Tag Archives: flightless cormorant

Boobies and Such Encountered In The Galapagos

I have returned from The Galapagos and a most amazing Voyage on the Samba.

Early AM kayak departure from the Samba

The experience was exhilarating, enlightening and enchanting (therefore exhausting) and at some point I shall edit a brief movie/slideshow and post it somewhere for those interested.

Until then, here’s a red-footed booby I encountered on the island of Genovesa where a veritable cornucopia of exotic birds feed, nest and fly about,  seemingly unconcerned  about human visitors.

Red-footed Boobies are spectacular divers, plunging into the ocean at high speeds to catch prey. They are beautifully adapted for diving, with sleek, torpedo-shaped bodies, closeable nostrils, and long wings that wrap around their bodies as they slice into the water. This one, nesting in a red mangrove, seemed unperturbed by me standing a foot away but was intrigued by my red (Olympus TG-5 underwater) camera.

Charles Darwin did not visit Genovesa and none of the boobies (blue or red-footed or otherwise) played a role in his Theory of Evolution to my knowledge. They are not endemic or unique to the Galapagos.

The Song Of the Flightless Cormorant

There are many endemic animal species in the Galapagos which likely influenced Darwin’s thinking. On the youngest island,

It is found on just two islands; Fernandina, and the northern and western coasts of Isabela. Distribution associates with the seasonal upwelling of the eastward flowing Equatorial Undercurrent (or Cromwell Current) which provides cold nutrient rich water to these western islands of the archipelago. The population has undergone severe fluctuations; the 1983 an El Niño-Southern Oscillation (ENSO) event resulted in a 50% reduction of the population to just 400 individuals. The population recovered quickly, however, and was estimated to number 900 individuals by 1999.

Fernandina,  I encountered the flightless cormorant. The Galapagos cormorant is the only flightless cormorant in existence.

Evolutionary biologist Patricia Parker (who is the senior scientist at the St. Louis Zoo) appears to be the leading researcher on endemic Galapagos bird species. She collected blood from the Galapagos cormorants, searching for mutations that might explain their useless wings.

She and her fellow researchers  discovered about a dozen mutated genes in the Galapagos cormorants known to trigger rare skeletal disorders in humans called ciliopathies, often characterized by misshapen skulls, short limbs, and small ribcages. Since Galapagos cormorants have short wings and an unusually small sternum, the researchers suspected this link was significant.

The Sexual Attractiveness of The Male Blue-footed Booby 

The blue-footed booby (BFB) is more famous on the Galapagos, primarily because of its mating dance but also because of its fascinating bright blue feet. During the mating dance the male booby prominently displays his sexy feet.

Blue-footed boobies on Isabela Island. Note the varying shades of blue in their feet

A fascinating study published in 2006 suggests that the brighter the blueness of the male booby feet, the healthier he is and the more likely he is to hook up with a female booby.

When male boobies were food deprived their feet became duller and when re-fed fresh fish the blueness brightened within 48 hours.

Variation of dietary carotenoids induced comparable changes in cell-mediated immune function and foot colour, suggesting that carotenoid-pigmentation reveals the immunological state of individuals.

In a second experiment the researchers captured male BFBs after their female mate had laid a first egg and painted a dull blue make-up on the male BFB feet. The females “decreased the size of their second eggs, relative to the second egg of control females, when the feet of their mates were experimentally duller. Since brood reduction in this species is related to size differences between brood mates at hatching, by laying lighter second eggs females are facilitating brood reduction.”

Another  study in 2011  found that  damage to the DNA  of sperm increases with the age of male blue‐footed boobies. Furthermore, like humans sexual attractiveness (foot colour) declines with age in the BFB and is correlated with sperm DNA damage. The authors speculated that. “By choosing attractive males, females might reduce the probability of their progeny bearing damaged DNA.”

I will leave discussions on the technique for acquiring BFB sperm and for applying make-up to their feet to less squeamish authors. In the meantime we can all rest easy with the knowledge that female BFBs like their human counterparts prefer youngish males with brightish  blue suede shoes.

Galapageinosly Yours,

-ACP

(Featured image credit: Cassiano “Zapa” Zaparoli)