Socio-ecological drivers of vertebrate biodiversity and human-animal interfaces across an urban landscape

Geographical association of biodiversity with cancer and cardiovascular mortality rates: analysis of 39 distinct conditions

Background

Biodiversity has been recognized as a positive contributor to human health and wellbeing. Cardiovascular disease and cancer are the two most significant global health burdens, and understanding their relationship with biodiversity forms an essential step toward promoting biodiversity conservation and human health.

Methods

The species richness of birds is a common indicator of biodiversity, given their vast numbers, distinctive distribution, and acute sensitivity to environmental disturbances. This ecological study utilized avian observation data derived from the eBird database, human health data from the International Health Metrics and Evaluation, and county-level statistics, including population characteristics, socio-economics, healthcare service, residential environment, and geographic and climatic characteristics in 2014. We aimed to extensively explore the individual associations between biodiversity (i.e., avian species richness) and age-standardized cause-specific mortalities for different types of cancers (29 conditions) and cardiovascular diseases (10 conditions) across the United States (US).

Results

Our multiple regression analyses that adjusted for a variety of socio-demographic and geographical factors showed that increased rarefied species richness of birds was associated with reduced mortality rates for three of the five most common cancers, namely, tracheal, bronchus, and lung cancer, breast cancer (in women only), and colon and rectal cancer. For cardiovascular conditions, a similar relationship was observed for ischemic heart disease and cerebrovascular disease-the two most frequent causes of mortality. This study provided extended details regarding the beneficial effects of biodiversity on human health.

Protecting China's major urban bird diversity hotspots

The Kunming-Montreal Global Biodiversity Framework puts forward a new conservation target to enhance urban biodiversity. Cities have a great potential for sustaining biodiversity and nurturing a healthy relationship between people and our nearest nature. It is especially important in developing countries such as China, which has a rich biodiversity and a rapidly growing urban population. Using citizen science data, we show that 48% of the national bird diversity and 42% of its threatened species have been recorded in the top-20 most avian-diverse cities of China. Urban bird diversity hotspots clustered along the eastern coast, indicating the importance of establishing an inter-city conservation network along the East Asian-Australasian Flyway. This urban conservation network would be a starting point to promote social recognition of biodiversity's relational value in a country with a vast population and an increasingly important role in meeting UN's Sustainable Development Goals.

Epidemiological connectivity between humans and animals across an urban landscape

Urbanization is predicted to be a key driver of disease emergence through human exposure to novel, animal-borne pathogens. However, while we suspect that urban landscapes are primed to expose people to novel animal-borne diseases, evidence for the mechanisms by which this occurs is lacking. To address this, we studied how bacterial genes are shared between wild animals, livestock, and humans (n = 1,428) across Nairobi, Kenya-one of the world's most rapidly developing cities. Applying a multilayer network framework, we show that low biodiversity (of both natural habitat and vertebrate wildlife communities), coupled with livestock management practices and more densely populated urban environments, promotes sharing of Escherichia coli-borne bacterial mobile genetic elements between animals and humans. These results provide empirical support for hypotheses linking resource provision, the biological simplification of urban landscapes, and human and livestock demography to urban dynamics of cross-species pathogen transmission at a landscape scale. Urban areas where high densities of people and livestock live in close association with synanthropes (species such as rodents that are more competent reservoirs for zoonotic pathogens) should be prioritized for disease surveillance and control.

Demystifying a buzzword: Use of the term "human-animal-interface" in One Health oriented research based on a literature review and expert interviews

As of today, 75% of infectious human diseases are caused by zoonotic pathogens, which use the interface between humans and animal species to cross. Due to this ability, zoonoses affect more than just one health sector and the effective control is a matter of the One Health concept. One defining feature of this concept is the "human-animal-interface". However, even though the term is ubiquitously used in the field of infectious disease research, a clear definition of the term is lacking, leading to a rather nebulous understanding of what this interface really encompasses. Based on this observation, this study aimed to analyze the use of the term "human-animal-interface" in scientific literature to identify patterns and categories facilitating a scientific categorization. A systematic literature search of two electronic databases was performed complemented by interviews with health experts in the field of zoonoses/One Health conducted between March 2019 and May 2021. From identified publications, keywords and interface descriptions were extracted and categorized. Interviews followed a questioning route, were audio recorded, transcribed, and qualitative content was inductively categorized. Findings are based on 208 publications and 27 expert interviews. "Transmission" and "zoonosis" were the most frequent literature-based keywords, while the interviewees clearly favored "interface" followed by "contact". Seven categories of contact interfaces were inductively derived: direct contact (physical contact), consumption of animal products, use of animal products (blood transfusion, skin), contact with animal products (blood, secretion, meat), indirect contact (dust, inhalation, droplets), environmental contact (same surface or food), vector contact). Precise descriptions of the interfaces varied greatly depending on the pathogen domain (bacterial, viral, fungal). Specific patterns could be identified that were consistent between the literature and experts. The study results showed a general concordance in defining and describing the human-animal-interface indicating a general understanding of the term. However, studies on a larger scale are recommended (e.g. systematic review) to allow a more thorough view of the understanding and definition of the human-animal-interface.

