RESULTS
Out of the five tagged seahorses there were two pairs and one
single male; the two males in the tagged pairs have been
re-sighted most frequently, particularly male No. 261
(Figure 3). Both of these males were repeatedly found within
metres of a seabed feature through the summer. Plotting the
GPS co-ordinates (including circles of GPS error, +3 m) for
all animals as polygons indicates home ranges up to 30 m
across (Figure 4). There is overlap in home range of a
female (No. 293) with two males (Nos 253 & 261). Allowing
for the positional uncertainty in the GPS positions, these
home range areas over the summer, cover 30 –400 m2
(average 167 m2
).
Both the males (Nos 253 & 261) were adults with fully
developed pouches but not pregnant when first tagged in
May. The mature female (No. 293) was located less than
2 m away from the male (No. 261) in dense seagrass. The
courtship display of one pair has been recorded on video,believed to be a first in the British Isles for this species. The
female swam 1 m towards the male at the edge of the seagrass
then both swam about 1 m into dense seagrass and started an
elaborate display. They held their snouts close to their trunks,
with tails entwined, the male swaying, jerking backward and
forward for 15 minutes before separating but still staying
close for several more minutes. All three tagged males have
been repeatedly pregnant. The longest series of observations
was of No. 261 which was continuously pregnant from late
May to early September.
One surprising observation made and photographed by
Trewhella and Hatcher, was the possible courtship display
between individuals of different species. The female H. guttulatus
and pregnant male H. hippocampus had their tails
entwined, both exhibiting courtship coloration. A pregnant
male H. guttulatus was within 1 m of the pair. In captivity it
has been known that species can inter-breed but this has
never been observed in the wild.