January 2023 – Discover-Nature

A Big, Cool One

Elephants are the largest land mammals and they live in a variety of habitats in tropical and subtropical regions. Their native habitat is often savanna, grassland or forest although they can also be found in desert, swamp, and highlands. These areas get twelve hours of sunlight each day, with warm, daily temperatures averaging from the lower 70s to above 100˚F for animals living in the desert. Heat and gravity are two natural factors that affect all large animals, and elephants have some unique methods and body design to compensate for both.

^{Walking in Kruger National Park by Simone Eman, simoneemanphotos}

Elephants have a massive skeleton with solid bones in their feet, legs, hips, and ribs that provide excellent support for all of their weight. Lots of muscles, both large and small, allow easy movement while still protecting their vital organs. But not all of the bones are solid. The skull is honeycombed throughout, so it is light enough that the neck can support the head and allow for many small and precise movements of the trunk, the ears, and the tusks. The brain is small for an animal of this size, but elephants are quick learners, have an excellent memory, and are one of the smartest animals.

^{Elephant’s foot by sboofek, Getty Images}

^{Elephants foot tread by skynavin, Getty Images}

While small animals, such as ants, can hang on to a vertical surface, elephants require a solid set of legs to stand and walk on. They actually stand on the tips of their toes, located along the front edge of the foot. The center and back of the foot is one large pad behind and under the toes that cushions each step and helps to carry their weight. The large, round flat of the foot spreads the weight evenly over a larger area, and their soles have treads to provide traction on slippery or uneven surfaces.

^{Elephant ears by Harvey Sapir, Pexels}

Heat from the sun, and from the exertion of the muscles performing under the tremendous weight of the body, must be dissipated efficiently. This task is handled by the elephant’s ears, which are very large and very thin. Hundreds of blood vessels run through each ear close to the skin to radiate heat away from the body. The blood, now cooled, can be circulated throughout the body. Skin over the rest of the body is thicker, but there is little to no fat underneath, nor is there any fur or hair covering the outside to trap heat. The skin also has many wrinkles creating much more surface area than smooth skin, allowing more heat to be lost to cooler air and water.

^{Celery anyone…by eugen_z, Getty Images}

An elephant’s trunk is a nose-arm-hand all wrapped into one. They can pick up large and heavy objects as well as being able to manipulate the sensitive tip to grab tiny and delicate objects. To help control the heat, they often will suck in a trunkful of water and using the end of the trunk like a shower head, spray all of the water across their body to wet down and cool off. Similarly, they can snuffle up a load of dust to spray across dry or wet skin to create a coating to help keep away biting insects and provide protection from the sun.

Elephants are built to move easily and efficiently in their environment, and they have several methods and adaptations to deal with their size and the heat. Next week we will discover more about family life and the lands they live in.

The Elephant Trunk

An elephant’s trunk is an amazing body part. It is a 300 pound nose-arm-hand about seven feet long. It contains 50,000 muscles, but no bones or cartilage, making it strong and flexible. A vast array of nerves controls it. Elephants use their trunks for a variety of tasks including:
• smelling an approaching rainstorm from 150 miles away
• locating food by smell including grass, branches, and fruit
• lifting objects up to 400 pounds
• reaching food 20 feet off the ground
• using it as a snorkel when swimming underwater
• using the top and bottom lip to pick up a single seed off the ground
• sucking up to 2.5 gallons of water and squirting it into their mouths
• sucking up water to squirt over their backs to cool off
• curling it around large quantities of food to place in their mouths
• controlling the shape and size of the nostril to modulate sounds
• snorting dirt to spray over their backs
• picking up and throwing objects in defense
• entwining with another’s trunk for a friendly hug

Duck Potato Salad

Walking around a freshwater marsh, we can observe dozens of plants and animals. Daily sunlight provides hours of energy, but it is only usable by the plants, which create their own food in a process called photosynthesis. Plants may be fully submerged, floating, or living above the water’s surface, but all are vital components of the food supply.

^{Marsh panorama by Beyond_Invisible, Getty Images}

Just as animals breathe, plants also need to exchange gases, taking in carbon dioxide and releasing oxygen. Plants living in a marsh, where they are fully or partially saturated with water, have developed several strategies for the gas exchange process. Spongy tissue is a universal adaptation of marsh plants. Both stems and leaves contain large airspaces surrounding food producing cells which are well distributed throughout the plant. Airspaces also keep the plants lightweight and enable stems, leaves and flowers to float on or reach above the water’s surface.