Relating biodiversity with health disparities of human population: An ecological study across the United States

Understanding biodiversity's contributions to human health is the first step toward fostering synergies between biodiversity conservation and health promotion - two major targets of UN's Sustainable Development Goals. The One Health approach acknowledges the health of people and biodiversity are interconnected and facing common threats. In this study, we aimed to unveil the geographical association between avian biodiversity and population health across the US. In this ecological study, we combined citizen science bird data from eBird, population health data from the Institute for Health Metrics and Evaluation, and county-level statistics of population characteristics, including socio-economics, healthcare service etc. Multivariate linear regression analyses were performed between bird biodiversity (measured by rarefied species richness of birds), key indicators of general public health (e.g., cause-specific mortality rate), and socio-economic health determinants of 2751 US counties. We found that a higher number of bird species was significantly associated with longer life expectancy after confounding adjustment (regression coefficient (95% CIs), 0·005 (0·003, 0·008)). Bird species richness calculated using the rarefied method consistently accounted for variance in age-specific mortality risks in both very young and old age groups (R² from 2% to 4%). Rarefied species richness of birds was negatively correlated with the majority of cause-specific deaths (12 out of 21 mutually exclusive causes of death), indicating a general synergy effect between biodiversity and human health. The associations with the top causes of deaths were regarded as highly significant, with considerable effect sizes, for example, for cardiovascular diseases (regression coefficient (95% CIs), -0·242 (-0·311, -0·174)). Our findings show human health is inseparable from the health of the shared environment and the well-being of all species. Bird species richness offers a valuable means to understand large-scale relationships between human health and the health of the environment. To enable equitable sharing of biodiversity's benefits to human health, more efforts should be made to understand two-way socio-ecological mechanism underlying human-biodiversity interactions.

Economic costs of invasive rodents worldwide: the tip of the iceberg

Background

Rodents are among the most notorious invasive alien species worldwide. These invaders have substantially impacted native ecosystems, food production and storage, local infrastructures, human health and well-being. However, the lack of standardized and understandable estimation of their impacts is a serious barrier to raising societal awareness, and hampers effective management interventions at relevant scales.

Methods

Here, we assessed the economic costs of invasive alien rodents globally in order to help overcome these obstacles. For this purpose, we combined and analysed economic cost data from the InvaCost database-the most up-to-date and comprehensive synthesis of reported invasion costs-and specific complementary searches within and beyond the published literature.

Results

Our conservative analysis showed that reported costs of rodent invasions reached a conservative total of US$ 3.6 billion between 1930 and 2022 (annually US$ 87.5 million between 1980 and 2022), and were significantly increasing through time. The highest cost reported was for muskrat Ondatra zibethicus (US$ 377.5 million), then unspecified Rattus spp. (US$ 327.8 million), followed by Rattus norvegicus specifically (US$ 156.6 million) and Castor canadensis (US$ 150.4 million). Of the total costs, 87% were damage-related, principally impacting agriculture and predominantly reported in Asia (60%), Europe (19%) and North America (9%). Our study evidenced obvious cost underreporting with only 99 documents gathered globally, clear taxonomic gaps, reliability issues for cost assessment, and skewed breakdowns of costs among regions, sectors and contexts. As a consequence, these reported costs represent only a very small fraction of the expected true cost of rodent invasions (e.g., using a less conservative analytic approach would have led to a global amount more than 80-times higher than estimated here).

