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Description:
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The abundance of Rio Grande wild turkeys (Meleagris gallopavo intermedia ) in
the southeastern Edwards Plateau of Texas has declined since the late 1970s . Because
knowledge of reproductive rates is important to understanding the dynamics of a
population , radio -tagged hens were monitored during the 2005–2007 reproductive
seasons to evaluate and compare reproductive parameters from areas with both declining
and stable population trends .
During January–March of 2005–2007 , turkey hens were captured and radiotagged
on 4 study areas ; 2 within a region of stable turkey populations , and 2 within a
region of declining populations . Monitoring occurred from January–July each season to
determine nest - site locations . Nesting attempts , nest fate , clutch size , initiation date ,
and nest age were recorded . Nests were monitored ≥3 times weekly in order to estimate
production parameters and daily nest survival . Poults were captured by hand and fitted
with a 1 .2 glue -on transmitter and monitored daily to estimate daily survival .
Estimates show production was greater in stable regions than declining regions of
the Edwards Plateau . Eighty -four percent of hens attempted to nest in the stable region and 67 % attempted in the declining region . Eighteen of 102 nests were successful (≥1
egg hatched ) , in the stable region and 7 of 60 nests were successful in the declining
region . Nest -survival analysis showed an influence of temporal variation within years ,
yet no differences in nest survival were detected between stable and declining regions .
Poult survival also showed no difference between regions .
The 2 overall objectives of this study were to determine if nesting parameters and
nest survival were limiting factors in Rio Grande wild turkey abundance in the Edwards
Plateau . Regional differences in production suggest the cause of the decline in the
southeastern portion of the Edwards Plateau could be associated with lower reproductive
output and consequently , success . Regional differences in nest survival were not
detected , thus not likely to cause differences in turkey abundance between regions . |