Floating wisps of green algae are primitive plants that have been on earth for over two billion years and are the basic food source for all life in the marsh. Millions of microscopic animals, crustaceans, insects, and small fish depend directly on green algae for their food. Green algae lack stems, leaves and flowers, but grow as long chains of nearly identical cells. Some algae are microscopic, some can be easily observed as green strands on or below the water’s surface and some grow to several hundred feet in length.

^{Duckweed forest pond by Sunsju, Aug 2019}

Duckweeds refer to a group of tiny, flowering plants that float on the surface of wetland areas. They reproduce by dividing their cells. This is a rapid process taking from 16 to 48 hours. In optimal growing conditions, with plenty of sunlight and nutrients available, the surface area of a pond can be covered in a very short period of time. Several species of pond plants grow long, narrow leaves with soft, nourishing cells providing a easy-to-eat and tasty treat for marsh dwellers. With large airspaces, these plants are able to stay afloat no matter how long they grow.

^{Spatterdock by Kirill Ignatyev, Jul 2011}

Plants with floating leaves, such as spatterdock, must have a method for preventing excess water from entering leaves and stems when they exchange gases. Plants have stomata, openings in the leaf where gases are exchanged. In terrestrial plants, stomata are located on the undersides of leaves to prevent rain from entering the opening. Floating leaves have stomata on the upper side of the leaf, providing far less exposure to water.

^{Water marigold by Gennady Alexandrov, May 2014}

Water marigold has two types of leaves, one that grows on the stem above the water’s surface and another that grows on the submerged stems. Leaves growing in air take in carbon dioxide and release oxygen through their stomata. Submerged leaves have very thin cell walls and exchange the same gases directly with the water surrounding them.

^{Arrowhead with bulb, -duck potato’, lower right, by Andriy Nekrasov, Getty Images}

Arrowhead is firmly anchored in the bottom of ponds, and has stems, leaves, and flowers growing above the surface. It reproduces by both seeds grown from pollinated flowers and bulbs grown on submerged stems. Bulbs remain submerged, attached to the stem and grow until they are mature enough to anchor themselves in the bottom silt and start another plant. While growing, the bulbs are very tasty and are a favorite food of many duck species, earning the nickname duck potatoes.

^{Wild celery, Vallisneria americana, by Schizoform, Jun 2022}

Wild celery produces both male and female flowers. Female flowers are attached to long stems that float on the water’s surface. Male flowers break off underwater and float to the surface unattached, where they are blown around until they meet a female flower, transferring pollen by contact. The pollinated flower coils downward back under the surface where the seeds develop and are released into the water to start a new plant wherever they land on the silt bottom.

Marsh plants come in many forms and each is well adapted to the unique conditions of the habitat in which they live.

Boreal Forest in Winter

The boreal forest is the largest tract of woodland on earth covering 11% of all land area, half again as large as the Amazon rainforest. It stores 30% of the sequestered carbon on earth. The area also contains a mosaic of wet meadows, ponds, lakes, marshes, and bogs interlaced among the trees. Tree species include many conifers, dominated by spruce, plus aspen, birch, willow and alder. The animal life is abundant, with every species that was there before European settlement still remaining.

^{Boreal Forest panorama by Mliberra, getty Images}

The boreal forest is distinguished by short, hot, wet summers and long, dry, cold winters. When the last glaciers retreated northward, many holes and fissures were left behind. As the ice melted, all of these depressions were filled with water. The underlying geology is mostly granite shield, a rock layer that holds the water in and contains few minerals that dissolve in water, yielding very clear water that does not promote algae or bacteria growth. Most lake life is found in the shallow, warmer edges which also provide support to nearly all of the land-based fauna.

^{From upper left clockwise: Alder tree by Mantonature, Getty Images Signature; Spruce trees by Hannu Koskela, Getty Images; Willow tree by smarko , Pixabay; Aspen trees by Adamisovitsch, Getty Images}

Winter time presents many challenges including less sunlight, colder temperatures, less available water, less food and shelter, and increased severe storms. Animals that are active daily have higher energy requirements in winter. They must often change their dietary sources to whatever is available in winter. Grey squirrels and beavers cache food during warmer periods. Birds eat foods higher in calories such as nuts, seeds, dried fruit, and insects found under tree bark. When changes are consistent from year to year, species develop adaptations to meet the requirements of each season and are able to live comfortably throughout the year.

Shelter becomes not only a place to hide from predators, but also provides protection from weather extremes. Snow of different thicknesses and weight covers the landscape. Snow is also a great insulator, keeping cold winds away from exposed skin. There is normally a layer of air between the ground and the snow cover immediately above. Temperatures in this space are warmer than the exposed air above the snow creating a winter habitat that is vitally important for many species. Mice and voles create burrows under the snow where they can huddle together for added warmth. Similarly, air pockets surrounded by a heavy growth of conifer needles create spaces above the snow cover for birds and some larger mammals to shelter. And many larger species will nestle into the snow pack to shelter from storms and wind.

