vocalization – Discover-Nature

Sounds of the Season

It is late summer, heading into fall, and now is the time of year that the afternoons and evenings grow noisier. Some of the loudest species we hear throughout the year are currently active, calling to maintain contact with family members, to warn of impending threats, or to seek mates.

Singing insects are out at all times of the day and night. Crickets, katydids, grasshoppers, and cicadas four insect families active from late afternoon through the nighttime hours. These species all produce calls using a process known as stridulation. The edge at the base of a front wing, called a scraper, is rubbed across the base of the opposite wing, which has a bumpy surface called a file. This movement can produce buzzing or chirping sounds as well as melodic tones.

^{Annual cicada, Neotibicen spp., by Tony Cheng, Sep 2013}

Annual cicadas, Neotibicen spp., are a large insect averaging two inches in size with brown, green, or black bodies and white undersides. Adult males find spots among the branches of trees and woody shrubs where they can hang out and call for a mate. Calls can be heard throughout the day as a loud buzzing for several seconds that slowly fades to silence. Cicadas get louder with warmer temperatures towards late afternoon but cease all calling as dusk settles.

^{Common true katydid, Pterophylla camellifolia, male & female by TJWalker, U of FL}

^{Grey bush cricket, Gryllidae spp., by LHG Creative Photography, Jul 2010}

^{Grasshopper by Peter Miller, Nov 2020}

Katydids, Pterophylla camellifolia, are well-camouflaged with long, green wings that look much like the leaves of the plants they hide in. Despite their appearance, katydids along with crickets, from the family Gryllidae, and grasshoppers, from the family Acrididae, cannot fly. Katydids choose to occupy branches in tall trees, while crickets and grasshoppers prefer lower vegetation, including tall ground cover, from which to call for a mate. These insects will call well into the night on warm summer evenings, but quickly fade away once temperatures start to drop.

^{Common true katydid male, Pterophylla camellifolia, Carter County, MO, OSF-online}

^{Jumping bush cricket, Hapithus saltator, two calling by Daniel Parker, Sep 2023}

Many of these calls are among the loudest made by wildlife. A sound chamber, made by bowing out the wings from the body to create a hollow space, serves to amplify the sound. From the high-pitched melodic notes of the katydid to the chirping of crickets and grasshoppers, these calls can resonate and carry long distances.

^{Great Horned Owl, Bubo virginianus, by Frank Lambert, Dec 2016}

^{Eastern Screech Owl, Megascops asio, by Paul Driver, Sep 2023}

Against this background, we may also hear night birds, especially owls. In northern Illinois, great horned owls, Bubo virginianus, produces a series of low-pitched hoots to warn off territorial invader, call to a young one, or attract a mate. Eastern screech owl calls, Megascops asio, utter a long trill, lasting three to six seconds. Owl’s calls are easy to recognize and can be heard over long distances, making them an effective method of communication in the dark.

^{Coyote, Canis latrans, by Paul Marvin, Apr 2012}

^{Northern Raccoon, Procyon lotor, by Paul Driver, Sep 2010}

Other sounds that you may hear at night include coyotes, Canis latrans, using yips and barks to maintain contact with other individuals, or by young when begging for food. Long, drawn out howling is used to mark territorial boundaries and is often heard in response to emergency vehicle sirens, which we think are perceived as threats by coyote populations. Raccoons, Procyon lotor, are another species that is very active during the late nighttime hours approaching dawn. If they are close by, you may hear purring or chittering sounds used between adults and their young. Whether alone or in a group, when they are startled, raccoons will aggressively defend themselves and other family members emitting loud barking noises. Screams and growls between fighting individuals are often heard.

Late summer evenings can be quiet and slow or full of noises and events. Taking time to walk or sit quietly in your own backyards and listen can be a rewarding experience. Come to the Jurica-Suchy Nature Museum or visit your local nature center to learn more about wild nights in your area.

^{Clockwise: Coyote, Canis latrans, by Paul Marvin, Apr 2012; Eastern screech owl-red morph, Megascops asio, by Laura M, Feb 2023; Great-horned owl, Bubo virginianus, by Don Miller, Jul 2016; Raccoon, Procyon lotor, by Alex ONeal, Aug 2010; Raccoon, Procyon lotor, by Ellya Selhub, Jan 2006}

Sounds of Spring

Thunder and heavy rain, soft rain and light wind, birds in the early morning, frogs in the evening, and maybe a coyote howl deep into the night are some of the sounds of spring. As cold temperatures ease into summer highs, walks through natural areas tend to be filled with many sights as well as opportunities to learn by being quiet and listening closely.

Calls and songs are used by many species for a variety of purposes. Thousands of birds are migrating through the area, especially on clear evenings, and calls help to keep birds together and establish who is the flight leader. Year-round species are re-establishing territories, using calls to warn intruders to stay away or warn family members of approaching threats. Frog species in particular are calling during evenings to find a mate, lay eggs, and begin the establishment of the next generation.

