Fróðskaparrit - 01.01.2002, Page 134

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ECOLOGY OF ENDOPARASITES OF THE ATLANTIC PUFFIN
such aspects as the dependence of the
prevalence and intensity of infestation on
host gender and age, as well as on sea-
son/migrations. No conclusive statements
can be drawn from the fmdings regarding
gender and age, but there is a consensus
that prevalence is dependent upon sea-
son/migrations.
The aim of this paper was to study, for
the first time, the entire metazoan parasite
fauna of the most common áuk of the At-
lantic area, the Atlantic puffin.
Materials and methods
Study area
The birds were collected on the exposed
east coast of the isle of Nólsoy (62°00’N,
6°40’W). The island is 8.8 km long and 2.2
km wide. The puffíns breed along the entire
exposed east coast, but are far most con-
centrated at the colony ‘Urðin’, a 1 km long
area with great piles of loose boulders and
stones mostly overgrown by turf. The birds
were collected while they were wheeling
using ‘fleygastong’, the traditional Faroese
fowling equipment, which comprises a tri-
angular net fastened to a pair of 1.5 m long
fibre glass supports lashed to a 3.5 m long
pole. With this equipment is it possible to
catch one puffin at the time as the birds fly
by. The pole is quickly levered up to make
the net overtake the passing bird, holding
the pole at the end with one hand, and ap-
proximately a meter higher up with the oth-
er. During the fowling season, the first ten
puffíns caught by the fowler each day were
used in the analyses. This restricted the di-
urnal collecting time to c. 8 to 11 a.m. The
collection took place from the 03 July to 02
August, 2000.
Dissection
All internal organs, except the lungs, were
dissected out and frozen at -18 °C. Subse-
quently, the organs were thawed, dissected
and examined separately. The small intes-
tine was divided into three parts of equal
length. The heart, trachea plus syrinx, oe-
sophagus plus crop, gizzard, duodenum,
the three sections of the small intestine and
rectum were cut up lengthwise, 'scraped and
rinsed. The internal membrane of the giz-
zard was also dissected and investigated.
The gallbladder was cut up, scraped and
rinsed. The kidneys and the Iiver were cut
up cross- and lengthwise, scraped and
rinsed. AU the material was subsequently
examined stereomicroscopically. Parasite
specimens were fixed in formalin (6 % by
volume) or preserved directly in ethanol
(70 % by volume).
During dissection, the abdominal fat re-
serves were weighed to the nearest 0.1 g us-
ing a digital balance as an indication of bird
fitness. The bird’s sex was also recorded.
The puffins were assigned to one of two age
categories based on the developmental
stage of the Bursa Fabricir, this body part
regresses during sexual maturation, one
reason for which is the presence of the sex
hormones testosterone or progesterone
(Møllerand Erritzøe, 2001). The size of the
Bursa Fabricii was measured to the nearest
mm using a digital Vernier calliper.
Mounting
Nematodes: Each worm was taken directly