Thursday, March 22, 2018 by Zoey Sky
A study conducted by researchers from Iowa State University revealed that a certain species of birds helps chili peppers grow in the wild.
According to the researchers, the data from their study helped them learn more about “a mutualistic, or mutually beneficial, relationship between birds and chili peppers in the Mariana Islands.”
Haldre Rogers, an assistant professor of ecology, evolution and organismal biology, explained that biodiversity can also indirectly have benefits for humans.
Monika Egerer, a graduate student at the University of California at Santa Cruz, led the study. Rogers was a co-author, together with Evan Fricke, an ISU postdoctoral research associate.
Rogers said that even though organisms rely on each other in “intricate and often poorly understood ways,” the decline of an animal species can still result in declines in plants with which the animal species share a mutualistic relationship.
For this study, Rogers et al. examined the donne’ sali chili plant, which is native to the forests of the Mariana Islands. Birds eat the plant’s peppers and the ingested seeds are then dispersed to other locations via their excrement.
The researchers ran various tests to see if gut passage improves the odds of chili seeds germinating. Video footage established which bird species primarily dispersed the seeds. The researchers then conducted feeding trials with captive birds to collect gut-passed seeds.
The seeds samples were used for planting trials to see how they performed compared to seeds that didn’t pass through birds.
According to Fricke, gut passage helps separate the seeds from the pulp of the chili plants. Once the seed is separated from the pulp, the likelihood of germination when the seeds settle on the ground is significantly increased.
The researchers also noted a “statistically significant improvement in seed germination separate from pulp removal in seeds passed through a local species of starling.” Based on their findings, gut passage through starlings offers other benefits to the performance of the chili seeds. However, identifying the cause wasn’t part of the experiments’ scope.
Interestingly enough, the name of the pepper plants includes the word “sali,” the local name for the Micronesian starling.
The island of Guam, which has a native bird population that suffered losses because of the introduction of an invasive predatory snake following World War II, highlights the importance of the symbiotic relationship between birds and the chili plants.
Since it didn’t have birds that dispersed the seeds, the researchers found much lower chili populations on Guam unlike in the other Mariana Islands.
The research team studied the donne’ sali chili plant due to its “unique social significance” to the people of the Mariana Islands. Fricke explained that the locals use the harvested chili plants as a source of income.
The chili plants are also a sought-after ingredient for spicy foods. He added that many local residents say that this type of chili plant is hard to cultivate, and that the cultivated plants aren’t as spicy as the wild chili variants.
Fricke noted that “public awareness of the importance of pollinating insects in growing crops and other important plants has increased in recent years.” He also expressed concern that appreciation for other symbiotic relationships, like seed dispersal, isn’t discussed as much. Fricke shared that he wishes studies like this can pave the way for growing interest in mutualism. (Related: Beyond The Heat: 7 Amazing Health Benefits Of Chilli peppers.)
He explained that the study can help us learn more about a mutualism that offers direct benefits, which should make us care more about conserving biodiversity.
If you’re not a big fan of spicy food, you might want to start eating more chili peppers, which have various health benefits like:
You can learn more about symbiotic plant and animal relationships and other fascinating scientific phenomena at WeirdScienceNews.com.