There are dozens of species active at this time of year, and as we have been taking nature walks on campus the last few days, here are some of the wildlife we are listening to (click on each picture to hear their call)…

^{Yellow-rumped warbler, Setophaga coronata, Mirceax, Getty Images}

Yellow-rumped warbler, Setophaga coronata, by Valerie Heemstra, 2024

^{Red-winged blackbird, Agelaius phoeniceus, by KenCanning, Getty Images Signature}

Red-winged blackbird, Agelaius phoeniceus, by Thomas Ryder Payne, 2022

^{Palm warbler, Setophaga palmarum, by Irving A. Gaffney, Getty Images}

Palm warbler, Setophaga palmarum, by Christopher McPherson, 2021

^{Northern waterthrush, Parkesia noveboracensis, by Carol Hamilton, Getty Images}

Northern waterthrush, Parkesia noveboracensis, by Lance A.M. Benner2017

^{Northern Parula, Setophaga americana, by Neil Bowman, Getty Images}

Northern Parula, Setophaga americana, by Richard E. Webster, 2023

^{Chipping sparrow, Spizella passerina, by Irving A. Gaffney, Getty Images}

Chipping sparrow, Spizella passerina, by David Tattersley, 2023

^{Blue-headed vireo, Vireo solitarius, Mirceax, Getty Images}

Blue-headed vireo, Vireo solitarius, by Thomas Magarian, 2024

^{Blue Jay, Cyanocitta cristata, by Miguel Opacic, Getty Images}

Blue Jay, Cyanocitta cristata, Sue Riffe, 2024

Bird songs have a structure and rhythm, and are repeated often to attract a mate, ward off rivals, or bond with a family member. Other calls give warning that danger is near, keep flocks together in flight, or create a pair bond, often between mother and chick.

Frogs and toads are mating and laying eggs in area ponds. Each species has its own distinctive call, used by the males to attract a mate, warn of potential danger, establish a territory, or to signal distress. Frog species being heard around campus at this time include the following (click on each picture to hear their call)…

^{American Toad, Anaxyrus americanus, by Mshake, Getty Images}

American Toad, Anaxyrus americanus, by Thomas Margarian, 2024

^{Boreal chorus frog, Pseudacris maculata, by Derwyn, Getty Images}

Boreal chorus frog, Pseudacris maculata, by Thomas Margarian, 2016

^{Spring peeper, Pseudacris crucifer by HuntImages, Getty Images Signature}

Spring peeper, Pseudacris crucifer by Paul Marvin, 2012

^{Northern Leopard Frog, Lithobates pipiens, by Jennifer Seeman, Getty Images}

Northern Leopard Frog, Lithobates pipiens, by Paul Marvin, 2015

Sometimes, coyote can be heard when walking in woodlands around campus late in the evening. There are a lot of different calls used by these canines to provide information to other individuals. You can listen below to a bark used to indicate a threat, a social call establishing an individual’s location, a begging call from a young one, and a howl audible over long distances to announce one’s presence. Other calls may include a woof to signal a low intensity threat, a yip to claim territory, a growl to threaten another animal, and a whine or yelp to show subservience to a more dominant individual.

^{Coyote, Canis latrans, barking by TakenPix, Getty Images}

Coyote, Canis latrans, bark by Paul Marvin, 2018

^{Coyote, Canis latrans, begging, by Keith Szafranski, Getty Images Signature}

Coyote, Canis latrans, begging call by Matthew L. Brady, 2025

^{Coyote, Canis latrans, social interaction by Michel Viard, Getty Images}

Coyote, Canis latrans, social call by Flor Sangermano, 2023

^{Coyote, Canis latrans, howling, by Keith Szafranski, Getty Images Signature}

Coyote, Canis latrans, howl by Paul Marvin, 2012

Additional wildlife sounds can be heard on campus around Lake Benedictine or in nearby forest preserves. Get out for a walk and be sure to listen throughout the day for bird species, and into the evening hours for frogs, toads, and coyotes.

Great Horned Owls

The great-horned owl, Bubo virginianus, is native to much of the Americas, including most of North America and Central America and about half of South America. It is the second heaviest owl in North America, right behind the snowy owl, Bubo scandiacus, weighing up to five-and-a-half pounds with a wingspan between three and five feet.

^{Great-horned owl, Bubo virginianus, by Andy Reago&Chrissy McClareen, Aug 2012}

^{Range and distribution of Great-Horned Owl, Bubo virginianus by BirdLife International, 2014}

Feathers cover the entire body, including their feet, and are varying shades of browns and grays. Their backs and heads are mottled or barred in several patches. This coloration, especially when coupled with mostly nocturnal activities, provides excellent camouflage. Their ‘horns’ are actually feathers sticking upwards on either side of their heads. These are called plumicorns, but their function is not well understood. The feather structure of the wing allows owls to fly silently and includes a serrated leading edge to disrupt turbulence and softer feathers behind to help deaden sound.

^{Great horned owl plumicorns by Jean-pol Grandmont, Aug 2013}

^{Great horned owl wing structure by Peter K. Burian, Aug 2015}

The owl’s ears are covered by feathers, but are not symmetrical with one being higher on the side of the head than the other. This arrangement provides the owl with the ability to triangulate sounds and precisely locate prey in the dark or when prey is hidden, such as when an animal is moving about under a layer of snow. Their flattened face, shaped as a round disc, also helps to direct sound to their ears. Like all owls, their eyes are fixed in the sockets, but the bird can swivel its head almost 180° to either side allowing it to see in all directions.

