Alarming Revelations from 16 Years of Road Surveys

Birds of prey, or raptors, play a crucial role in South Africa's ecosystems as top predators and scavengers, helping to control rodent populations and clean up carrion. Yet, a groundbreaking study has uncovered troubling signs of widespread population drops across central South Africa. Led by researchers from the University of Cape Town's FitzPatrick Institute of African Ornithology, the analysis draws on an impressive 391,789 kilometers of road counts conducted between 2009 and 2025. This dedicated fieldwork, carried out by Ronelle Visagie of the Endangered Wildlife Trust's Birds of Prey Programme, provides a robust dataset for tracking changes in raptor abundance.

The research highlights how these majestic birds—think eagles, buzzards, falcons, and vultures—are faring in a landscape increasingly shaped by human activity. While raptors are known for their slow reproductive rates and large home ranges, making them particularly vulnerable, this study offers the first long-term, quantitative evidence of declines in the region using road-based monitoring.

How Road Counts Work as a Monitoring Tool

Road counts involve driving standardized routes and recording sightings of target species, calculating abundance as individuals per 100 kilometers driven. This method is cost-effective and covers vast areas, ideal for wide-ranging species like raptors that are difficult to monitor through nest searches or point counts. Visagie's transects spanned central South Africa, focusing on 18 raptor species and eight large terrestrial birds for comparison.

Unlike citizen science atlases that rely on presence checklists, road counts capture relative abundance trends more reliably over time, especially when conducted by a single observer to minimize bias. The study's statistical analysis used generalized linear mixed models to detect significant changes, revealing patterns that atlas data might miss.

Key Findings: Half of Species in Significant Decline

Of the 26 species assessed, 13 showed significant declines—a staggering 50%—while only three exhibited increases, and ten remained stable. Eight raptors dropped by more than 50% over the 16 years, signaling a conservation crisis. Large raptors suffered steeper losses, particularly outside protected areas, underscoring their sensitivity to landscape-scale changes.

• Secretarybird (Sagittarius serpentarius): 68% decline, from Endangered to potential Critically Endangered status.
• Jackal Buzzard (Buteo rufofuscus): Over 50% drop.
• Verreaux’s Eagle (Aquila verreauxii): Steep decline despite protected habitats.
• All three migratory species—Lesser Kestrel (Falco naumanni), Amur Falcon (Falco amurensis), Steppe Buzzard (Buteo buteo vulpinus)—declined significantly.

Increases were noted in White-backed Vulture (Gyps africanus, Critically Endangered but recovering locally), Greater Kestrel (Falco rupicolus), and White-necked Raven (Corvus albicollis).

Species Spotlights: From Eagles to Falcons

The Secretarybird, South Africa's iconic long-legged hunter of snakes and rodents, exemplifies the crisis with its 68% plunge. Known for terrestrial foraging in grasslands, its decline mirrors trends in Kenya and Botswana, linked to habitat loss and poisoning. Verreaux’s Eagle, a specialized rock hyrax predator, faces threats from expanding infrastructure in rugged terrains it favors.

Migratory raptors like the Amur Falcon, which winters in South Africa after epic journeys from Asia, are hit hard across hemispheres. Resident Spotted Eagle-Owl (Bubo africanus), previously Least Concern, warrants status review after substantial drops. These patterns highlight how even 'common' species are vulnerable, urging proactive measures.

Photo by polina miloserdova on Unsplash

Road Counts vs. Atlas Data: Why Methods Matter

The Southern African Bird Atlas Project 2 (SABAP2), a citizen science powerhouse, tracks distribution via checklists but showed conflicting trends—half the species increasing, only three declining. Road counts aligned in just 50% of cases, proving superior for abundance monitoring of low-density raptors. Arjun Amar from UCT emphasizes combining tools: "Citizen science atlases like SABAP2 are vital, but multiple approaches give the full picture."

This discrepancy underscores the need for method-specific interpretations in conservation planning. For more on SABAP2, visit their site.

Primary Threats Driving the Declines

Despite stable land use in the study area, subtle threats accumulate: agricultural poisoning from pesticides and rodenticides, illegal persecution by farmers viewing raptors as livestock threats, and infrastructure collisions. Power lines cause electrocution, while proliferating wind farms pose collision risks—191 vultures injured/killed from 2020-2025 per Vulpro data. Human population growth (projected 79% in Africa) exacerbates habitat fragmentation and prey scarcity.

Climate change alters prey dynamics and migration, compounding issues. Lead author Santiago Zuluaga notes, "Steep declines in key species like Secretarybirds suggest landscape-wide pressures." For the full study, see Biological Conservation.

Ecological and Societal Implications

Raptors regulate pests, reducing crop damage and disease vectors like rodents carrying plague. Their decline disrupts food webs, potentially surging prey populations and affecting agriculture. Vultures prevent disease spread by scavenging; their loss (e.g., White-backed Vulture recovery notwithstanding) risks anthrax outbreaks. In South Africa, where raptors indicate ecosystem health, these drops signal broader biodiversity erosion amid global avifauna collapse (73% since 1970 per WWF).

Human-raptor conflicts highlight the need for coexistence strategies, benefiting both biodiversity and communities reliant on healthy landscapes.

University Research Leading Conservation

UCT's FitzPatrick Institute spearheads this work, training ornithologists and integrating fieldwork with advanced stats. Arjun Amar's team exemplifies higher education's role in evidence-based policy. Collaborations with EWT translate data into action, like poisoning response and infrastructure mitigation. Explore conservation biology programs at South African universities via AcademicJobs research jobs.

Such studies foster careers in ecology, vital as South Africa addresses biodiversity loss.

Photo by Joshua Kettle on Unsplash

Ongoing Conservation Initiatives

EWT's Birds of Prey Programme monitors nests, responds to poisonings, and educates landowners. UCT projects target Verreaux’s Eagles amid habitat loss. Vulture-safe power lines and wind farm curtailment (shutting turbines during flights) show promise. For details, check EWT efforts.

• Nest monitoring and protection.
• Anti-poisoning campaigns.
• Infrastructure retrofits.
• Citizen science expansion.

Future Outlook and Calls to Action

With Africa's population boom, intensified monitoring is essential. Zuluaga urges, "Detect declines early to act before critical levels." Policymakers must prioritize raptor-safe development; researchers call for pan-African road count networks. Individuals can report sightings to SABAP2 or support EWT. Academic institutions like UCT continue driving solutions through PhD programs and grants, offering opportunities for aspiring conservationists in South Africa.

This study, published in Biological Conservation, sets a benchmark for proactive wildlife management.