April 2023 – Discover-Nature

Bee An Early Pollinator

There are over 20,000 species of bees world-wide, and more species are found every year. Bees are important pollinators, especially in early springtime. Other pollinator species abound, and all are important to the life-cycle of flowers, but bees are thought to increase seed production by about 70%.

^{Dandelions on day 100 by Mike Deal, Apr 2010}

The bees we see in our gardens are all adults, emerging from their nests between early spring and late summer. The first to emerge are the bumblebees. They have wingbeats of about 200 strokes per minute and a metabolic rate that is double that of a hummingbird, allowing them to generate plenty of body heat to stay warm during cool spring weather. Orchard bees are the next out as soon as daily temperatures stay in the mid-50s. Native honeybees may also come out at about this time, but imported bees cannot fly in temperatures less than 60˚F. Early blooming flowers including dandelion, jewelweed, aster, goldenrod, and clover, are important sources for pollen and nectar in spring.

^{Honeybee covered in zucchini pollen by John Kimbler, Getty Images}

As crop plants start to flower, including fruit trees and vegetables, a large pollinator workforce is needed. Almost one-third of the food consumed by humans comes from plants requiring pollination. As pollen is collected by bees, the grains are spread over the bee’s body, allowing some of those grains to rub off and pollinate subsequent plants as the bee follows a route visiting various flowers. Adult bees feed mostly on nectar, eating very little of the pollen they collect. Pollen is brought to the nest to feed their young.

^{Bumblebee in flight with loaded corbicula by mirceax, Getty Images}

Honeybees and bumblebees have a bare spot on their back leg called a corbicula, surrounded by inward curving hairs. As pollen is collected from each flower, it is scraped into this holding area, which may amount to 20% of their body weight while in flight. After landing, a bee grips a flower tightly with its jaws and legs. Snuggling close to the anthers, the bee vibrates and dances to disrupt the pollen inside and let it fall onto their bodies. They proceed to groom all the pollen grains into the corbicula before moving onto the next blossom. When the corbicula full, the bee will fly straight to the nest, unload all of the pollen, and return immediately to where they left off to collect more.

^{Honeybee collecting pollen into scopa by baianliang, Getty Images Signature}

Other bees store pollen in scopa, tufts of hair on their legs and abdomens. As pollen covers the bee during its flower visits, the four front legs are used to scrape the pollen down past their abdomen where the two back legs pack it into the scopa. Some bees may carry the pollen dry, and others may mix in a little nectar to form a dough-like substance that easily sticks to their body hair.

Brown honeybee heading into narrow opening by Gregory Johnston

Buzz pollination video @ This Vibrating Bumblebee Unlocks a Flower’s Hidden Treasure | Deep Look

Pollen collection has resulted in the development of several adaptations found among many bee species. Electrostatically charged body hair attracts pollen. The charge is a result of air moving across the body while the bee is in flight. When plants are small enough that only the bee’s head fits inside, hooked hairs on faces and under chins allow easy pollen collection. Some plants keep pollen in anthers, long tubes that must be turned upside down and shaken to release the pollen. Many bee species use buzz pollination, hanging onto the anthers to tip them, then vibrating their wing muscles to loosen the pollen, allowing it to fall on themselves.

^{Red head bee, Pachyprosopis eucyrta, licking up nectar by Jean&Fred Hort, Mar 2014}

Nectar provides carbohydrates in the form of sugars and amino acids. Bees use their tongues to lick it or suck it up. Several species have longer tongues for use on deep-necked flowers. Honeybees collect nectar and bring it back to their hives to store it. Over time, some of the water content evaporates, forming honey. This is used as food over winter or at times when other food is scarce. Some bumblebees have been shown to also collect and return nectar to the hive, but don’t create true honey. This nectar is used as nourishment for the hive-bound queen only, not as a food source for the entire colony.

As we begin to see the many blossoms of spring and summer, remember that adult bees are only out in our gardens for a short period of their lives. We can assist their work as pollinators by allowing early spring flowers to finish their blooms before cutting them down.

^{Bumblebee on flower from skitterphoto, Pixabay}

^{Bumblebee collected pollen by vinkirill, Getty Images}

Schedule Change

Discover-Nature is making some changes for the summer. We will have a new blog coming out the 2nd and 4th Fridays of each month.

The Site Navigation pages are being updated with each new blog, as well as some older additions. If you are looking for a specific species, my Archives By Species page lists all of the blogs by common name followed by genus/species.