^{Great horned owl talons by Curtis Bouvier, May 2010}

Great horned owls hunt from a perch, observing the area below them before diving swiftly and silently from far above. Their diet consists of small mammals, birds, amphibians, and a variety of snakes. Their talons are powerful and deadly, with a grip comparable to much larger birds such as golden eagles. Most prey is killed by being pierced or crushed in the talons. Owls may hunt and kill for more than their immediate needs and will cache their kills for future meals.

Great horned owls are not migratory. When an owl is ready to mate, courtship occurs in late fall and pairs mate for life, establishing a territory together in which they will live their entire lives. Most territorial defense is through hooting at a transgressor, but rare physical confrontations have been observed. If an owl cannot establish its own territory, it will live in silence among the fringes of other territories.

^{Great-horned owl juveniles, Bubo virginianus, by Alan Vernon, Jun 2010}

^{Great horned owl female & juvenile on nest by John Kees, Apr 2012}

Males are responsible for picking a nest site, almost always taking over a nest constructed by another species. Mated pairs breed once every two to three years, laying from one to six eggs. Egg laying occurs between late February and early April. The female alone incubates the eggs, never leaving the nest, while the male hunts and brings her food. After about 33 days, the eggs hatch. Young owls will start to fly after seven weeks, but take a full month or more to become proficient.

^{Great horned owl calling, Bubo virginianus, by Michael & Katie LaTour, Jan 2019 (at 0:02, 0:10)}

^{Great-horned owl pair calling by Bushman, Dec 2013 (at 0:18, 0:41, 0:51, 1:22)}

Owls are more often heard than seen. Although the females are larger than males, females have a smaller voice box and thus a higher pitched hooting call ending with a slight rising note. Juveniles can make hissing or screeching sounds and are often misidentified as barn owls, Tyto furcata.

You can learn more about these magnificent birds at the Jurica-Suchy Nature Museum. Make a reservation to come see us by visiting our website at: https://ben.edu/campus-links/jurica-suchy-nature-museum/ (click on Register to Visit the Museum).

Bird Song

As spring approaches, many bird species will be migrating across the country from warm winter sites back to summer nesting areas to mate and raise young. For many bird watchers, a favorite activity is to identify birds by their songs. Songbirds have an organ called the syrinx that produces the lyrical notes we can listen to. Birds may produce one or more notes at a time creating complex calls and melodies. Some of these songs are used to attract a mate, or to identify itself to another family member, or as calls of warning about any approaching danger. Night traveling species may use calls to keep the flock together while flying, but most calls are heard throughout daylight hours.

In the upper Midwest, in prairie and wetland areas, the first migrators in early March will include ruby-crowned kinglets, blue-winged teals, loggerhead shrikes, upland sandpipers, and eastern bluebirds. As night time temperatures become warmer and stable, summer tanagers, Baltimore orioles, and up to 35 warbler species will begin moving through this area. Some species to watch for in northern Illinois are American white pelicans, common loons, Northern pintail ducks, and yellow-bellied sapsuckers.

You can find many excellent observation spots in your area by searching online for “spring birding hotspots in your area”. Another favorite forecasting site to follow migrating bird groups is the University of Cornell’s BirdCast Project website.

American white pelican, Pelecanus erythrorhynchos, by Manjith Kainickara, Nov 2010

Call from a young chick by Andrew Spencer, XC36292

Baltimore oriole, Icterus galbula, by Tony Castro, May 2013

Alarm call by Joost van Bruggen, XC864040

Call by Gus Mueller, May 2007

Blue-winged teal, Spatula discors , by Alan D. Wilson

Call by Jonathon Jongsma

Common loon, Gavia immer, by John Picken, Jul 2011

Tremolo call by Darwin Long, Apr 2006

Eastern bluebird, Sialia sialis, by Sandysphotos2009, Apr 2010

Call by Jonathon Jongsma, Jun 2011

Loggerhead shrike, Lanius ludovicianus, by Jeffrey Gammon, Dec 2020

Alarm call by Bobby Wilcox, XC418584

Call by Ed Pandolfino, XC455607

Northern pintail, Anas acuta, by J.M. Garg, Jun 2007

Call by Paul Driver, Feb 2012

Pied-billed grebe, Podilymbus podiceps, by Mdf, 2005

Begging call by José Dellacasa Bravo, XC946741

Nocturnal flight call by David Tattersley, XC811994

Pair contact call by Richard E. Webster, XC971465

Ruby-crowned kinglet, Regulus calendula, by Tony Castro, Jun 2019

Call by Christian Kerihuel, XC814137

Sandhill crane, Grus canadensis, by Jeffery Gammon, Jan 2017

Call by National Park Service, Jan 2004

Left: Summer Tanager female, Piranga rubra, by Gonzalo Zepeda Martinez, Jan 2016

Right: Summer Tanager male, Piranga rubra, by Charles J. Sharp, Feb 2023

Call by Lance A. M. Benner, XC426315

Upland sandpiper, Bartramia longicauda, by Johnath, Jun 2010

Call by Andrew Spencer, XC104334

Yellow-bellied sapsucker, Sphyrapicus varius, by Rhododendrites, Feb 2021

Call by G. McGrane, 2006

At the Jurica-Suchy Nature Museum, our nature journaling club, Nature-Doodlers, will be meeting on March 29th, 10am, at the museum to learn about bird observations, drawing and recording our sightings. Make a reservation to come out to this free event by clicking on the QR Code below:

Salamanders

Salamanders are in the order of amphibians named Caudata, which includes mudpuppies, newts, and sirens. There are about 760 species of salamanders worldwide and 121 species are endangered. With the exception of a few in the Amazon basin, they are found only in the northern hemisphere. They live in habitats that provide sufficient humidity levels to keep their skin moist, from sea level to nearly 15,000 feet in altitude.

