Anna+K

So this bird and a cat walk into a bar... An experiment on bird's sense of smell by Anna Kasibhatla

Guiding Question : ﻿This is what I will be testing my hypothesis on
 * Will cat fur in one bird feeder affect how many birds go to that feeder?

Hypothesis : ﻿This is what I will support or refute with my experiment
 * I think that the birds will favor the feeder without the cat hair because cats are natural predators of birds.
 * Smells are processed through something in the brain called the olfactory bulb. The olfactory bulb recognizes smells and links them to thoughts. Olfactory receptor genes basically receive smells and send them to the olfactory bulb. Based on their environment, different species have different amounts and types of olfactory receptor genes that work. Humans, for example, do not have much dependence on smell, so they do not use very many of their olfactory receptor genes, only about 40%, and their detailed sense of smell diminishes over time. Birds, however, depend on their sense of smell a lot, so they have a much higher percent of working olfactory receptor genes. In short, this is why I believe that birds will be able to smell the cat fur, because they have a good and instinctive sense of smell.

[|Click here for article on bird's sense of smell]

Procedure for Investigation : ﻿This is the procedure I will follow for my experiment


 * Set out two equal sized bird feeders in two different locations. One on south side of house hanging from crape myrtle tree, the second on the eastern side of the house, hanging from other crape myrtle.
 * Allow three days for birds to find the feeders
 * Harvest fur from feline species (cat).
 * Place cat hair in a sock and tie shut.
 * Secure sock to top of one bird feeder.
 * Return feeders to original locations.
 * Observe and weigh feeders every day for five days and take pictures to record progress.
 * I will use the chart below to record how much seed has been eaten from each feeder, then graph the results.
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Graph information gathered using a bar graph and compare the two measurements.
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Post results.
 * ~  ||~   ||~ Seed Eaten (in ounces) ||~   ||~   ||~   ||~   ||
 * ||= Day 1 ||= Day 2 ||= Day 3 || Day 4 || Day 5 ||
 * = Feeder with cat fur ||= 3 ||= 3 ||= 5 ||= 5 ||= 4 ||
 * = Feeder without cat fur ||= 2 ||= 3 ||= 5 ||= 4 ||= 3 ||

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Materials <span style="font-family: Tahoma,Geneva,sans-serif;">: ﻿This is what I will need for my experiment
 * <span style="font-family: Tahoma,Geneva,sans-serif;">2 milk cartons
 * String or twine
 * Glue 4
 * wooden skewers
 * Scissors
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Bird seed
 * <span style="font-family: Tahoma,Geneva,sans-serif;">A small scale
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Chili powder (to attract birds and repel squirrels)
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Camera

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Results and Data <span style="font-family: Tahoma,Geneva,sans-serif;">:



<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Interpretation of results <span style="font-family: Tahoma,Geneva,sans-serif;">: This graph shows that the birds actually prefer the feeder with cat fur. On every single one of the five days, the amount of seed eaten from the feeder with cat fur was greater than or equal to the amount of seed eaten from the feeder without cat fur. This may be because the birds could not smell the cat fur strongly enough, or because birds do not need to smell cats in the wild in order to survive, and those olfactory genes do not work anymore. I found it interesting that the birds consumed the most combined food of all the five days of the experiment on the day that it snowed (experiment day 3, 12-4-10). It is possible that the snow earlier that day had prevented them from coming to the feeders, and they were really hungry.

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Conclusion <span style="font-family: Tahoma,Geneva,sans-serif;">: <span style="font-family: Tahoma,Geneva,sans-serif;">My experiment refuted my hypothesis that stated that I think birds will eat more seed from a feeder without cat fur as opposed to a feeder with cat fur. The birds actually preferred the feeder with cat fur, and it obviously did not effect their habits at all. My hypothesis was proven null, which means it was refuted. I found that the birds knocked some seed out of the feeder and on to the ground, and ate most of that. While I was watching my feeder, I saw mostly chickadees and titmice, both of whom stay in North Carolina all winter, but I saw a few bright red male cardinals.

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Control Variables <span style="font-family: Tahoma,Geneva,sans-serif;">: These are the things I will keep the same in my experiment
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Type of seed
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Type of feeder
 * <span style="font-family: Tahoma,Geneva,sans-serif;">Location and height of feeder

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Independent Variable <span style="font-family: Tahoma,Geneva,sans-serif;">: This is the one component I will change between the two feeders and measure the difference
 * <span style="font-family: Tahoma,Geneva,sans-serif;">The presence of cat fur

<span style="color: #0000ff; font-family: Tahoma,Geneva,sans-serif;">Other Possible Dependent Variables <span style="font-family: Tahoma,Geneva,sans-serif;">: ﻿These are more things I may discover about bird behavior
 * <span style="font-family: Tahoma,Geneva,sans-serif;">How long it takes birds to find a feeder
 * <span style="font-family: Tahoma,Geneva,sans-serif;">If the weather has any effect on the feeding habit of birds

Other Variables : These are things that may interfere with my experiment that I will have to avoid
 * Squirrels that will eat the seed instead of the squirrels. I will control this variable by mixing in chili powder with the bird seed, because birds like chili powder, and squirrels do not.
 * Birds taking the cat fur to add to their nest. If this happens I will let them take it and add more fur.
 * The birds may be scared off by the sock blowing in the wind. If this happens I will find a different way of attaching the cat hair to the feeder, like gluing it to a piece of cardboard and attaching the cardboard to the feeder.
 * The milk carton feeders will be too light and will be blown out of the tree by wind and their contents emptied. I will control this variable by attaching small weights to the bottom of the feeders or try a different type of feeder.