The Impact of Climate Change and Habitat Loss on African Elephants in the Greater Virunga Landscape: A Dynamic Simulation Study


Artwork for Bill Madden’s music video “Mother”. The artwork was created by Kasia Haldas. CC BY-NC-ND 3.0.

Introduction

African elephants, the majestic giants of the savannah and forests, are facing unprecedented threats from habitat loss, human-wildlife conflicts, and the looming specter of climate change. A recent study by Simon Nampindo and Timothy O. Randhir, published on January 31, 2024, in PLOS Sustainability & Transformation, uses dynamic modeling to unravel how these factors are influencing elephant populations in the Greater Virunga Landscape (GVL), a biodiversity hotspot in Africa.

Greater Virunga Landscape with vegetation map.
Greater Virunga Landscape (GVL) with vegetation map. Developed by Simon Nampindo and Timothy O. Randhir in collaboration with the WCS Uganda program. The GVL straddles Uganda, Rwanda, and the Democratic Republic of Congo.

Understanding the African Elephant Crisis

The African elephant, once roaming freely across vast stretches of the continent, is now confined to fragmented habitats, with populations experiencing alarming declines. The 2016 IUCN African Elephant Status Report highlighted a 30% decline over ten years, with human activities and climate change at the heart of this crisis. Elephants play a pivotal role in their ecosystems, from seed dispersal to landscape modification, making their decline a matter of global environmental concern.

The Study: A Closer Look

Nampindo and Randhir’s study is a testament to innovative conservation science, employing dynamic simulation models to analyze the effects of changing climates, habitat loss, and water resource availability on the age-class structure of elephant populations. Their research, underpinned by data from the GVL — an area spanning Uganda, Rwanda, and the Democratic Republic of Congo — provides a comprehensive understanding of how different age classes of elephants respond to environmental stressors. This approach is crucial for developing targeted conservation strategies.

Conceptual model for population dynamics of elephants in GVL, linking climate, habitat changes, and resource variability to population shifts over 50 years.
Conceptual model for population dynamics of elephants in GVL, linking climate, habitat changes, and resource variability to population shifts over 50 years.

Key Findings

The study reveals several critical insights:

  • Climate Change Impacts: Older elephants are more vulnerable to climate change, affecting their survivability and migration patterns. This vulnerability is attributed to direct impacts, such as disease and physiological stress, and indirect ones, like habitat alteration and drought-induced deaths such as fire and risk of predation.
  • Habitat and Water Resources: An improvement in habitat quality and water availability positively affects elephant populations, emphasizing the need for conservation efforts that enhance these critical resources.
  • Future Projections: Without mitigating environmental and anthropogenic stressors, the GVL could see a demographic shift towards younger elephants, potentially impacting the long-term viability of these populations.

Conservation Implications

The research underscores the necessity for a transboundary management approach, incorporating climate change mitigation, cooperation among conservation agencies, and partnerships with relevant stakeholders. It also highlights the importance of understanding age-specific responses of elephants to environmental changes, facilitating the development of comprehensive conservation strategies that address water availability and habitat quality.

To ensure the survival of African elephants in the face of climate change and habitat loss, the study recommends:

  • Enhanced Transboundary Cooperation: Strengthening collaboration across borders to ensure cohesive conservation efforts.
  • Habitat Restoration and Protection: Implementing measures to improve habitat quality and connectivity, including reforestation and the establishment of wildlife corridors.
  • Community Engagement: Involving local communities in conservation efforts, providing them with sustainable livelihood options to reduce human-wildlife conflicts.

The study by Nampindo and Randhir offers a critical roadmap for the conservation of African elephants in the Greater Virunga Landscape. By focusing on the dynamic interplay between climate change, habitat loss, and elephant population dynamics, their work provides valuable insights for crafting resilient conservation strategies. As we face the challenges of a changing planet, such research is indispensable for guiding our efforts to preserve the natural world and its magnificent inhabitants.