^{Northern zig-zag salamander, Plethodon dorsalis, by John P Clare, 2016}

^{Marbled salamander, Ambystoma opacum, by Jupiterimages, PhotoImages}

The smallest species are lungless salamanders of southern Mexico, growing to an inch in length. The largest species are the Chinese great salamanders, about six feet in length. They are often mistaken for lizards, having smooth or bumpy skin, but can be easily identified by their total lack of scales. All salamanders have a tail which is rounded in terrestrial species but slightly flattened and often crested in aquatic species. Most salamanders are grey, brown, or white, but a few terrestrial species are brightly colored. Cave dwelling salamanders often lack all pigment and appear pinkish-white in daylight.

^{* Western lesser siren, Siren intermedia nettingi, by Peter Paplanus, 2013}

^{Long-tailed salamander, Eurycea longicauda longicauda, by Meghan Alessi, Getty Images}

Salamanders, other than cave-dwellers, tend to have well-developed eyes. Research shows they are very attuned to differentiating brightness, but cannot see colors. Their eyes are large and provide nearly 360 degrees of view. Salamanders have no external ears, but can detect vibrations received through their jaw bones. Although some species can emit small squeaks, salamanders have no vocal chords or voice box and do not use vocal communications. Their sense of smell is well-developed and plays an important part in locating prey and mates.

^{* Hellbender, Cryptobranchus alleganiensis}
^{alleganiensis, by Jason Ondreicka, Getty Images}

^{Cave salamander, Eurycea lucifuga, by Alfred Crabtree, 2012}

Salamanders may have functional lungs, non-functioning lungs, or no lungs. All species have the ability to exchange gases directly through their skin and the membranes inside their mouth and throat, but this also requires that the skin remain moist at all times. Terrestrial salamanders depend on moisture found in deep leaf litter, holes in trees in temperate zones, or moisture collected in bromeliads growing on trees in tropical zones.

^{Four-toed salamander, Hemidactylium scutatum,}
^{by Jason Ondreicka, Getty Images}

Salamanders have three sets of glands located under the skin, covering their entire body. Mucous glands secrete a sticky liquid that is spread over their body keeping the skin from drying out. When salamanders are in the water, the mucous acts as a lubricant, enhancing their swimming ability. A second set, called the granular glands, produce toxins and odors unique to each species that helps to deter predators and attract mates. A third set of glands is a mixture of the first two, doing a little bit of the work of each.

^{Small-mouthed salamander, Ambystoma texanum,}
^{by Jupiterimages, PhotoImages}

^{Tiger salamander, Ambystoma tigrinum tigrinum, by John P Clare, 2013}

Salamanders are not as noticeable as many other species. They prefer secrecy and out-of-the-way hiding places. Most species are active at dusk and into the nighttime. All salamanders are carnivorous, feeding on small crustaceans, insects, spiders, and their favorite food – worms. Predators include snakes, lizards, fish, birds, and small mammals. Salamanders defend themselves by exhibiting threatening poses and emitting toxins, many with a bad odor. As a last defense, they may voluntarily lose their tails to a predator, a trait known as autotomy. A new tail can be grown within a few weeks.

Salamanders are easy to care for and their habitats are easily duplicated making them widely distributed in the pet trade and for use in laboratories. Additional conservation impacts come from habitat fragmentation, or habitat degradation, or habitat loss due to draining of wetlands and forest clearing.

^{Northern slimy salamander, Plethodon}
^{glutinosus glutinosus,}
^{by Jason Ondreicka, Getty Images}

^{Red-backed salamander, Plethodon cinereus cinereus, by Steve Byland, Getty Images}

In Illinois, we have 20 species of salamanders, pictured throughout this blog. Seventeen are terrestrial and three are aquatic (*). Consider coming to the Jurica-Suchy Nature Museum or a nature museum near you to learn more about salamanders in your area.

Spotted salamander, Ambystoma maculatum, by Louisianatreefarmer, Getty Images
Blue-spotted salamander, Ambystoma laterale, by Jason Ondreicka, Getty Images
Central newt, Notophthalmus viridescens louisianensis, by Andrew DuBois, 2016
Dusky salamander, Desmognathus fuscus conanti, by Jason Ondreicka, Getty Images
* Mud puppy, Necturus maculosus maculosus, by Andrew Hoffman, 2010
Three-toed salamander, Amphiuma tridactylum, by Peter Paplanus, 2016
Southern two-lined salamander, Eurycea cirrigera, by Peter Paplanus, 2021
Mole salamander, Ambystoma talpoideum, by Andrew DuBois, 2016
Dark-sided salamander, Eurycea longicauda melanopleura, by Andrew Hoffman, 2010

Ostrich

The ostrich, the largest and heaviest bird, is one of the handful of birds that cannot fly. They live in arid and semi-arid habitats in Africa, as well as in a small population of once captive birds that were released into the wilds of Australia. Several sub-species of the common ostrich, Struthio camelus can be found across most of Africa, while the Somali ostrich, Struthio molybdophanes, is only found in the far east around the Horn of Africa.

