Editor's note: From the deep sea to the mountains, from deserts to rainforests, plant imprints are found everywhere on earth. A world of changing years, climate change, geological movement, habitat change, plants that have endured and remain diverse in evolution. Voice of the Chinese Academy of Sciences and the Wuhan Botanical Garden of the Chinese Academy of Sciences jointly opened "Flowers and Flowers of All Things", where we pay attention to the survival, competition, reproduction and death of plants, display the strange and colorful nature of the natural world, interpret the thousands of meteorological phenomena of life, explore the magical secret of life, and pay tribute to this silent and vigorous world.
When we walk into the world of birds and enjoy their pleasant chirping, we may worry about whether the wild birds will be fed? What do they eat? In fact, wild birds eat "meat" and "vegetarian" in addition to eating. Which plants provide a "vegetarian meal" for the birds? Here we get to know the food source plants together!
The so-called "food source plants" are plants that can provide nectar, fruits, seeds and other "rations" to animals. Ginkgo biloba, acacia, toon, national locust, euphorbia, persimmon, chestnut, purple leaf plum, jujube tree, mulberry tree, silk cotton wood, and linden belong to this category. The four seasons rotate, the food source plants continue to grow and multiply, and they are a feast for wild birds. There are sweet nectar powder in spring, juicy berries in summer, fruitful fruits in autumn, and nuts everywhere in winter.
Purple Leaf Plum (Source: China Plant Image Library)
"Nectar tree" - rice dough flowers
In the spring, flowers bloom and bring food to the birds. There are more birds visiting flowers, but not necessarily "professional" nectar eaters, and the nectar provided by plants to birds is more a reward for pollinators, of course, birds do not visit flowers for the purpose of pollinating plants.
The beak used by birds to suck nectar is very smooth, and only the nectar glands located in the tissues inside or outside the flowers can be sucked into the mouth, so birds that feed mainly on nectar are more inclined to have long beaks, such as the sunbird family. Birds with short beaks, such as starlings and puffinaceae, are more opportunists and do not feed on nectar, but feed on nectar with shorter flower tubes and shallower positions.
The dispute between the middle long beak and the short beak of the hummingbird (image from the Internet)
The long beak and short beak correspond to different lengths of flower tubes, each with its own place. The tubular corolla of the bird-borne plant hides the nectar deeply, so that the bird's feathers first contact the pollen, so as to achieve the purpose of plant pollination. At the same time, in order to put an end to unearned gains, the long flower tube of the plant provides a relatively high component of nectar sucrose, and most of the short-beaked bird species digestive system lacks enzymes to decompose sucrose, and the nutrients are not easy to be absorbed, which is often said to be "eating white".
The vast majority of plant nectar is colorless, and in recent years, it has been found that the nectar of at least 70 plants in nature is very rare, showing strange yellow, orange, red, brown, green, blue, black and other colors. Gaoligong Mountain is a sacred place for bird watching, and the rice clusters on the mountain provide a large amount of bird food nectar for the nectar birds.
Rice Flower (Source: China Plant Image Library)
Leucosceptrum canum is a large, rare large woody plant in the family Leucoscephalidae. It has been studied that the nectar of the rice dough flower is tan, and the rice dough flower is also the only colored nectar plant found so far in the family Lipaceae. It can attract more than 40 species of birds to feed on it.
The chemical structure of flowers and birds and DPBQ (Source: Reference 3 )
The study conducted an experimental study of bird behavior on Zosterops japonicus, one of the pollinators of rice dough flowers, and compared with the bird behavior responses of nectar, honey, (-)-DPBQ and (+)-DPBQ, it was finally confirmed that DPBQ mainly attracted pollinator birds by its color. A novel class of plant nectar pigment substances has been discovered, revealing for the first time the elusive chemical and ecological functions of colored nectar plants.
Comparison of different concentrations of DPBQ solution with nectar (e) of rice dough flowers (Image source: Reference 3 )
It turns out that the rice dough flower transmits palatability information by changing the color of the nectar, and only the short-beaked bird species that are effectively pollinated can be identified!
"Bird Tree" - Camphor
Camphor (Image source: Chinese Plant Image Library)
In the Tang Dynasty poet Shen Yazhi's "Wenzhu Yan Erzhu", "Under the cover of the camphor, the clouds are draped." "Let people feel the lushness of the camphor tree. The "Camphor Tree" written by Shu Yuexiang in the Song Dynasty said: "The branches of the tree are flat and the dragon walks, and the wind and rain are cold in the middle of the air." Spring comes with flakes of flowing red leaves, who put down the beach with inscription poems. The image describes the camphor. Evergreen tree camphor, tall and tall, the canopy is lush all year round, and the fruit is full and fruitful. Small green-white flowers bloom in May to June, fruit in July to August, camphor fruit spherical, 7-8 mm in diameter, ripe camphor fruit in late autumn has changed from green to purple-black berries.
Squid (Image from the Internet)
More than ten species of birds, such as grey magpies, spotted doves, squid, squid, grey owls, purple howling owls, grey starlings, mercerous starlings, yellow-bellied, large, and red-headed long-tailed, are regular customers and consumers of camphor tree fruits. As a result, the camphor tree is likely to be called the "bird tree", which is a place for birds to gather together. Fruit-bearing plants like camphor are very important for wintering birds, regardless of taste, at least to feed them and overwinter safely.
