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Dictionary P-S - BirdForum Opus

This section is aimed at explaining the bird and biology specific vocabulary you are likely to meet in other threads in Birdforum.

This page is divided into several sections: Dictionary A-C, Dictionary D-F, Dictionary G-L, Dictionary M-O, Dictionary P-S and Dictionary T-Z.


Palmation: more or less the same as webbing; see Legs and Feet. Semipalmated really means "with half palmations".

Pamprodactyl: Having all four toes on each foot pointing forwards as in the swifts. See Legs and Feet.

Parapatry, parapatric: two populations that are each others neighbors, or in other words occur on opposite sides of a common border, for example being separated by a river or some other habitat difference. Often used about closely related taxons that may even have hybrid zone at the border.

Paraphyly, paraphyletic: opposite of monophyletic, which see.

Parasitise, parasitize: in the context of birds, this most often refer to Brood parasite.

Partial Albinism: This is a term that some people use a lot and some claim should not be used at all. The best usage of "partial albinism" is to describe the bird that has completely normal colours in part of its plumage but one or more feather areas that are completely white. Bare parts will be normal. See also "Leucism", "Albinism".

Passage migrant: a migrating bird that is passing through an area on the way to it's destination.

Patagial mark: an area along the leading edge of the underside of the wings (parts of the underwing coverts) stretching from the body to the wrist which in some hawks (such as Red-tailed Hawk) will have a contrasting darker colour.

Pectoral, pectoral tufts: the pectoral area of a bird is essentially the breast or chest area. The Pectoral Sandpiper has striping on the underside limited to the pectoral area. Pectoral tufts are feather areas of usually contrasting color that are sitting on the side of the breast in many sunbirds. These tufts may be hidden by the folded wing but may become visible when the bird slightly changes the way it holds its wing.

Phylogeny: The evolutionary relationship among species (or other taxonomic units). A phylogenetic analysis can be based on morphology, plumage or DNA sequences, or any combination thereof; the results are often illustrated as a phylogenetic tree. See also Clade.

Pishing: A technique to attract birds to you by using sounds made using your lips and mouth. It was first developed in the USA, for attracting woodland birds, by making high-pitched squeaking noises it proved possible to attract many small passerines. Some people achieve this by noisily kissing the back of their hands. Another technique which can produce good results is to rub a piece of polystyrene on wet glass. Yet another approach is to make insistent 'pssssss, psssss, pssss' noises. In the UK, Long-tailed Tits Aegithalos caudatus and Great Tits Parus major are often the first to respond. If they are agitated they will start to make 'mobbing' type noises themselves. You can end up with quite a crowd of small birds excitedly squeeking and chipping. Occasionally this will attract predators, such as Eurasian Sparrowhawk.

Polyandry, polyandrous: mating system where one female mates with several males in one mating season; often, that implies that for each male she lays 1 or more eggs that the male then incubate and thereafter raise the young without her help. Found in a number of different birds including for example Cassowary and other large, flightless birds, and in phalaropes and other shorebirds.

Polygamy, polygamous: this is a catch-all phrase for the situation where males or females or both have more than one sexual partner in a single breeding season. If it is strictly only one of the sexes that have additional partners, then either polyandry or polygyny, could be used as more specific descriptors, if it is with certainty both sexes that have additional partners, then polygynandry can be used.

Polygynandry, polygynandrous: used when it is known that both sexes in a species has additional partners.

Polygyny, polygynous: In polygynous species the male tries to mate with more than one female during the breeding season. Male Bowerbirds for example build a bower to attract as many females as possible. The female then has to build and attend the nest alone.

Polymorphic: A polymorphic species shows multiple morphs within a population. This includes sexual variation but also variation in the same sex; e.g. the females of Black-billed Cuckoo are either black or dark brown with bars, while several screech owl species have red, grey and even brown morphs.

Polytypic: the opposite of monotypic, i.e., a species with many subspecies (or another taxon with many members). For example, the Bananaquit is a polytypic species containing 41 subspecies according to the Clements checklist.

