Color Vision

-
Blue-eyed black lemur (Eulemur flavifrons).


 I have decided to paint the containers different colors/markings. One color will be filled with treats, and the other color will be empty. The goal is to see how quickly the animals pick up on this, if they do, and focus their energy on opening the correct colored containers.

In doing the research for this project, I needed to figure out what colors to use. I discovered that most lemurs are red/green colorblind. This means they have trouble distinguishing those colors from others. Therefore, I am thinking that I will use yellow and blue paints for both the red-tailed monkeys (who have full color vision) and the lemurs, who are red/green colorblind.

https://www.healthline.com/health/deuteranopia

Interestingly, there are sometimes individual lemurs born with full color vision, kind of like how there are sometimes individual humans born colorblind. Since lemurs are the oldest, most "primitive" of primates, we can infer that once upon a time, this is how our ancient primate ancestors were too.

But lemurs have been very successful without seeing all the colors, so why did other primates, and humans, evolve color vision?

This article on a scientific study into lemurs with color vision shed some light onto that question:


https://phys.org/news/2016-12-female-lemurs-vision-advantages-group.html


The researchers found that female lemurs with color vision actually had an advantage over those without out, the benefits of which was also seen in their troop members with normal lemur vision. The color-seeing lemurs were better able to find food in hard times, and thus had an improved BMI, and reproductive fitness over troops without a color-seeing lemur. Fascinating!! So, our primate ancestors likely had these same advantages, and for them, color-seeing was selected for. 

I wonder, with enough time, would future lemurs become color-seeing too? Maybe if the selection pressures for it increase. And if humans don't completely destroy Madagascar, thus driving lemurs into extinction.


(Also, fun fact! Blue-eyed black lemurs are the only primates besides humans known to have blue eyes! They are also one of only two lemur species that are truly sexually dimorphic. The males are black while the females are red).



Comments

Post a Comment

Popular posts from this blog

Phase Two Data

-
Image
  Red-tailed monkey participants by Steve Gotz Phase Two Data I felt like this project was extremely successful! I accomplished everything I set out to do despite being a one-woman research team (couldn't have done it without the zookeepers of course!) and gathered lots of interesting observations and data. Also it was just plain fun! Who doesn't want to watch cute monkeys and lemurs everyday? I'll relay the data from this phase below:                                   Here the monkeys showed that they definitely favored the blue boxes over the yellow ones! Interestingly however, their interest in the blue boxes waned across the first three days, then spiked on the last day. Their interest in the yellow boxes was increased on the first day of Phase Two compared to the following days, but remained about the same on days two through four. And the data from the lemurs: Remember  to keep...
Read more

Results

-
Image
  Ring-tailed lemur participant, Amy Ta-dah! After comparing the data and drawing my conclusions from the results, I created a presentation which I gave live at the Summer Undergraduate Research conference for my university, and then later recorded it for YouTube, which I will include in the next post. I will present the results below: Here we have a side-by-side comparison of the data from Phase One with both the monkeys, and lemurs. Taking into account that the lemurs could likely smell the food in the blue boxes once they got close enough while the monkeys likely could not, these results are pretty much what I would have expected.    Overall, the monkeys visited both colors of boxes less, while the lemurs visited them more. Some of this I account for the increase in the crowned lemurs' participation during Phase Two. I think the most useful data in regards to the participant animals' cognition came from my own observations during the study. Of both the lemurs and the m...
Read more

Research Plan!

-
Image
 I want to be able to measure behavioral differences between the two species --- how their interactions with the new stimulus differ between each other and what that may mean. How quickly do the animals investigate the new items? How quickly do they figure out that they hold food and how to get into them?How quickly and how well do they figure out, if they do, that only certain containers hold a reward? And finally, how well, if they do, do they remember everything they have learned from their previous encounters with the stimulus, after a period of absence from it? So, the stimulus and protocols need to be the same for both, which shouldn't be a problem as the stimulus will be designed to fit both primate species capabilities.  At first, I was thinking of doing plastic boxes with a lift lid. This would work easily as far as putting food items inside and watching them interact with them. However, after purchasing a lift-lid box, filling it with tuna and cat treats and presenti...
Read more