\[ **BT: [[chordates]]** ] --- # birds [[Several bird species exhibit a mosaic of male and female characteristics.]][^1] - see also: [[genetics#mosaicism]] --- ## classification of birds | order | family | genus | species | common name | | ---------------------------- | ---------------------------------------------- | --------------------------------- | ------------------------------------------------------------ | ---------------- | | [[#Passeriformes (Order)]] | [[birds#Corvidae (Family)\|Corvidae (Family)]] | | | [[birds\|crows]] | | | | | | [[ravens]] | | [[#Anseriformes (Order)]] | [[#Anatidae (Family)]] | | *[[birds#Anser caerulescens (Snow goose)\|A. caerulescens]]* | snow geese | | [[#Charadriiformes (Order)]] | [[#Scolopacidae (Family)]] | *[[#Calidris (Genus)\|Calidris]]* | *[[#Calidris pugnax (ruff)\|C. pugnax]]* | ruffs | | | | | | | --- ## Anseriformes (Order) ### Anatidae (Family) #### *Anser* (Genus) ##### *Anser caerulescens* (snow goose) [[Female–female pairs of snow geese have been observed raising their young together. Male–male snow geese mounting has also been observed.]][^2] --- ## Passeriformes (Order) ### Corvidae (Family) Corvidae is a family of oscine passerine birds that contains the crows, ravens, rooks, magpies, jackdaws, jays, treepies, choughs, and nutcrackers. In colloquial terms, the crow family is made up of corvids. Currently 135 species are included.[^3] Corvids are derived from [[countries of the world#Australia|Australian]] ancestors, and spread throughout the world from there.[^4] #### crows Crows are found in most parts of the world—except southern [[Earth#South America|South America]].[^5] They are smaller than [[#ravens]] and (generally) not as thick-billed.[^6] They have a wingspan of approx. 50 cm. Crows live together, hunt together, defend territories, and care for young together.[^7] Crows in [[countries of the world#Australia|Australia]] have white irises.[^8] [[We’ve found Neolithic era paintings of ravens (or crows) in Tajo Segura, Cadiz, Spain.]][^9] #### ravens - see: [[ravens]] ## Charadriiformes (Order) ### Scolopacidae (Family) **Sandpipers.** #### *Calidris* (Genus) ##### *Calidris pugnax* (ruff) - see: [[ruff]] [^1]: Amanda Leigh Mascarelli, ‘[[Mascarelli, ‘Male–Female Flexibility in Animals’, 2015|Explainer: Male–Female Flexibility in Animals]]’, *ScienceNewsExplores*, 31 July 2015, [https://www.snexplores.org/article/explainer-male-female-flexibility-animals](https://www.snexplores.org/article/explainer-male-female-flexibility-animals). [^2]: Julia D. Monk et al., ‘[[Monk et al, ‘An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals’, 2019|An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals]]’, *Nature Ecology & Evolution*, vol. 3, no. 2 (2019), p. 1625, <https://doi.org/10.1038/s41559-019-1019-7>. [^3]: ‘Corvidae’, Wikipedia, last edited 5 January 2026, 20:35 (UTC), <https://en.wikipedia.org/wiki/Corvidae>. [^4]: ‘Corvidae’, Wikipedia, last edited 19 February 2025, 17:24 (UTC), <https://en.wikipedia.org/wiki/Corvidae>. [^5]: ‘Crow’, *Encyclopedia Britannica*, updated 23 February 2024, <https://www.britannica.com/animal/crow-bird>. [^6]: ‘Crow’, *Encyclopedia Britannica*, updated 23 February 2024. [^7]: ‘Crow’, *Encyclopedia Britannica*, updated 23 February 2024. [^8]: ‘Little crow (bird)’, Wikipedia, last edited 1 March 2025, <https://en.wikipedia.org/wiki/Little_crow_(bird)>. [^9]: Betty Coon Wainwright, ‘[[Coon Wheelwright, ‘A Storytelling of Ravens’, 2013|A Storytelling of Ravens]]’, *Jung Journal: Culture & Psyche*, vol. 7, no. 1 (2013), p. 10, <https://www.jstor.org/stable/26596516>.