Halloween Appropriate Oddities of Our Natural World

Scientific Name: Craspedacusta sowerbyi; Bryozoan spp.; Hirudinea

Common Name(s): freshwater jellyfish; Moss Animal, Bryozoan; Leech

Freshwater Jellyfish – Chris Fuller

Bryozoan – ©Missouri Department of Conservation

Freshwater Leech – ©Ulrich Kutschera

Freshwater Jelly: Chris FullerBryozoan ©Missouri Department of Conservation

Freshwater Leech – ©Ulrich Kutschera

Identification and Ecology:

The ocean isn’t the only place where strange creatures can be found. Freshwater can support its fair share of interesting animals. For example, freshwater jellyfish, moss animals, and leeches all inhabit freshwater environments.

Freshwater jellyfish are most recognizable in their medusa, or jellyfish form of its lifecycle. The small bell-shaped medusa form is translucent with a white- to- green coloring and range from 0.2 to 1 inch in diameter. Jellyfish do not have a digestive system with two openings like most animals. Instead, they have only one orifice for both ingestion and expulsion of waste. The freshwater jellyfish has a digestive system called the gastrovascular cavity which is composed of four radial canals and one central canal, which are easily visible with the naked eye, and a mouth on the ventral surface of the bell. Between 50 and 500 tentacles surround the bell of the medusa, each containing specialized stinging cells called nematocysts which immobilize prey. They are preyed upon by fish and other aquatic life.

Bryozoans are a group of invertebrate animals inhabiting both ocean and freshwater environments. They are a colonial animal. Individuals, called zooids, only measure about 1/64 inches in length, while colonies can range from golf ball to volleyball-sized. These sedentary colonies are usually attached to sticks or rocks. Freshwater zooids are simultaneous hermaphrodites, serving as both male and female with sperm and sometimes eggs being released into the water where they fertilize and settle on a surface. Each zoid has a small ring of tentacles around a mouth for filter feeding. Bryozoans are preyed upon by other invertebrates, fish, and snails.

Leeches are in the subclass Hirudinea and are a type of segmented worm. Other segmented worms include earth worms. Most species of leech live in freshwater, while some inhabit marine or terrestrial environments. They can range in size from 0.5 to 12 inches in length. While most species are

hematophagous, parasitically consuming a host’s blood, some are predatory, preying mostly on small invertebrates. The most well-known and studied leeches are the medical leeches, for example Hirudo medicinalis. Leeches generally prefer a certain type of animal to feed on, some attaching to turtles, some to fish, and others to mammals, including humans. Like freshwater zooids, leeches are also hermaphrodites, containing both male and female sexual organs. They require a mate, with each partner fertilizing the other. Eggs are deposited on the underside of logs, sticks, rocks, or plants. Medical leeches are important for some treatments. Their saliva contains anticoagulants, to keep blood flowing, and anesthetics, to reduce or eliminate pain. They have been used to great effect in aiding the recovery process after certain types of surgery, including body part reattachment.

Range:

All these animals are found all over the globe. They inhabit many of the world’s freshwaters to various degrees. The freshwater jellyfish originated in China, but has since been spread across the world. Various bryozoan and leech species are native to much of the earth.

Special Notes:

The freshwater jellyfish is not considered dangerous to humans or larger organisms. The stinging cells in this species are very small and unlikely to penetrate human skin. Freshwater jellyfish blooms happen sporadically. Usually, a bloom can be observed every year or every other year on at least one of Bella Vista’s lakes. Bryozoans can be found in all our lake with careful observation while swimming or boating. They may be mistaken for the egg sacs of other animals. Leeches are found on all Bella Vista lakes and streams, but feed almost exclusively on fish and turtles. Although some may try human blood if given the chance!

Scientific Name: Ambrosia trifida

Common Name(s): Giant Ragweed, Great Ragweed, Texan Great Ragweed, Tall Ragweed, Blood Ragweed, Perennial Ragweed, Horseweed, Buffaloweed, Kindhead

Photos by Kayla Sayre, Bella Vista POA Fisheries & Water Quality Sr. Technician
Illustration from Aquatic and Wetland Plants of Southwestern US, 1972 

Identification: 

Giant ragweed is in the Asteraceae family, the second largest family of flowering plants, and is in the genus Ambrosia, which is composed of different ragweed species. Ragweed species originated from the United States where this genus holds the largest diversity. Species in this genus share characteristics of being monecious, meaning they can only reproduce by pollination and cannot self-pollinate like some other flowering plants. They have inflorescences, or flower clusters, that are spikes in shape with some smaller flower spikes around the base. 

