Which is stronger, a birds sense of smell or eyesight ?

[Steve_In_Cheshire]

The reason i ask this is i did the usual this morning at 7am and put the food out for the birds, this includes scattering some mealworms and sultanas on the lawn for the blackbirds and our thrush along with some sunflower hearts and seed for the collared doves.

Now when i put the food out their was no snow, 20 minutes after i had put the food out the lawn was like a white blanket and about an inch thick and it covered all the food on the lawn.

The collared doves have just turned up for their breakfast and they are happily eating the seed from underneath the snow, i always put it in the same place for them. Do you think they found it by smell or by going to the same place and having a mooch around ? The snow is a bit deeper at the min as well.

The blackbirds have also been finding the sultanas and mealworms from under the snow.

[Dogghound]

I was alway led to believe that birds smell is not great but their sight is very developed. Perhaps they are used to it being there, seeds etc dont really have a strong smell.

[Tormentil]

Found this explanation of birds sense of smell.........

Most birds are primarily "sight animals" as their superb eyes, colorful plumage, and nonacoustic signals attest. But their sense of hearing is obviously also very acute -- as in the case of night-hunting owls, which use sound to locate their prey. Most birds seemingly would have little use for smell; in the airy treetops odors disperse quickly and would be of minimal help in locating obstacles, prey, enemies, or mates. Yet the apparatus for detecting odors is present in the nasal passages of all birds. Based on the relative size of the brain center used to process information on odors, physiologists expect the sense of smell to be well developed in rails, cranes, grebes, and nightjars and less developed in passerines, woodpeckers, pelicans, and parrots. By recording the electrical impulses transmitted through the bird's olfactory nerves, physiologists have documented some of the substances that birds as diverse as sparrows, chickens, pigeons, ducks, shearwaters, albatrosses, and vultures are able to smell.

The sense of smell seems better developed in some avian groups than others. Kiwis, the flightless birds that are the national symbol of New Zealand, appear to sniff out their earthworm prey. Sooty Shearwaters and Northern Fulmars are attracted from downwind to the smell of fish oils, squid, and krill, and when tested, investigate the area around a wick releasing such odorants. Other tubenoses such as the Ashy Storm-Petrel and Pink-footed Shearwater are also attracted to the same stimuli.

When they return at night from foraging in the Bay of Fundy, Leach's Storm-Petrels appear to use odor to locate their burrows on forested Kent Island, New Brunswick. They first hover above the thick spruce-fir canopy before plummeting to the forest floor in the vicinity of their burrows. Then they walk upwind to them, often colliding with obstacles on the way. In one experiment the storm-petrels moved toward a stream of air passing over materials from their own burrow, rather than one passing over similar materials from the forest floor. In another experiment, individuals whose nostrils were plugged or whose olfactory nerves had been severed were unable to find their way back to their burrows. These results suggest that the storm-petrels locate their burrows by smell where there is heavy forest cover; they do not seem to use smell to find their burrows on unforested Pacific Islands. Interestingly, there is also some evidence that the smells in air currents near their lofts help pigeons navigate.

There has been a long controversy over the degree to which vultures use odor to help them find food. Mostly the argument has been over whether sight or smell is more important, but it has also been suggested, by those with a flair for the absurd, that vultures listen for the noise of the chewing of carrion-feeding rodents or insects or even use an as yet undiscovered sense. Nonetheless, the sight-odor argument remains unsettled. While Turkey Vultures, for example, seem to have a good sense of smell, quite likely it is not good enough to detect the stench of decomposing food from their foraging altitudes. Experiments have shown that their threshold for detecting the odors of at least three different products of decay is too high to permit sniff location from high altitude. Whether or not the birds are more sensitive to the smells of other components of decomposition remains to be determined. More work will need to be done before we know whether vultures use sight or smell or both to locate the dead animals they feed on.

[ron1863]

I think it depends on the type of bird, as some depend on keen eyesite such as birds of prey.
What sense does a bird such as the Blackbird use when hunting for worms, does it hear the worm??

[galanthus]

My birds have all done the same. Around 4 inches of snow covered my 2 ground feeders yesterday, the blackbirds, thrushes and collared dove instantly went to where they were. The blackbirds even went straight to the place where I always place apples and they dug them out Must be a degree of habit involved too I would think, given that they're there every day.

[squishy]

it's different for different birds raptors have amazing vision, but vultures, on the other hand, have a fantastically acute sense of smell.

very interesting subject

[aeshna5]

Many seabirds such as petrels + shearwaters also have a good sense of smell.

[Hobjob]

New world vultures (Cathartidae(includes condors)) have a good sense of smell -- Old world vultures (Accipitridae) don't.