User:Laurak9/sandbox

Week 3 Evaluating Wikipedia

Article: Empididae (Balloon flies)

The information is relevant to the topic. The topic covers a reasonably good overview of the taxonomy, ecology, etc. The article is relatively informative but succinct, without distracting irrelevant information. A few typos and awkwardly-worded sentences are grammatically troubling.

The article seems neutral. Information is presented in a factual, unbiased manner. The topic is not inherently controversial, and does not particularly support any given position. When the article mentions potentially disputable facts, the writer is careful to avoid taking a particularly strong position with wording such as “seems” or “appears”. There are no particular viewpoints that are over or underrepresented. In general, the article does not delve especially deep into any specific subtopic, keeping the information on a fairly broad level. However, when the article does mention things that could be considered viewpoints, it does not elaborate (e.g., mentions “Brachystomatidae are also sometimes separated as a distinct family, but this seems to be in error,” then fails to provide any information on how or why this in “in error,” nor what the correct information is.) The topics covered by the article are not entirely well-balanced; the article focusses somewhat heavily on describing physical attributes of the flies, while attempting to cover the rest of the flies’ life cycle, reproduction, etc. in a very general subsection entitled simply “Biology”.

The links work, and the sources do seem to support the claims made by the article. However, sourcing is sporadic, with entire paragraphs lacking citations, so some claims are not specifically supported. The article is somewhat sparsely referenced. (Despite being over 800 words long, the article only uses three in-text citations, citing any given references only once). The reference section is also oddly formatted. The sources are neutral, peer-reviewed sources such as scientific articles, without any obvious bias. Of the few references used, all are from at least 10 years ago and half are from around thirty years ago, so it is possible that some of the information is out of date.

The article provides a reasonable overview of the topic, however some information could definitely be added. More detailed information regarding the life cycle of the flies, as well as mating behaviour, ecology and other traits could be useful additions. For instance, the article mentions that this family of flies has diverse mating strategies, but fails to provide much additional elaboration.

There is not a great deal of talk going on about this article, with only one comment on the talk page. There is a mention of a user having added an external link relevant to the article, and no discussion of the articles content or suggestions for improvement. The article is rated C-class for quality, and has been designated as low-importance. It falls within the “Insects” WikiProject.

The Wikipedia article is more in-depth than our class discussion on this topic, although it does not cover all the same information. This article has a wider scope, focussing on balloon flies in general, rather than the specific mating behaviour nutrition-less balloon fixed action pattern discussed in class. The article is also much more focussed on the biology and description of the insects, rather than their behaviour.

Week 6 Article Topic & Sources

Article: Animal song

I have chosen to expand the article on animal song, which is currently a stub article limited to a short introduction with no citations. I have found a book which has the Wikipedia introduction paragraph verbatim, so I will be editing the current introduction and adding the appropriate citation. I will provide a few general examples of animals that perform animal songs and the purposes of these song behaviours. Since “song” is not a well-defined term, I will take a broad approach to the topic including a variety of vocalizations, including calls from birds, anurans (frogs), cetaceans, insects, etc.

Sections will be as follows (or similar):

Function of vocalizations. Here, I will include subsections for function of vocalizations in mating behaviour, communication, warning/alarm calls, aggressive behaviours and defense, and kin recognition. I will provide examples of animals that perform each type of vocalization, giving information on why the behaviour is important to the animal’s fitness.

Anatomy and sound production. This section will be broken down into smaller subsections by type of animal, since animals produce sounds in a variety of ways. I will include information on organs and brain regions important in the production of vocalizations in various animals, and emphasize the diversity of ways in which sound is produced by animals.

Evolution and speciation. I will include selection pressures leading to the evolutionary development of animal song vocalization behaviour, and discuss the relevance of sexual selection as an evolutionary pressure to develop elaborate songs.

Social transmission and learning. I will discuss the transfer of song/vocalization patterns among various animals, including examples of transmission of song from parent to offspring, and among other conspecifics.

Other forms of animal music. This section will provide an overview of other non-vocal music-like behaviours in animals, such as drumming behaviour in primates.

Possible bibliography may include:

Bao, S. (2015). Perceptual learning in the developing auditory cortex. European Journal Of Neuroscience, 41(5), 718-724. doi:10.1111/ejn.12826

Bryant, G. A. (2013). Animal signals and emotion in music: Coordinating affect across groups. Frontiers in Psychology, 4(990), 1-13. doi:10.3389/fpsyg.2013.00990

Byers, B. E., & Kroodsma, D. E. (2009). Female mate choice and songbird song repertoires. Animal Behaviour, 77(1), 13-22. doi:10.1016/j.anbehav.2008.10.003

de Waal, F. (2016). Are we smart enough to know how smart animals are? New York, NY: W. W. Norton & Company.