Camphor fruit (Image source: China Plant Image Library)
The seed maturity of camphor tree is related to meteorological factors, and the maturation process of camphor seeds lasts for about 7 months, and the fresh weight, dry weight and development time of seeds are positively correlated with the development time during the whole development process. The growth of seed 10000 grain mass was maximized 150 days after flowering, and the seed maturity was moderately correlated with the average temperature. The growth of seed maturity and the increase of 1,000 grain quality showed a certain positive correlation with the cumulative sunshine hours. Light did not significantly promote the germination of camphor seeds, and the germination rate of old seeds was higher than that of newly collected seeds in that year, and the germination rate of seeds that removed seed coat was higher than that of seeds that did not remove seed coat, regardless of new and old seeds.
A natural product is extracted from the roots, stems, branches and leaves of the camphor tree, the main ingredient is dextran, which is made of camphor and placed in the wardrobe to prevent insects and moths. People also use the fragrance of camphor leaves to smoke food, and there is camphor tea duck in Sichuan, with cypress branches, camphor leaves and tea leaves as smoke. The green seeds of the camphor tree can be used to refine edible camphor oil, which has a special aromatic and spicy taste.
"Spicy Tree" - Black Oak
On the black oak tree, a kind of "lethal" poisonous insect with a strong "lethality" called "foreign spicy seed" will often gather, and when passing under the black oak tree, it will worry about the foreign spicy seed falling on the body, and occasionally there will be birds pecking at them to "open the meat to relieve hunger". In addition to its body full of "spicy" poisonous insects, the sap of the black oak tree itself is poisonous, if splashed on the skin, it will feel the same pain of being stung by the poisonous insects of "foreign spicy", so the black oak is commonly known as "spicy tree". It is not useless, and studies have confirmed that the extract of the root bark of the tree has an inhibitory effect on E. coli and Shigella at different temperatures of 60 degrees, 80 degrees and 100 degrees.
Black oak fruit (Source: China Plant Image Library)
The ripe fruit of the black oak resembles popcorn, and the pear-shaped spherical shape of the blackberry is green when it is not ripe, and turns brownish-black when ripe, splitting into 3 pieces, revealing 3 bulbous seeds. The seed is covered with a white waxy pseudocoat, and its seed word sebiferum is "waxy fruit". The ancients used the wax on the seeds of the black oak to make soap and candles, removed the waxy seed oil, the oil of the black oak seed is poisonous and inedible, but can be used to light a lamp, the "Materia Medica" mentions that this oil is "very bright". Now the seeds can also be squeezed for high-grade lubricants for airplanes and automobiles.
Dark green embroidered bird (image from the Internet)
Dark green embroidered birds and magpies prefer to eat the seeds of the black tree, but why don't birds get poisoned by eating seeds? It turns out that birds will choose a stage with relatively low seed toxicity to eat, at the same time, birds have a strong metabolism, food stays in the intestine for a short time, toxicity can not fully play a role, and birds will eliminate toxic and unpalatable parts before eating. Birds have a unique physiological mechanism against toxins, and some birds will also eat some soil to detoxify.
Maitree Magpie (Image from the Internet)
Animal taste essence is to avoid the body to ingest toxic and harmful substances of a protective mechanism, some plant fruits in the seed immature will contain more alkaloids, so the taste is very poor, this is the plant needs to ensure that their seeds before maturity, not from external influences and destruction. After the plant seeds mature, they need to be eaten by specific animal groups, with the help of animal power to spread the seeds, then the plant will release odor pheromones, some birds can accurately feel the pheromones released by the plants, real-time selection of food source plant nectar, fruit, seed eating period, to avoid harm, to ensure that in the wild can solve their own "food and clothing problems."
Persimmon tree (Image source: Qianjiang Evening News)
For example, after the persimmon fruit is red, it will still hang on the branch for a while and "no one cares", but after a while, it will be found that the birds will peck the persimmon fruit as promised. Singing and singing in the same persimmon tree, frolicking and playing.
Bird persimmon eating scene (Source: Qianjiang Evening News)
Different birds have different preferences for fruit, peacebirds like to eat begonia berries, goldfinch likes to eat cypress fruit, large spotted woodpecker likes to eat oak fruit, willow warbler birds like to eat Tang di fruit. Birds in the wild food source plants are very rich, wild hawthorn, wild rose, raspberry, mulberry, Privet, sour dates, etc., they provide food for wild "vegetarian" birds, birds will also be the fruit of the undigested seeds, through the way of feces excretion, spread to farther places, so that plants continue to reproduce. Birds and plants live together, mutually beneficial, co-evolving, mutually promoting development, promoting and maintaining ecological balance.
bibliography:
1. Chen Guohua,Shao Wei,He Xiaowen,Zou Kun. A Preliminary Study on the Antibacterial Activity of Water Extracted from Eucalyptus Root Bark [J] Medical Papers, March 2009
2. Fan Hui. Research on reproductive biology of camphor trees [D] Master's thesis of Fujian Agriculture and Forestry University in 2014
3. Li Shenghong,Luo Shihong. Secondary metabolites and their ecological functions of rice flower [J] Organic Letters, August 2012
Source: Wuhan Botanical Garden, Chinese Academy of Sciences