Jan 15
Umvelt: the way in which organisms of a particular species perceive and experience the world
- Different species, despite sharing the same environment, will experience that
environment differently
- One environment might be very stressful for one animal but the perfect environment for
another animal
Sight-
Photoreceptors: light-detecting cell, they vary dramatically from one species to another
Opsins: proteins in all photoreceptors
- Every animal that can see does so with opsins (pretty sure opsins only evolved once,
meaning that all of the animals that can see share a common ancestor)
4 levels of vision
1. Photoreceptors without eyes: can only detect light (jelly fish, octopus skin)
2. Shared photoreceptors: can detect light and infer its direction (swallowtail butterflies
have these on their initials to help with mating)
3. Clusters of photoreceptors: true eyes but poor vision and can see light and infer
directions to see large shapes
4. Complex eyes with full vision: included depth perception and increased acuity, doesn't
necessarily mean they can see color though
We do not understand why birds are attracted to big areas of light but since about 500 species
of birds migrate, they get distracted when trying to migrate
- Lights draw them to urban areas and they can die from structure collisions
- They can also die from just circling for hours and being exhausted
- We can help this by making lights blink instead of stay solid
- Bats and insects don't perceive red lights in the same harmful way they perceive white
and bright lights
Smell-
In the forebrain and is linked to memory and learning
When a mammal inhales, odorants ( the molecule that contains “smell”) enters the nasal
passage which are coated with olfactory epithelium
- The epithelium contains long neurons that have “odorant receptors” and then the
neurons project all the way back to the olfactory bulb
Compared to humans, dogs have more olfactory epithelium and have dozens of times more
olfactory receptors and a larger portion of their brain dedicated to smell
● Only 17% of dog behavior studies published in the past decade describe the odor
environment in which experiments are done (most studies do not consider smell when
researching dog behavior)
● Dogs are more likely to interact, and interact for longer, with scented toys
- Precedence of scent also significantly reduced stress and increased exploration
