Repeated road counts across South Africa show that half of the country’s surveyed raptor and large terrestrial bird species have declined significantly over recent decades, adding to a growing body of evidence that Africa’s birds of prey are in serious trouble. A study in Biological Conservation found that 13 of 26 such species recorded lower encounter rates in recent transects compared with historical baselines. The findings land on top of a continent-wide synthesis showing 88% of 42 African savanna raptor species in decline, raising hard questions about whether current conservation frameworks are keeping pace with the scale of loss.
Half of South Africa’s Surveyed Raptors in Decline
The South African study, published in Biological Conservation, compared long-term road count data to measure changes in how frequently surveyors encountered raptors and large terrestrial birds along standardized routes. Of the 26 species assessed, 13 had declined significantly, according to repeat transect data collected across the country. That result is striking because road counts are among the simplest, most cost-effective tools available for tracking raptor populations over large areas, and their consistency over time makes the signal difficult to dismiss as noise.
What makes the South African data especially concerning is timing. These declines are occurring even as the country maintains one of Africa’s better-resourced protected area networks. The pattern suggests that reserves alone cannot buffer raptors from threats operating across the wider environment, from poisoning events to the steady conversion of open habitat into farmland. For species that range widely, such as martial eagles and secretarybirds, a park boundary offers limited protection when the birds spend much of their lives outside it.
The South African work also highlights how vulnerable large terrestrial birds are when their life histories intersect with human land uses. Ground-nesting species face trampling by livestock, disturbance from vehicles, and direct persecution. When these pressures accumulate over decades, even modest annual declines can translate into steep long-term losses, which is exactly what the road surveys now reveal.
A Continent-Wide Pattern of Collapse
South Africa’s results echo a far larger dataset. A peer-reviewed synthesis in African savanna ecosystems compiled standardized road-transect encounter rates from multiple regions, covering roughly 20 to 40 years of survey effort. The study, co-led by researchers from the University of St Andrews and The Peregrine Fund, found that 37 of 42 raptor species had declined, with 29 of those 42 species dropping by 30% or more over three generation lengths, the threshold used by the IUCN to classify species as threatened.
Those numbers carry a blunt implication: the formal conservation status assigned to many of these raptors may be out of date. If 69% of species already meet the IUCN’s quantitative criterion for threatened status based on road-survey trends alone, a significant gap exists between what the data show and how these birds are classified on paper. That gap matters because conservation funding, legal protections, and land-use planning decisions all flow from official status assessments.
The synthesis drew on multiple national datasets, integrating them into a single analysis of multiregional trends. Using standardized methods, the authors showed that declines were not confined to a handful of hotspots but spread across a wide swath of the savanna biome. As summarized in an open-access overview, the work underscores how raptor losses could undermine ecosystem functioning and climate resilience, given the role these predators play in regulating prey populations and scavenging carcasses.
The scale and consistency of the declines also challenge the assumption that protected areas alone can secure raptor populations. Many of the road transects pass through national parks and reserves, yet the overall trends remain negative. This suggests that threats originating in unprotected landscapes, such as poisoning or habitat conversion, can spill over into supposedly safe havens, or that the protected areas themselves are too small or fragmented to sustain viable populations of wide-ranging species.
Road Surveys as an Early Warning System
The road-transect method works by recording how many individuals of each species a trained observer encounters per unit of distance driven, typically expressed as individuals per 100 km. Because the routes, speed, and protocols stay the same across decades, changes in encounter rates serve as a reliable proxy for population trends. The approach has now been applied in Kenya, where surveys conducted between 1970 and 1977 were repeated from 2003 to 2020, revealing sharp drops in linear encounter rates for multiple raptor species, as documented by long-term Kenyan transects.
In northern Botswana, a separate team repeated historical baseline transects first driven between 1991 and 1995, finding significant species-level declines roughly 20 years later and pointing to poisoning and land-use change as likely drivers. These results, detailed in repeat Botswana counts, align closely with the Kenyan and South African patterns, reinforcing the conclusion that raptor losses are widespread rather than localized anomalies.
