Antarctic Warming Changes Penguin Breeding Cycles

Highly suspect piece from Living Green. To begin with Antarctic sea ice is increasing, not decreasing and this has been the case for the last 50 years or so. Moreover the Antarctic Peninsula is not at all representative and the portion under discussion is not even in the Antarctic but protrudes north of the Antarctic Circle into the Southern Ocean.

Three penguin species that share the Western Antarctic Peninsula for breeding grounds have been affected in different ways by the higher temperatures brought on by global warming, according to Stony Brook University Ecology and Evolution Assistant Professor Heather Lynch and colleagues.

The work by Lynch and her team is contained in three papers that have been published online in Polar Biology, Ecology and Marine Ecology Progress Series (MEPS).

Lynch and her colleagues used a combination of field work and, increasingly, satellite imagery to track colonies of three penguin species – Adélie, chinstrap and gentoo. The Adélie and chinstrap migrate to the peninsula to breed, while the gentoo are year-round residents. (Penguins are only found in the Antarctic, and not in the Arctic.)

The Antarctic is considered one of the world’s most rapidly warming regions. Warmer temperatures move up the breeding cycle, causing the penguins to lay their eggs earlier. The resident gentoo population is able to adapt more quickly and advance their “clutch initiation” by almost twice as much as the other species. Lynch believes this may allow them to better compete for the best nesting space. The Adélie and chinstrap are unaware of the local conditions until they arrive to breed and have not been able to advance their breeding cycles as rapidly.

In addition, the gentoo prefer areas with less sea ice, and have been able to migrate further south into the Antarctic as the sea ice shrinks. The chinstrap and Adélie species rely more heavily on the abundance of Antarctic krill, which require sea ice for their lifecycle.

The result – the gentoo numbers are increasing while the other two species have noticeably dwindling populations on the Antarctic Peninsula.

Living Green

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One response to “Antarctic Warming Changes Penguin Breeding Cycles

  1. You have to wonder about some of these “researchers” and how they manage to get their false claims out and published. The British Antarctic Survey cannot be described as a skeptic organisation and this is what they say:

    http://www.antarctica.ac.uk/about_antarctica/wildlife/birds/penguins/adelie.php

    “Closely packed Adélie rookeries of many thousands of pairs are found all around the Antarctic continent, (not just the Peninsula, as the paper claims) on ice-free slopes and islands, often far from open water.
    Though they have the highest mortality for juveniles and adults of any penguins species, they are a successful species, with two and a half million pairs.” (That’s a dwindling population?)

    Chin Straps prefer it warmer: http://www.antarctica.ac.uk/about_antarctica/wildlife/birds/penguins/chinstrap.php

    “Named after the black band of feathers under their chin, chinstrap penguins are probably the most abundant penguin in the Antarctic regions, with an estimated population of nearly eight million pairs, concentrated on the Antarctic Peninsula. (noticeably dwindling?)

    They nest on ice-free slopes with thousands of breeding pairs, sometimes with their closest relatives, Adélie and gentoo penguins. The highest slopes are the most popular (they become ice-free first) and they use their beak and claws to reach seemingly improbable spots.

    They form a strong pair bond, returning each year to the same nest site with the same partner. Because of their warmer breeding location, chinstraps enjoy a longer breeding season than the Adélie.” (They like warm!)

    http://www.antarctica.ac.uk/about_antarctica/wildlife/birds/penguins/gentoo.php

    No one knows where the name “gentoo” came from, but they are one of the least numerous Antarctic penguins, with about 300,000 breeding pairs. There are large differences in gentoo penguins from different locations. Fledging is far quicker in the south (62-82 days) than in the north (85-117 days) and gentoos from the south are smaller than their northerly relatives. Unusually for penguins, their breeding times are not well synchronised and their breeding success fluctuates greatly from year to year.

    You can see an interactive distribution map here:

    http://www.penguinworld.com/map/map.php

    So gentoos are increasing and the other two dwindling? Shouldn’t
    Professor Lynch and her colleagues hand the money back and get proper jobs?

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