Associations between abundances of free-roaming gamebirds and common buzzards Buteo buteo are not driven by consumption of gamebirds in the buzzard breeding season.

Releasing gamebirds in large numbers for sport shooting may directly or indirectly influence the abundance, distribution and population dynamics of native wildlife. The abundances of generalist predators have been positively associated with the abundance of gamebirds. These relationships have implications for prey populations, with the potential for indirect impacts of gamebird releases on wider biodiversity. To understand the basis of these associations, we investigated variation in territory size, prey provisioning to chicks, and breeding success of common buzzards Buteo buteo, and associations with variation in the abundances of free-roaming gamebirds, primarily pheasants Phasianus colchicus, and of rabbits Oryctolagus cuniculus and field voles Microtus agrestis, as important prey for buzzards. The relative abundance of gamebirds, but not those of rabbits or voles, was weakly but positively correlated with our index of buzzard territory size. Gamebirds were rarely brought to the nest. Rabbits and voles, and not gamebirds, were provisioned to chicks in proportion to their relative abundance. The number of buzzard chicks increased with provisioning rates of rabbits, in terms of both provisioning frequency and biomass, but not with provisioning rates for gamebirds or voles. Associations between the abundances of buzzards and gamebirds may not be a consequence of the greater availability of gamebirds as prey during the buzzard breeding season. Instead, the association may arise either from habitat or predator management leading to higher densities of alternative prey (in this instance, rabbits), or from greater availability of gamebirds as prey or carrion during the autumn and winter shooting season. The interactions between gamebird releases and associated practices of predator control and shooting itself require better understanding to more effectively intervene in any one aspect of this complex social-ecological system.

Broadening the toolset for stakeholder engagement to explore consensus over wolf management.

Facilitating coexistence between people and large carnivores is critical for large carnivore conservation in human-dominated landscapes, when their presence impacts negatively on human interests. Such situations will often require novel ways of mediating between different values, worldviews and opinions about how carnivores should be managed. We report on such a process in an agricultural area of recent wolf recovery in central Italy where unsolved social tensions over wolf presence have radicalized opinions on either side of the wolf debate, resulting in a stalemate. Where previous mitigation policies based on top-down damage compensation have failed, we tested the potential for applying a participatory approach to engage different stakeholder groups in a dialogue aimed at sharing a deep understanding of the problem and co-creating potential solutions. We based our approach on the theory of meta-consensus, using a decision support tool known as Multi Criteria Decision Analysis (MCDA). Over the course of three months, we carried out five workshops with stakeholder representatives from farming, hunting and environmental associations, and one biologist. Stakeholders shared several objectives and agreed over many management interventions, including the management of free-ranging dogs, the implementation of damage prevention measures, and a damage compensation system suitable for farmers. The process facilitated agreement over actions aimed at improving relations between stakeholders and enhancing the state of knowledge on the issues at stake. Most importantly, we recorded positive social and relationship outcomes from the workshops, and observed a willingness from participants to engage in further discussions over disputed management preferences. Overall, we found MCDA to be a useful tool for laying the groundwork for further participatory and deliberative processes on wolf management. However, challenges ahead included the involvement of a larger number of representatives of different social sectors, and a simplification of the methodology which some participants found too complicated and time consuming.

Assessing the Effectiveness of a Community-based Livestock Insurance Program.

