We collected chicken fecal samples from 8 farms 2020-2022. A subset of these samples (96) had DNA extracted and sequenced so we could determine what plants and arthropods chickens were eating. We were able to identify 75 families of arthropods, and 77 families of plants, from these fecal samples.
This figure shows the arthropods and plant families we detected from fecal samples. The left side lists all of the arthropod families we found, and the right side all of the plant families we found. The thickness of the bars indicates the proportion of that family found out of the total number of families, and the color indicates season.
We also characterized each separate taxa (species, genus, and family) into an ecological guild to better understand how they interact with the environment. Arthropods were classified as carnivores (eats or parasitizes other arthropods), pest (crop or livestock pests), detritovores/decomposers, or grain pests (arthropods associated with stored grain or animal feed). Plants were classified as feed (plants found in feed or pasture or provided by the grower as food scraps), weeds, or other.
This figure shows the proportion of occurrence, or how often arthropods and plants of a specific ecological guild are being eaten compared to others. Panel (A) shows arthropods and panel (b) shows plants. Dots are colored according to the key on the right; bars indicate variance.
We found that while plant diet of chickens was not significantly different between spring and fall, arthropod diet was significantly different between season. In both seasons, carnivore, pest, and decomposer arthropods made up roughly the same amount of the diet. Feed and weed plants together made up less than 25% of the diet, while plants classified as other made up the majority. From our preliminary data, we cannot say for sure whether chickens have a net positive or negative effect on biological control.