Thursday, December 6, 2012

Reproductive Plots


Black-footed Albatross (BFAL) and Laysan Albatross (LAAL) began laying their eggs weeks ago, and I’ve since been conducting a bi-weekly check of all nesting birds within four defined plots around the island. The aim of this annual study is two-fold, first to quantify the average timing of egg laying, incubation, hatching and fledging, and second to track the long term breeding success of known pairs within the plots. In summary, as of last check there were 167 BFAL and 100 LAAL nests, corresponding to the same numbers of breeding pairs, totaling 534 individual breeding birds. BFAL numbers have peaked and are expected to platue in the following weeks, with LAAL numbers reaching their max by mid December. With the assistance of others, I systematically walk around each plot and look for nests containing an egg. If an egg is present that nest receives a numbered orange marker, and the field readable alpha-numeric auxiliary bands of both parents are read and noted. If either of the parents are missing their band, either because it fell off or it was never put on, we band them. This involves one person grabbing the bill and scooping the bird up into a cradle position, while another uses banding pliers and spreaders to attach a long-term metal band on the left leg and a plastic alpha numeric on the right. For the most part the birds remain relatively calm during this process, although they often kick a bit. I’ve already received battle scars to my arms and legs from the sharp nails of their webbed feet during these kicking bouts. Some of them have perfected their aim and are just the right size to kick directly in the family jewels; I suspect these birds have been conspiring with Stan. Field work in the bird world, however, hasn’t officially begun until you’ve been shit on, which happened to me yesterday.

The female, once the egg has been laid, will leave the nest and hand over the first incubation shift to the male, so it can take weeks to finally read the bands of both parents. Sometimes there are anomalies, for instance in plot two there is a nest with both a LAAL and BFAL parent incubating an egg. Hybrids between these two species have been observed, but are uncommon. We have a local suspected hybrid named Prius that returns to the same spot on the island every year. Prius resembles a BFAL but awkwardly dances and calls like a LAAL, and understandably has thus far been unsuccessful at attracting a mate. I also found a nest in plot four (the first nest in the plots with an egg in fact) with two eggs, possibly indicating much to the disapproval of the Republican base the presence of two female parents, a behavior well documented in bird societies. It is likely that one of these eggs will be kicked out of the nest, or that both eggs are non-fertile and will fail, unless of course either of the females had been raped by the many gangs of bachelor males that cruise throughout the colony looking for trouble.

Approximately 60 days past laying, if all eggs miraculously survive the incubation phase, we’ll have at least 267 fluffy chicks wobbling about the plots, slurping of partially digested squid and toothbrushes collected by their parents from the reservoir of human waste that is the Pacific. Looking at the numbers the bulk of chicks will be hatching around my birthday on January 13th. Chicks, once hatched, take even longer to develop, especially if their parents are loading them with bits of plastic bags, cigarette lighters, and bottle caps.  Many will still retain their downy plumage when we depart the island in March, and most will not fledge until well into June and July, when hopefully I’ll be back surfing along the California Coast, with dog and beer waiting for me in the truck. It is highly probable that a fraction of the albatross I’ll surely observe soaring over swells next summer in Monterey will be birds that have hatched right here on Tern. I still find that to be an incredible thought.

1 comment:

  1. Your writings....I feel like I'm there....great job, and humor intact! What a birthday present forthcoming! That is incredible...the realization that some albatross sightings this summer in Monterey may have actually been born on Tern.

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