(1) Stable water levels and a well developed network of tranasses allowed trapper access even 

 during periods of extreme low water. 



(2) Water level and salinity management created a diversity of vegetation and habitat 

 conditions conducive to furbearers. 



(3) Since large alligators are furbearer predators, areas having high populations of large 

 alligators and low furbearer populations were targeted for the selective harvest of alligators. 



(4) Certain areas within each semi-impoundment were burned so that food and cover remained 

 available during the revegetation process. 



The relatively low furbearer harvest in semi-impoundment 9 may be attributed to poor trapper 

 access from extreme water hyacinth infestation. From the 1975-76 season through the 1984-85 

 season, approximately 50% or more of the area remained choked with water hyacinths despite 

 herbicide treatments. In 1985, brackish water introduction into semi-impoundment 9 was successful 

 in eradicating water hyacinths. Access was then opened to the entire area and the harvest 

 increased to 1/1.9 ha during the last 2 years. 



Effects of Drawdowns on Fur Harvest 



Drawdowns did not appear to adversely affect nutria populations from the 1975-76 season 

 through the 1985-86 season. In six instances the harvest of nutria improved after spring-summer 

 drawdown. In seven instances, the nutria harvest decreased after a drawdown, and in six instances, 

 there was no apparent difference. 



Since natural droughts and floods occur periodically, nutria and other furbearers have apparently 

 adapted to a wide range of conditions. During a nutria tagging study in Louisiana, Kays (1956) 

 concluded that nutrias usually remained in one general area throughout their lives. Adams (1956) 

 stated that data from tagged nutrias strongly indicated that the daily cruising range seldom exceeded 

 0.18 km and under favorable conditions the range may be less. During an 11 month mark and 

 recapture study, Robicheaux (1978) found that 80% of recaptured nutrias moved less than 0.4 km 

 from the previous capture site. Even during drawdown, it appeared that nutrias did not emigrate 

 from the LPWMA but remained within their home range. 



Alligator Harvest 



Alligator (Alligator mississippiensis) skin lengths over an 11 -year period averaged 203.2 cm at 

 LPWMA and averaged 213.9 cm for the State of Louisiana (Tables 7a and 7b) (Joanen and 

 McNease 1987; LA Dep. Wildl. Fish., unpubl. harvest records 1984-86). These data reflect a stable 

 alligator population for both LPWMA and Louisiana. A progressive decrease in skin lengths over 

 time would indicate a decline in the alligator population. 



Over an 11 -year period the average success rate was 99.3% for LPWMA and 94.4% for the 

 State of Louisiana. The excellent hunter success rate at LPWMA was due to a high alligator 

 population and hunter efficiency. Sixty-four alligators were harvested in 29 hunting days in 1975, 

 and 61 were harvested in 2 days in 1985. 



'Semi-impoundments were used by alligators when Little Pecan Bayou and adjacent oilfield canals 

 became highly saline (Figure 2). Little Pecan Lake was managed as a permanent fresh to 



306 