^{Common ostrich, Struthio cameus, Tanzania by Patrick Gijsbers, Getty Images Signature; Female Somali ostrich, Struthio molybdophanes, in Kenya by Ninara, Dec 2013; Male Somali ostrich, Struthio molybdophanes, in Kenya by Christiaan Kooyman, Jan 2003}

Ostrich males, called roosters, are predominantly black and can grow to 9′ and 180 pounds, while the slightly smaller females, called hens, have grayish-brown feathers and top out at about 6′ and 240 pounds. They live 30-40 years in the wild. Ostrich eyes, at almost 2″ in diameter, are the largest eyes of any land animal. Their species, camelus, refers to their long necks, large eyelashes, long legs, and their ability to go without water for extended periods.

Birds that can fly have many strong flight muscles attached to their sternum, which is shaped like a keel, an elongated structure which is narrow at the top and flares out at the bottom. However, the sternum of the ostrich is flattened and their wings are quite small. They do have powerful legs that allow them to sprint over 40mph and run long distances at an average speed of 31mph. Their long legs can cover 10-16 feet in a single stride. They only have two toes with one having a long claw that can dig into the ground for extra traction.

Notice the flattened sternum on the lower right of the ostrich compared to a flying bird below with a much larger bone.

^{Above: Flying bird shows large keel for flight muscles by LeeLiyi, Jun 2006}

^{Left: Ostrich skeleton, Museum of Veterinary Anatomy, FMVZ USP Wagner Souza e Silva, Dec, 2015}

Ostriches live in small family groups called herds. An average herd is about a dozen birds, led by one dominant male and one dominant female, called pack leaders. When males are ready to breed, they make a booming sound using an air sac in their throats that can be heard over long distances. When a female approaches, the male will puff out his chest, bow to the female, and do a dance that includes much tail shaking. This is repeated several times until the female indicates whether or not she will mate.

Ostrich eggs in shallow sandy depression, Namibia, by Th Trede, Getty Images

A dominant male digs a shallow nest 9 to 10 feet wide and mates with several females. Each mating results in 7-10 eggs laid together in the one nest. Ostrich eggs are the largest of any egg in the world weighing about 3 pounds, equal to 2 dozen chicken eggs. One male and one female will take turns incubating about 20 of the eggs, while the remaining eggs are ejected from the nest. Babies hatch in six weeks and are the size of a chicken when born, but they will grow about a foot a month, reaching adult size in six months.

Ostrich toes & claws by Mirko Vuckovic, Getty Images

Ostriches are omnivores mainly eating roots, seeds, and leaves, but will also eat insects, rodents, and snakes. They lack teeth; and as with many birds, they ingest small pebbles to help grind their food in the stomach. They are most vulnerable when eating or protecting their nests, and predators include lions, cheetahs, hyenas, and jackals. When threatened, an ostrich will not bury its heads in the sand. The bird may lie down on the ground with its head and neck stretched out to present a lower profile. They may run away, but if that is not possible, especially when protecting a nest, they will stand their ground. Their legs and sharp claws are powerful enough to deliver a kick capable of killing an adult lion. Many predators will not attack an adult ostrich, but their eggs are a delicacy for predators, vultures and other opportunists.

Many farms raise these birds, harvesting feathers and leather for clothing, plus meat and eggs for food. Although they are not considered endangered, ostriches are still threatened by habitat loss and poaching. At the Jurica-Suchy Nature Museum you can view an adult ostrich, nest and eggs, plus see our new display on the skeletal structure of birds including our adult ostrich skeleton.

Cicadas

Cicadas are found in habitats with deciduous trees on every continent except Antarctica. There are about 3,000 species worldwide; and 170 make their home in North America, including several species divided into three groups with 13-year or 17-year life cycles, found exclusively in the eastern and central United States. The map below shows where various groups are located.

Cicadas hatch from eggs laid in tree branches. After dropping to the ground and burrowing into the soil, they spend the majority of their lives as a nymph living underground. Using their rostrum, a long, sharp rigid structure that can penetrate the outer layer of tree branches and roots, they feed on the sugar and water flowing through the xylem tissue of the tree. Species classified as annual cicadas actually live from one to nine years, some emerging each summer. They are active for four to six weeks to mate, lay eggs, and then they die.

Look closely to see the rostrum sticking out in front of the nose

Magicicada after emerging from final molt by Karly Tuminello

Cicadas have wide set eyes, short antennae, and large, clear wings with membranes clearly visible. The surfaces of their outer wings are covered by small, blunt, waxy spikes. They are water repellant, keeping the insect dry. These spikes can also break up and kill any potentially harmful bacteria landing on the surface.