Financial mechanisms to mitigate the costs of negative human-carnivore interactions are frequently promoted to support human coexistence with carnivores. Yet, evidence to support their performance in different settings is scarce. We evaluated a community-based livestock insurance program implemented as part of a broader snow leopard conservation effort in the Tost Tosonbumba Nature Reserve, South Gobi, Mongolia. We assessed program efficiency and effectiveness for snow leopard conservation using a results-based evaluation approach. Data sources included program records from 2009 to 2018, as well as surveys conducted in 2016 and 2017, which allowed us to compare key indicators across communities that participated in the insurance program and control communities. Program coverage and number of livestock insured rapidly increased over the years to reach 65% of households and close to 11,000 livestock. Participants expressed satisfaction with the program and their contributions increased over time, with an increasing proportion (reaching 64% in 2018) originating from participant premiums, suggesting strong community ownership of the program. Participants were less likely to report the intention to kill a snow leopard and reported fewer livestock losses than respondents from control communities, suggesting increased engagement in conservation efforts. These results together suggest that the insurance program achieved its expected objectives, although it is challenging to disentangle the contributions of each individual conservation intervention implemented in intervention communities. However, in the first three years of the program, snow leopard mortalities continued to be reported suggesting that additional interventions were needed to reach impact in terms of reducing retaliatory killings of large carnivores.

Patterns of satellite tagged hen harrier disappearances suggest widespread illegal killing on British grouse moors.

Identifying patterns of wildlife crime is a major conservation challenge. Here, we test whether deaths or disappearances of a protected species, the hen harrier, are associated with grouse moors, which are areas managed for the production of red grouse for recreational shooting. Using data from 58 satellite tracked hen harriers, we show high rates of unexpected tag failure and low first year survival compared to other harrier populations. The likelihood of harriers dying or disappearing increased as their use of grouse moors increased. Similarly, at the landscape scale, satellite fixes from the last week of life were distributed disproportionately on grouse moors in comparison to the overall use of such areas. This pattern was also apparent in protected areas in northern England. We conclude that hen harriers in Britain suffer elevated levels of mortality on grouse moors, which is most likely the result of illegal killing.

Functional specialization of intestinal dendritic cell subsets during Th2 helminth infection in mice.

Dendritic cells (DCs) are essential in dictating the nature and effectiveness of immune responses. In the intestine DCs can be separated into discrete subsets, defined by expression of CD11b and CD103, each with different developmental requirements and distinct functional potential. Recent evidence has shown that different intestinal DC subsets are involved in the induction of T helper (Th)17 and regulatory T cell responses, but the cells that initiate Th2 immune responses are still incompletely understood. We show that in the Th2 response to an intestinal helminth in mice, only CD11b+ and not CD11b- DCs accumulate in the local lymph node, upregulate PDL2 and express markers of alternative activation. An enteric Th1 response instead activated both CD11b+ and CD11b- DCs without eliciting alternative activation in either population. Functionally, only CD11b+ DCs activated during helminth infection supported Th2 differentiation in naive CD4+ T cells. Together our data demonstrate that the ability to prime Th2 cells during intestinal helminth infection, is a selective and inducible characteristic of CD11b+ DCs.

Impact of wild prey availability on livestock predation by snow leopards.

An increasing proportion of the world's poor is rearing livestock today, and the global livestock population is growing. Livestock predation by large carnivores and their retaliatory killing is becoming an economic and conservation concern. A common recommendation for carnivore conservation and for reducing predation on livestock is to increase wild prey populations based on the assumption that the carnivores will consume this alternative food. Livestock predation, however, could either reduce or intensify with increases in wild prey depending on prey choice and trends in carnivore abundance. We show that the extent of livestock predation by the endangered snow leopard Panthera uncia intensifies with increases in the density of wild ungulate prey, and subsequently stabilizes. We found that snow leopard density, estimated at seven sites, was a positive linear function of the density of wild ungulates-the preferred prey-and showed no discernible relationship with livestock density. We also found that modelled livestock predation increased with livestock density. Our results suggest that snow leopard conservation would benefit from an increase in wild ungulates, but that would intensify the problem of livestock predation for pastoralists. The potential benefits of increased wild prey abundance in reducing livestock predation can be overwhelmed by a resultant increase in snow leopard populations. Snow leopard conservation efforts aimed at facilitating increases in wild prey must be accompanied by greater assistance for better livestock protection and offsetting the economic damage caused by carnivores.

Enteric Helminths Promote Salmonella Coinfection by Altering the Intestinal Metabolome.

