Scientists studied long-eared owls in Hungary to understand how city living affects what they eat and where they hunt. By examining owl droppings (called pellets), researchers found that owls living in cities eat more types of food but have a harder time finding their favorite prey—small rodents like voles. Owls in villages could find food easily within 3 kilometers, but owls in cities had to search much wider areas. This research shows how human development changes nature and how owls adapt to survive in urban environments.

The Quick Take

  • What they studied: How the size of cities and towns affects what long-eared owls eat during winter and how far they have to fly to find food
  • Who participated: Long-eared owls living in three Hungarian settlements during winter 2016-2017: a small village (Udvar), a town (Mohács), and a city (Pécs). Researchers collected 3,000 owl pellets total to analyze
  • Key finding: Owls living in cities ate a wider variety of prey but had to work harder to find food because cities have fewer natural habitats. City owls needed to hunt across much larger areas compared to village owls
  • What it means for you: This research suggests that urban development significantly impacts wildlife survival strategies. While owls are adaptable, cities with less green space make it harder for them to find their preferred food sources. This may apply to other wildlife in urban areas as well

The Research Details

Researchers collected owl pellets—the parts of prey that owls can’t digest and cough up—from three different-sized settlements in Hungary. They analyzed 1,000 pellets from each location to see what the owls had eaten. By identifying the bones and teeth in the pellets, scientists could determine exactly which animals the owls hunted.

To understand where owls hunted, researchers compared the types of small mammals found in the pellets with the types of habitats (forests, open fields, wetlands, and buildings) that existed at different distances from where the owls roosted. They looked at areas within 1, 2, and 3 kilometers around the owl roosts to see if the prey matched the available habitats.

This method is like being a detective—the pellets tell the story of what the owls ate, and the habitat maps show what food should have been available. By comparing these two pieces of information, scientists could understand how owls adapt their hunting to different environments.

This approach is valuable because it shows how human development directly affects wildlife food chains. Instead of just observing owls, scientists can use pellets to get detailed information about entire small mammal communities in different areas. This helps us understand the real-world impact of city growth on nature

The study collected a large sample size (3,000 pellets total), which makes the results more reliable. The researchers used a scientific method called ‘species accumulation curves’ to determine how many pellets they needed to study to get accurate results. The fact that they studied three different settlement sizes allows for meaningful comparisons. However, the study only looked at one winter season in one region of Hungary, so results may vary in other places or years

What the Results Show

The research revealed a clear pattern: as cities got bigger, owls had to change their hunting behavior and diet. In the small village, owls could find enough of their favorite food (voles and other small rodents) by hunting within about 3 kilometers of their roost. In the town, the hunting area needed to be larger. In the city, owls had to hunt across an even wider area because natural habitats were scarce.

Interestingly, city owls ate a much wider variety of prey species than village owls. While this shows they’re adaptable, it also suggests they couldn’t rely on their preferred foods. The researchers found that city owls needed to analyze 1,000 pellets to get a complete picture of their diet, while village owls only needed 300 pellets—showing that village owls ate more consistently from the same food sources.

The connection between available habitats and owl diet was strongest in villages. In villages, the types of small mammals the owls ate matched almost perfectly with the habitats available nearby. In towns, this match was weaker, and in cities, it was weakest of all. This suggests that city owls have to travel far beyond their immediate surroundings to find food.

City owls showed greater dietary diversity and more even distribution of prey types compared to village and town owls. This means city owls ate many different species in roughly equal amounts, rather than relying heavily on one or two favorite foods. While this demonstrates flexibility, it indicates the owls were making do with whatever they could find rather than hunting their preferred prey. The study also highlights that owls provide an important service by controlling small mammal populations, which can otherwise become pests in agricultural and urban areas

This research builds on existing knowledge that urbanization affects wildlife. Previous studies showed that cities reduce habitat availability, but this study provides specific evidence of how that affects a predator’s hunting behavior and diet. The findings align with broader ecological research showing that animals in cities must adapt their feeding strategies, often by becoming less specialized and eating a wider variety of foods

The study only examined one winter season (2016-2017) in one region of Hungary, so results may differ in other years or locations with different climates and urban layouts. The research focused only on long-eared owls, so findings may not apply to other owl species or predators. The study didn’t measure how well the owls were actually surviving or reproducing in these different environments, only what they were eating. Additionally, the analysis depended on identifying prey from small bones and teeth, which requires expertise and may occasionally be inaccurate

The Bottom Line

Based on this research, city planners and environmental managers should consider preserving or creating green spaces, wetlands, and natural habitats within urban areas. This would help maintain healthy populations of small mammals and support predators like owls. For homeowners in urban areas, maintaining gardens with native plants can contribute to local habitat diversity. These recommendations have moderate confidence because the study is solid but limited to one region and time period

This research matters most to city planners, environmental scientists, and wildlife managers who make decisions about urban development. It’s also relevant to farmers and rural communities who benefit from owls controlling rodent populations. Birdwatchers and nature enthusiasts interested in urban wildlife will find this informative. However, the findings are specific to long-eared owls in European climates, so they may not directly apply to other regions or owl species

Changes in owl populations and hunting patterns would likely take years to observe after habitat improvements are made. If cities increased green spaces and natural habitats, owls would probably show behavioral changes within one to two seasons, but population-level improvements would take several years to become apparent

Want to Apply This Research?

  • Users interested in urban wildlife could track local owl sightings and the types of habitats near sighting locations using GPS coordinates and habitat photos. Over time, this creates a personal database showing how owl presence correlates with green space availability in their area
  • Users could identify and map green spaces, parks, and natural areas within 3 kilometers of their home, then work to visit or support conservation of these areas. They could also participate in citizen science projects that monitor local owl populations or small mammal communities
  • Long-term tracking could involve seasonal monitoring of owl activity in different neighborhoods, documenting habitat changes over years, and correlating these with owl presence. Users could photograph and identify small mammals in their area to understand the local prey base available to predators

This research describes owl behavior and diet in specific European locations and may not apply to other regions, climates, or owl species. The study examines what owls eat but does not provide medical or health advice for humans. While the research suggests that urban development affects wildlife, individual experiences with local wildlife may vary. Anyone concerned about local owl populations or wildlife management should consult with local wildlife experts or environmental agencies. This information is for educational purposes and should not be used as the sole basis for environmental policy decisions without consulting additional research and local experts.