Giant ragweed grows between 3 and 12 feet tall depending on the soil nutrients. They have many branch stems that come from the central stem in an opposite formation. The branching stems are green, and the central stem is green with purple, both are covered in white hairs. Giant ragweed has two types of simple leaves. The mature leaves are 12 inches long and 8 inches wide and have 3 to 5 lobes with serrate margins, while the newly emerging terminal leaves are lanceolate. The upper stems of the plant terminate into cylindrical, spiked female flowers that are 3 to 6 inches long and produce seeds once pollinated. These flowers are yellow-green and have no petals or sepals. Additionally, the plant has smaller spiked male flowers that cluster around the base of the terminal flower and release pollen. 

Similar Species 

The terminal height and leaf morphology distinguish giant ragweed from common ragweed, A. artemisiifolia.

Range: 

Giant ragweed is native to most of the continental United States excluding Nevada. 

Ecology: 

Giant ragweed prefers moist soil which is fertile or loamy as well as partly shady. However, they can also tolerate clay or gravel soil in dry conditions and full sunlight. It can grow taller in its preferred conditions and can easily reach heights up to 12 feet. Giant ragweed is commonly found along woodland margins, moist clay prairies, near rivers, and thickets. However, it can also be found in vacant lots, cropland, abandoned fields, poorly drained waste areas, roadsides, railroads, and fencerows.  

Giant ragweed is an important food source for insects and indirectly helps insectivorous migrating songbirds. Since giant ragweed is a wind pollinator, pollinating insects are not normally attracted to its flowers. Instead, the primary consumers of giant ragweed are insects with piercing mouthparts which drink the juices in the ragweed’s stem. For this reason, giant ragweed attracts migratory songbirds which eat insects that congregate on this plant in the fall, including indigo buntings, song sparrows, white throated sparrows, American redstars, and yellow warblers. 

Giant ragweed can provide habitat and food for a small handful of mammals or birds. Mammals generally avoid eating giant ragweed because it is bitter. However, some vole species will eat their roots. The seeds of ragweed are tough and hard to digest so are avoided by most birds, but the Northern bobwhite quail, mallard duck, and greater prairie chicken do eat them. Since it grows in herbaceous patches, it can be used as habitat or cover for small mammals avoiding predators. 

Special Notes: 

Here in Bella Vista, giant ragweed is found most predominantly along forest edges and newly disturbed areas such as drainage ditches. It is among the first colonizers to return to powerline easements after tree and brush removal. Ragweed is rarely found in open fields. 

Native peoples used preparations from the leaves and roots as astringents, skin disinfectants, fever reducers among other things. The plant is edible, but extreme care should always be used to identify wild growing plants. 

Giant ragweed grows in close association with one another and can easily grow in shaded and moist disturbed locations. For this reason, they can be good to keep because they can help combat erosion of soil in drainage areas. It is also a notable seasonal allergen because of its wind-born pollen. 

Scientific Name: Passerina ciris

Common Name(s): painted bunting, Mexican canary, painted finch, pope, nonpareil

Dan Pancamo

Identification:

Painted buntings are songbirds in the cardinal family (Cardinalidae). They are often regarded as the most beautiful bird in North America and are given the nickname nonpareil meaning “without equal.” In the second year of life, the male comes into his breeding colors with a dark-blue head, green back, red bottom, and red chest. The females and juvenile males are a vibrant green and yellow color which helps them to camouflage.  They are 4.5 to 5.5 inches in length and weigh about half an ounce. They have a wingspan of 8.3 to 9.1 inches.

Range:

Painted Buntings have two subspecies based on their breeding locations (red/orange) which results in subsequent genetic variation.  Passerina ciris ciris breeds in the Southeastern United States.  Passerina ciris pallidir breeds in the South-central United States and Northern Mexico.  Painted Buntings overwinter (blue) in tropical forests or densely vegetated savannas in Southern Florida, Cuba, the Bahamas, the Coast of Mexico, and Central America.  Between seasons they travel overnight to reach new territories.

Ecology:

Painted Buntings live in thickets, woodland edges, riparian (vegetation along streams) areas, brushes, and shrubbery.  They breed in hammocks (usually hardwood ‘islands’ surrounded by wetlands) and scrublands.

