Bird diversity drops in human-dominated habitats, Nepal study suggests – Mongabay

Report on the Impact of Anthropogenic Pressures on Avian Biodiversity in Nepal’s Southern Plains

Introduction

A recent study conducted in the Parsa-Koshi Complex of Nepal’s southern plains reveals a significant decline in avian biodiversity due to human activities. The research, published in the Journal of Environmental Management, highlights how anthropogenic pressures are homogenizing landscapes, thereby threatening terrestrial ecosystems and undermining progress towards key Sustainable Development Goals (SDGs), particularly SDG 15 (Life on Land).

Methodology

Researchers conducted a year-long study analyzing 238 bird species across two distinct habitat types:

1. Natural Habitats: Forests and riverine areas.
2. Anthropogenic Habitaments: Farmlands and human settlements.

The study assessed avian diversity, ecological functions (diet, mobility, body size), and phylogenetic ancestry. Computer models were utilized to compare this data against the level of human activity and landscape patterns, testing the hypothesis that human disturbance acts as an environmental filter on bird communities.

Key Findings

• Habitat Homogenization: Human activities, including farming, logging, infrastructure development, and mining, simplify complex landscapes. This homogenization reduces the variety of available habitats essential for diverse bird species.
• Biodiversity Loss: Human-dominated areas exhibit lower species richness and support birds with similar ecological functions and evolutionary traits. These areas show high “nestedness,” indicating that the surviving species are merely a subset of those found in more robust, natural ecosystems.
• Functional Clustering: In settlements and farmlands, there is strong functional clustering. This suggests that human disturbance filters out sensitive species, allowing only resilient and adaptable birds (e.g., pigeons, mynas, crows) to thrive.
• Phylogenetic Clustering in Natural Habitats: Unexpectedly, natural forests also showed signs of phylogenetic clustering. This is attributed to disturbances like logging and hunting within these areas, which remove sensitive species and leave behind closely related, resilient groups such as flycatchers and babblers.
• Importance of Mosaic Landscapes: Landscapes with a heterogeneous mix of forests, fields, and wetlands support a greater number and variety of bird species by providing diverse ecological niches and resources.

Analysis and Connection to Sustainable Development Goals (SDGs)

The study’s findings have direct and significant implications for several United Nations Sustainable Development Goals.

SDG 15: Life on Land

The research provides critical evidence for the challenges facing SDG 15, which aims to protect, restore, and promote the sustainable use of terrestrial ecosystems and halt biodiversity loss. The observed homogenization of landscapes and the decline in avian species diversity are direct contraventions of this goal. The filtering effect of human activity, which eliminates unique and sensitive species, demonstrates a clear failure to protect biodiversity (Target 15.5). The impact of deforestation and habitat degradation from logging and agriculture underscores the urgent need for sustainable forest management (Target 15.2).

SDG 11: Sustainable Cities and Communities

The contrast between natural and anthropogenic habitats links directly to SDG 11. The study shows that the expansion of human settlements and associated infrastructure development reduces the resilience of local ecosystems. To achieve sustainable communities (Target 11.6), development must incorporate strategies that reduce the adverse per capita environmental impact, including the protection of surrounding natural habitats and biodiversity.

SDG 12: Responsible Consumption and Production

The report identifies unsustainable production patterns as a primary driver of habitat loss. Activities such as logging and sand and gravel mining, as mentioned in the study, exemplify the need for responsible resource management as outlined in SDG 12. Achieving sustainable management and efficient use of natural resources (Target 12.2) is essential to mitigate the pressures on avian habitats.

Recommendations and Conclusion

The study concludes that anthropogenic pressures are driving bird communities toward reduced resilience and increased homogenization, threatening the ecological integrity of the region. To counteract these trends and advance the SDGs, the following actions are recommended:

• Protect and Restore Habitat Quality: Implement and enforce regulations to control deforestation, manage sand and gravel extraction sustainably, and prevent unplanned infrastructure expansion. This directly supports SDG 15.
• Maintain Landscape Heterogeneity: Conserve and restore mosaic landscapes that provide a wide range of resources and shelter for diverse species. This approach enhances ecosystem resilience.
• Strengthen Habitat Connectivity: Establish and protect habitat corridors, especially along river systems and forest ridges, to allow species to move between fragmented landscapes in response to environmental stressors.
• Promote Community Participation: Engage local communities in the management of national priority forests and Important Biodiversity Areas (IBAs) to ensure conservation efforts are sustainable and effective.

