AUTUMN 1994/VOLUME 8, NUMBER 4

Project FeederWatch
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Birds Like Millet and Milo, Too!
BY KENNETH V. ROSENBERG AND RICK BONNEY

Please cite this Page as:
Rosenberg, K.V. and Bonney, R. 1994. The National Science Experiments: Birds Like Millet and Milo Too!  
Birdscope, Volume 8, Number 4.

Seed Preference Test yields exciting results

Feeder birds like sunflower seeds best, right? Not necessarily. According to the Cornell Lab of Ornithology's Seed Preference Test (SPT), when given the choice of three types of seeds-black-oil sunflower, white millet, or red milo-many common species, such as chickadees, titmice, and Evening Grosbeaks, did choose sunflower. But most ground-feeding species across North America chose millet, and some even preferred milo.

    Nearly 5,000 bird watchers contributed data for the SPT, which was conducted
by the largest corps of volunteer researchers ever assembled. Some individual
participants had trouble attracting birds to their experimental setups (see "How Science Works,"); nevertheless, the cumulative result of their efforts was a resounding success. Together the kitchen-window scientists recorded nearly half a million bird visits to pieces of cardboard set on the ground in backyards across North America. What's more, the data show seed preferences for nearly 30 bird species-surprising preferences, in some cases. In particular, the number of species that chose millet or milo was unexpectedly high (see the table below).

    For those of you who are unfamiliar with the experiment, here's some background. The SPT was designed by scientists in the Lab's Bird Population Studies program to find out which seeds birds like best. Conventional wisdom says that birds don't like red milo, but many participants in Project FeederWatch, especially from the Southwest, had told us their birds love it. We wanted to find out whether milo has been getting a bad rap.

    In addition, we wanted to provide an opportunity for bird watchers to participate
in a real scientific experiment-to experience, first hand, the scientific process.

    And what did they find? First, birds that usually feed in trees-or at your hanging
feeder-seemed to prefer sunflower seeds. These are birds such as chickadees,
nuthatches, and finches. In contrast, the seed of choice for most birds that normally
feed at ground level was millet. Every species of native North American sparrow that came to the cardboard, as well as the House Sparrow, a weaver finch introduced from Europe, preferred millet over the other two seed types. This group includes the Dark-eyed Junco, the most widespread feeder bird in North America (see table in PFW Annual Report article).

    And what about the much-maligned milo? Five ground-feeding species ate lots of
it, and three-the Steller's Jay, Curve-billed Thrasher, and Gambel's Quail-actually
seemed to prefer it. What's more, all of the species that ate substantial amounts of milo are birds that live only in the Southwest or West Coast regions. So, at this early stage in our analyses, the claims of FeederWatchers that birds in the Southwest eat more red milo than birds in the East seems to be confirmed. Seed preference table

    Why do western species like milo? We'll offer some speculation in the next issue
of Birdscope. We'll also take a closer look at how the seed preferences of some
species change over different parts of the continent. And, we'll explain why our results are inconclusive for some species, such as the Inca Dove, which made 36 percent of its visits to milo and 39 percent to millet. For that species and a few others, we still need more data.

    So watch the next Birdscope for more information. And in the meantime,
keep experimenting with different types of seeds to see who comes for dinner.

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