Rochelle Katlego Mphetlhe’s thesis at the University of Cape Town further showed how repeat road surveys can quantify national abundance changes of raptors across Botswana, offering granular spatial stratification that journal-length papers often compress. By breaking down encounter rates by habitat type and region, such work can highlight where declines are steepest and which landscapes still function as partial refuges.
Taken together, the Kenya, Botswana, and South Africa datasets form a chain of evidence stretching across eastern and southern Africa. Each study was conducted independently, yet they converge on the same conclusion: raptors are disappearing from the roads where they were once reliably seen. In that sense, road surveys are acting as an early warning system, signaling large-scale ecological change before it becomes obvious through more visible collapses, such as rodent outbreaks or carcass accumulation.
Why Raptors Are Vanishing
No single cause explains the breadth of these declines. The Nature Ecology and Evolution synthesis identified the conversion of wooded habitats to agricultural land as more damaging to biodiversity than many other human activities, and raptors that depend on savanna mosaics are directly exposed to that pressure. As trees are cleared for crops and grazing, nesting sites vanish, prey communities shift, and the open perching and soaring corridors that raptors rely on shrink.
Poisoning compounds the problem. Across Africa, raptors die after feeding on carcasses laced with pesticides, sometimes set deliberately to kill predators that threaten livestock, and sometimes as collateral damage from poaching operations targeting elephants or other large mammals. Expert commentary on the synthesis highlighted poisoning and persecution as persistent threats that are difficult to regulate across national borders; one such analysis of ongoing threats emphasized how scavenging species, particularly vultures, can be wiped out in large numbers by a single poisoned carcass.
The interaction between habitat loss and poisoning is worth examining more closely than most coverage allows. As open land is converted to intensive agriculture, livestock densities often increase along the remaining edges of wild habitat. That, in turn, can heighten conflict with carnivores and encourage the use of toxic baits. Raptors and scavengers, which patrol these same edges in search of food, are inadvertently funneled into landscapes where the risk of poisoning is highest.
Infrastructure development adds another layer of risk. Expanding road networks increase vehicle collisions and make it easier for people to access remote areas with pesticides or snares. Power lines and energy infrastructure can cause electrocution or collision mortality for large soaring birds. While these threats may be more localized than habitat loss, their cumulative effect over decades can be substantial, especially for long-lived species with low reproductive rates.
Are Current Protections Enough?
The emerging picture from road surveys is that current conservation frameworks are not keeping pace with the rate of decline. Many African countries list raptors as protected species on paper, but enforcement is thin, and resources for monitoring are limited. Where protected areas exist, they may not be large enough to encompass the full home ranges of wide-ranging raptors, or they may be surrounded by landscapes where poisoning and habitat conversion continue unchecked.
One implication of the multiregional analyses is that threat assessments and Red List categorizations may need urgent revision. If a majority of savanna raptors already meet the IUCN thresholds for threatened status based on observed declines, then conservation planning should assume that many of these species are more imperiled than currently recognized. That, in turn, could justify stronger measures, from tighter pesticide regulation to targeted anti-poisoning campaigns and the strategic expansion of protected corridors.
There are also lessons for how monitoring is organized. The road-transect approach has proven its value as a relatively low-cost, repeatable method that can be scaled across countries. Ensuring that historical routes are re-surveyed at regular intervals, and that data are shared through collaborative platforms, would help maintain an early warning system for raptors and other large birds. In many cases, the infrastructure for such surveys already exists; what is missing is sustained funding and coordination.
Ultimately, the declines documented along Africa’s roads are not just about raptors. These birds sit high in the food web, and their disappearance signals deeper changes in the ecosystems below them. Whether conservation policy can adjust quickly enough to match the speed of these losses remains an open question, but the evidence from repeated road counts is clear: without more ambitious action, many of Africa’s most iconic birds of prey will continue to slip from view.
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*This article was researched with the help of AI, with human editors creating the final content.