Post-ocular: mostly in connection with the words "spot" or "stripe": many hummingbirds have a white spot behind the eye or a stripe starting behind the eye continuing diagonally backwards-down.

Preening: activity where feathers are put back in order, usually using bill and/or feet. In most groups of birds, oils from the uropygial glands are distributed over the feathers as part of the preening activity. When preening involves two birds, it is called mutual preening or allopreening. Preening is analogous to what in mammals is known as grooming.

Primaries: a group of flight feathers, see Wings which also explains "primary projection". The number of primaries differ among different groups of birds with most birds normally having ten, but some passerines (e.g. buntings) only having nine; flightless birds like penguins may have none or only a few vestigial primaries.

Precocial: about a bird that is well developed at hatching, is able to thermoregulate and often are able to feed. The hatchlings of these birds are often able to run around soon after hatching and will most often leave the nest in less than 24 hours. See also Altricial for the opposite. Many birds hatch in a state between the extremes, so that there is a continuum rather than two clearly separated groups. See also Semi-altricial.

Pullus: original meaning seems to have been nestling, often used for any young bird that is still in down. See also Juvenile in J.


Qualitative trait: something that can be scored as present or absent. For example in different subspecies of Greater Antillean Oriole, the upper rump can be yellow or black.

Quantitative trait: something that will be scored as a number. This could be the length of the bill, width of the bill, or in an oriole, the percentage of the underside that is yellow vs black.


Racquets: areas of (usually the tail) feathers where the outer and inner sections have normal barbs but they are separated by an area where the barbs have fallen off leaving only the shaft. Such structures probably are used as ornaments. For examples, see individual species of Motmots and some hummingbirds such as the members of genus Ocreatus.

Ramsar: The Convention on Wetlands is an intergovernmental treaty providing the necessary framework for conservation and use of wetlands. It was adopted in Ramsar, Iran in 1971 and finalised in 1975. Nearly 90% of UN member states, have signed up to the convention. [7].

Ramus, rami: the basic meaning of this word is forked or branched, often into parallel branches (ramus is singular, rami is plural). In birds, the most frequent use is for some swiftlets such as Himalayan Swiftlet. In these, the basal part of the back feathers can have barbs that are contrasting white-tipped. These are called rami, presumably because the barbs have barbules on both the proximal and distal upper sides. Some descriptions of swiftlets stress the presence vs absence of these rami even though they would be expected to be hidden by contour feathers.

Range: another word for distribution.

Ranging: some (most?) birds have the ability to separate sounds on a much finer time-scale than humans. The theory about ranging is that they use this ability to discern the extent of echoes in the sound of a singing competitor (for example from trees in the surrounding area) and thereby are able to determine the distance to the singing bird without relying on the amplitude of the song; the amplitude will vary with the orientation of the singer[1].

Rectrices: (singular: rectrix) tail feathers, see General Anatomy. The number of tail feathers differ among species, sometimes even among closely related species like Wilson's Snipe and Common Snipe.

Remiges: (singular: remex) flight feathers of the wing, see General Anatomy.

Rictal, rictus: rictus describes the skin where the two mandibles meet, synonymous with rictal flanges or gape flanges (this is often swollen and red in Bananaquit). In many species that specialise in catching insects in flight, this area contains bristles. Species that have rictal bristles include for example nightjars and many flycatchers (including in both the unrelated old world and new world families). Theories that state that bristles have a role in aiding prey capture has been refuted at least in new world flycatchers (but not necessarily in nightjars). Other possible explanations for their presence are protection of the eyes of the bird (for example from flapping wings of the prey) or some kind of sensory function not directly related to capture of prey[2], [3].

