Global warming-induced migratory bird body size reduction and shape change

https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.13434

by bookofjoe • 7 years ago

90 16 7 years ago

onlinelibrary.wiley.com

allovernow• 7 years ago

I don't have access to the article, and there really isn't anything given in the abstract to actually link the change in body size to global warming. I hope the article does a better job than "warmer temperatures are expected to reduce bird size and here are a bunch of bird species which have gotten smaller over the last 4 decades, therefore climate change."

throwaway5752• 7 years ago

It is a scientific paper, not an "article". The abstract is pretty clear summarizing the findings and I'm not sure what you would otherwise expect from the abstract of a paper.

When I search for the paper's title, I found the full text on the third result https://www.biorxiv.org/content/10.1101/610329v1.full

edit: leaving as is but, "research article" or "paper", i was replying to the common usage meaning of "article". Anyway, my point about the abstract stands and the rest of the paper supports it well.

vixen99• 7 years ago

It is indeed an article though you and the comment you're 'correcting' leave out the word 'research'. Articles submitted by scholars and scientists with their groundbreaking research are termed as research articles. The article describes a model of what might be as in climate models. As you say, we also use the word 'paper' with 'peer-reviewed' if it's published in a peer-reviewed journal.

there_the_and• 7 years ago

A scientific paper is a type of article.

SolaceQuantum• 7 years ago

I think the money finding from the abstract is that temperatres above 40C predicts changes in bird size and wingspan length over an n > 70,000 specimens.

shealutton2• 7 years ago

Given that HN has had articles on the decline of the insect population (https://en.wikipedia.org/wiki/Decline_in_insect_populations) and the decline in bird populations (https://www.nytimes.com/2019/09/19/science/bird-populations-...), I am surprised that food supply is not listed as one of the causes of body changed.

neo4sure• 7 years ago

here you go https://www.scientificamerican.com/article/does-global-warmi...

chrisco255• 7 years ago

Macronutrients shift by minor amounts (single digit percentages), but there is more overall food. CO2 causes a more efficient use of water in photosynthesis and improves overall crop yields. The last time CO2 was in the thousands of PPM, the ancestors of birds...AKA dinosaurs...thrived and grew to enormous sizes.

smackay• 7 years ago

There are few details in the abstract but wing length is notoriously difficult to compare across measurers - the standard method of measuring the leading edge of the wing by gently straightening the primaries along a stopped ruler can easily generate differences of 2-3mm for different people measuring the same bird. It can be done for small groups of people who work together - wader ringers (shorebird banders if you are in the Americas) where they deliberately practise to standardise their technique. If the sample sizes are good then the error should be consistent across time so the conclusion might still be sound.

https://en.wikipedia.org/wiki/Bird_measurement#Wing

The good news from this is that nature is splendidly adaptable and able to compensate for changes that occur within a few decades. That says that plants and animals are a lot more robust than we think they are.

UPDATE: One confounding factor is that standards in handling birds are always improving so there's no way of telling whether measurements are comparable across time.

UPDATE: Thanks to throwaway5752 for finding the full text. The birds were measured by a single observer so you can ignore everything I said. Interesting result.

romaaeterna3• 7 years ago

There have been huge changes in habitat during the same period, driven largely by urbanization and changes in agricultural patterns, that dwarf any changes driven by climate. We actually had Ectopistes migratorius go completely extinct by 1901, due to habitat destruction, not climate change.

mempko• 7 years ago

Climate change at the human accelerated rate IS habitat destruction.

romaaeterna3• 7 years ago

But the important thing is the rate. How would you measure the habitat destruction? Distinct species per unit area? Biomass per unit area? Climate change affects no possible proxy that you could select as fast as a bulldozer and a housing development. (And in recent years, climate change has been positive for global biomass.)

chiefalchemist• 7 years ago

Birds eat insects, yes? If there's been a reduction in insects then wouldn't that impact birds' development?

Global warming-induced migratory bird body size reduction and shape change

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