and releasing Judas animals to locate conspecifics for culling. In the IAS management context, most of this is a kind of necro-labor, where non-human workers, wittingly or unwittingly, end up as assassins, snitches, moles, thieves and destroyers of their targets, the undesired invasives. We argue that wild animal labor has been invisibilized insofar as these non-human laborers either are said to perform their “natural” behaviors or relegated to nature/property themselves, that is, the product of labor. Our paper further helps de-exceptionalize human labor over nature and make visible the kinds of contracts that we are entering into with non-human laborers and hence also our duties and responsibilities. Our focus on labor specifically in invasive species eradication helps highlight the harms involved in the necro-labor that targets undesirable species.
Introduction
Neoliberal biopolitics involves outsourcing labor to multiple actors, institutions, and non-governmental organizations to enable “governance at a distance” (Rose and Miller, 1992; Rutherford and Rutherford, 2013). For example, citizens may be enrolled as biopolitical subjects in citizen science programs and in invasive species monitoring and management (Boonman-Berson et al., 2018; Bowker and Star, 2000). While analysis of neoliberal biopolitics tends to focus on the human, the outsourcing of labor now includes projects in which wildlife managers enlist non-human actors, including animals. In this way, “nature has become a technology of government, harnessed to secure human life in the face of looming disaster” (Kanoi et al., 2022: 7). Non-human labor is increasingly packaged as a cost-effective, nature-based solution and a critical weapon in the arsenal in the so-called war against invasive alien species (IAS) (Munishi and Ngondya, 2022; Orion, 2015). In particular, non-humans are recruited for death work or necrolabor, put to work to selectively encourage or eradicate other species to maintain a good or biodiversity or biosecurity.
In terms of non-human labor, these nonhuman workers are not merely producing value or surplus, or “maintaining guilds,” as per the Millennium Ecosystem Assessment. Instead, they are arguably enrolled as worker-soldiers to serve particular goals and agendas around desired species configurations. The notion of animals as biocontrol agents—living beings tasked with mitigating the excesses of an unruly species, be it plant or animal—forces us to think seriously about such things as animals as workers under human design, the emergence of contractual relations with non-human actors, and the responsibilities, for example, animal welfare that these contracts imply or wholly omit. In this paper, we examine how the exclusion of nonhuman life from the category of labor structures these relationships in the IAS mitigation context. We argue that recognizing this work as labor might reconfigure our sense of the social relations and obligations that engaging nonhuman laborers entails, particularly in necrolabor. Understanding these activities as labor reframes the morality of interventions in nature more broadly, and the (repeated) relegation of non-human actors to domains of utility for capitalism and our benefit (Dashper, 2020; Porcher and Estebanez, 2019).
Using one species to control another (“biocontrol” through “the perfect enemy”) has a long and not unproblematic history (Thompson, 2014). For example, when Indian mongooses were introduced in Hawai’i in the late 1800s to act as a control of rat populations in sugar cane fields, they failed at their assigned task, since the diurnal mongooses mostly ignored the nocturnal rats, opting instead to decimate native and ground-nesting bird populations. In Australia, famously, cane toads were brought over to control cane beetles for the same purpose, but quickly spread and became an invasive species needing control in their own right. Despite these ill-fated interventions, nonhuman labor is increasingly deployed in IAS control at various scales. In this paper, we typologize non-human labor in invasive species management into five categories. This allows us to think through the biopolitical implications of some of the following work:
deploying one species as biosensors and loggers of ecological conditions (biosensor); introducing one species to predate on another (invasive/pest) species (predation); using animals as placeholders to prevent/deter another species from establishing a habitat by, for example, occupying the same niche or location (placeholder/niche); using individual animals to locate and/or monitor remaining populations (Judas); using non-human actors to infiltrate and undermine invasive species from within (moles)
These non-human biopolitical subjects may be thought of as complicit in biopolitical, or even necropolitical projects—the use of social and political power to dictate how some may live and how some must die (Mbembé and Meintjes, 2003). From the perspective of managers, these plants or animals are our helpers in the fight against IAS: convivially described as “coworkers, supervisors, and collaborating scientists” (Fitzgerald et al., 2021: 4). Most of the time, however, these species are wild, which places their unwitting enrollment in the human project of invasive species management on a more tenuous ethical ground (von Essen and Allen, 2016). This is so, because, it is a development that draws what may be called wild sovereigns (species in the wild) into the Zoopolis with resultant expectations (Donaldson and Kymlicka, 2011), but notably without extending equivalent citizenship-type rights or duties to them (Coulter, 2016). On Brouwer (2018)'s argument, enlisting nonhuman labor fundamentally changes our relationship with the species by pushing them further into liminal position.
In our cases expounded in what follows, involving so-called necrolabor, we show that the endeavor is framed as militarized labor, displaying similarities to the work of war: as the war or battle against invasive species. All in all, we demonstrate that invasive species management is now a multispecies collective endeavor, but that labor is not always performed knowingly, willingly, or sustainably, and it may also be greenwashed under current discourse of nature-based solutions. We make wild nonhuman labor visible to suggest that as these organisms provide services to humans, humans become ethically bound to these non-human workers. While not legally recognized as workers, this framing highlights the reciprocal obligations of people and the organisms they employ.
