Barn owls are a great example of a local animal that is also extremely helpful. Owls are intriguing birds that easily capture the attention and curiosity of birders.
Owls can rotate their necks degrees. No other agriculture has utilized barn owl pest management programs more than grape growers. Vineyards attract high number of rodents. The low height of the vines allows growers to erect boxes as low as eight feet off the ground, and the rows between the vines give barn owls ample runways for successful hunting.
In North America, Barn Owls have been found to produce one to two pellets per day on average. The minimum interval between eating and casting is about 6. Barn owls do not have many predators. Nestlings are sometimes taken by stoats and snakes. Adults may be killed by great horned owls occasionally. Barn owls in western Europe are much smaller than those in North America. They only hunt small rodents like mice, not larger mammals like dogs or cats.
Even small dogs are too big for a barn owl to hunt. Like all predators, owls play an important role in nature by removing from prey populations individuals that can be considered surplus.
Most wildlife populations produce more offspring than their habitats can support. Most adult, healthy owls are considered safe from most predators but injured, small species or young owls do have a higher risk from predators.
The light at night changes according to the lunar cycle. How do barn owls deal with these radical changes in light levels from night to night? We thought they would have a harder time hunting the rodents they need to feed their offspring on moonlit nights.
In the bright moonlight, owls should be more easily spotted by prey such as mice. If this was true, hunting on moonlit nights would be even trickier for white owls than for red owls, simply because white is more reflective and therefore more visible in the moonlight than dark red plumage.
By studying this rich data set, we found that barn owls do indeed have a harder time on moonlit nights. This was true for red barn owls, but not, surprisingly, for white barn owls.
On the contrary, white barn owls seemed to be doing just as well during full moon nights as when there was no moon. Perplexed, we decided to look at the problem from the perspective of the rodents that barn owls hunt every night.
Our experiment investigated how common voles — the main prey of barn owls — see and react to white and red owls under full and new moon light conditions. But their faces, bellies and the undersides of their wings range from all white to all red. These silent hunters search out voles, mice and shrews, mainly at dusk and dawn.
Red and white barn owls sometimes catch different amounts of prey. Luis M. As an evolutionary ecologist, he studies how species have adapted to their environments. To find out, he teamed up with Alexandre Roulin, another evolutionary ecologist at the University of Lausanne. Roulin had been studying barn owls in western Switzerland since He has hundreds of nest boxes on farms in the area. Those owls use the nest boxes. That makes it easy for the scientists to find their nests, catch the birds and study their behaviors.
The pair then recorded activity for three or four nights at each nest box. By studying the video and camera images, they could tally the prey that each owl caught. The scientists also caught each bird and measured the color of its feathers. They did this using a color key. Lastly, they recorded the phase of the moon on each night of hunting. During the brightness of a full moon, they expected white owls would stand out more.
All of the owls hunted well during a new moon. The darkness did, in fact, make it easier for these birds to sneak up on their prey.
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