Display | Investigative |
Aggressive | Sexual
The black curl of the penis of this male Arctic hare can be seen below its stomach.
David Gray's observations during the late winter breeding
season at Sverdrup Pass on Ellesmere Island (April and May)
are the first to document an unusual display-behaviour by
male Arctic hares (Lepus arcticus). This behaviour marks
the start of the Arctic hare's breeding season.
The display behaviour occurs at the end of a resting and
grooming period. The behaviour follows grooming of the body
fur. While the male stands with legs tensed, the long, slender,
dark-coloured penis is uncoiled and stretched out along the
belly, often extending out beyond the forelegs. This whip-like
extension of the penis lasts about 1.5 seconds and is repeated
up to 12 times in one bout.
David Gray first saw this behaviour in early April. It is
most common in late April and early May. Later in the season
it coincides with other breeding behaviours; it goes on until
the mating season is over in late May. It happens within
large groups of both sexes and also when a male is alone.
The Arctic hare standing third from the left is a male doing a penis diplay.
The function of this behaviour may be to visually stimulate
females into breeding and receptivity. Male Arctic hares
show increased interest in females before the females are
actually receptive. Therefore, males must be reproductively
active in order to initiate the breeding season. The male
Arctic hare's display behaviour may be triggered by the increase
in daylight in March (in the High Arctic, light levels steadily
increase from December to April). The timing of the male
display coincides with the time that breeding should commence
in order for young hares to have time to sufficiently develop
The timing is another reason to think that something besides
increasing light levels in spring stimulates female Arctic
hares into receptivity, even though lengthening daylight
stimulates some other female mammals (including some hare
species) into receptivity. By the time the females need to
be receptive, no further increase in the amount of daylight
is possible because by mid April the sun is above the horizon
for all 24 hours of the day.
The timing of receptivity, copulation and ovulation is important.
(Ovulation is stimulated by copulation). All breeding needs
to occur in a limited and specific time so that the young
are born at the optimum time for adequate summer feeding
and growth that will allow them to survive the coming winter.