Intestinal helminth infections occur predominantly in regions where exposure to enteric bacterial pathogens is also common. Helminth infections inhibit host immunity against microbial pathogens, which has largely been attributed to the induction of regulatory or type 2 (Th2) immune responses. Here we demonstrate an additional 3-way interaction in which helminth infection alters the metabolic environment of the host intestine to enhance bacterial pathogenicity. We show that an ongoing helminth infection increased colonization by Salmonella independently of T regulatory or Th2 cells. Instead, helminth infection altered the metabolic profile of the intestine, which directly enhanced bacterial expression of Salmonella pathogenicity island 1 (SPI-1) genes and increased intracellular invasion. These data reveal a novel mechanism by which a helminth-modified metabolome promotes susceptibility to bacterial coinfection.

Intestinal Epithelial Cell-Intrinsic Deletion of Setd7 Identifies Role for Developmental Pathways in Immunity to Helminth Infection.

The intestine is a common site for a variety of pathogenic infections. Helminth infections continue to be major causes of disease worldwide, and are a significant burden on health care systems. Lysine methyltransferases are part of a family of novel attractive targets for drug discovery. SETD7 is a member of the Suppressor of variegation 3-9-Enhancer of zeste-Trithorax (SET) domain-containing family of lysine methyltransferases, and has been shown to methylate and alter the function of a wide variety of proteins in vitro. A few of these putative methylation targets have been shown to be important in resistance against pathogens. We therefore sought to study the role of SETD7 during parasitic infections. We find that Setd7-/- mice display increased resistance to infection with the helminth Trichuris muris but not Heligmosomoides polygyrus bakeri. Resistance to T. muris relies on an appropriate type 2 immune response that in turn prompts intestinal epithelial cells (IECs) to alter differentiation and proliferation kinetics. Here we show that SETD7 does not affect immune cell responses during infection. Instead, we found that IEC-specific deletion of Setd7 renders mice resistant to T. muris by controlling IEC turnover, an important aspect of anti-helminth immune responses. We further show that SETD7 controls IEC turnover by modulating developmental signaling pathways such as Hippo/YAP and Wnt/ß-Catenin. We show that the Hippo pathway specifically is relevant during T. muris infection as verteporfin (a YAP inhibitor) treated mice became susceptible to T. muris. We conclude that SETD7 plays an important role in IEC biology during infection.

Schistosoma mansoni Larvae Do Not Expand or Activate Foxp3+ Regulatory T Cells during Their Migratory Phase.

Foxp3(+) regulatory T (Treg) cells play a key role in suppression of immune responses during parasitic helminth infection, both by controlling damaging immunopathology and by inhibiting protective immunity. During the patent phase of Schistosoma mansoni infection, Foxp3(+) Treg cells are activated and suppress egg-elicited Th2 responses, but little is known of their induction and role during the early prepatent larval stage of infection. We quantified Foxp3(+) Treg cell responses during the first 3 weeks of murine S. mansoni infection in C57BL/6 mice, a time when larval parasites migrate from the skin and transit the lungs en route to the hepatic and mesenteric vasculature. In contrast to other helminth infections, S. mansoni did not elicit a Foxp3(+) Treg cell response during this early phase of infection. We found that the numbers and proportions of Foxp3(+) Treg cells remained unchanged in the lungs, draining lymph nodes, and spleens of infected mice. There was no increase in the activation status of Foxp3(+) Treg cells upon infection as assessed by their expression of CD25, Foxp3, and Helios. Furthermore, infection failed to induce Foxp3(+) Treg cells to produce the suppressive cytokine interleukin 10 (IL-10). Instead, only CD4(+) Foxp3(-) IL-4(+) Th2 cells showed increased IL-10 production upon infection. These data indicate that Foxp3(+) Treg cells do not play a prominent role in regulating immunity to S. mansoni larvae and that the character of the initial immune response invoked by S. mansoni parasites contrasts with the responses to other parasitic helminth infections that promote rapid Foxp3(+) Treg cell responses.