Final Thoughts

This comprehensive study not only advances our understanding of the intricate relationships between elephants and their environment but also serves as a clarion call for urgent, collaborative conservation action. The fate of Africa’s elephants hangs in the balance, and it is incumbent upon us all to heed this call and act decisively to secure their future.

Guardians of Genetic Diversity: Revive & Restore Spearheads Pioneering Biobanking Project

Field biologists enter a restoration site for the endangered Preble’s meadow jumping mouse. Credit: Kika Tuff / Revive & Restore
Field biologists enter a restoration site for the endangered Preble’s meadow jumping mouse (Zapus hudsonius preblei). Credit: Kika Tuff / Revive & Restore

A Landmark Biobanking Initiative

In a pioneering effort to counter the escalating threats of biodiversity loss, Revive & Restore, in conjunction with the U.S. Fish & Wildlife Service, has initiated the first agency-wide biobanking program for U.S. endangered species. This strategic effort intends to indefinitely preserve living cells from these species, thus conserving their invaluable genetic diversity. The technique used to conserve endangered species by storing their genetic material is known as cryopreservation.

“Biobanking gives us the chance to save irreplaceable genetic diversity,” explains Seth Willey, Deputy Assistant Regional Director at the US Fish & Wildlife Service’s Southwest Region. “If done right, it creates a marker-in-time and gives future recovery biologists options, like genetic rescue, that are only possible if we act now.”

Biobanking has three core applications:

  • Preserving Genetic Diversity: Cryopreserving cells help maintain the genetic diversity, which is crucial for future restoration projects.
  • Managing with Genomic Insight: Sequencing DNA from preserved cells can offer insights into wildlife management and restoration opportunities.
  • Genetic Rescue through Technology: By leveraging advanced biotechnologies, the stored genetic material can reintroduce genetic diversity, refine reproductive tools, and possibly recover extinct species.

The biobanking procedure consists of four phases:

  1. Collaboration: Engage with field biologists for effective tissue sample collection.
  2. Collection: Process collected samples either for primary cell culture or immediate cryopreservation.
  3. Protection: Store frozen cell lines and tissue in a national repository for long-term preservation.
  4. Application: Utilize these samples to construct a reference genome accessible to researchers for conservation activities.

Less than 14% of over 1,700 U.S. threatened or endangered species have cryopreserved living tissue. This initiative intends to change this, starting with the biobanking of 24 selected endangered mammals including the Mexican Wolf, Sonoran Pronghorn, Florida Bonneted Bat, and Preble’s Meadow Jumping Mouse.

Ryan Phelan, Executive Director of Revive & Restore, stated, “This is about creating a legacy of America’s natural history before it is lost.” The program has garnered support and participation from notable institutions like ViaGen Pets & Equine and the U.S. Department of Agriculture, among others.

Furthermore, to assist field biologists in biobanking, Revive & Restore has introduced resources like sample collection protocols and visual aids available on their project webpage.

In short, this multi-institutional partnership is poised to significantly advance the preservation of U.S. endangered species, marking a significant stride in conserving America’s rich biodiversity.

Understanding the Impact of Climate Change on Marine Mammals

Mother and baby sperm whale
A mother sperm whale and her calf off the coast of Mauritius. The calf has remoras attached to its body. Credit: Gabriel Barathieu, January 26, 2013.

Our oceans are suffering the impact of climate change. From inshore environments to the deep ocean, marine ecosystems are undergoing significant transformations due to rising temperatures, increased carbon dioxide levels, and shifting environmental conditions. This research article by National Oceanic and Atmospheric Administration (NOAA) researchers published in PLOS ONE delves into the intricate relationship between climate change and marine mammals. The study focused on the United States’ western North Atlantic (WNA), Gulf of Mexico (GOMx), and Caribbean waters.

Drivers Impacting Marine Life

Global climate change has ushered in a multitude of alterations that stem from a handful of key drivers. Rising levels of heat and carbon dioxide in the Earth’s atmosphere are at the forefront. Here’s a closer look at the other major factors:

1. Increasing Ocean Temperatures

As the Earth’s temperature rises, so too do the temperatures of our oceans. This phenomenon is particularly evident in the western North Atlantic (WNA), where sea surface temperatures have been increasing rapidly. These rising temperatures have direct and indirect consequences for marine mammals that call these waters home.

