Associate Professor Graham Hall’s report on the collection of head and wing samples from the 2015 season points to some interesting changes.
In 2009, Field & Game Australia launched a project to collect detailed information about the species, sex and age of the birds being harvested during the annual Victorian duck hunting season.
The aim of the study is to gather data over time that may eventually form part of a robust Adaptive Harvest Management model, and contribute to the better understanding of the biology of waterfowl in Victoria.
The 2015 report details 482 samples provided by hunters although no samples were contributed from southwest Victoria.
Professor Hall said the presence of FGA staff in key locations or the presence of a very active branch like Sale, increased the number of samples collected.
The number of collected samples continues to increase year on year and the number of “other” species collected in 2015 was the highest for several years. Grey teal made up the majority of samples, which was consistent with previous seasons, but all game species were present.
The mean wing notch length of all species collected in 2015 was similar to measurements in most other years, except 2012.
Professor Hall said comparing the start and end of the 2015 season suggests the bird populations had maintained their body condition without any major changes in wing notch length.
“For Black ducks the issue of hybridisation with Mallards is now known to statistically affect the head and bill length with ‘pure’ Black ducks having a 3 cm smaller length than ‘hybrid’ birds. However, the notch length of the Black ducks and their hybrids is similar.”
As for bird movement, the 2015 harvest continued the appearance of modest numbers of hardhead at the end of the season and Pink-eared ducks at the start of the season.
Professor Hall said these results reinforced the data that these inland species were constantly moving throughout their range in search of more benign climes in response to perceived harder climatic conditions.
During previously wet seasons Chestnut teal have been abundant in the harvest. However, during 2015 only 28 specimens were returned by hunters, suggesting that this species may have moved to other areas outside of Victoria.