One of the ecological issues of recent years has been the role of invasive species and how they affect local birds and mammals. Recent studies show that berries produced by native plants are best for birds. Besides that, the birds prefer local varieties over the fruits of introduced species.
Studies of native bayberries have shown that they contain more fats, carbohydrates, and nutrients that birds need to survive. Amanda Gallinat of Utah State University said that invasive fruits are usually nutrient-poor. For people who enjoy watching birds, that is something to keep in mind when choosing plants for their yards.
Viburnums such as arrow-wood viburnum produce berries that are high in fats and carbohydrates, which help birds prepare for making long migration flights. For birds that stay around in the cold weather, another factor that favors native plants is how long they hang on to their berries. Winterberry is a native holly that can hold its berries well into the cold months.
When you talk about the design built into the migrations and lives of birds, it is not just the birds’ design but also the design of the nutritional system that supports them. Native plants are best for birds because they often give the birds better nutritional support than species brought in from other areas of the world.
God’s design for life is best, but humans often introduce non-native plants and animals that sometimes become invasive species. People may introduce non-native species with good intentions, or perhaps invasive species arrive by accident with foreign cargo. Either way, we must learn to be better stewards of the planet over which God gave us dominion. (See Genesis 1:28.)
It’s an evergreen tree that can live for 500 years and grow up to 33 feet (10 meters) tall. However, it usually doesn’t live for more than 100 years or grow taller than 10 feet (3 meters). It is often associated with Christmas because people use it in wreaths and garlands, and you see it pictured on many Christmas cards. What does European (or English) holly (Ilex aquifolium), also known as Christmas holly, have to do with Christmas?
The connection to Christmas goes back to medieval times in Europe. People said that the sharp-pointed evergreen leaves reminded them of the crown of thorns Christ was forced to wear at His crucifixion. The berries, which are red during the Christmas season, reminded them of the blood Christ shed, and the white flowers stand for purity.
European holly grows as a tree or a bush. The berries are mildly toxic to people and harmful to dogs or cats. However, they provide winter food for birds, rodents, and other animals. The flowers are sources of nectar for bees and butterflies. European holly grows in shady areas in forests, and it can form a dense thicket along forest borders. Because it is a dense evergreen with sharp points, people often use it for privacy hedges.
In its native areas of Europe and other regions, holly is an ornamental plant admired for its beauty. However, since people brought it to North America’s west coast, it has become an invasive species. It thrives in the shade of forests and crowds out species native to that area. Washington state has called it a weed.
Like other plant species, European holly has an ecological niche to fill. Problems often arise when people do something to upset the balanced relationship that God has designed into nature. From the beginning, humans have done things to upset our relationship with God. That brings us back to Christmas and the reason God came to Earth in the form of a human who lived a pure life and shed His blood on the cross to redeem us. Christmas holly reminds us of that.
When humans throw the world of plants and animals out of balance, the result is extinctions. We can destroy God’s designed balance when we introduce a non-native species into an environment. The introduced species without natural predators uses up local resources leaving native species without food. There are many examples.
One example is the brown tree snake (Boiga irregularis) which was accidentally introduced to Guam aboard a military cargo ship after World War II. Those snakes are native to Australia and Indonesia where natural predators control them. On Guam, they have decimated 50 percent of the native bird and lizard species and two of the three bat species on the island. The brown tree snakes considered those native species to be tasty treats, and the snakes had no predators to control them. The result was the extinction of many species, some of which existed nowhere else on Earth. Alien invasions of brown tree snakes forever changed the ecosystem of Guam.
In other cases, humans throw nature out of balance by their direct actions. An example of that is the over-hunting of sea otters. Sea otters kept the purple sea urchins in check. Steller’s sea cows (Hydrodamalis gigas)were giant relatives of manatees, and they lived on kelp. Without control by sea otters, the purple sea urchins ate so much of the kelp that Steller’s sea cows had no food, and they became extinct. However, the research project indicated that direct interference by humans in cases like this has less impact on extinctions than the alien invasions have.
Sometimes humans make the mistake of bringing in another non-native species to control the first one. That technique often makes the problems worse. Usually, by the time people discover the problem of alien invasions, it’s too late to fix it.
The research concludes that 25 percent of plant extinctions and 33 percent of animal extinctions were caused by alien invasions – the introduction of non-native species. The bottom line is that humans have not been good stewards of the planet God has given us to enjoy and protect. God gave humans the responsibility to have dominion over creation and “rule over the fish of the sea and the birds of the air and over every living creature that moves on the ground” (Genesis 1:28). Romans 13:1-4 indicates that those who rule over people have the responsibility to protect. We might say the same of us who rule over the creatures.