^{Magicicada species showing short antennae & clear wings by Karly Tuminello}

Beneath the wings are muscular structures called tymbals which can be flexed creating a sound like banging a drum. The buzzing sound commonly associated with cicadas is a result of rapidly flexing these muscles. Tymbals are found on both sexes, and are used to hear sound as well as produce sound. Males often form large groupings to enhance their sound and attract more females to a single location.

Magicicada waiting for wings to harden after molting by Karly Tuminella

Nymphs start to emerge when underground soil temperatures are above 64⁰F, usually in late May in the northern hemisphere. Males emerge about two weeks before females. After emerging, the nymph will find a suitable perch and molt to reveal a fully winged adult; then spend from one to six days waiting for their wings to harden. Males fly up into nearby deciduous trees to find a suitable mating perch and begin calling to attract a female, which will join the male after her molt is complete. After mating, the female lays about 600 eggs. She cuts 25 to 30 small slits in branches and deposits about 20 eggs in each where they will remain for six to ten weeks before hatching. Both sexes may mate several times with different partners, although most only mate once.

Cicada’s mouth parts are strong enough to pierce tree bark, but they do not bite or sting, although they may pierce human skin if handled roughly. They do not pose any danger to humans and have not been known to carry any harmful disease. They feed on sap, not foliage, so they pose no threat to mature trees. Younger or smaller trees with only a few branches may be overwhelmed by the many slits made by a female laying a full brood of eggs. Lots of slits may cause scarring that could kill smaller branches.

^{Empty cicada husks provide food for many species by Karly Tuminello}

Cicadas and their empty husks do provide food for many predators including birds, fish, mammals, herps, and other insects. The emergence of the periodical cicadas will provide a feast for their predators, whose populations will boom next year before being reduced by less available food over the following several years. One theory for why there are periodical species concludes that cicadas emerging in mass numbers can overwhelm the predators need for food, allowing a great number of cicadas to breed and maintain their own high population. Other theories also exist to explain this natural phenomenon, but whatever the reason, they are harmless insects with a very interesting life cycle for us to observe this year.

Extinct & Endangered – pt.2

The International Union for Conservation of Nature (IUCN) gathers data through research and field projects on all known species of plants and animals. They work to educate people on conserving nature and sustainably using natural resources. The IUCN publishes a document known as The Red List providing the conservation status of all species. There are nine possible levels including Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild, Extinct, Data Deficient, and Not Evaluated.

An endangered species is one that is likely to become extinct in the near future, either world-wide or locally in a known range. Critically endangered species are at extreme risk of extinction in the immediate future. A species is vulnerable when its population and breeding numbers are at risk, but have a chance to improve. Several factors considered are the current population size, how fast the population has increased or decreased over a short period of time, whether breeding rates are high or low, and what threats exist from habitat loss, poaching, and invasive species.

^{Eskimo curlew, Numenius borealis, @ Field Museum of Natural History by James St. John, Oct 2014}

The Eskimo curlew, Numenius borealis, spends northern hemisphere summers breeding on the Alaskan and western Canadian tundra. As the weather turns colder, they migrate to Argentina by flying east to the Atlantic Ocean, and then south. Although nests are built on open ground, they are difficult to find and study. Food includes berries, insects, and snails, but incubation and rearing habits have never been clearly identified. During migration in the mid-1800s, populations would darken the skies as tens of millions of birds followed the warmer weather. Eskimo curlews were hunted on both continents year-round. If a bird was wounded, the other flock members would circle back, becoming additional targets for hunters. Development cuts up large breeding areas to smaller sections reducing food sources and enabling predators to severely impact populations. The species is listed as critically endangered, although there has not been a confirmed sighting since 1963.

^{Proboscis Monkey, Nasalis larvatus, by Chris Smallwood, Jul 2013}

^{Proboscis Monkey, Nasalis larvatus, female with young by Martha de Jong-Lantink, Jun 2020}

The proboscis monkey, Nasalis larvatus, another endangered species, is found mostly in the mangrove forests in Borneo; it is one of the largest monkeys native to Asia. Living in swamps and lowland areas along rivers, they are excellent tree climbers and swimmers, having the ability to swim underwater for short distances. Their large noses, smaller in females and upturned in juveniles, are thought to make their calls louder and more attractive to the opposite sex. They communicate through a variety of calls to signal alarm and threat warnings, and to keep infants and group members close. Rapid loss of habitat to logging and oil palm plantations, plus hunting for their meat, considered a delicacy in some areas, have reduced populations by more than half in the last fifty years.

^{Whooping Crane, Grus americana, by Trish Gussler, May 2018; Whooping Crane, Grus americana, by Diana Robinson, Mar 2018; Whooping Crane, Grus americana, by Evangelio Gonzalez, Dec 2018}

The whooping crane, Grus americana, is one of only two crane species native to North America, and it remains on the list of endangered species although it may be starting a comeback. Birds build a nest on a slight rise in a marsh where one or two eggs are laid. Normally only one egg survives, and the juvenile stays with the parents for six to eight months. Populations were never large, but prior to European settlement, there were an estimated 10,000 birds. Hunting for meat and feathers, in addition to predation and habitat loss, drastically reduced population size from the mid 1800s to the early 1900s. Through several programs of captive breeding, wetland management, and extensive efforts to assist the juveniles in learning migration routes by following ultralight aircraft, populations have rebounded to about 600 today.

