The effect of the nasal anatomy on the behaviour patterns of the European elk (Alces alces)
Abstract
This final thesis suggests that the European elk’s (Alces alces) nose is anatomically unique
when compared to reindeer and roe deer. The nasal bone has reduced in size, and the
cartilages of the nose have enlarged giving the moose a distinctive appearance. This thesis
aims to analyse explanations for the specific nasal anatomy in the elk and interpret which
could connect the anatomy of the nose to their behaviour while introducing the evolutionary
differences with other species. For this thesis, 37 European elk heads were collected from
the hunters of Satakunta, Finland. Two reindeer and two roe deer specimens were also
included. After, the analyzed data was used to make connections to the behavior of the elk.
This thesis discusses temperature regulation adaptation of the nasal respiratory system and
its extent to aid in the survival of the elk in the northern climate. The elk is classified as a
selective browser and has numerous typical adaptations that may have influenced the
anatomy of the nose. The European elk has separated nostrils, which has been suggested to
allow an enhanced ability to locate the source of the olfactory signal. Enhanced stereoolfaction is hypothesized to be one of the reasons behind the nasal anatomical differences in
the elk. This thesis suggests that aquatic foraging and diving could be an essential factor in
the evolution of the nasal anatomy. The European elk is the only non-aquatic artiodactyl
that forages in the aquatic environment. The nostrils unique narial structures and closure
could be connected to the foraging method. The final thesis research revealed the elk has
the shortest nasal bone compared to outgroups. The nostrils are situated furthest away from
each other when compared to outgroups. The nasal turbinates are the longest of the studied
species but proportionally take less space in the nasal cavity. The nasal cavity in the elk is
enlarged volume-wise and lengthwise. The lateral nasal cartilages are farther away from
each other than in outgroups. The nasal cavity is also more open due to the wider inner
structures. Antud kirjeldav lõputöö käsitleb põdra (Alces alces) nina anatoomiat võrdluses põhjapõdra
(Rangifer tarandus) ja metskitsega (Capreolus capreolus) kes kuuluvad samuti hirvlaste
sugukonda. Põdra ninaluu pikkus on vähenenud ja ninakõhred suurenenud ning ninal on
omapärane välimus. Lõputöö eesmärgiks oli analüüsida põtrade nina anatoomia iseärasusi
ning leida seoseid nina anatoomia ja põtrade käitumise vahel ning tuua välja erinevusi teiste
hirvlastega võrreldes. Töö koostamiseks koguti Soome Satakunta jahimeestelt 37 põdra
pead. Võrdlevanatoomiliselt uuriti 2 põhjapõdra ja 2 metskitse pead. Kogutud andmeid
analüüsiti ja püüti leida seoseid põdra erinevate käitumuslike iseärasustega. Käesolevas
töös arutletakse ka nina morfoloogia kohastumist kehatemperatuuri reguleerimisel kuna see
soodustab põdra ellujäämist põhjamaises kliimas. Põder on selektiivne mäletseja, kelle nina
ja tundlik ülamokk on anatoomiliselt kohastunud okste, lehtede, võrsete jms haaramiseks.
Kuigi põdral on väike ninapeegel, on ninasõõrmete vahemik pikk, mis väidetavalt
võimaldab paremini tuvastada lõhnade allikat ning suunda ehk kasutada nn stereohaistmist.
Varasemates uuringutes on kirjeldatud spetsiaalseid anatoomilisi struktuure, nt padjandid
ninaesiku seinas, mis võimaldavad ninasõõrmeid sulgeda. Taoline nina ehitus laseb loomal
muuta õhu liikumist ninaõõnes ning kergendada sukeldumist hankimaks toiduks veetaimi.
On ju põder ainus mitteveeline hirvlane, kes elab soode ja veekogude ligiduses ning otsib
neist toitu.