Indirect effects of primary prey population dynamics on alternative prey.

We develop a theory of generalist predation showing how alternative prey species are affected by changes in both mean abundance and variability (coefficient of variation) of their predator's primary prey. The theory is motivated by the indirect effects of cyclic rodent populations on ground-breeding birds, and developed through progressive analytic simplifications of an empirically-based model. It applies nonetheless to many other systems where primary prey have fast life-histories and can become superabundant, thus facilitating impact on alternative prey species and generating highly asymmetric interactions. Our results suggest that predator effects on alternative prey should generally decrease with mean primary prey abundance, and increase with primary prey variability (low to high CV)-unless predators have strong aggregative responses, in which case these results can be reversed. Approximations of models including predator dynamics (general numerical response with possible delays) confirm these results but further suggest that negative temporal correlation between predator and primary prey is harmful to alternative prey. Finally, we find that measurements of predator numerical responses are crucial to predict-even qualitatively-the response of ecosystems to changes in the dynamics of outbreaking prey species.

Spatial regulation of IL-4 signalling in vivo.

Type 2 immune responses are defined by the cytokines interleukin 4 (IL-4), IL-5 and IL-13 and the cellular and physiological changes that these cytokines induce, including IgE production, eosinophilia, mast cell degranulation, mucus secretion and smooth muscle contraction. Together these responses provide a "weep and sweep" reflex that is optimised to expel parasitic worms. The same response can also be pathological when mis-timed or activated inappropriately. Current understanding of the orchestration and regulation of type 2 immunity is rapidly advancing, with recent identification of participating innate cells and elucidation of the cytokine signals responsible for their activation. In vivo, the outcome of cytokine signalling is critically dependent on timing, location and context. In this commentary, we describe the spatiotemporal control of type 2 cytokine signalling, consider its implications for bystander cells, and discuss its significance during co-infection.

Perinatal antibiotic-induced shifts in gut microbiota have differential effects on inflammatory lung diseases.

BACKGROUND: Resident gut microbiota are now recognized as potent modifiers of host immune responses in various scenarios. Recently, we demonstrated that perinatal exposure to vancomycin, but not streptomycin, profoundly alters gut microbiota and enhances susceptibility to a TH2 model of allergic asthma. OBJECTIVE: Here we sought to further clarify the etiology of these changes by determining whether perinatal antibiotic treatment has a similar effect on the TH1/TH17-mediated lung disease, hypersensitivity pneumonitis. METHODS: Hypersensitivity pneumonitis was induced in C57BL/6 wild-type or recombination-activating gene 1-deficient mice treated perinatally with vancomycin or streptomycin by repeated intranasal administration of Saccharopolyspora rectivirgula antigen. Disease severity was assessed by measuring lung inflammation, pathology, cytokine responses, and serum antibodies. Microbial community analyses were performed on stool samples via 16S ribosomal RNA pyrosequencing and correlations between disease severity and specific bacterial taxa were identified. RESULTS: Surprisingly, in contrast to our findings in an allergic asthma model, we found that the severity of hypersensitivity pneumonitis was unaffected by vancomycin, but increased dramatically after streptomycin treatment. This likely reflects an effect on the adaptive, rather than innate, immune response because the effects of streptomycin were not observed during the early phases of disease and were abrogated in recombination-activating gene 1-deficient mice. Interestingly, Bacteroidetes dominated the intestinal microbiota of streptomycin-treated animals, while vancomycin promoted the expansion of the Firmicutes. CONCLUSIONS: Perinatal antibiotics exert highly selective effects on resident gut flora, which, in turn, lead to very specific alterations in susceptibility to TH2- or TH1/TH17-driven lung inflammatory disease.

Commensal-pathogen interactions in the intestinal tract: lactobacilli promote infection with, and are promoted by, helminth parasites.