Dugatkin, L. A. (2014). Principles of animal behaviour (3rd ed.). New York, NY: W. W. Norton & Company.

Kelley, D. B. (1997). Generating sexually differentiated songs. Current Opinion In Neurobiology, 7(6), 839-843. doi:10.1016/S0959-4388(97)80144-4

Liska, J. (1993). Bee dances, bird songs, monkey calls, and cetacean sonar: Is speech unique? Western Journal of Communication, 57(1), 1-26. doi:10.1080/10570319309374428

Ljubičić, I., Hyland Bruno, J., & Tchernichovski, O. (2016). Social influences on song learning. Current Opinion in Behavioral Sciences, 7, 101-107. doi:10.1016/j.cobeha.2015.12.006

Panksepp, J., & Trevarthen, C. (2009). The neuroscience of emotion in music. In S. Malloch, C. Trevarthen, S. Malloch, C. Trevarthen (Eds.), Communicative musicality: Exploring the basis of human companionship (pp. 105-146). New York, NY, US: Oxford University Press.

Payne, R. B. (1983). The social context of song mimicry: Song-matching dialects in indigo buntings (Passerina cyanea). Animal Behaviour, 31(3), 788-805. doi:10.1016/S0003-3472(83)80236-X

Rohrmeier, M., Zuidema, W., Wiggins, G. A., & Scharff, C. (2015). Principles of structure building in music, language and animal song. Philosophical Transactions of the Royal Society B: Biological Sciences, 370(1664), 1-15. doi:10.1098/rstb.2014.0097

Sakaluk, S. K., & Belwood, J. J. (1984). Gecko phonotaxis to cricket calling song: A case of satellite predation. Animal Behaviour, 32(3), 659-662. doi:10.1016/S0003-3472(84)80141-4

Searcy, W. A., & Beecher, M. D. (2009). Song as an aggressive signal in songbirds. Animal Behaviour, 78(6), 1281-1292. doi:10.1016/j.anbehav.2009.08.011

Seyfarth, R. M., & Cheney, D. L. (2010). Production, usage, and comprehension in animal vocalizations. Brain And Language, 115(1), 92-100. doi:10.1016/j.bandl.2009.10.003

Tyack P. L., Clark C. W. (2000). Communication and acoustic behavior of dolphins and whales. In: Au, W. W. L., Fay, R. R., Popper, A. N. (Eds), Hearing by Whales and Dolphins. Springer Handbook of Auditory Research, vol 12. New York, NY: Springer

Introduction

Animal song is not a well-defined term in scientific literature, and the use of the more broadly defined term vocalizations, is in more common use. Some sources distinguish between simpler vocalizations, termed “calls”, reserving the term “song” for more complex productions. Song-like productions have been identified in several groups of animals, including cetaceans (whales and dolphins), birds, anurans (frogs), and humans. Social transmission of song has been found in groups including birds and cetaceans.

Anatomy of Sound Production

Mammals

Most mammalian species produce sound by passing air from the lungs across the larynx, vibrating the vocal folds. Sound then enters the supralaryngeal vocal tract, which can be adjusted to produce various changes in sound output, providing refinement of vocalizations. Although morphological differences between species affect sound production, neural control is thought to be more essential factor in producing the variations within human speech and song compared to those of other mammals.

Cetacean vocalizations are an exception to this general mechanism. Toothed whales (Odontocetes) pass air through a system of air sacs and muscular phonic lips, which vibrate to produce audible vocalizations, thus serving the function of vocal folds in other mammals. Sound vibrations are conveyed to an organ in the head called the melon, which can be changed in shape to control and direct vocalizations. Unlike in humans and other mammals, toothed whales are able to recycle air used in vocal production, allowing whales to sing without releasing air. Some cetaceans, such as humpback whales, sing continuously for hours.