A new tag cloud can be found on the right hand bar, and all blogs are included in the Archives By Category pages.

Watch the Site Navigation menu on the right-hand bar, for a few new entries coming out over the summer.

Thank you all for reading the blog and supporting your local nature museums and programs!

The Ocean Deep

Seventy percent of the Earth’s surface is under the ocean, and only a small portion is in shallow water along continental shelf areas. The ocean is divided into five zones; the sunlight zone, above 650 feet; the twilight zone, extending to 3300 feet; the midnight zone, down to 13,000 feet; the abyssal zone, down to 21,300 feet; and the hadal zone, extending to the bottom of the ocean. Below 3,000 feet, no light penetrates from the surface; the water temperatures are freezing; and oxygen levels are very low. The pressure exerted on any surface at sea level is 14.7 pounds per square inch (psi), and humans can withstand three to four times this amount, or 45 psi to 60 psi. At 3,000 feet deep, the pressure is 1,345 psi.

^{Delta submersible by Robert Schwemmer, CINMS, NOAA, Oct 2010}

Pressure keeps sea water from becoming solid ice, even when it is at freezing temperatures. It also makes exploring the ocean difficult, requiring special submersible vehicles. Everything moves more slowly under pressure, and a submersible can take an explorer deep into the ocean given enough time and oxygen. Deep sea creatures can survive because the structure of their bodies is lean and contain no air spaces. Let’s take a look at a few of the wondrous creatures that live in these habitats.

^{Humpback anglerfish by August Brauer in Public Domain}

In the darkness of deep areas, many species find food and mates by touch. Others may use bioluminescent communication – the ability to create light from a chemical reaction between luciferin and oxygen within an organism’s body. Lights show up as spots of various colors on different parts of the body and may be used for attracting a mate, confusing a predator, or attracting prey. Lanternfish have several spots located on their heads, undersides, and tails. Female anglerfish and dragonfish have a shaft that protrudes from their head out in front of their mouths with a glowing tip attracting prey within striking distance. Gulper eel use the lighted tip of their tail as a lure to attract a meal.

^{Tripod fish by NOAA Okeanos Explorer Program, Public domain, 2010}

^{Fangtooth fish by Sandra Raredon-Smithsonian Institution, Public domain}

Tripod fish have two pelvic fins and a tail fin that are elongated and can be filled with fluid to stiffen them, allowing the fish to stand on the ocean bottom while conserving energy. Two long, wavy pectoral fins act as arms to detect prey floating or swimming by and push the prey toward their mouths. Fangtooth fish is another species that can detect vibration and nearby movement. This species is only six inches in length, but have the largest teeth in proportion to their body size of any fish in the ocean. The long lower fangs fit into pouches in the roof of their mouths so their teeth do not pierce their brain cavity.

^{Dragonfish teeth array by UC San Diego Jacobs School of Engineering, May 2019}

The dragonfish, another small fish about six inches long, has a frightening array of teeth located on its jaws and tongue. Their teeth are transparent and their bodies are black, making them impossible to see even in depths where there may be some light. The jaws are loosely hinged, allowing the fish to open its mouth wider than normally hinged jaws would allow. Prey swimming nearby may not notice the wide opening, nor be able to detect the transparent teeth, making the dragonfish a top predator of invertebrates, squid, and shrimp. In addition, when biting, they inject a highly toxic poison to paralyze and kill their prey. This toxin can be dangerous to humans getting bitten or attempting to eat this species.

^{Giant spider crab by Michael Coghlan, Jan 2014; Gulper eel by Claf Hong, Mar 2005; Lanternfish, Myctophum punctatum1 by Emma Kissling}

Some fish practice diel vertical migration, a pattern of movement where a species feeds near the surface at night and moves back into deeper waters to rest during the day. Lanternfish come up to feed on zooplankton and fangtooth fish feed on squid in shallow waters. Some species, including anglerfish and gulper eels, have elastic-like skin for their mouths and stomachs. Mouths can be opened extremely wide to swallow prey larger then themselves. The food is contained in a similarly elastic stomach which shrinks slowly as digestion progresses. Several different species of spider crabs roam the ocean depths scavenging for meat or plant material that falls to the bottom.

Deep-sea animals are seldom seen, but are not immune from climate change and human impacts. Scientists continue to study changes in deep-sea food webs caused by overfishing, ocean acidification, and expanding low-oxygen zones. Learn more about the habitat and species of these areas at the Jurica-Suchy Nature Museum at Benedictine University or your local nature museum or aquarium.