Ring species (also German, rassenkreis): a situation where a number of populations/subspecies exists around an area where the species does not occur (usually because the center in uninhabitable for that particular species. For example, imagine that population A interbreeds freely with the nearest members of population B even though B is somewhat changed in an important way. Likewise, B interbreeds with C, C interbreeds with D, and D interbreeds with E. But at the ends of the circle, A and E meets, and they are not able to interbreed. For this to be a classical ring species, this situation has to be established in location and the interactions between the different parts (A with B, etc) have to have been continuous through a long period. A number of examples have been described that look like ring species, but the requirement that this has been going on for a long time have not been met in any of them. The most frequently cited examples within birds are the large white-headed gulls (the Herring Gull complex) and Greenish Warblers (including Two-barred Warbler and Green Warbler), but in both cases have recent studies shown that the concept is not accurate[4], [5]. The Song Sparrow has also been proposed as a Ring Species[6].

References R

  1. Morton & Stutchbury (2001). Behavioral Ecology of Tropical Birds. Academic Press. ISBN 0-12-675556-6.
  2. Lederer, R. J. (1972). The Role of Avian Rictal Bristles. Wilson Bulletin 84 (2):193-197.
  3. Conover, M. R., & Miller, D. E. (1980). Rictal bristle function in Willow Flycatcher. Condor 82 (4): 469-471.
  4. Liebers, D., et al. (2004). The herring gull complex is not a ring species. Proc. R. Soc. Lond. B 271: 893–901.
  5. Alström, P. (2006). Species concepts and their application: insights from the genera Seicercus and Phylloscopus. Acta Zoologica Sinica 52 (Supplement): 429–434.
  6. Patten, Michael & Pruett, Christin. (2009). The Song Sparrow, Melospiza melodia, as a ring species: Patterns of geographic variation, a revision of subspecies, and implications for speciation. Systematics and Biodiversity. 7(1):33-62. https://doi.org/10.1017/S1477200008002867.
  7. Ramsar The Convention on Wetlands, https://www.ramsar.org/


Scapulars: the feathers of the shoulder region, see Wings.

Schizochroism: see discussion under Leucism.

Secondaries: a group of flight feathers, see Wings.

Semi-altricial: birds where the hatchlings have downs and open eyes but are still dependent on their parents for everything else. See also Precocial and Altricial for two related concepts.

Semipalmated: "with half palmations", or in other words, with slight webbing between the toes.

Sensu: Latin; 'in the sense of'. Usually used in two terms, sensu stricto ('in the strict sense' - splitting close relatives separately), and sensu lato ('in the broad sense' - lumping close relatives together), for defining the taxonomic treatment of a bird. Also sometimes as "sensu Bloggs et al., 2016", to describe the treatment adopted by a particular paper by the named author(s).

Sex determination in birds: Sex determination in birds is caused by their chromosomes: birds born with ZZ chromosomes as a rule develop into males while those with ZW chromosomes develop into females (this is in addition to a large number of chromosomes that are not involved in sex determination). Mammals such as humans also depend on chromosomes for sex determination, but in mammals the two identical chromosome (XX) are found in a female which the male has two different chromosomes (XY). As per 2016, it was uncertain whether the determination in birds arose from a counting mechanism (two ZZ = male, one Z = female) or from a dominantly acting gene on the W chromosome forcing the sexual development into becoming a female. The counting mechanism might be better presented as a ratio mechanism: is it one or two Z chromosomes among the full chromosome complement. As per 2016, this was the favorite hypothesis[2]. The alternative system of a dominant factor would be equivalent to the system in mammals, where presence of the SRY gene on the Y chromosome initiates the determination of the sex as male, and without this, the development in a mammal becomes female. The big difference is that if there is a dominant female-determining gene on the W chromosome, the default development in a bird should be male while the default development in a mammal is female. One additional factor of bird sex determination that should be mentioned is that in female chicken, and many but not all other bird species, the right side gonad initially develops but later fails in the female while both side gonads are active in males. No matter what the determining mechanism might be, the presence of estrogen in females does make a major difference versus the lack thereof in bird developing as males.

Sexual selection: this is a form of natural selection in which a member of one sex (more often the female) selects a mate based on one particular trait. The trait in question can be ornamentation, behaviour ("dancing ability") or whatever. Extremes of sexual selection are often seen in species that perform lekking.

Speciation: the process of two populations going from being one species to being two species. This can happen during a period of geographic isolation (allopatry, vicariance) or in sympatry.