Non-human labor—Literature review
Can the work of non-humans justifiably be seen as labor? John Locke theorized nature or the wild in opposition to labor: land and materials were removed from a state of nature through the application of human labor. Labor is thus a defining characteristic of the liberal subject, and not a property of the wild or non-human. Karl Marx famously relegated nature and the non-human to a role of resources, fixed capital, or even raw material. He maintained that human beings plan their labor, while animals and other organisms do not. Hence, even if they produce value and goods like bees producing honey, there is a fundamental difference in, among other things, intentionality. On this interpretation, non-humans can and do work—which may be broadly defined as effort expanded toward a particular purpose—but they cannot meaningfully labor. Since then, however, revisionist labor studies have opened the discussion to considering also how non-human actors are enrolled in production and value-creation, having their labor extracted as “unpaid energies” (Moore, 2015). This is not dissimilar, feminist scholars argue, to how capitalism has depended on the unwaged, unacknowledged labor of women in the home since its origins (Lange, 2021). Curiously, the reason why female reproductive labor has gone unnoticed is because it has been understood as being “part of nature,” not work (Ortner, 1972). Acknowledging the labor of non-human actors’ is seen as a necessary next concession in this theoretical development, without needing to “entirely reinvent the wheel” (Coulter, 2016: 139)
A gradual move of seeing labor as less of a defining attribute of humans, and more as, for example, distributed agency (Bennett, 2010) or hybrid labor done by non-human actors and nature itself (Battistoni, 2017), has now entailed a shift in thinking about the protagonists of labor. To Brouwer (2018), animals are capable of performing many different kinds of work, and using instruments of labor, but they may do so differently to human labor. In some instances, animals do perform labor in a remarkably human sense: the beaver clearly has a “blueprint” planning behind its labor. Theories extending labor have been inspired by actor-network-theory, post-humanism, and new materialism. A key talking point regarding nature's labor has centered on the role of the body in performing productive or reproductive labor (Coulter, 2016). The bodily labor of animals has also been a straightforward topic in non-human labor discussions, observing how even in the pre-capitalism era, humans have used animals’ bodies to operate machinery, plow fields, hunt, and for transport (Porcher and Estebanez, 2019). There is a long history of beasts of burden, deployed in colonial as well as indigenous settings (Saha, 2017). Animals’ labor has also been readily deployed in war, celebrated in contexts such as the Animals in War Monument in London, albeit fittingly emblazed with the words “they had no choice” (Coulter, 2016: 142)
The other bodily labor currently being discussed is metabolic labor. In some ways, this is not conceptually an abrupt departure from Marx, who argued that labor is the driving force of metabolic interactions—humans transforming natural resources to meet their end, which is then distorted under capitalism. Adapting the metabolic metaphor, Barua (2019) explains the metabolic process as that by which non-human laborers produce useful products and surplus with their bodies through “rendering,” that is, transforming inputs to usable matter which hold value to us. Since metabolic labor is performable without sentience, it can be attributed to agents such as plants and bacteria (Lorimer, 2020; Palmer, 2021). Thus, agro-sciences now assign soil organisms the positions of agricultural laborers, putting them work to improve soil productivity and to cut human labor costs “by occurring at scales and temporalities inaccessible to the farmer” (Krzywoszynska, 2020). Similarly, artisanal cheesemakers identify microbes as “co-laborers” in producing cheese (Paxon, 2013). In the marine context, farmers now enlist cleaner fish to predate on an invasive parasite that destroys salmon (Erkinharju et al., 2021). Rather than associated with exploitation of labor, the turn is often heralded as a nature-based one (Lorimer, 2020).
Metabolic labor has been differentiated also from affective labor, which non-human animals may perform for us in various capacities, particularly in therapeutic, health, and entertainment industries (Barua, 2020). But the third form of labor, that ecological labor, is arguably most relevant in relation to enrolling nature and non-human laborers in the workforce. On this understanding, popularized and formalized in the ecosystems services framework, animals, plants, bacteria, and fungi can be ecosystem engineers, pioneers, architects, and workers, forming part of a wild guild (Blattner, 2020). Their work may involve pollination, seed dispersal, waste treatment, nutrient recycling, water quality maintenance, and more, something Krzywoszynska (2020) calls these metabolic-ecological labor (244), which we are only now beginning to appreciate. In thinking of metabolic activities performing ecological relationships and activities in this way, one can conceptualize a kind of “biospheric service economy” out in nature (Nelson, 2015). Coulter (2016) suggests these important productive activities form bases for human industries, yet are rarely recognized.
What distinguishes labor from everyday activities performed by nature regardless of human intervention? If nonhuman actors are “doing what they always do,” with varying levels of sentience and without consciousness of their work as “labor,” and humans simply harness value from it, it may be asked “what's the harm?” Indeed, following Tsing (2015), animals and plants may be said to “have their own projects inherent to the phenomenon of life experienced by them, independent of any contact with humans” (Hancock, 2019). Some explanations are offered as to this by Coulter (2016) and Brouwer (2018). They distinguish nonhuman labor in terms of voluntary, subsistence, and coerced forms. To ecologists, particularly since the Millennium Ecosystem Assessment, utilizing nature's regulatory and provisioning work has thus been a moral non-issue (Rippa, 2024)—the kind of voluntary or subsistence work they would do “naturally” as part of an ecosocial reproduction, in Coulter's terms, an echo of historical understandings of women's reproductive labor. But more critical animal studies scholars suggest that non-human agents never labor by default, and that the process invariably involves exploitation and expropriation (Hribal, 2003). The effort and artifice of extracting labor from non-humans crucially involves the subjects being “reimagined, reconstructed, and redeployed to make them amenable to humans” (Kanoi et al., 2022: 7).