The intestinal microbiota are pivotal in determining the developmental, metabolic and immunological status of the mammalian host. However, the intestinal tract may also accommodate pathogenic organisms, including helminth parasites which are highly prevalent in most tropical countries. Both microbes and helminths must evade or manipulate the host immune system to reside in the intestinal environment, yet whether they influence each other's persistence in the host remains unknown. We now show that abundance of Lactobacillus bacteria correlates positively with infection with the mouse intestinal nematode parasite, Heligmosomoides polygyrus, as well as with heightened regulatory T cell (Treg) and Th17 responses. Moreover, H. polygyrus raises Lactobacillus species abundance in the duodenum of C57BL/6 mice, which are highly susceptible to H. polygyrus infection, but not in BALB/c mice, which are relatively resistant. Sequencing of samples at the bacterial gyrB locus identified the principal Lactobacillus species as L. taiwanensis, a previously characterized rodent commensal. Experimental administration of L. taiwanensis to BALB/c mice elevates regulatory T cell frequencies and results in greater helminth establishment, demonstrating a causal relationship in which commensal bacteria promote infection with an intestinal parasite and implicating a bacterially-induced expansion of Tregs as a mechanism of greater helminth susceptibility. The discovery of this tripartite interaction between host, bacteria and parasite has important implications for both antibiotic and anthelmintic use in endemic human populations.

Multiscale factors affecting human attitudes toward snow leopards and wolves.

The threat posed by large carnivores to livestock and humans makes peaceful coexistence between them difficult. Effective implementation of conservation laws and policies depends on the attitudes of local residents toward the target species. There are many known correlates of human attitudes toward carnivores, but they have only been assessed at the scale of the individual. Because human societies are organized hierarchically, attitudes are presumably influenced by different factors at different scales of social organization, but this scale dependence has not been examined. We used structured interview surveys to quantitatively assess the attitudes of a Buddhist pastoral community toward snow leopards (Panthera uncia) and wolves (Canis lupus). We interviewed 381 individuals from 24 villages within 6 study sites across the high-elevation Spiti Valley in the Indian Trans-Himalaya. We gathered information on key explanatory variables that together captured variation in individual and village-level socioeconomic factors. We used hierarchical linear models to examine how the effect of these factors on human attitudes changed with the scale of analysis from the individual to the community. Factors significant at the individual level were gender, education, and age of the respondent (for wolves and snow leopards), number of income sources in the family (wolves), agricultural production, and large-bodied livestock holdings (snow leopards). At the community level, the significant factors included the number of smaller-bodied herded livestock killed by wolves and mean agricultural production (wolves) and village size and large livestock holdings (snow leopards). Our results show that scaling up from the individual to higher levels of social organization can highlight important factors that influence attitudes of people toward wildlife and toward formal conservation efforts in general. Such scale-specific information can help managers apply conservation measures at appropriate scales. Our results reiterate the need for conflict management programs to be multipronged.

The development and survival but not function of follicular B cells is dependent on IL-7Rα Tyr449 signaling.