^{Spruce grouse by Impr2003, Getty Images}

^{Willow ptarmigan by Alex Berger, Mar 2022}

Spruce grouse, Canachites canadensis, and willow ptarmigan, Lagopus lagopus, are not able to fly more than several yards. They grow feathers on their feet to insulate them and aid in traction. Grouse use the air layer at ground level to shelter in.

^{Portrait of a snowshoe hare by Jim Cumming, Getty Images}

^{Canada lynx by Carol Gray, Getty Images}

Ptarmigan, along with snowshoe hares, Lepus americanus, and short-tailed weasels, Mustela erminea, all change color to pure white to hide from predators. Snowshoe hare and Canada lynx, Lynx canadensis, have very large feet that aid in walking on snow without sinking in. Arctic fox, Vulpes lagopus, are winter specialists with compact bodies and short legs and ears that limit their exposure to cold, and large, furry paws that enable them to walk on top of the snowpack. With their long, bushy tails wrapped around their heads, they can withstand winds and temperatures to fifty below zero.

^{Stayin’ warm, Arctic fox by PEDRE, Getty Images Signature}

You can learn more about this cold but wondrous habitat by searching online for boreal forest, referring to the southern portions of the habitat, or taiga, referring to the northern portions. Also, look for information concerning seasonal adaptations for species in your own area, or visit a local natural history museum such as the Jurica-Suchy Nature Museum in Lisle, Illinois.

Junco Winter Adaptations

Juncos spend the winter spread across the United States. They spend summers at breeding areas in southern Canada, and in fall males migrate to the northern states while females migrate farther south. Males have several adaptations that allow them to more easily survive in colder climates, and allow them to return early to breeding areas to claim the best territory for attracting a mate among the females that come back a few weeks later.

^{Male dark-eyed junco, Junco hyemalis by Christian Gott, dec 2022}

^{Female dark-eyed junco, Junco hyemalis by Joseph Higbee, Dec 2014}

Junco males are small, round-bodied birds with a slate gray back and are larger and weigh more than females. According to Bergmann’s Rule, large bodies have a smaller surface area relative to their volume, and are therefore able to retain more heat than longer or skinnier bodies. Being able to retain more heat for longer periods, an average-sized male junco can go two hours longer without food than an average female, and a large male may go more than ten hours longer between meals. This can be an essential factor when living through a colder period.

^{A cozy tree cavity by Steve Valasek, Apr 2014}

^{Accommodations for one… by Hedera Baltica, May 2016}

Tree cavities provide excellent places to shelter in winter. At night and in severe weather, juncos seek a small, tight space big enough for a single bird that provides protection from wind and moisture. During daytime hours, while foraging, juncos can often be found in conifer trees whose year-round needles provide a windbreak and a place to remain out of sight of predators.

^{Male junco with fluffed-out feathers by Ken Gibson, Dec 2016}

Juncos have a normal body temperature of 107˚F, well above the average outside temperature on a winter day which could be between -10˚F and +20˚F. Maintaining body heat requires a high-caloric diet to create the heat and resources to not allow the heat to escape. Birds have muscular control over their feathers and are able to fluff them, trapping air next to their skin. Preening is a daily activity where oil secreted from a gland above the tail is rubbed on all of their feathers providing a moisture barrier that keeps water, snow, and cold winds away from their skin. Both feathers and trapped air make up two layers of insulation that work efficiently to retain body heat.

During extreme weather, it may be advantageous to remain sheltered and inactive when the amount of calories burned to get a meal is more than the calories in the meal. When sheltering for longer periods, juncos may intentionally lower their body temperatures a few degrees, entering a state of torpor. This state lasts for only a few hours, but saves enough energy so that the bird does not need to forage for an extended period during a day. Using muscular control, birds can generate body heat by contracting and releasing their muscles, similar to shivering in mammals, and bring their body temperatures back to normal and resume daily activities.

^{Juncos feeding on ground by mwms1916, Apr 2015}

^{Juncos feeding on ground feeder by synspectrum, Nov 2015}

Northern U.S. flocks of juncos in winter are 70% or more males, while most females spend winters in the southern U.S. This is also true for several other species that migrate with juncos including tree sparrows, song sparrows, and mourning doves. Juncos will be leaving in late winter to return to breeding grounds across Canada, but for the coming few months we will certainly enjoy their presence in our area.