In reflecting on non-human labor, the literature has made visible the broad contours of work across various species. Recent volumes like Besky and Blanchette’s (2019) How Nature Works: Rethinking Labor on a Troubled Planet, make strides in further deconstructing work. However, such volumes have a focus on “semi-domesticated creatures of late industrialism such as cows, pigs, sugarcane, tea bushes, ginseng, guinea pigs, bacteria, honeybees, mushrooms, and orangutans […] beings that have been—and still are being—shaped to work” (14) there remains a gap on problematizing the enrollment of ostensibly wild non-human subjects, out there in nature. Such labor is more elusive to trace out in terms of metaphors and similarities to human work, not least because the employer “has no obligation to the worker” (Kosek, 2019: 153), few if any welfare laws govern such “contracts,” and the labor pool is ephemeral, needed only at certain times. To date, Brouwer (2018) provides the perhaps most robust attempt at theorizing work done by non-domestic animals, examining pigeons, bees, and urban scavengers like rats, as waste disposers.
Moreover, whereas chapters in Besky and Blanchette (2019) highlight injustices for the non-human laborer in being forced to labor (and their entangled human workers in equally precarious situations), an outstanding task engaging environmental justice, animal ethics, and biopower, now becomes to consider how non-human labor in invasive species management is directed to visit injustices upon targets: unruly forms of life that threaten biodiversity. Hence, our point is that non-human labor in IAS management may have added precarity and justice components, insofar as we ostensibly have no moral obligations to wild animals enrolled in labor (unlike domestic animals), and the “any means necessary” approach to eradicating IAS licenses dubious practices against targets of the labor as well as the laborers. We now synthesize these labor forms across five categories, detailing the worker, the desired outcome, and the victim/recipient of the labor.
Synthesis—Five careers for non-human laborers
Biosensors—Snitches
The maxim “if you can’t monitor it, you can’t manage it” has informed invasive species management in the 21st century. It is the first step in IAS eradication. But since managers cannot have eyes and ears everywhere, an alternative has been to utilize non-humans as biosensors, biologgers, or simply “indicator species,” sentinel species of environmental change and degradation in remote habitats (Siddig et al., 2016). These organisms may be natural or genetically modified for this purpose. Species sensitive to environmental and ecosystem changes vary in their presence and flourishing depending on the presence of invasive species, alerting managers to their occurrence. On land, butterflies and bees provide an indicator for invasive plant monitoring. In Lake Victoria, the invasion of the water hyacinth, resulting in de-oxygenation of the water and subsequent reduction in fish stocks, enabled researchers to use these fish species to gauge the spread of the plant (Kateregga and Sterner, 2007).
Panov et al. (2009) assessed aquatic insect species, including damselflies and dragonflies, as indicators of ecosystem change and the presence of invasive species. In so doing, they attributed to these aquatic insects the role of “key indicator, flagship, or umbrella species” (208). They could perform their role particularly well, they argue, because as native island species on Hawaii, they were much less flexible in their niche requirements and were thus susceptible to changes, resulting in more precise monitoring. However, while these damselflies and dragonflies did correlate with other native fauna, it was not always possible to treat them as clear indicators of invasives. The invasion ecology and conservation community thus remain divided on the reliability of indicator species signaling the presence of invasive species. Andelman and Fagan (2000), for example, question their role as conservation surrogates, wondering if they might not be “expensive mistakes.” Indeed, it is not always possible to prove single causations behind a native/resident species and an invasive one, nor to control for all variables influencing how these indicator species thrive (Siddig et al., 2016). As Kosek (2010) shows, insects been used in historical and contemporary defense industrial contexts, from beetles dropped on crop fields during the Cold War to scientists deploying bees as fieldworkers, taking hundreds of field samples a day, to allow scientists to test for radioactivity or the presence of various chemicals. Human engagement with bees has taken the form of “a new bee managerialism,” in which bees are remade in response to human interests and needs (while humans have also tactically adopted elements of bee behavior (656).
The phenomenon of enlisting agents to surveil others, as opposed to doing the work oneself, is now a pervasive feature of modernity and of surveillance society (Lyon, 2001). In the human context, it has increasingly involved transposing a vigilance regime onto citizens, who are trained to become watchful and attentive to the ongoings of others. In this way, the government achieves the trickling down of surveillance from above to from below or amid (Ivasiuc et al., 2022). While these sensing animals do not personally deliver the death blow to their invasive species targets—nor do placeholders—they may be understood as taking part of a broader necrolabor project. Indeed, the pervasive use of animals for spying or warning in war (Coulter, 2016) shows that sensing work can easily be deployed as part of a multispecies militaristic endeavor.
