Wednesday, September 30, 2015

Galapagos Birds: Magnificent Frigatebirds

The first Magnificent Frigatebird appeared early on our first day on the boat, and they were nearly constant companions to our boat when it was cruising. They came very close.

The male's bright red neck pouch during breeding season is visible from quite a distance.

Our first landing took us to an island rookery where numerous Frigatebirds were concentrated on ill-formed nests in very low bushes.  During breeding season, the male is often seen with the pouch inflated to create a display of vitality. As nesting progresses, the neck pouch recedes as seen above.

Frigatebirds are an aggressive bird with a reputation for stealing food from any other bird, as it returns from the sea. Various sources call them pirate birds or condors of the sea. They seem to eat anything.  Their aggressive nature was also displayed towards neighboring nests, and it appeared to include unattached males seeking to displace other males from a nest. The male seen below landed near the couple on the nest and displayed what he likely considered a superior inflated pouch.  Note the colors on his neck hackles.

The intruder neither intimidated the male, nor evoked any visible interest from the female partner.    A stare-down developed.

A physical conflict soon developed. The female seemed impassive to the fight as it progressed.

The conflict continued beak-to-beak with no way of knowing which one was winning.

The fight ended with no apparent knock-out blow, as the intruder suddenly abandoned the fight. There was no victory celebration, and the female was as impassive as ever. Some degree of calm returned.

The breeding appears to be spread out over a span of time; we saw a mix of  courting pairs, small chicks and much larger chicks. The  female lays a single egg.  An adult guards the lone chick for the first weeks, but as it gains size both adults go to sea for food, and it is left alone to await a feeding visit. So it was that we came upon nests that had a single chick of pretty good size.  Many chicks were panting in the intense equatorial sun and alertly watching the sky, likely looking for an adult returning with food. The chick below is seen to be shedding its down for juvenile feathers.

As noted, the nest construction is sparse and unkempt.  There seems to be a shortage of building materials, and the low bushes have little to support a more elaborate construction. Nest malfunctions happen and chicks fall out, such as is probably the case below.  It is likely doomed, and the nesting pair will have to start over.

A visit to the Galapagos is done with the requirement that you do not to interfere with  nature's processes, and that you stay on the trails to minimize your impact.  This chick will not be returned to its nest, nor even approached. That hands-off policy is a key to keeping the islands true to their heritage. There appears to be no shortage of Frigatebirds.

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