IL-7 is a critical cytokine for lymphocyte development. Recent work has highlighted critical roles for IL-7 signaling in mature T cell homeostasis and function, but its role in B cells is less well characterized. Using a knock-in mouse possessing a Tyr to Phe mutation at position 449 (IL-7Rα(449F/449F) mice) within the cytoplasmic SH2-binding motif of IL-7Rα, we evaluated the role of IL-7Rα Y449 motif in spleen B cells. IL-7Rα(449F/449F) mice had reduced numbers and increased death of follicular B cells compared to WT, but had significantly more follicular cells than IL-7Rα(-/-). The death of IL-7Rα(449F/449F) follicular cells was not due to a failure to respond to BAFF or lower levels of BAFF, a critical B cell survival factor. Marginal zone B cells were unaffected by the IL-7Rα(449F/449F) mutation. Any role for TSLP was ruled out, as TSLPR(-/-) mice had an identical B cell phenotype to wild-type mice. Bone marrow chimeras and the absence of IL-7Rα on B cells suggested that IL-7 did not directly regulate mature B cells, but that an IL-7-responsive cell was influencing B cells. IL-7 was also critical at the checkpoint between the T1 and T2 stages in the spleen. IL-7Rα(-/-) mice fail to develop T2 cells, but IL-7Rα(449F/449F) show a reduction compared to WT but not complete absence of T2 cells. We also tested the functional responses of IL-7Rα(449F/449F) to antigens and infection and found no difference in antibody responses to T-dependent or T-independent antigens, or to Influenza/A. IL-7 was important for generation of antibody responses to the intestinal worm H. polygyrus and for naive levels of IgA. Taken together, this suggests that IL-7 regulates follicular B cell numbers and survival in a cell-extrinsic manner, via a bone-marrow derived cell, but is not critical for antibody production outside the gut.

Th2 cell-intrinsic hypo-responsiveness determines susceptibility to helminth infection.

The suppression of protective Type 2 immunity is a principal factor driving the chronicity of helminth infections, and has been attributed to a range of Th2 cell-extrinsic immune-regulators. However, the intrinsic fate of parasite-specific Th2 cells within a chronic immune down-regulatory environment, and the resultant impact such fate changes may have on host resistance is unknown. We used IL-4gfp reporter mice to demonstrate that during chronic helminth infection with the filarial nematode Litomosoides sigmodontis, CD4(+) Th2 cells are conditioned towards an intrinsically hypo-responsive phenotype, characterised by a loss of functional ability to proliferate and produce the cytokines IL-4, IL-5 and IL-2. Th2 cell hypo-responsiveness was a key element determining susceptibility to L. sigmodontis infection, and could be reversed in vivo by blockade of PD-1 resulting in long-term recovery of Th2 cell functional quality and enhanced resistance. Contrasting with T cell dysfunction in Type 1 settings, the control of Th2 cell hypo-responsiveness by PD-1 was mediated through PD-L2, and not PD-L1. Thus, intrinsic changes in Th2 cell quality leading to a functionally hypo-responsive phenotype play a key role in determining susceptibility to filarial infection, and the therapeutic manipulation of Th2 cell-intrinsic quality provides a potential avenue for promoting resistance to helminths.

ICOS controls Foxp3(+) regulatory T-cell expansion, maintenance and IL-10 production during helminth infection.

Foxp3(+) regulatory T (Treg) cells are key immune regulators during helminth infections, and identifying the mechanisms governing their induction is of principal importance for the design of treatments for helminth infections, allergies and autoimmunity. Little is yet known regarding the co-stimulatory environment that favours the development of Foxp3(+) Treg-cell responses during helminth infections. As recent evidence implicates the co-stimulatory receptor ICOS in defining Foxp3(+) Treg-cell functions, we investigated the role of ICOS in helminth-induced Foxp3(+) Treg-cell responses. Infection of ICOS(-/-) mice with Heligmosomoides polygyrus or Schistosoma mansoni led to a reduced expansion and maintenance of Foxp3(+) Treg cells. Moreover, during H. polygyrus infection, ICOS deficiency resulted in increased Foxp3(+) Treg-cell apoptosis, a Foxp3(+) Treg-cell specific impairment in IL-10 production, and a failure to mount putatively adaptive Helios(-) Foxp3(+) Treg-cell responses within the intestinal lamina propria. Impaired lamina propria Foxp3(+) Treg-cell responses were associated with increased production of IL-4 and IL-13 by CD4(+) T cells, demonstrating that ICOS dominantly downregulates Type 2 responses at the infection site, sharply contrasting with its Type 2-promoting effects within lymphoid tissue. Thus, ICOS regulates Type 2 immunity in a tissue-specific manner, and plays a key role in driving Foxp3(+) Treg-cell expansion and function during helminth infections.