Animal assassins—Predation
In the old nursery rhyme “There Was an Old Lady Who Swallowed a Fly,” the introduction of one species to predate/eat the one before begets an endless loop of introducing more predators at a higher trophic level to control the one below. This escalating problem logic is now familiar in ecology, and the basic premise still holds weight. Introducing predators to control an invasive species is predicated on the fact that the invasive organism has left behind its guild of natural enemies that previously regulated its population (termed the Enemy Release Hypothesis, by which escape from past constraints boosts their fitness (Colautti et al., 2004)), and now needs to be checked by a surrogate predator. Inserting a new or native predator to re-instate constraints on their fitness thus becomes “an exercise in community re-assemblage” (Hoddle, 2004: 39) to control and mitigate them.
However, famous historical examples of predator introductions have yielded unanticipated trophic consequences from the biological control agent “going rogue,” such as impacting non-target organisms. Cane toads in Australia and stoats, ferrets, and weasels introduced to predate on rabbits in New Zealand, have spawned negative ecosystem effects and created problems of their own with these predators decimating native biota (Simberloff and Stiling, 1996). Not all predator introductions have obvious negative unintended consequences, and more modest attempts persist today, such as the successful translocation of the endemic New Zealand falcon to vineyards to predate on invasive and pest bird populations in the “Falcons for Grapes” project (Kross, 2012). Often as part of projects characterized as rewilding, the restoration of apex predators—including large carnivores—is increasingly championed as a conservation strategy that can control invasive species at the same time as it can rebuild lost guilds from which predators were extirpated (Selonen et al., 2022). The assigned task of these introduced predators is said to be to “buffer our natural systems against some of the worst of human impacts” (Twining et al., 2022).
Some proposed projects currently include restoring the Florida panther to control invasive feral pigs in the US, and reintroducing lynx to control sika deer in Europe (Guilfoyle et al., 2023; Twining et al., 2022). In the eastern Mediterranean Sea, following an influx of invasive species from the Suez Canal, interspecies predation politics are currently underway for the Pterois miles lionfish, as well as several species of pufferfish of the Lagocephalus genus. Lionfish are invasive across many locations: they have been termed “the Norway rats of the Atlantic and the Caribbean” (Washington-Post, 2024). It is imperative to enlist non-human predators to control their numbers while these species can be eaten by humans, their venomous spikes make this difficult. Despite vigorous campaigns to encourage human consumption, citizen volunteers have not been able to eat their way out of this problem. 1 The dusky grouper has been put forward as one species that could “naturally” predate on these invaders, particularly around Crete. Cousin species of groupers in the Red Sea feed on lionfish, indicating that Mediterranean groupers should also be able to tolerate the prey's venom.
There are, however, several obstacles for putting these potential gourmands in place. Only large individuals of dusky grouper can prey on lionfish, but groupers of this size are endangered due to overfishing. The standard size grouper is of a size of the plate, meaning that few groupers have the chance to reach that age. Further, the groupers are not intuitive workers. They have to develop an appetite for these newcomers. Free divers and marine enthusiasts in Crete have joined forces with “stewards of the seas” elsewhere to teach apex predators that these alien species are edible, work that has also been attempted elsewhere. However, research indicates that there are difficulties in “teaching” these animals to predate on lionfish, as it requires much human involvement, including “spoon-feeding” them to sharks at first, which also makes them associate humans with food (Washington-Post, 2024). The necessity of training these animals to perform the desired task reinforces the claim that they are engaging in human-directed labor.
In examples we may think of as less violent, herbivores are brought in to graze on invasive grasses and weeds. Goats, for example, are sometimes used for targeted grazing to control various invasive plant species such as kudzu, buckthorn, honeysuckle, and Japanese knotweed. In Pittsburgh, Pennsylvania, they have been deployed as contract workers, managed by an NGO that hires them out to clear spaces of invasive or otherwise undesirable plants on a fee-for-service model. While the goats are intuitive workers by being quite eager to consume these plants, their workplace needs to be prepared for them by human workers (fenced and cleared of poisonous plants). After this preparation, the herd is brought to the site “and immediately gets to work eating the vegetation” (Allegheny Goatscape, 2024). While this work is intuitive, it is not leisure for the goats but instead is demanding labor that not all animals are equipped to perform. As goats age or become infirm, they are unable to navigate the steep terrain of the city and are no longer sent out to graze.
Although predation and/or eating may not be the chief trophic interaction between the target species and the introduced predator, research also suggests that the presence of apex predators has an inhibiting effect on particular invasive species, like the wolf on the raccoon dog in Finland (Selonen et al., 2022). This is elaborated below, in the category of “placeholder” non-human actors.
Placeholder/niche occupying animals—Theft
At Schiphol airport in 2021, domestic pigs were sent out into two-hectare fields between runways, thus converting what was once an abandoned sugar beet plantation into a muddy field. This “pig patrol” was tasked to do so to deter birds from landing on these fields and colliding with planes or getting sucked into their engines. The pigs ate or otherwise ruined the food that attracted the birds, and also chased away individual birds that landed. The approach was described as dispatching the as a “double enemy: he tries to catch the geese and he also eats their food. It's a dual attack” (theguardian). The logic of this solution—to use one species to out-compete or deter another by, for example, occupying or destroying its niche—is also frequently applied in invasive species management.