Painted Buntings mainly feed by hopping around and foraging for food such as seeds of grasses, sedges, and forbs.  In the winter they exclusively eat seeds.  During breeding season, especially when females are nesting, they seek-out small invertebrates such as spiders, snails, grasshoppers, and caterpillars.  Interestingly, they sometimes pick off insects caught by spider webs.

Mating season begins in late April and extends through the beginning of August, but most activity occurs mid-May to mid-July.  Males arrive one week prior to females to establish territories.  Males are most visible during mating season as they sing on exposed perches to advertise their territory and alert females of their presence.  In addition to singing, male buntings will fly in a bouncing manner that is similar to butterfly flight.  They also have an upright display of fluffing feathers, bowing, and wing quivers that are used to attract females.

Females weave their nests into low, dense vegetation.  Each brood is around 4 eggs which are grey-white with spots of brown.  The female incubates the eggs for 10 days.  Young are born underdeveloped “altricial” and require parental care.  Females alone will care for the young after hatching.  Young fledge 12 to 14 days after hatching.  Females lay another brood 30 days after the first set hatches.

Special Notes:

You can see Painted Buntings along roadsides, on forest edges, and in gardens.  The males are especially noticeable at the peak of their mating season when they display for females.  Painted buntings stay in Arkansas from late April until August and begin migration to their wintering habitat late August to early September.

Scientific Name: Corvus brachyrhynchos, Corvus ossifagus

Common Name(s): American Crow, Fish Crow

©Wikimedia Commons © Rhododendrites

Identification:

Crows are large black birds with black feathers, black eyes, and a large black beak. They are common birds within their ranges and are generally easily identified. The common raven which can be confused with crows, is not found in Arkansas. The two species of crow found in Arkansas are the American crow and the fish crow. The American crow measures 16-20 inches in length, and weights 11-22 ounces, while the fish crow is smaller in both size and weight. There are other physical differences between the two species, however, it is very difficult and inconsistent to identify each species visually. Instead, the best way to differentiate these two species is by their calls. American crows call with the classic “caawww-caawww-caawww” that most people associate with crows, while fish crows call with a similar but much shorter and more nasally “ahh-ahh-ahh” sound. During calls, fish crows also tend to tilt the head back more noticeably and puff out the throat feathers

Range:

The species range of the American crow and the fish crow overlap in the southeastern and eastern United States. However, the American crow’s range extends over nearly the entirety of the lower 48 states, while the fish crow’s range is limited to the aforementioned southeastern and eastern United States.

Ecology:

Crows are omnivorous and will eat anything that is easily available. For example, they will consume carrion, all types of invertebrates, reptiles, amphibians, small rodents, fish, nuts and seeds, grains, and human scraps. American crows are one of the few observed species of birds making and using tools to obtain food. Crows are intelligent and adaptable and will make their home in temperate forests near water, in agricultural field, or in urban areas.

While similar in appearance and diet, American crows and fish crows differ in their reproductive strategies. American crows are monogamous and form large family groups with juveniles from previous years staying with the group to assist in raising new hatchlings. Breeding starts early and egg laying has been observed as early as April. A clutch consists of 3-9 eggs, and there is 1, maybe 2, broods per year. Both males and females build nests. Sexual maturity is reached at two years of age, but many do not leave their family group until four or five years of age.

Fish crows are seasonally monogamous, with the female building the nests. Males may accompany females to gather nest material, but they do not participate in nest building. Breeding occurs in a similar time frame as American crows, with 2-6 eggs per clutch with one clutch per year. Although they are not as family group oriented as American crows, they will nest loosely together, with nests within 100 feet of each other.

Crows are very intelligent and very social. This leads to a number of interesting behaviors, such as young crows playing with objects to learn how to manipulate, birds teaching one another and sharing information such as food location and grouping together to ward off threats. Often American crows and fish crows will cooperate and socialize together, but in disputes, fish crows almost always yield to American crows. Crows also have an excellent memory and recognize faces and individuals. There are many documented cases of particular humans earning the ire of crows and subsequently being harassed by not only the offended crow, but other crows who were informed of the human’s wrongdoing. On the other hand, there are many cases of humans befriending crows which subsequently bring gifts to their human friends or harass other humans they perceive as threats to their human friends

Special Notes:

Here in Bella Vista, both American and fish crows can be observed, but American crows are more dominant. They can often be seen by roadsides scavenging for carrion. They may even visit bird feeders, if tempting enough!