Speciation in sympatry: for two species to arise in sympatry is a difficult process to prove. For this to happen, one current idea is that sexual selection would be combined with some ecologic differences for sympatric speciation to happen. One example is mentioned in Vidua.

Species: the most important unit in taxonomy, and perhaps therefore, many different definitions of the word species exists (called species concepts). A thorough discussion of the different species concepts is far beyond the scope of this dictionary. See this Birdforum thread for a short discussion and for references to several papers on the subject.

Speculum: a contrastingly coloured area of the secondaries; see Wings. This designation is most commonly applied to dabbling ducks, but can also be used for parrots to mention one other group.

Subspecies: a geographically defined population that differs in some defined way from another population. If it is impossible to say where one population ends and the other starts (because there is a very wide gradual variation (cline)) then there really is one population and they are the same subspecies, even if the most distant birds are very different. If there are within 1100 km, 500 km with type A, 100 km of gradual change, and 500 km with type B, then types A and B would normally be treated as two subspecies. There is a certain degree of personal interpretation as to when an area of mixture is narrow and stable (the two taxonomic units are different species), a little wider or unstable (the two taxa are subspecies) or a little wider yet (one subspecies). See this BirdForum thread for a discussion of the topic. In Opus, subspecies are currently listed based on Clements Checklist[1] with occasional mention of differences of opinion in other checklists. Also note that some taxonomists consider the concept of subspecies to be too loosely defined to be of any value and therefore do not recognise any.

Subsume: used in taxonomy to indicate that one group no longer exists because all members were included under a different group. A typical example would be a genus which no longer is used because all species in that genus have been subsumed into another genus (see e.g., Sporophila).

Subterminal: near the end of something such as a feather or a tail. One example would be a bird with white at the very end of the tail and with a black band just inside of that; that bird would have a black subterminal band.

Supraloral: a term used for the area just above the lore/loral area, which in turn is the area between the eye and the base of the bill. For the lore, see the passerine head drawing in the Topography#Heads section.

Superspecies: a term used for a group of very closely related species that are too distinct to be subspecies of the same species, and which are more closely related with each other than with other members of the genus. The term superspecies are most frequently used about a group where the members are allopatric.

Sympatry, sympatric: about two populations that occur in the same or at least overlapping areas. See also Speciation in sympatry.

Synanthropic: about a species that is usually living in close proximity to humans. Synonymous with eusynanthropic, and opposite of exanthropic.

Syndactyl: Having the third and fourth toes on each foot joined for at least part of their length. This is found in the kingfisher family. See Legs and Feet.

Synonym (abbreviation, Syn.): Two (or more) different names for the same thing. There are two important variants in ornithology:

  • Nomenclatural synonym - this is where the two different names mean exactly the same bird. Thus for example when the genus Sterna was split, the Sandwich Tern was moved from Sterna to Thalasseus; the old name Sterna sandvicensis is a nomenclatural synonym of the new name Thalasseus sandvicensis.
  • Taxonomic synonym - this is where the two different names mean slightly different birds, which some people might consider different, but others might consider to be the same. Birds which look like Sandwich Terns in North America are treated by some ornithologists as a different species Cabot's Tern Thalasseus acuflavidus, but others consider them the same species; for them, Thalasseus acuflavidus is a taxonomic synonym of Thalasseus sandvicensis.

Synonymise, synonymised: this is obviously related to being a synonym, above. It is used when trying to say that a taxonomic identifier is no longer used, because it is no longer considered significantly different from another taxonomic identifier. The most frequent use of this in Opus is when more than one subspecies has been described but one of them is no longer in use. The reason for no longer considering a subspecies valid can be either of the two mentioned above.

References S

  1. Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2016. The eBird/Clements checklist of birds of the world: v2016, with updates to August 2016. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
  2. https://karger.com/sxd/article/10/5-6/288/296439/Sex-Reversal-in-Birds

This page is divided into several sections: Dictionary A-C, Dictionary D-F, Dictionary G-L, Dictionary M-O, Dictionary P-S and Dictionary T-Z.