The origin of the Icelandic horse has been researched twice; one comparative study with
the Norwegian breed Nordland/Lyngen horse,
where several similarities were found.
Not only do the two breeds look very similar,
it also came up that several of the Nordland horses taking
part in the experiment proved to perform the tölt,
a gait characteristic for the Icelandic horse.
The genetic relations has also been researched,
showing that the breed is closely related to Norwegian breeds,
but also the Shetlands pony and the Mongolian horse.
From a study entitled: REPRODUCTION OF ICELANDIC HORSES KEPT UNDER FREE-RANGE CONDITIONS
by Marit Smistad, Szent Istvan University, May 2006:
1) Attainment of puberty
Puberty was attained at the age of two or three years (70% and 90% respectively)
for the mares,
and stallions generally attained puberty by two years of age.
Differences were observed compared to horses kept indoors
with good nutritional status.
Some cases showed that well-fed horses could attain puberty already by one year of age.
2) Reproductive efficiency
The horses which took part in the project showed relatively high productive rate;
with over 80% live foals born. Surprisingly 70% of the twin foals survived (16 cases).
From this we can conclude that the survival rate is about the same as in housed horses.