Restoring or introducing a competitive plant to deter an invasive plant, for example, is an approach seen in some parts of the world. Two principal factors undergird this approach. First, changed vegetation (often in boosting biomass or diversity in the resident community) can produce biotic resistance, allowing native plants to suppress invaders at a basic level (Catford et al., 2009). Here, established species exert a priority effect on niches that inhibit subsequent arrivers (Mwangi et al., 2007). They may also provide an insurance effect of species diversity to boost community-wide resilience further buttressing their defense. For example, in Hawai’i, establishing a combination of two to three native species was more effective compared to, for example, monocultures in inhibiting the invasion of an invasive grass (Megathysus maximus) (Ammondt and Litton, 2012).
Second, abiotic restraints—referring to environmental conditions such as limited nutrients and low light—can be produced to further resist invaders. Hence, contriving for landscapes to be harsh and nutrient-poor, by lowering nutrient availability, or adding carbon, also becomes a way to repel invaders who thrive in these abiotic conditions. One example of this is to introduce a crop plant cover on bare soil to lower light availability, which Iannone and Galatowitsch (2008) showed suppressed 89% of invasion by P. arundinacea, although it also came with collateral damage, limiting desired species by 57%. In wildlife management, introducing unexciting or nutrient-poor plants has been termed engineering “ecologies of boredom” for unwanted wildlife (Bauer et al., 2019). It involves carefully removing attractants and lures, replacing them with other species who then become the non-human laborers playing as a placeholder or repellent role toward the unwelcome guests. For this bottom-up engineering of the landscape approach to work, however, the identity of the invader—and hence its functional niche—needs to be clearly understood in advance (Byun et al., 2018). In these situations, the non-human laborers are not generally termed workers, perhaps because most do not involve sentient organisms. They are rather termed “factors” of the environment, not dissimilar to Marx’ instruments.
Judas animals—Betrayal
For gregarious species that seek out their conspecifics in the wild, the Judas technique has been applied by managers, providing a backdoor into eradicating invasive or feral populations. Feral camels, donkeys, goats, and raccoon dogs are among the most known contemporary examples. The approach works by the principle of capturing and outfitting an individual animal with a GPS tracker and releasing it to find members of its own species, which may otherwise be difficult for cullers to find. Upon location, hunters can cull these animals, retrieve the Judas-tracked individual, and re-release it for another mission elsewhere. When successful, populations decline and it will be harder and harder for the tracked individuals to locate conspecifics. In Sweden, where this has involved capturing, sterilizing, and releasing tracked raccoon dogs in the north, the project became so successful that there were at one point not enough wild raccoon dogs to capture and turn into Judas animals, by which point captive-reared ones had to be imported from Finland and released in Sweden to perform their Judas duty. Similarly, in New Zealand, a large-scale eradication of goats in Egmont National Park followed the simple tactic wherein “you just track the Judas goat down and shoot their mates,” but this had diminishing returns as the population rapidly declined (Smith, 2015).
Goats on South American islands, including the Galapagos, and donkeys in northern Australia, illustrate other cases where there was a logic of escalation to the Judas approach. Often, Judas animals are female. In the Galapagos, one-third of the goats were female, one-third male, and the final third were specially hormone-tampered with female goats, whose estrus has been prolonged from 20 days per year to 180 days, resulting in more gregarious behavior, specifically seeking out male goats. These goats were also sterilized, as becoming pregnant reduced their sociality. These “Mata Hari” or “Super Judas” goat individuals (Bocci, 2017; Wanderer, 2015), quickly “betray the locations of male admirers” (Nelson, 2007: 299). Bocci (2017) writes of the field operation: “With a scalpel, anesthetics, and hormones, [the project] recombined the elements of female goats into oversexualized individuals, devoid of the ability to bear life but with an irresistible talent for delivering death” (432–433).
In Judas Work: Four Modes of Sorrow, Rose (2008) writes that the Judas technique that involved radio collaring donkeys in Australia to find conspecifics “betrays the donkey's own sociality as well as assaulting the basis of empathy between humans and donkeys” (62). She also relays anecdotal reports that female donkeys (jennies) now start to learn the implications of their betrayal on the pack, insofar as seeing how “where they go, death follows,” which ultimately leads them to stop looking for others, isolating themselves from the pack. Although unverified reports, other scholars also critique the Judas technique for intraspecies betrayal (Wanderer, 2015) and point to the high costs asked of the Judas spies who, “Having just recovered from the previous massacre, the collared goats were expected to have found the strength once again to look for peers” (Bocci, 2017: 432).
In terms of these individual Judas animal laborers, they are often subject to contradicting forms of care and duty. On the one hand, they are expected to perform necrolabor. On the other hand, they are in some ways better provided for than wild conspecifics. They receive veterinary care, welfare checks and feeding. Raccoon dogs in Sweden, for example, are referred to as “cherished co-workers” and “project partners” and provided with top-of-the-line care that treats them for any infections and parasites (von Essen, 2023). Scientists feel “responsibility” toward them during this, but turn them out the next day, resulting in “biology of betrayal” (Wanderer, 2015).