^{JSNM Extinct Endangered display; JSNM Eskimo curlew, Numenius borealis; JSNM Proboscis monkey face, Nasalis larvatus; JSNM Proboscis monkey, Nasalis larvatus; all pictures by DonArnold, Feb 2024}

In the final blog on this topic, we will take a look at a few success stories – species that have recovered with populations that continue to get stronger. Many nature museums have information and extinct species on display to learn from. All of the above species, and more, can be found at the Jurica-Suchy Nature Museum, so please stop by, or visit a local nature museum where you live.

Night Buzzers

Have you had your windows open in the evenings and heard the night noises? Chirping, trilling, and buzzing sounds all provide a delightful background to quiet evenings in autumn. The sounds come from a variety of insect species including crickets, katydids, and cicadas.

^{Riley’s Tree cricket by EdwardSnow, Getty Images}

One method insects use to produce these unique songs is called stridulation. Crickets have a scraper on the edge of one wing and a serrated ridge on the opposite wing. When the scraper is moved across the ridge, a chirp can be heard. Crickets may move their wings slowly creating a continuous chirping sound, or more rapidly, creating a smoother and higher-pitched trilling. Katydid also uses this method with a row of stridulatory veins on the undersides of both forewings. Each row has small teeth-like protrusions. When the wings are rubbed together and the teeth slide over each other, a similar clicking sound can be heard.

^{Tree cricket from Pixabay}

^{Katydid by Pixabay}

^{Cicadas in the forest from Pixabay}

Cicadas use another method involving an organ called a tymbal to creating their unique night buzzing. The tymbal, located on their abdomen, is a pair of ribbed membranes that can be flexed against each other. When they are engaged, a ticking sound is created. When moved rapidly, the continual ticking is heard as a buzzing sound. Behind the tymbal, a hollow chamber in the body is used to amplify the sounds.

^{Speckled Bush Cricket by EVO GT, Aug 2012}

^{Common tree cricket nymph by Vinicius Rodrigues de Souza}

Stridulation in cricket species can only be performed by male crickets. Each species has a unique set of sounds, and there are songs for attracting a mate over a distance as well as a courtship song when she draws near. He may also use a warning sound to ward off any other males infringing on his territory. Tree crickets have long, skinny bodies, live in trees, are nocturnal, and their color is adapted to their habitat. In order to project their call further, they may pull a leaf together around themselves to amplify the sound.

^{Katydid by ElizabethPack, Getty Images}

^{Katydid by Macroworld, Getty Images Signature}

Katydids are nocturnal, from 1/2 to 5 inches in length with a leaf-like appearance that provides excellent camouflage for this tree-dweller. There are over 8000 species in the United States, each with its own distinctive song. Katydids can create everything from soft to loud, harsh sounds. Both sexes can create sound and it is used for many forms of communication. There are songs to attract a mate, songs to warn off potential competitors, songs that provide information about a potential mate, and songs that warn the nearby community of danger.

^{Cicada exoskeleton by GrigoriosMoraitis, Getty Images Signature}

Cicadas create a buzzing sound that can be heard across short distances. Much of the buzzing we attribute to them comes from several individuals together in one area. Songs are unique among each species and used similarly for attracting mates and establishing territory. In addition, a large group of cicadas will use buzzing to drive away potential insect predators who are intimidated by louder sounds including robber flies, mantises, and spiders.

Maybe you will take a stroll this evening, or open your windows for some nighttime air. Be sure to listen for the music in the background of the evening.

^{A night chorus from Pixabay}

Frog Calling

Spring has arrived bringing rising temperatures, warm winds, and spring rains to the upper Midwest. This is the time of year when many amphibians, most notably salamanders, frogs, and toads, start their annual breeding periods. Illinois has nineteen native frog species. They are secretive and difficult to find most of the year; but spring is the season for mating, and males will leave their woodland homes and make their way to the nearest pond on nights when temperatures stay in the forties or above.

Frogs use a variety of different calls. Advertisement calls, the loudest calls voiced by male frogs, advertises their presence and availability to potential mates. The courtship call, a slight variation of the advertisement call, is used as a female gets close to direct her to the exact location where the male is waiting. If a male mounts an unreceptive female, or mounts another male, which can happen by mistake in the dark, a release call is emitted to inform the male to stop and look for another potential mate. Aggressive calls may be used by one male towards another who gets too close. And if any frogs are attacked by a predator, a loud distress call is made. This may be to startle the attacker or warn other frogs in the area.

^{Waterfall Glen gray tree frogs calling by DonArnold, 2022}

Calls are created by filling the lungs with air, and then blowing out a steady stream of air over the vocal chords. When calling, the mouth and nostrils are normally closed. The air is passed from the lungs, over the vocal chords in the larynx and into the air sac under the mouth. This air sac, shown in many frog pictures, amplifies the sound to help it carry farther. Calling requires considerable energy and may increase the metabolic rate, the rate at which calories are used, from ten to twenty times the resting rate of an individual. For frogs with breeding periods lasting many weeks, the expenditure of calories will cause a male to lose a significant amount of body weight.

