L3 Proximate mechanisms of behaviour - bird senses Flashcards
What is the pathway of a reaction to a stimulus?
Sensory input -> Processing in the brain -> motor response
What is a sensory modality?
how and what we perceive after stimulus
What are the sensory modalities in birds?
Vision, Hearing, Touch, smell, taste, echolocation
How are birds eyes specialised?
Two fovea in the eye, providing clearer vision
What is sensitivity in eyes?
The ability to see in poor light
What is resolution in the eye?
The ability to resolve things, how much detail you can see in
What is the trade off between sensitivity and resolution?
Resolution decreases with decreasing light, sensitivity more useful in this case, in fixed eye size
How do birds see colour?
Have four types of cone cell photoreceptors that translate light into nervous impulses. Birds have four and can see in ultraviolet. Cone cells in birds contain a coloured oil droplet
Why is the ability to see UV important in birds?
Allows for prey detection - UV in urine trails
Functions in mate attraction
Where are bird ears located?
On the side of the head
Describe the arrangement of the avian cochlear
Avian cochlea. The sensory epithelium, consisting of hair cells and supporting cells, rests on the basilar member (BM).
The hair cells range in height from tall
How well can a bird hear?
Audiogram is similar to that of humans
What are Herbst corpuscles and where are they found?
nerve endings found in the mucus membrane of the tongue, and beak
What is the bill tip organ?
Contains lots of herbiest corpuscles, very pressure sensitive, allows for detection of buried or submerged prey
What is commonly believed about bird see?
Most birds seem to lack this sense, however anatomical evidence reveals olfactory lobe in certain species