Infiltrators—Moles
Similar to Judas animals, non-human infiltrators can be deployed to reach where humans cannot. Unlike Judas animals, however, infiltrators do not just seek out and unwittingly alert managers to the locations of conspecifics—they perform their own necrolabor to destroy them in situ. And unlike Judas animals, which operate at the level of flocks/packs, infiltrators undermine an organism from within. In this way, infiltrators also demonstrate parallels to assassins, our first category. The difference is in the way they perform their necrolabor. Examples of non-human infiltrators deployed in invasive species management and pest control include parasitoid wasps finding, laying eggs within, and ultimately killing other insects like the invasive emerald ash borer (Yang et al., 2012). Another example is the use of the parasitoid wasp Trissolcus japonicus to control the brown marmorated stink bug, an invasive agricultural pest that feeds on a range of crops. The wasp effectively parasitizes the eggs of the stink bug, which undermines their own hatching. In 2020 in Italy, one of the country's largest biocontrol programs successfully utilized this wasp against the bug (Costi et al., 2022).
In recent attention-grabbing headlines, other species of wasps can be deployed in an infiltrator capacity to control their host's behavior, effectively “zombifying” them to help their own larva survive (Miller and Adamo, 2021). This has been attempted for example in Thailand, speaking of a “wasp army” (National Geographic). The army of females Anagyrus lopezi wasps, in particular, inject their eggs directly into the bodies of mealybugs which, upon hatching, “eat” their way out of their hosts (Fanani et al., 2020). Charles Darwin observed this phenomenon and declared it to be so evil that God could not have a hand in human evolution (Miller and Adamo, 2021). Rearing wasps and releasing wasp cocoons to areas also in Western and Central Africa to target the invasive mealybug, predating on the cassava plant, Miller and Adamo (2021) note that the project saved an economy: “So next time you’re online and see wasps being unfairly maligned, consider the millions of humans across the world who are alive and able to feed themselves because of them.”
Discussion
If we trust invasion ecologists, both human citizens and non-human workers need to combine forces to fight in the “war” against IAS. The war effort may broadly be in monitoring, eradicating, or preventing the establishment of IAS. For non-human laborers, this effort is extracted without consent, and benefits are generally denied to them. The benefits of such an arrangement to human managers are clear: there is nothing owed to this labor force and few interventions may be needed to direct or extract labor if it is occurring in the wild. This has an added bonus of “naturalizing” work conceptually (Besky and Blanchette, 2019; Kosek, 2019): it is what they would be doing anyway, unencumbered by human agendas. Our five careers of non-human work in IAS involve varying levels of human contrivance in setting up and extracting the labor. Brouwer (2018) and Coulter (2016) discuss this in terms of mandating tasks/work, separated from, for example, voluntary work or subsistence work done by animals regardless of human agendas. In the case of Judas animals, these “wild” workers needed to be tampered with medically in catch and release efforts, involving sterilization and the implanting of tracking chips or provision of collars. In trying to get fish to predate on invasive fishes in the Mediterranean, humans have to spoon- and hand-feed them to start with. In this way, the career proceeds with a traineeship with human involvement. In other cases, animals simply needed to be released or deployed, via ground or air, and follow their own instincts or inclinations without much steering or micro-management on the ground.
Maximising value—Of what?
The necrolabor entailed in the above cases distinguishes the labor from what we may traditionally think of as surplus-generating productive labor. Indeed, these nonhuman workers generate value by eliminating others, in ways that may increase ecosystems services or the productivity or desirability of the landscape for their human managers. Drawing on the ideas of Waring, perhaps these sorts of cases do not only involve a shift in the thinking of the protagonists of labors, but also in the metric of how we estimate value and profit, particularly in relation to nature. Coulter (2016) writes that the addition of death and killing in animal labor forms present a difficulty to think with, but refers to death work in industries and on the farm. Wild animals killing other wild animals is even thornier. While value is notoriously difficult to empirically pin down in many cases (Kallis and Swyngedouw, 2018), the case context begs the question: what sort of capital accumulation is this, with one involving death and killing?
We build on the argument of Saha (2021), that dead value is produced. Saha explained the history of bounties in terms of dead value: “the value of a crocodile's remains was not so much its material worth, perhaps transformed into consumer products, but instead a sign of the diminishing threat to cattle in a changing ecology. In other words, the value of a dead crocodile was closely related to the value of cattle as undead capital.” While authors like Saha and Kosek (2010) have described these as part of colonialism and empire-building, the value of a dead/absent invasive species must be understood in relation to the value of biodiversity and biosecurity as desirable goods. Brouwer (2018) comes closest to approximating value-through-elimination labor, by showing how urban rats and scavengers “waste work” removes hazards and diseases, effectively maximizing biosecurity. The dead value produced by these nonhuman workers can also be understood in terms of ecosystem services (the products and services that ecosystems provide to humans). The elimination of threats to capital accumulation is also presently evident as a burgeoning industry in conservation, in which biodiversity has become the banner under which we wage war in nature and using nature.
War, by conservation
The war metaphor often accompanies IAS eradication, extending to the labor by nonhumans in this battle. It is not surprising, therefore, that various authors have observed the intersection of ecology and warfare, and of going to war, over, with, or utilizing nature. Guarasci and Kim (2021) write about the inextricability of war and ecologies, while Russell (2001)provides a historical perspective on the conjoined development of war and the control of nature. Kosek (2010), likewise, cautions about martial ecologies in his analysis of the militarization of the honeybee and its deployment in empire-building. In Duffy (2016)s War, by Conservation and its follow-up Security and Conservation (2022), a militarized approach to securing nature tends to exhibit moral boundaries between simplistic caricatures of good guys versus bad guys, such as endangered species and invasive species and poachers versus rare animals.
