Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ontogeny of aerial righting and wing flapping in juvenile birds   Mechanisms of aerial righting in juvenile Chukar Partridge (Alectoris chukar)
were studied from hatching through 14 days post hatching (dph). Asymmetric
movements of the wings were used from 1 to 8 dph to effect progressively more
successful righting behaviour via body roll. Following 8 dph, wing motions
transitioned to bilaterally symmetric flapping that yielded aerial righting via
nose down pitch, along with substantial increases in vertical force production
during descent. Ontogenetically, the use of such wing motions to effect aerial
righting precedes both symmetric flapping and a previously documented behaviour
in chukar (i.e., wing assisted incline running) hypothesized to be relevant to
incipient flight evolution in birds. These findings highlight the importance of
asymmetric wing activation and controlled aerial manoeuvres during bird
development, and are potentially relevant to understanding the origins of avian
flight.

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The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: math
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: comp-gas
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg