Hêng-ûi-ha̍k (Eng-gí:ethology), ha̍k-chiátōng-bu̍t hêng-ûi (animal behaviour), sī choan-bûn ián-kiù tōng-bu̍t hêng-uî (iā ū kóng "hêng-tōng") êtōng-bu̍t-ha̍k hak-kho. Hiān-tāi ê hêng-uî-ha̍k tāi-io̍k sī tuì 1930 nî-tāiNikolaas Tinbergen kapKonrad Lorenz khai-sí. Chit-ê ha̍k-kho ê ián-kiù kapsim-lí-ha̍k chin ū kau-chhap.
Chiam-tùi chit bûn ha̍k-būn, Tinbergen thê-chhut liáu 4 hāng būn-tê:
- Kong-lêng (function): Hêng-ûi tùi tōng-bu̍t chûn-oa̍h kapseⁿ-thòaⁿ ê éng-hióng sī jû-hô? Ūi-siá tōng-but sī á-né êhoán-èng, m̄-sī pa̍t khoán hoán-èng?
- Goân-in (causation; in-kó): Sī siá-mi̍hchhì-kek ín-khí hoán-èng, i koh sī á-ná siū chòe-kīn êha̍k-si̍p lâi siu-kái?
- Hoat-io̍k (development): Tùi teh nî-hòe hêng-ûi sī á-choán kái-piàn, jî-chhiá sī siá-mi̍h khoán ê chá-kîkeng-giām tùi tōng-bu̍t tián-hiān hêng-ûi sī pì-iàu--ê?
- Chìn-hòa ê le̍k-sú (evolutionary history): Hêng-ûi kap siong-koanbu̍t-chéng ê siong-sū hêng-ûi pí-kàu khí--lâi sī á-ná, i tī hun-hòa kòe-têng tiong koh khí-sian sī á-ná?
