Birds of a Feather Feed Together

Part of the Young Naturalist Awards Curriculum Collection.

by Sarah, Grade 10, Virginia - 2008 YNA Winner
Figure 1: corn.

Growing up in a family that has always enjoyed observing birds, I was curious about the different species of birds in my neighborhood. Although I live far away from town, my neighborhood shows little hospitality toward animals. Birds are some of the few animals that are able to benefit from land development and an increase in people; they are able to feed at bird feeders set out by helpful families. As I observed the birds that fly into my neighborhood to rest on rooftops and peck at the seeds in plastic containers, I wondered if certain bird species preferred a particular seed type. Do they only eat at feeders that contain their favorite seeds? Or do they eat whatever is given out to them? Why would they eat only certain types of seeds? I wanted to get to know the native bird species in my area and understand what each species prefers to eat. I hoped I would be able to use this knowledge to create an ideal seed mixture for native birds so they will continue to stay in my neighborhood.

Figure 2: niger.

I decided to learn more about the native birds of western Albemarle County by documenting their preferences for certain seeds. In this experiment I looked to find the best seed mixture for minimum waste, maximum variety, multiple visits, and maximum appeal for the native species in my area. Although I live in a housing development, I hoped to attract multiple birds and determine each species' seed choice.

Figure 3: safflower

I created a list of local species from two sources, the Cornell University Lab of Ornithology and the "Seed Preference Guide" pamphlet I received from the bird specialty store where I bought my seed. Both listed common native birds and what their seed preferences were. I chose 15 species native to western Albemarle County, which are the birds most likely to visit my feeder. They were: the morning dove, the downy woodpecker, the red-bellied woodpecker, the Carolina chickadee, the tufted titmouse, the white-breasted nuthatch, the blue jay, the Carolina wren, the white-throated sparrow, the song sparrow, the dark-eyed junco, the Northern cardinal, the American goldfinch, the house finch, and the house sparrow.

Figure 4: sunflower.

To prepare for my project, I researched what types of seeds I should include in my experiment. I found that corn (Figure 1), niger (Figure 2), safflower (Figure 3), sunflower (Figure 4), peanut (Figure 5), and millet (Figure 6) are six seeds that are used at feeders and around homes to attract birds. I went to my local bird specialty store and found all six seeds in five-pound bags. I then constructed a feeder that could be easily accessed by all types of birds. I nailed six open black containers to a long board and then tied the board to the railing on my back porch (Figures 7 and 8). I decided to fill each container with 100 grams of a certain seed (Figure 9). In the end, I had six containers, each filled with a different kind of seed (Figure 10). I created charts for each of the types of seeds, with a column for each bird that was likely to come to the feeder. Each row was labeled with the date.

Figure 5: peanut.

To collect my data, I surveyed which species of bird visited each type of seed to figure out which seeds each bird preferred. However, while I was preparing my project, I considered the fact that I would not be able to witness all the visits that the birds made at my feeder because I would be attending school for most of the day, so I decided to also weigh the seed once it became low to determine how much of the seed was consumed (Figures 11 and 12). I made my observations of bird intake in the mornings before school, after school, and on weekends. I collected a kitchen scale and weighed each type of seed. Then I recorded the mass of seed consumed by subtracting the ending mass from the starting mass of 100 grams. After I had weighed all my seed, I would replenish the feeder by weighing out 100 grams of each seed and pouring it into each container, but in a different order to make sure the birds were eating a certain seed because of preference instead of placement. However, when it rained, I would remove the feeder from the porch railing so the seeds would not become wet and change in weight. I would then put out two tube feeders because, as seen in Figures 13 and 14, birds would continue to come to the railing and instead of discouraging them from coming back, I gave them a little bit of seed from the tube feeders. I conducted my project for five weeks, from Monday, October 29, to Sunday, December 2.

Figure 6: millet.
Figures 7-9: Sarah prepares the containers.
Figures 11-12: Sarah weighs the seed before replenishing the containers.

After I had collected the data from the five weeks of my project, I organized my results into charts and graphs to try to answer the questions I created. I first looked at the amount of seed consumed over the time period I held my experiment.

Figure 10: Six containers each filled with a different kind of seed.
Grams of Seed Consumed for Each Seed Type.