^{NoName Marsh, Boreal Chorus & Spring Peeper by DonArnold, Mar 2022}

Many different species of frogs lay their eggs in the same ponds. Males arrive early in the evening and begin advertising, while females arrive a bit later and identify a potential mate based on his call. When a gravid female approaches, the male clasps her from on top and holds on. After a time, the female releases her eggs in the water, and the male immediately fertilizes them by releasing sperm into the water around the egg sac. Depending on the species, all of the eggs may be deposited in one egg sac or in several separate egg sacs. Egg laying can last several minutes to several hours. After each group of eggs is laid, the male and female may separate or rest for a brief period and then move to another spot to deposit more eggs.

Their skin is moist and cool to the touch. It is permeable, allowing air to pass directly through it into their circulatory system, helping to remove some of the workload from the lungs and heart. This can be especially useful during inclement weather. However, the skin’s permeability makes them susceptible to drying out, so they live in or close to water or high humidity environments. Their lifestyle includes being active mostly at night or on overcast days when it is cooler and more humid.

^{From left: Spring peeper calling by Andrew Hoffman, Jan 2000; Ornate chorus frog calling by FWC Fish & Wildlife, Jan 2014; Green tree frog calling by Eyeweed, Dec 2009}

Many frog populations have been impacted by losses of both wetland and forest habitat. Wetlands are used for breeding and forests provide sheltered areas with shade, ground cover, and higher humidity than areas open to bright sunlight. During spring evenings or overcast days, listen closely as you pass by these shady areas and nearby ponds to catch sound or sight of these wonderous small creatures.

At The Waterhole

Last week, we discovered adaptations that allow elephants to deal with gravity and heat. Asian elephants live mostly in tropical forests that are warm from plenty of sunlight, although very little light reaches through the canopy to the forest floor. Rainfall may be intermittent, and shade-tolerant vegetation changes with a lack or an abundance of water. African savannas have lots of grasslands with a few trees and shrubs. They have distinct wet and dry periods, but grasses grow deep root systems that sustain them throughout the year. African woodlands are more open than Asian forests allowing a variety of trees and shrubs that grow well in full sunlight.

Elephants live in large groups, called herds, led by the strongest adult female. The herd members include all the females plus any males who not yet teenagers. The matriarch knows where to find food and water. She is aggressive when it comes to protecting the rest of the herd and is always the first to confront any threat. Males grow into bulls and will start to fight other males in their teen years. Once this aggression starts, the matriarch will kick the young bull out of the family. Bulls travel alone or together with other bulls, but it is a dangerous time for them because they do not have the support and knowledge of the matriarch for finding food and water.

_{^{The Herd by WLDavies, Getty Images Signature}}

Elephants are old enough to mate in their mid-teens. Pregnancy lasts 18-22 months, and each cow has a baby once every five years until they are in their forties. The herd is very social and several females take care of each calf. Water holes are places where the herd engages in many social activities. Elephants use water to drink, to swim and play in, and to bathe. However, bathing for an elephant means getting dirty, not clean. Elephants stir up the edges of a water hole to create mud to wallow in. Or they will cover themselves with water followed by dirt sprayed on their bodies with their trunks. Dried mud provides cooling from the sun and keeps biting insects away from tender skin. Elephants love water and bathe often, helping to keep skin moisturized.

Lovely mud by bucky_za, Getty Images Signature

Food eaten daily includes about 300 pounds of grass, tree bark, fruit, and other green vegetation. Elephants also need salt to supplement their diet. Their tongues are too short to lick anything not in their mouth, so they use their tusks to dig furrows in the ground and pile up soil and stones. Large stones can be placed into their mouth to lick salt from, and small stones are ground up by their huge molars. Food eaten daily includes about 300 pounds of grass, tree bark, fruit, and other green vegetation.

African elephants are larger than Asian elephants and males are larger than females in all species. Asian elephants average life span is about 80 years in the wild, while African elephants live only 60 years. They are excellent swimmers, often submerging their whole body underwater except for their trunks, which are used as snorkels to breathe. On land, they are slow moving, but can run short distances at better than 20 mph. They use many vocalizations to communicate such as grunts, rumbles, trumpets, screams, and purrs, and they can use their trunks to modulate sounds.

A thousand years ago, ivory was a hot commodity, and hunters exterminated elephants in North Africa. In the last century, after remaining populations were severely depleted by the late 1800s, many countries banned the trade of ivory. Elephants are recovering today, but poaching continues to be a serious threat. As more humans have moved into their native ranges, existing populations have to live in smaller areas. At their rate of food consumption, vegetation does not have enough time to grow back, and herds today are experiencing food shortages. Several conservation organizations are working to provide land for the establishment of wider ranges, care for orphaned elephants, and combat poaching.

You can see and learn more about these wondrous animals at your local zoo or natural history museum.

^{Clockwise above: African bush elephants by designerpoint, Pixabay; Masai Mara elephants by tankbmb, Getty Images; African elephant by Donvanstaden, Getty Images; Friends by cocoparisienne, Pixabay; Asian elephant by miharing, Getty Images}