In conclusion, addressing the drivers of avian biodiversity loss in Nepal is not only a conservation imperative but also a critical component of achieving a sustainable development pathway aligned with global goals for life on land, sustainable communities, and responsible production.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

• SDG 15: Life on Land

  This is the most prominent SDG addressed. The article focuses entirely on the impact of human activities on terrestrial ecosystems, specifically bird habitats in Nepal. It discusses the loss of biodiversity, degradation of natural habitats like forests and wetlands, and the need for conservation and sustainable management of these environments.

• SDG 11: Sustainable Cities and Communities

  The article contrasts natural habitats with “anthropogenic (farmland and settlement)” areas. It highlights how human-dominated landscapes and infrastructure development lead to habitat homogenization and biodiversity loss, which connects to the goal of making human settlements sustainable and minimizing their environmental impact.

• SDG 12: Responsible Consumption and Production

  The article mentions specific human activities like “logging” and “sand and gravel mining” as drivers of habitat degradation. These activities relate to the extraction and use of natural resources, linking the issues to the need for sustainable management and consumption patterns.

2. What specific targets under those SDGs can be identified based on the article’s content?

• SDG 15: Life on Land
  • Target 15.1: “By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands…” The article directly supports this by emphasizing that birds prefer “a mix of forests, fields and wetlands” and that conserving these habitats is crucial for their survival.
  • Target 15.5: “Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity…” This target is central to the article’s findings, which state that human activities “reduce the number and variety of birds” and lead to the “loss of many species” and “homogenization” of bird communities. The recommendation to control deforestation and regulate extraction directly addresses reducing habitat degradation.
  • Target 15.9: “By 2020, integrate ecosystem and biodiversity values into national and local planning, development processes…” The study’s conclusion that “Important Biodiversity Areas (IBAs) should be maintained with national priority” and forests managed with community participation is a direct call to integrate biodiversity values into planning.
• SDG 11: Sustainable Cities and Communities
  • Target 11.4: “Strengthen efforts to protect and safeguard the world’s cultural and natural heritage.” The natural habitats discussed, such as the Parsa-Koshi Complex, are part of Nepal’s natural heritage. The article’s focus on the negative impacts of “settlements,” “farming,” and “infrastructure development” on these areas highlights the need to protect them from unsustainable expansion.
• SDG 12: Responsible Consumption and Production
  • Target 12.2: “By 2030, achieve the sustainable management and efficient use of natural resources.” The article identifies unsustainable resource extraction activities like “logging, hunting and sand and gravel mining” as key threats to bird habitats. The recommendation to “control deforestation” and “regulate sand and gravel extraction” directly aligns with this target.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

• Species Diversity and Richness: The article explicitly measures the “number and variety of birds” in different habitats. A higher number of species in an area would indicate healthier, more natural ecosystems.
• Habitat Heterogeneity vs. Homogenization: The study contrasts “heterogeneity in their habitats” (a mosaic of forests, rivers, etc.) with landscapes that are “increasingly homogenizing.” The diversity and mix of habitat types within a landscape can be used as an indicator of ecosystem health.
• Ecological Function Diversity: The article mentions that natural habitats support species performing “a wide variety of ecological roles (such as eating insects, dispersing seeds).” The number and variety of these functions within an ecosystem serve as an indicator of its resilience and health.
• Phylogenetic Clustering: The study uses this as a specific measure to assess “the proximity of species that remain in an area in the evolutionary family tree.” It acts as a scientific indicator to understand the impact of disturbances on the evolutionary diversity of a community.
• Nestedness: The study uses “nestedness” as a metric, where high nestedness in human-modified areas “suggested loss of many species.” This can be used as a quantitative indicator of biodiversity loss.
• Presence of Sensitive/Indicator Species: The article notes that “collared scops-owls (Otus lettia) and Western hooded pitta (Pitta sordida)” were rare outside of forests. The presence or absence of such sensitive species can indicate the quality and integrity of a specific habitat.

SDGs, Targets, and Indicators Summary

Source: news.mongabay.com