Once I had organized and analyzed my data, I was able to draw conclusions about the questions I had at the launch of this project. Although I was unable to observe all the visits the birds made to the feeders because of my absence during the day when I was at school, I can still depend on the observations I was able to make before and after school and the amount of each seed consumed to draw my conclusions. However, some birds, such as the Carolina chickadee, blue jay, song sparrow, and Northern cardinal, only visited a few times, and therefore they did not provide enough data to draw conclusions. More observations would be necessary to include them in the project. From my data I can infer that the best mix of seeds to minimize waste would be millet and sunflower, because both these seeds had the highest consumption rates, as seen in the bar graph. Although it is possible that the remaining seed on the ground blew away in the wind, it still shows that these two seeds would serve best if someone wanted very little seed waste. These seeds would probably be best if they were scattered on the ground for the birds, as the seed waste could easily blow away from the area. Another good mixture that would guarantee plenty of visits from birds would be niger and sunflower seeds, because both these seeds received the most visits. But if someone wanted a mixture that would attract many different birds, it would have to include sunflower, safflower, and niger. These three seeds were consumed by the largest variety of birds.

Amount of Seed Consumed in Grams.

It is obvious that birds do have a preference for certain seeds, but why do they have a favorite? Birds usually eat the most from feeders during the wintertime when food is scarce or hard to find. Different seeds have different nutritional values, and during the winter birds need more fats and proteins to keep warm and have enough energy. As seen in Figure 15, seeds differ in fat percentages. There is a clear correlation between my results for bird preferences and the fat percentages in the seeds they choose, which I found on the labels of the bags of seed I bought. More birds prefer the seeds that have a higher fat percentage. Peanut, niger, and sunflower have the highest percentages of fat and were very popular with all the birds.

Number of visits each species of birds made at each seed.
Most Popular Seed Consumed by Species.

Comparing these results with the pamphlet I received at the bird specialty store, I was able to see many similarities between the bird species and their favored seed types. The morning dove favored sunflower, safflower, cracked corn, and millet, therefore liking everything. The red-bellied woodpecker liked the sunflowers, corn, and peanuts, both according to both the pamphlet and my conclusions. However, the research I found before the project states that they also like safflower, although they never visited that feeder during the project. The dark-eyed junco enjoys sunflower, niger, and corn but also consumed safflower and millet at my feeder, although the pamphlet suggests that dark-eyed juncos do not prefer these seeds. The American goldfinch enjoyed sunflower and niger but also visited the safflower at my feeder. The house finch ate everything at my feeder during the project, but the brochure states that they do not like corn, peanuts, or millet. Millet had the fewest visits by the house finch; although they did consume some millet seeds, they preferred the other three. The house sparrow is listed as liking all six seeds in the pamphlet, but they did not visit the safflower or peanut at all, and the niger only once. For the most part, the information I gathered during my experiment and the list of birds in the pamphlet I received with my seeds are very close, and the birds in my area seem to like the seeds that they are thought to prefer.

Number of Species that Visited Each Seed Type.

For this project, there were a few problems in the habitat in which the experiment took place. The housing development that I live in is close to a wooded area, but other houses surround my home. My yard does not have any mature trees, so I do not have many birds living in or visiting my yard. This affected my experiment, because I did not receive visits from all the species of birds I had expected to collect. Although I had diverse species at my feeder, I wonder whether my data and results would have been altered or affected if I had observed more species. If I continued my project, I would like to change my observation time so that I could observe the birds more and take notes on their behavior toward other species. I would also like to use the conclusions I drew at the end of this project to see if mixtures of seeds would get the most bird visits.

A table with fat percentages for: Corn 2%, Niger 40%, Safflower 3%, Sunflower 35%, Peanut 48%, and Millet 2%.
Figure 15: Fat Percentages

In conclusion, I have found that the best seed mix for this part of western Albemarle County is niger, sunflower, and millet because they were enjoyed by many birds and meet my requirements for minimum waste, maximum visits, and maximum diversity of species.

Farrand Jr., John. The Audubon Society Master Guide to Birding: Gulls to Dippers . New York: Alfred A. Knopf, 1983.
Farrand Jr., John. The Audubon Society Master Guide to Birding: Old World Warblers to Sparrows . New York: Alfred A. Knopf, 1983.
Gooders, John. The Practical Ornithologist . New York: Simon & Schuster Inc., 1989.
Peanut . Wikipedia. Retrieved from the World Wide Web on 6 December 2007.
Schulemann, Gaby. Food Nutrition . Birds Online. Retrieved from the World Wide Web on 6 December 2007.
Seed Preference Guide . Wild Birds Unlimited.
What to Feed Birds . Cornell Lab of Ornithology. Retrieved from the World Wide Web on 6 December 2007.