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.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04032006-151427 |
| Date | 07 April 2006 |
| Creators | Siwarski, Thomas Michael |
| Contributors | Andy Nyman, Robert Cox, Frank Rohwer |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04032006-151427/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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