Duffy writes that a recent neoliberalization of security in conservation now involves private sector actors and their animals. Hence, dogs and African pouched rats, for example, are important actors combating the illegal wildlife trade (Duffy, 2022). She discusses “Killer,” a K9 recruit in Kruger National Park, as performing parachute jumps in service of conservation. These sensational examples, Duffy writes, of “enrolling animals as part of greenwashing for weapon manufacturers … [contributes] to the wider militarization of society.” Kosek's bees, described as “six-legged soldiers” extending the reach and intelligence of human senses in undermining the enemy, form an additional rich example of the militarization of animals in the industry of war, whether waged for security or biosecurity. In a similar way as the bee has been “instrumentalized as a means of tracking and tracing the boundaries of dangerous subjects and suspect objections” (Kosek, 2010: 670), the nonhuman workers deployed against invasive species find themselves in similar forms of employment. This should compel researchers to examine necrolabor in IAS eradication with greater care than some other work tasks.
What does the job contract as a necrolaborer entail?
In recent environmental ethics scholarship, our duties to non-humans are seen as not a function of their sentience or inherent rights, but as a function of our relationship to them. Palmer (2010), for example, stipulated four kinds of relationships with wild animals, applying on both species/populations and individual levels: causal, kinship, affective, social, and contractual. The contractual relation is perhaps the least explored in the literature (but for some examples, see Cohen, 2007; Morris, 1991; Palmer, 1997; Rowlands, 1997). This may be because there has been reluctance to apply contractarianism to non-humans, who cannot reasonably consent to such a contract as rational individuals (Smith, 2012). Hence, it has been declared as unjust to bind non-humans to contracts. It appears, however, that non-humans have not escaped what may be highly disadvantageous shadow contracts which, while not formally stipulated, still compel them to certain obligations.
The conscription of non-human workers in IAS management demonstrates some semblances of worker rights only in the case of Judas animals. These wild animals whose bodies we modify, displace, or otherwise contrive to perform labor are placed in a causal relationship with us: that is, we are responsible for their predicament. Hence, on Palmer's reasoning, we owe them specific obligations. To Brouwer, there is “minimal necessity” to ascribe labor rights to wholly wild animals (41) that we do not intersect with or directly modify. However, Brouwer seems to suggest that by virtue of laboring to produce value for humans, they become liminal, “standing closer to the community” (62). As contended by Donaldson and Kymlicka (2011), this very transformation compels the creation of some rights, as appropriate to the particular animal.
In reality, implanting predators, releasing wasps, or filling up an area with placeholder species, however, do not appear to compel much in terms of follow-up duties in practice. This may indicate that the relative care extended to Judas animals is not morally motivated through entering contracts with them, but simply a practical matter—these animals are a great deal more valuable than the average species member since they are invested with expensive technology. Maintaining them in reasonable health is then strategic self-preservation, much as treating Judas raccoon dog individuals for any infections so they can live longer. Brouwer (2018) suggests that perhaps, “we should assign labor rights to them for the time in which this is taking place” (43), but this may be insufficient if we fundamentally altered some behavior, location, or genetics of the laborer. These goats, furthermore, have clearly been displaced and affected in ways that impact their lives beyond work hours. An outlier, goats tasked to graze on invasive plants in Pittsburgh do compel follow-up care, receiving goat pensions in the form of ongoing housing and food even after they are no longer able to labor. They may receive this follow-up care because they effectively enter into relationships of care with their minders, who come to know and value them as individuals.
We argue contract violations by non-humans—by underperforming or performing the wrong tasks in the wrong places—furnishes an important conceptual bridge to scholarship on non-human resistance, which is a topic now covered in the growing animal labor studies scholarship. Particularly so-called “mandated” work in Coulter's (2016) term—separate from, for example, subsistence work and voluntary work by animals—can involve refusals and autonomy, opting out of the labor scheme. While far more examples occur for domestic and industrial non-human workers, including cows escaping abattoirs, pack donkeys refusing their loads, and zoo animals attacking visitors (Colling, 2020; Wadiwel, 2015), our examples enable us to tease out how refusals to work can take place also in the wild. It is an open question whether cases of wild non-human workers opting out of their contracts and work tasks constitute anything intentional on a collective level, beckoning toward unionizing. But the functional result may nevertheless be ruptures in the necropolitical regime, such as failed invasive species eradication projects or disrupting human plans for their use, as in the case of a feral goat on Guadalupe Island, Mexico, who escaped from a transport to a slaughterhouse and subsequently taught other goats to avoid shepherds’ corrals (Wanderer, 2015).
Who is eligible for a labor contract?
Just as there are outstanding questions pertaining to non-humans’ resistance and class consciousness as a labor force, are questions around just what sort of harm is involved in turning them into workers to manage IAS. Randle (2022) argues for “placing the questions of “Who's doing the work?” and “Are they being compensated?” into conversation with traditional environmental justice queries about “Who's being harmed?” and “Who's benefiting?” (87). Given the breadth of non-human organisms we have engaged here across IAS management projects, and the different manners in which their labor is extracted, the answer to this question no doubt varies across species and tasks. This is called for also by Waring (1988), asking us to consider suitable compensation also for a diversity of tasks whose outcomes struggle to be captured in extant economic metrics.
