Discover how video cameras transformed our understanding of the Northern Goshawk's feeding habits and revealed fascinating ecological insights.
High in a pine tree somewhere in the Czech forest, a female Northern Goshawk tears meticulously at her latest catch. Until recently, this meal—like thousands before it—would have remained a mystery to science. For centuries, ornithologists struggled to understand the feeding habits of this powerful, elusive predator. Traditional methods provided glimpses, but never the full picture. Then, everything changed when researchers pointed a video camera at the nest.
What they discovered overturned assumptions and revealed fascinating complexities in the diet of this master hunter. This is the story of how video camera technology transformed our understanding of the goshawk's eating habits, providing insights that are reshaping conservation strategies and revealing the intricate relationships between predators and their prey.
24/7 observation without disturbing nesting birds
Accurate documentation of prey species
Eliminating biases of traditional methods
The Northern Goshawk (Accipiter gentilis) has long been recognized as a powerful avian hunter, capable of taking prey much larger than itself. As a top predator in many forest ecosystems, it plays a crucial role in maintaining ecological balance 7 . Understanding exactly what goshawks eat provides vital information about forest health and the complex food webs that sustain biodiversity.
Historically, researchers relied on two main methods to study raptor diets:
Collecting bones, feathers, and fur from beneath nests and plucking posts to identify prey species.
Studying the regurgitated indigestible parts of meals to determine dietary composition.
While these methods provided valuable data, both suffered from significant limitations. Prey remains tend to overrepresent larger animals with more conspicuous bones and feathers, while pellets better preserve mammal fur than bird feathers. Small prey might be completely consumed, leaving no trace whatsoever . These methodological biases made it impossible to get a complete, accurate picture of what goshawks were actually eating.
| Method | Description | Key Limitations |
|---|---|---|
| Prey Remains Analysis | Collecting bones, feathers, and fur from nests and plucking posts | Overrepresents larger prey; small prey may leave no traces |
| Pellet Analysis | Examining regurgitated indigestible materials | Bird feathers preserve poorly compared to mammal fur |
| Direct Observation | Watching nests from a distance | Extremely time-consuming; limited to daylight hours |
The advent of affordable, durable wildlife camera technology in the early 2000s revolutionized raptor diet studies. For the first time, researchers could continuously monitor nests without disturbing the birds, capturing every meal delivery in precise detail.
Traditional methods: prey remains and pellet analysis with significant biases
Advent of affordable wildlife camera technology
Pioneering Czech study using video cameras for goshawk diet research
Combined approaches with GPS tracking and advanced analysis
The value of this approach was demonstrated in a remarkable study from central Norway, where cameras captured a surprising event: a subadult goshawk attacking and killing three Gyrfalcon nestlings 3 . This dramatic documentation of intraguild predation—where one predator species preys on another—would have been nearly impossible to capture using traditional methods and highlighted the potential of camera technology to reveal unexpected ecological interactions.
In 2009, researchers in the Chřiby Upland of the Czech Republic conducted a pioneering study specifically designed to harness this new technology for understanding goshawk feeding ecology 6 . Their methodology and findings provide an excellent case study in how video cameras can transform our understanding of predator diet.
The research team established monitoring at two goshawk nesting territories in the vicinity of Buchlovice at the southeastern edge of the Chřiby Upland. Their approach was meticulous:
Researchers installed automatic digital video cameras with recording devices at strategic locations near goshawk nests, ensuring clear views of nest activity without disturbing the birds.
Monitoring covered the critical period from when chicks hatched until they fledged (left the nest), capturing the peak hunting activity when parents were provisioning for their young.
The team used cost-effective, efficient technology adapted to field conditions, proving that sophisticated monitoring didn't require extravagant budgets.
The cameras recorded all activity at the nests, allowing researchers to later analyze footage and identify every prey item delivered to the nest.
Location: Chřiby Upland, Czech Republic
Nests Monitored: 2 goshawk territories
Monitoring Period: Hatching to fledging
Key Innovation: Non-invasive video monitoring
| Prey Type | Specific Examples | Percentage of Diet |
|---|---|---|
| Birds | Thrushes (Turdus genus), various songbirds | 89% |
| Mammals | Red squirrels (Sciurus vulgaris), small rodents | 9.5% |
| Other/Unidentifiable | - | 1.5% |
The study monitored the nests continuously, recording 89% birds, 9.5% mammals, and 1.5% other animals or unidentifiable components of food in the goshawk's diet 6 . Birds of the genus Turdus (thrushes) were the most frequently delivered prey at both locations, while among mammals, the red squirrel (Sciurus vulgaris) was most common.
The camera research revealed more than just percentages—it provided unprecedented insight into goshawk hunting behavior and prey selection. The dominance of birds in the diet (89%) confirmed the goshawk's specialization in avian prey, but the specific composition varied between nest sites, suggesting that goshawks are opportunistic hunters that exploit locally abundant prey species.
Cameras captured not just what goshawks eat, but how they hunt, deliver prey to nests, and feed their young—revealing complex behavioral patterns.
Video evidence allowed researchers to calculate the actual biomass of different prey types, providing a more accurate picture of ecological impact.
This finding was echoed in a North American study of the American Goshawk (Accipiter atricapillus), where researchers using similar methods found that despite consuming 32 different prey species, the diet was dominated by pine squirrels (Tamiasciurus spp.), which accounted for 14-61% of the biomass consumed . This pattern of "functional specialization"—focusing on locally abundant prey while maintaining the flexibility to switch to alternatives—may be a key to the goshawk's success across diverse habitats.
| Research Method | Advantages | Disadvantages | Best For |
|---|---|---|---|
| Video Cameras | Comprehensive data, precise identification, behavioral context | Higher cost, technical challenges, potential disturbance during setup | Detailed diet composition, behavioral studies |
| Prey Remains | Simple, inexpensive, long-term data | Biased toward larger prey, incomplete picture | Long-term population trends |
| Pellet Analysis | Good for mammal identification, non-invasive | Poor preservation of bird remains, identification challenges | Mammal-focused diet studies |
| Combined Methods | Compensates for individual method limitations | Time-consuming, requires multiple skill sets | Most accurate overall assessment |
Modern raptor diet research requires specialized equipment carefully deployed to minimize disturbance to nesting birds.
Weatherproof models with infrared capability for night recording; these are the primary data collection tools that capture all nesting activity.
Systems that save footage automatically, often with motion activation to conserve power and storage space while capturing all relevant activity.
Programs like BirdNet Analyzer (used in related avian research) that can help process large volumes of data 4 .
Recent research using GPS tracking has revealed that male and female goshawks use territory differently, with females having home ranges five times larger than males outside the breeding season 5 —findings that complement our understanding of how they access different prey resources.
The deployment of video cameras to study goshawk diets has transformed our understanding of this magnificent predator. What began as a simple question—"What do goshawks eat?"—has revealed surprising complexities about their hunting strategies, ecological roles, and behavioral adaptability. The 89% avian diet confirmed their specialization, while the variety within that percentage demonstrated their remarkable flexibility.
These insights come at a crucial time. As goshawks face changing habitats and conservation challenges, understanding their feeding ecology becomes essential for effective protection. Perhaps most excitingly, video technology continues to reveal new surprises. From the unexpected predation on Gyrfalcon nestlings in Norway 3 to the urban goshawks of Berlin that hunt pigeons among city streets 7 , each observation adds another piece to the puzzle. As cameras become more sophisticated and less expensive, we can look forward to even deeper insights into the secret lives of these aerial hunters—proving that when it comes to understanding nature, sometimes the best approach is simply to watch closely, and let the animals show us what they do.