Native is a term used to denote an indigenous plant that has evolved overtime to beneficially interact with the diverse elements of its ecosystem. More specifically the plant has evolved to convert the sun’s energy (through photosynthesis) into biomass – which is then consumed by herbivore (plant-eating) members of the ecosystem who have co-evolved with the plant to overcome its physical and chemical defenses. For this reason, Native plants efficiently transfer energy through an ecosystem.
Non-Native or Alien is a term used to denote a plant that has been either introduced or that has accidentally spread to an ecosystem in which it is not native. Therefore, it has not evolved to beneficially interact with the diverse elements of its ecosystem. While Non-Native plants undergo photosynthesis, and convert solar energy into biomass, that mass is not consumed by many (if any) members of its non-native ecosystem because they have not adapted to overcome the physical and chemical defenses of the plant (which is why Non-Native plants are often labeled “Pest-Free”). For this reason, Non-Native plants do not efficiently transfer energy through an ecosystem, in affect they waste it.
Because they are consumed by herbivores and subject to indigenous pathogens Native Plants are in most cases controlled – unable to grow/spread vigorously and thus dominate their respective ecosystem. Whereas Non-Native Plants are often not controlled because few if any of the herbivores and pathogens can consume them. This situation leads to Non-Native plants out-competing (for limited resources like light, water, and space) the Native Plants – and overtime this means Non-Native Plants will spread (some become invasive), while the Native Plants will diminish. Which isn’t good news for the ecosystem because most of its members rely upon the Native Plants either directly or indirectly for survival.
Insect populations are among the first to suffer when Non-Native Plants replace Native Plants because they limit and in some cases, deplete the food sources insects require for survival. The great majority of insects are considered “Specialists” – which means that they have adapted (over many years) to only use specific native plant species for hosting and for food – when those Native Plant species are displaced by Non-Native Plants, the insect is forced to leave its current habitat or vanishes due to starvation. This has all led to has to significant decreases in insect biodiversity.
Which is a particularly devastating situation for birds – as many species of birds primarily eat insects and nearly all birds require insects while breeding and rearing their young. Without a diversity of insects, bird populations will suffer – especially the species (like: Warblers, Tanagers, Vireos) that depend on insects the most.
Choosing Native Plants over Non-Native Plants promotes a healthier ecosystem and is key not only to attracting more birds but even sustaining them long term – below is a list of bird-friendly plants native to the United States - click on the plants to find out which specific states they are distributed in and which birds they are known to attract.