Conclusions

These findings strongly suggest that available information represents a substantial underestimation of the global costs incurred. We offer recommendations for improving estimates of costs to fill these knowledge gaps including: systematic distinction between native and invasive rodents' impacts; monetizing indirect impacts on human health; and greater integrative and concerted research effort between scientists and stakeholders. Finally, we discuss why and how this approach will stimulate and provide support for proactive and sustainable management strategies in the context of alien rodent invasions, for which biosecurity measures should be amplified globally.

Population genomics of Escherichia coli in livestock-keeping households across a rapidly developing urban landscape

Quantitative evidence for the risk of zoonoses and the spread of antimicrobial resistance remains lacking. Here, as part of the UrbanZoo project, we sampled Escherichia coli from humans, livestock and peri-domestic wildlife in 99 households across Nairobi, Kenya, to investigate its distribution among host species in this rapidly developing urban landscape. We performed whole-genome sequencing of 1,338 E. coli isolates and found that the diversity and sharing patterns of E. coli were heavily structured by household and strongly shaped by host type. We also found evidence for inter-household and inter-host sharing and, importantly, between humans and animals, although this occurs much less frequently. Resistome similarity was differently distributed across host and household, consistent with being driven by shared exposure to antimicrobials. Our results indicate that a large, epidemiologically structured sampling framework combined with WGS is needed to uncover strain-sharing events among different host populations in complex environments and the major contributing pathways that could ultimately drive the emergence of zoonoses and the spread of antimicrobial resistance.

Phylogeography and phylogenomic analyses of E. coli isolates collected from humans and domesticated and wild animals across 99 households in Nairobi reveal strong intra-household, and lower but detectable inter-household and inter-host, strain-sharing patterns.

Wealth and urbanization shape medium and large terrestrial mammal communities

Urban biodiversity provides critical ecosystem services and is a key component to environmentally and socially sustainable cities. However, biodiversity varies greatly within and among cities, leading to human communities with changing and unequal experiences with nature. The "luxury effect," a hypothesis that predicts a positive correlation between wealth, typically measured by per capita income, and species richness may be one indication of these inequities. While the luxury effect is well studied for some taxa, it has rarely been investigated for mammals, which provide unique ecosystem services (e.g., biological pest control) and exhibit significant potential for negative human-wildlife interactions (e.g., nuisances or conflicts). We analyzed a large dataset of mammal detections across 20 North American cities to test whether the luxury effect is consistent for medium- to large-sized terrestrial mammals across diverse urban contexts. Overall, support for the luxury effect, as indicated by per capita income, was inconsistent; we found evidence of a luxury effect in approximately half of our study cities. Species richness was, however, highly and negatively correlated with urban intensity in most cities. We thus suggest that economic factors play an important role in shaping urban mammal communities for some cities and species, but that the strongest driver of urban mammal diversity is urban intensity. To better understand the complexity of urban ecosystems, ecologists and social scientists must consider the social and political factors that drive inequitable human experiences with nature in cities.

Discovering and Applying the Urban Rules of Life to Design Sustainable and Healthy Cities

The city and its urban biome provides an extreme laboratory for studying fundamental biological questions and developing best practices for sustaining biodiverse and well-functioning ecological communities within anthropogenic built environments. We propose by studying urban organisms, urban biotic communities, the urban biome, and the interactions between the urban biome and peri-urban built and natural environments, we can (1) discover new 'rules of life' for the structure, function, interaction, and evolution of organisms;(2) use these discoveries to understand how novel emerging biotic communities affect and are affected by anthropogenic environmental changes in climate and other environmental factors; and (3) apply what we have learned to engage residents of the urban biome, and design cities that are more biologically diverse, are provided with more and better ecosystem services, and are more equitable and healthier places to live. The built environment of the urban biome is a place that reflects history, economics, technology, governance, culture, and values of the human residents; research on and applications of the rules of life in the urban biome can be used by all residents in making choices about the design of the cities where they live. Because inhabitants are directly invested in the environmental quality of their neighborhoods, research conducted in and about the urban environment provides a great opportunity to engage wide and diverse communities of people. Given the opportunity to engage a broad constituency - from basic researchers to teachers, civil engineers, landscape planners, and concerned citizens - studying the translation of the rules of life onto the urban environment will result in an integrative and cross-cutting set of questions and hypotheses, and will foster a dialogue among citizens about the focus of urban biome research and its application toward making more equitable, healthy, livable, sustainable, and biodiverse cities.