Gs. Fowler et al., HORMONAL AND REPRODUCTIVE EFFECTS OF LOW-LEVELS OF PETROLEUM FOULING IN MAGELLANIC PENGUINS (SPHENISCUS-MAGELLANICUS), The Auk, 112(2), 1995, pp. 382-389
Petroleum fouling has many deleterious consequences for marine vertebr
ates, ranging from increased energy expenditure to the death of the or
ganism. We measured circulating levels of reproductive and adrenocorti
cal hormones in Magellanic Penguins (Spheniscus magellanicus) that wer
e partially covered with petroleum following a marine oil spill off th
e Patagonian coast, and in a non-oiled control group. Levels of lutein
izing hormone, androgens and estradiol, but not progesterone, were low
er in oiled penguins than non-oiled control birds. Corticosterone was
higher in oiled than control females, but did not differ and was basal
in males. Few of the pairs with an oiled partner later established ne
sts with eggs. Even low levels of oil fouling in Magellanic Penguins a
ppear sufficient to interfere with reproduction. Oiled penguins that w
ere held captive for washing had elevated levels of corticosterone, an
d appeared to be stressed both by captivity and by the washing process
.