Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks
I estimated when juvenile tail molt occurs for several commonly harvested duck species, mallards (Anas platyrhynchos), northern pintails (A. acuta) (hereafter referred to as pintails), gadwalls (A. strepera), lesser scaup (Aythya affinis), and redheads (A. americana). Tests showed that aging mallard...
Main Author: | |
---|---|
Format: | Text |
Language: | unknown |
Published: |
LSU Scholarly Repository
2006
|
Subjects: | |
Online Access: | https://repository.lsu.edu/gradschool_theses/2905 https://doi.org/10.31390/gradschool_theses.2905 https://repository.lsu.edu/context/gradschool_theses/article/3904/viewcontent/uc.pdf |
id |
ftlouisianastuir:oai:repository.lsu.edu:gradschool_theses-3904 |
---|---|
record_format |
openpolar |
spelling |
ftlouisianastuir:oai:repository.lsu.edu:gradschool_theses-3904 2024-09-15T17:39:18+00:00 Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks Siwarski, Thomas Michael 2006-01-01T08:00:00Z application/pdf https://repository.lsu.edu/gradschool_theses/2905 https://doi.org/10.31390/gradschool_theses.2905 https://repository.lsu.edu/context/gradschool_theses/article/3904/viewcontent/uc.pdf unknown LSU Scholarly Repository https://repository.lsu.edu/gradschool_theses/2905 doi:10.31390/gradschool_theses.2905 https://repository.lsu.edu/context/gradschool_theses/article/3904/viewcontent/uc.pdf LSU Master's Theses Aythya affinis lesser scaup Anas strepera gadwall redhead Anas americana tail molt age determination mallard Anas platyrhynchos northern pintail Anas acuta morphometric measures Environmental Sciences text 2006 ftlouisianastuir https://doi.org/10.31390/gradschool_theses.2905 2024-08-08T04:27:17Z I estimated when juvenile tail molt occurs for several commonly harvested duck species, mallards (Anas platyrhynchos), northern pintails (A. acuta) (hereafter referred to as pintails), gadwalls (A. strepera), lesser scaup (Aythya affinis), and redheads (A. americana). Tests showed that aging mallards by notched tail feathers became unreliable the earliest (early September), followed closely by pintails (mid-late September), with gadwalls being the latest of the dabbling ducks to lose reliability in aging by notched tail feathers (late November). Lesser scaup and redheads retained their notched tail feathers throughout January and the completion of hunting season. Based on initial banding and band recovery data I was able to separate birds into three age classes, juvenile (59), 1.5 years old adults (11), and adults 2.5 years old or older (23), creating a total sample size of 93 birds. From this sample of known-age banded birds I recorded five morhpometric variables including weight, wing length, bill length, tarsus length, and total length to determine if body size is related to ages over 1 year. Tests revealed that the only significant difference between the age classes was in wing length. However further tests showed that differences were not apparent between the 1.5 year old and 2.5 year old or older adults. Text Anas acuta LSU Digital Commons (Louisiana State University) |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
unknown |
topic |
Aythya affinis lesser scaup Anas strepera gadwall redhead Anas americana tail molt age determination mallard Anas platyrhynchos northern pintail Anas acuta morphometric measures Environmental Sciences |
spellingShingle |
Aythya affinis lesser scaup Anas strepera gadwall redhead Anas americana tail molt age determination mallard Anas platyrhynchos northern pintail Anas acuta morphometric measures Environmental Sciences Siwarski, Thomas Michael Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
topic_facet |
Aythya affinis lesser scaup Anas strepera gadwall redhead Anas americana tail molt age determination mallard Anas platyrhynchos northern pintail Anas acuta morphometric measures Environmental Sciences |
description |
I estimated when juvenile tail molt occurs for several commonly harvested duck species, mallards (Anas platyrhynchos), northern pintails (A. acuta) (hereafter referred to as pintails), gadwalls (A. strepera), lesser scaup (Aythya affinis), and redheads (A. americana). Tests showed that aging mallards by notched tail feathers became unreliable the earliest (early September), followed closely by pintails (mid-late September), with gadwalls being the latest of the dabbling ducks to lose reliability in aging by notched tail feathers (late November). Lesser scaup and redheads retained their notched tail feathers throughout January and the completion of hunting season. Based on initial banding and band recovery data I was able to separate birds into three age classes, juvenile (59), 1.5 years old adults (11), and adults 2.5 years old or older (23), creating a total sample size of 93 birds. From this sample of known-age banded birds I recorded five morhpometric variables including weight, wing length, bill length, tarsus length, and total length to determine if body size is related to ages over 1 year. Tests revealed that the only significant difference between the age classes was in wing length. However further tests showed that differences were not apparent between the 1.5 year old and 2.5 year old or older adults. |
format |
Text |
author |
Siwarski, Thomas Michael |
author_facet |
Siwarski, Thomas Michael |
author_sort |
Siwarski, Thomas Michael |
title |
Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
title_short |
Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
title_full |
Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
title_fullStr |
Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
title_full_unstemmed |
Reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of North American ducks |
title_sort |
reliability of determining adults from juvenile ducks by presence or absence of notched tail feathers in various species of north american ducks |
publisher |
LSU Scholarly Repository |
publishDate |
2006 |
url |
https://repository.lsu.edu/gradschool_theses/2905 https://doi.org/10.31390/gradschool_theses.2905 https://repository.lsu.edu/context/gradschool_theses/article/3904/viewcontent/uc.pdf |
genre |
Anas acuta |
genre_facet |
Anas acuta |
op_source |
LSU Master's Theses |
op_relation |
https://repository.lsu.edu/gradschool_theses/2905 doi:10.31390/gradschool_theses.2905 https://repository.lsu.edu/context/gradschool_theses/article/3904/viewcontent/uc.pdf |
op_doi |
https://doi.org/10.31390/gradschool_theses.2905 |
_version_ |
1810479073049182208 |