Example whale song - Humpback whale (Megaptera novaeangliae)

Red-eyed tree frog (''Litoria chloris'') showing inflated vocal sac while vocalizing

Anurans

Like mammals, anurans possess a larynx and vocal folds, which are used to create vibrations in sound production. However, frogs also use structures called vocal sacs, elastic membranes in the base of the mouth which inflate during sound production. These sacs provide both amplification and fine-tuning of sounds, and also allow air to be pushed back into the lungs during vocalizations. This allows air used in sound production to be recycled, and is thought to have evolved to increase song efficiency. Increased efficiency of sound production is important, as some frogs may produce calls lasting for several hours during mating seasons. The New River tree frog (Trachycephalus hadroceps), for example, spends hours producing up to 38,000 calls in a single night, which is made possible through the efficient recycling of air by the vocal sac.

Sample frog sounds - Upland Chorus Frog (Pseudacris feriarum)

Avian respiratory and vocal anatomy

Birds

When birds inhale, air is passed from the mouth, through the trachea, which forks into two bronchii, which connect to the lungs. The primary vocal organ of birds is called the syrinx, which is located at the fork of the trachea, and is not present in mammals. As air passes through the respiratory tract, the syrinx and the membranes within vibrate to produce sound. Birds are capable of producing continuous song during both inhalation and exhalation, and may sing continuously for several minutes. For example, the skylark is capable of producing non-stop song for up to 1 hour. Some birds change their song characteristics during inhalation versus exhalation. The Brewer’s sparrow (Spizella breweri) alternates between rapid trilling during exhalation interspersed with a second, lower-rate trill during short inhalations. The two halves of the syrinx connect to separate lungs, and can be controlled independently, allowing some birds to produce two separate notes simultaneously.

Song production of skylark

Insects

Insects such as crickets are well-known for their ability to produce loud song, however the mechanism of sound production differs greatly from most other animals. Many insects generate sound by mechanical rubbing of body structures, a mechanism known as stridulation. Orthopteran insects, including crickets and katydids, have been especially well-studied for sound production, and use scraper-like structures on one wing to sweep over file-structures on an opposing wing to create vibrations, producing a variety of trilling and chirping sounds. Locusts and other grasshoppers stridulate by rubbing hind legs against pegs on wing surfaces in a up and downward motion. Cicadas produce sound at much greater volumes than Orthopterans. Cicadas rely on a pair of organs called tymbals on the base of the abdomen behind the wings. Muscle contraction rapidly deforms the tymbal membrane, emitting several different types of sounds. Insects thus produce a variety of sounds, using various mechanisms distinct from other animals.

Functions of Vocalizations

Vocalizations can play a wide variety of different roles. In groups such as anurans and birds, several distinct types of notes are incorporated to form songs, which are sung in different situations and serve distinct functions. For example, many frogs may use trilling notes in mate attraction, but switch to different vocal patterns in aggressive territorial displays. In some species, a single song incorporates several note types which serve different purposes, with one type of note eliciting responses from females, and another note of the same song responsible for warning competitor males of aggression.

Mating and courtship

Vocalizations play an important role in the mating behaviour of many animals. In many groups (birds, frogs, crickets, whales etc.), song production is more common in males of the species, and is often used to attract females.

Bird song is thought to have evolved through sexual selection. Female songbirds often assess potential mates using song, based on qualities such as high song output, complexity and difficulty of songs, as well as presence of local dialect. Song output serves as a fitness indicator of males, since vocalizations require both energy and time to produce, and thus males capable of producing high song output for long durations may have higher fitness than less vocal males. It is thought that song complexity may serve as an indicator of male fitness by providing an indication of successful brain development despite potential early-life stressors, such as lack of food. Social transmission of songs allows for development of local dialects of song, and female songbirds also typically prefer to choose mates producing local song dialects. One hypothesis for this phenomenon is that selecting local mates allows the female to choose genes specially adapted to suit local conditions.

Frog song also plays a prominent role in courtship. In túngara frogs (Engystomops pustulosus), male frogs increase the complexity of their calls, adding additional note types when greater numbers of competitor males are present, which has been found to attract greater numbers of female frogs. Some species change their courtship calls when females are especially nearby. In male glass frogs (Hyalinobatachium fleichmanni), a long frequency-modulated vocalization is produced upon noticing another nearby frog, but is changed to a short chirping song when a female approaches. Several species (e.g. dendrobatid frogs (Mannophryne trinitatis), ornate frogs (Cophixalus ornatus), splendid poison frogs (Dendrobates speciosus), switch from long-range loud trilling sounds to short-range quieter chirps when females move closer, which is thought to allow mate attraction without alerting competitor males to female locations.

Although highly complex song-like production has been identified in whales, the function is still somewhat elusive. It is thought to be involved in courtship behaviour and sexual selection, and singing behaviour becomes more common during the breeding season.

Aggression and territorial defense

Another major function of song output is to indicate aggression among males during breeding seasons. Both anurans and birds use singing in territorial displays to confer aggressive intent. In Eastern smooth frogs (Geocrinia victoriana), for example, courtship songs involve shorter notes to attract potential mates, and are followed by longer tones to repel males. Frequency of sounds produced generally negatively correlates with body size both within and among species, and allows competing males to assess body size of vocalizing neighbouring frogs. Male frogs typically more readily approach higher frequency sounds, likely because the frog producing the sound is assessed to be a smaller, less dangerous competitor.

In territorial birds, males increase song production rate when neighbouring males encroach on their territory. In great tits, nightingales, blackbirds and sparrows, playing song recordings slows the rate at which males establish territories in an unoccupied region, suggesting these birds rely on song output in establishing territorial boundaries. Experimentally muted Scott’s seaside sparrow (Ammodramus maritimus) lose control of their territories to other males. Thus, territorial birds often rely on song production to repel conspecific males.

Individual recognition

Like the human voice, bird song typically contains sufficient individual variability to allow discrimination of individual vocal patterns by conspecifics. Such discrimination is important to mate recognition of many monogamous species. Seabirds, for example, often use vocalization patterns to recognize their mate upon reunion during the breeding season. In many colonial nesting birds, parent-offspring recognition is critical to allow parents to locate their own offspring upon return to nesting sites. Cliff swallows (Petrochelidon pyrrhonota) have been demonstrated to preferentially respond to parental songs at a young age, providing a means of vocalization-based offspring recognition.

Social Transmission and Learning

Learned vocalizations have been identified in groups including whales, elephants, seals, and primates, however the most well-established examples of learned singing is in birds. In many species, young birds learn songs from adult males of the same species, typically fathers. This was first demonstrated in chaffinches (Fringilla coelabs). Chaffinches raised in social isolation develop abnormal songs, however playing recordings of chaffinch songs allows the young birds to learn their species-specific songs. Song learning generally involves a sensitive learning period in early life, during which young birds must be exposed to song from tutor animals in order to develop normal singing as adults. Song learning occurs in two stages: the sensory phase and the sensorimotor phase. During the sensory phase, birds memorize the song of a tutor animal, forming a template representation of the species-specific song. The sensorimotor phase follows, and may overlap with the sensory phase. During the sensorimotor phase, young birds initially produce variable, rambling versions of adult song, called subsong. As learning progresses, the subsong is replaced with a more refined version containing elements of adult song, called plastic song. Finally, the song learning crystallizes into adult song. For song learning to occur properly, young birds must be able to hear and refine their vocal productions, and birds deafened before the development of subsong do not learn to produce normal adult song.

The sensitive period in which birds must be exposed to song tutoring varies across species, but typically occurs within the first year of life. Birds in which song learning is limited to the initial sensitive period are referred to as closed-ended learners, whereas some birds (e.g. canaries), continue to learn new songs later in life, and are called open-ended learners. Some species of birds, such as the brown-headed cowbird (Molothrus ater), parasitize other bird species, laying their eggs in the nests of other birds such that the heterospecific bird raises the chicks. Although most birds acquire song learning within the first year, brown-headed cowbirds have a delayed sensitive period, occurring approximately one year after hatching. This may be an adaptation to prevent the young birds from learning the songs from the foreign bird species. Instead, the fledgling birds have a year in which to find conspecifics, and learn their own species-specific song.

Birds are generally predisposed to favour learning of conspecific songs, and will typically preferentially learn the song form conspecific animals rather than heterospecifics. However, song learning is not completely restricted to within-species songs. If exposed to heterospecific birds of another species in absence of same-species birds, young birds will often adopt the song of the species to which it was exposed. Although birds are capable of learning song production purely from audio recordings of birdsong, tutor-student interaction may be important in some species. For example, white-crowned sparrows preferentially learn the songs of song sparrows when exposed to recordings of white-crowned sparrows and live song sparrows. In other words, the interactive nature of a live tutor seems to trump the familiarity of the recordings from conspecifics.

While vertical transmission (parent-offspring) is a common element of song learning, horizontal transmission among animals of the same generation can also occur. Male humpback whales produce various songs over their lifetime, which are learned from other males in the population. Males in a population conform to produce the same mating song, consisting of a highly stereotyped vocal display involved in mate attraction. The cultural transmission of these songs has been found to occur across great geographic distances over years, with one study noting song transmission across the western and central South Pacific ocean populations over an 11-year period.