Maple Trees

Maple trees in the northern U.S. are coming into bloom at this time of year. Maples bloom in late winter and early spring, and the flowers come in green, yellow, orange, and red hues. There are about 130 species worldwide, and except for one species, all are found in the northern hemisphere across Asia, Europe, Africa, and North America. Thirteen maple trees are native to North America, and we will take a look at a few of the more common ones.

^{Holland Red Maple Swamp, Wisconsin State Natural Area by Joshua Mayer, May 2012}

Several species are large trees, reaching from 40′ to 65′ in height with 20″ to 60″ diameter trunks. Trunks are dark grayish-brown with ridged bark. Crowns appear generally rounded and root systems are widely spread. Maple trees do well in most habitats, particularly moist to wet soil, along streams or in bottomlands.

^{Sugar maple in spring by J Stephen Conn, Jul 2007}

Sugar maple, Acer saccharum, is well known for its maple syrup, marketed world-wide. When temperatures drop below 40˚, maple trees stop growing and excess starch is stored until temperatures start to rise again. Enzymes in the tree change the starch into sugar which is carried by tree sap flowing through the xylem and phloem cells, located just beneath the bark. A tap gently pounded through the bark intercepts some of the sap and collects it into buckets. It takes 40 gallons of sap to produce one gallon of maple syrup. Historically, the wood was used for railroad rails, plow blades, and wagon wheels. After burning, its ashes are rich in potash and make excellent fertilizer as well as an additive for soap and pottery glazing.

^{Maple tree tapping by PublicDomainPictures , Pixabay}

Black maple, Acer nigrum, is a close relative to the sugar maple, and these two species easily hybridize. Both species are shade tolerant, often found growing together for several years as understory trees. Sap from black maple trees may also be used in maple syrup production. Black and sugar maples are hardwoods, stronger and harder than other maple species, and valued for use as basketball court and bowling alley floors, workbenches, cutting boards, and baseball bats.

^{Bowling alley by vtwinpixel, Getty Images; Maple & other baseball bats by Comstock Images: Maple workbenches from thelinke, Getty Images Signature}

Red maple, Acer rubrum, provides food from seeds, buds, and flowers for squirrels, chipmunks, deer, moose, and elk. In winter, stumps and small twigs are an important food source for rabbits. Pollen is produced early in the spring and is a much needed food source at this time of year for bees and other pollinators. Red maple is also attractive to insects and fungi, which invade the wood and create many open cavities in trunks and large branches, favored as nesting sites for wood ducks and other species.

^{Red maple buds & flowers by Martin LaBar, March 2010}

^{Baby squirrel in maple tree by William Krumpelman, Getty Images}

Red maple has several qualities that have made it a widely used ornamental tree. It grows well in shady sites; it is tolerant of flooding and water-logged soils; it is one of the first to colonize disturbed sites and anchor the soil, and it has a rapid growth rate, colorful flowers and foliage, and lives 75 to 100 years. Maple flavored drinks, such as tea, are made from inner bark scrapings. Bark is also used in the production of ink and black or brown dyes. The wood is used for smoking meat and in the production of some whisky varieties.

Silver maple, Acer saccharinum, is a fast growing tree with a root system attracted to any source of water. It is easily grown in shady areas and wet soils, make it a well-liked ornamental tree. However, it causes many sewer and drain issues in urban settings in its search for water. The wood is hard but very brittle, and branches easily break in heavy winds. This often results in trunks having hollow cavities used for shelter by various animal species including wood ducks and squirrels. Seeds are abundant and are a favorite for birds and small mammals. The sap makes a delicious syrup, but requires twice as much volume as sugar maple trees, making it not commercially viable.

Box elder, Acer negundo, is another maple species that is often found near water. This tree easily tolerates drought and extreme cold, although the wood is weak compared to other maple species, and branches often break when subjected to heavy loads of snow and ice. Box elder produces abundant seeds late in the year that provide a great winter food source for mice, squirrels, and seed-eating birds. Branches are small in diameter, so it is not often used for lumber, but it has several uses as pulp wood for producing crates, boxes, and composite wood panels.

^{Under the spreading maple by Jo Zimny, Oct 2020}

As you are out walking in your area, be sure to look for the many species of maple trees that grow in yards and woodlands, often distinguished by bright flowers, abundant seeds, and lively green foliage. Also, be sure to take the chance to observe their spectacular fall foliage later in the year.