Possibly, and as managers would have us believe, there are genuinely those cases where the nonhumans do not suffer from being turned into laborers, as it builds on their innate capacities (to find conspecifics, to predate, to grow, to incubate others). Indeed, the naturalization and invisibilization of nonhuman labor is sometimes manifested in assertions that they benefit from the labor themselves and that having a task is good for them. Consider, for example, the maxim that service or herding dogs “naturally” (“he loves to work”) perform this labor, thriving under the assignment (Porcher, 2017). In this example, the extracting of labor becomes a way for us to imagine we facilitate the flourishing and thriving of the worker, who would otherwise suffer frustration from its lack of self-realization. On the opposite end, when sentient animals are called in to eradicate IAS, more harms may occur on levels we might conceptualize as both immediate welfare and more abstract affective levels.
For one, we know that relocation and deployment of animals of the kind asked for by, for example, introducing predators to a new habitat (to predate on IAS) have high mortality rates, stress levels, and suffering for the individuals selected. Secondly, gregarious pack animals may well suffer emotionally to some extent when repeatedly bringing about the death of their conspecifics. Thirdly, as Fair and McMullen (2023) critically posit, there are clearly instances of animal labor involving the undermining of the animal's own existence; through various processes they are alienated from their labor and “irrevocably estranged from their ‘species being’” (208) (or capacity to flourish), like broiler chickens. The extent to which such risks are present in the categories of labor in IAS management outlined above is clearly evolving and difficult to predict.
Finally, and in opposition to the-labor-as-harmful argument, with the turn to see labor as something metabolic-ecological to be carried out by, for example, bacteria and plants, does that mean these workers are not seen as sentient enough to meaningfully suffer harms of the kinds affecting animals? By using the terms non-human, we potentially open up for a broad remit of workers who may even include non-living aggregates, machines being a prominent example. We also suggest that the lines between living non-human workers and mere mechanical aggregates are becoming blurred. In a recent cutting-edge project to enroll non-human labor against IAS—in this case as biosensors—eDNA is used to inspect the presence of potential hitchhiking species in the ballast of transnational ships, a common vector of invasive aquatic species. eDNA is a non-human aggregate, but its livingness is up for debate: it is organic, in the sense of comprising ells, eggs, tissues, scales, exoskeletons and other microscopic fragments. But on a spectrum of sentience, this non-human assemblage of shed tissues cannot reasonably be compared on its labor to those of, for example, Judas animals like goats and raccoon dogs. In a similar way, we observe that “dead” forms of non-human matter can also be put to work against invasive species, such as using poultry to bait nets and traps to catch invasive frogs in California. However, we caution drawing the boundaries around “who can labor” so broadly.
Conclusion
We have argued that it is necessary to think seriously about the ethical implications involved in the enlistment of non-human actors in efforts to control invasive species. Much of this enlistment, we argued, goes toward necro-labor: death or killing is typically mandated in some way. This also makes the context of IAS elimination a compelling case for challenging recent conceptualizations of animal work as care work, part of ecosocial maintenance (Brouwer, 2018; Coulter, 2016). To be sure, the labor these animals perform is not found in one form of obvious destruction. It manifests in a diversity of that we have typologized as assassins, placeholders, betrayers, biosensors, and infiltrators, each being a form of labor deemed necessary in human efforts to control environments and maximize the twin goods of biodiversity and biosecurity. In this way, while beneficial to us, they are from an interspecies ethics perspective dubious characters: narcs (giving up the location of conspecifics or other species), thieves (stealing habitat or resources), assassins (sent to cull one population) and or infiltrating agents (assimilated genetically as vectors). Moreover, we must also entertain the possibility that collateral harms can attend these jobs that also victimize some people: for example, the use of biocontrol pesticides against IAS have clearly also historically undermined human health.
Furthermore, these animals can incur harm in their pursuit of these goals, such as with Judas animals who suffer a psychological toll from their repeated unintentional betrayals of their kin or be violently removed if they unwittingly stray from their intended roles. We have shown there is yet no means to negotiate contracts or bases to obtain what could be understood as consent, while these animals are still beholden to terms that dictate their well-being. Hence, we mobilize the idea of a contract to suggest one means of thinking about the obligations we might have to these non-humans and as a method to get past the invisibilization of these animals laboring in narratives that “naturalize” their work. Thus, we have argued that as projects to control invasive species and manage different environments expand through the increased utilization of metabolic and ecological labor this “wild workforce,” it is not outlandish to regard these animals as co-laborers and thus to more seriously consider the reciprocal obligations of people to the non-human actors recruited. As Coulter (2016) has proclaimed, doing so forms an important part of a project on interspecies solidarity, where better conditions for human workers often correlate with better treatment for animals.
Highlights
Neoliberal biopolitics involves enrolling nonhuman workers to provide “nature-based solutions” and biocontrol, raising a question about the ethics of nonhuman labor Nonhuman labor is most striking in invasive species management because the labor is often directed to do harm unto others Nonhuman labor is performed in careers of sometimes questionable integrity including “thieves,” “assassins,” “snitches,” “betrayers” and “moles” We show how labor can be forcibly extracted or involve letting nonhumans go about their “natural” projects Nonhuman labor compels consideration of labor contracts, including refusals to work, care to workers, and pensions
Footnotes
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Svenska Forskningsrådet Formas (BIOrdinary: Biodiversity dilemmas in ordinary places grant number 2022-01778).