2. Rising Sea Levels

One of the most visible effects of climate change is the rise in sea levels. This phenomenon is especially pronounced in regions like the southeastern United States, Gulf of Mexico (GOMx), and the Caribbean Sea. The accelerating sea level rise poses a significant threat to coastal ecosystems and the marine life they support.

3. Decreasing Dissolved Oxygen

Climate change also contributes to declining levels of dissolved oxygen in our oceans. This is a particularly alarming trend for marine mammals, as many of them rely on oxygen-rich environments to thrive.

4. Declining Sea Ice Coverage

In polar regions, the decline in sea ice coverage is a stark indicator of climate change. This has profound implications for marine mammals like polar bears and seals, which depend on sea ice as a platform for hunting and resting.

5. Ocean Acidification

The increasing levels of carbon dioxide in the atmosphere are not only raising temperatures but also leading to ocean acidification. This can have devastating effects on marine life, particularly species with calcium carbonate shells or skeletons.

6. Shifting Precipitation Patterns

Climate change also drives changes in precipitation patterns, impacting the salinity of ocean waters. These shifts can have cascading effects on marine ecosystems and the species that inhabit them.

Impacts on Marine Mammals

The effects of climate change are not limited to the physical environment; they also dramatically affect marine communities, including marine mammals. Here are some of the key ways in which climate change impacts these majestic creatures:

1. Altered Distribution and Behavior

Marine mammal species with restricted geographical distributions and habitat tolerances are particularly vulnerable. The changing conditions of their environment leave them with limited opportunities to adapt.

2. Disrupted Prey Availability

Marine mammals rely on stable environments where prey availability is relatively predictable. Climate change can disrupt these ecosystems, leading to food scarcity and challenges in feeding.

3. Climate-Related Shifts in Distribution

Some marine mammal populations, such as ice-associated seals and subarctic cetaceans, have already shown shifts in distribution due to climate change. These changes have significant implications for their conservation and management.

4. Predictive Challenges

Predicting climate-driven changes in marine mammal distribution, phenology, and abundance is a complex task. However, advancements in modeling tools and approaches are improving our ability to make informed predictions.

Assessing Climate Vulnerability

Understanding the vulnerability of marine mammals to climate change is crucial for their conservation. Climate vulnerability assessments (CVAs) play a pivotal role in identifying species at risk. These assessments take into account factors such as exposure, sensitivity, and adaptive capacity.

Trait-Based CVAs

One approach to CVAs involves trait-based assessments, which consider the biological or ecological traits of species that are linked to climate responses. While this method provides less resolution than quantitative approaches, it offers a rapid and adaptable way to assess vulnerability.

NOAA’s Role in Marine Mammal Protection

In the United States, the NOAA has a mandate to protect and recover marine mammal species under the Endangered Species Act (ESA) and Marine Mammal Protection Act (MMPA). To address climate-related threats to marine mammals, NOAA conducts trait-based CVAs for stocks in the WNA, GOMx, and Caribbean waters.

Conclusion

Climate change presents a profound challenge to marine mammals in the United States’ WNA, GOMx, and Caribbean waters. It is a complex issue that requires a multifaceted approach to address. As the world grapples with the consequences of a changing climate, it is imperative that we prioritize the conservation and protection of these incredible creatures. NOAA’s efforts, including trait-based CVAs and vulnerability rankings, provide valuable tools for understanding and mitigating the effects of climate change on marine mammals.

By comprehensively assessing vulnerability and taking proactive measures, we can work towards safeguarding the future of our marine mammal populations.

Source: Lettrich, M.D. et al. (2023). Vulnerability to climate change of U.S. marine mammal stocks in western North Atlantic, Gulf of Mexico, and Caribbean. PLoS ONE, 18(9), e0290643.