Adjusting for body mass change in white‐tailed deer during hunting season

Abstract

Age-specific body mass is a variable of interest to managers and hunters of white-tailed deer (Odocoileus virginianus). Long hunting seasons across much of the southern United States include most of the period of active rut, when individual body mass fluctuates over time. Adjusting body mass for harvest date would improve accuracy of age-specific mass estimates and enable managers to make valid comparisons among years with different harvest patterns. We used 17 years (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007) of harvest records from the Delta, Thin Loess, and Lower Coastal Plain (LCP) soil regions of Mississippi, USA, to develop age-and regionspecific models of average daily mass at harvest for male and female deer over a 121-day hunting season. Models of female mass peaked in early winter near median population conception date. Among females, yearling mass exhibited the most marked fluctuations, with a projected increase of 7.3% from the start of hunting season to its seasonal peak. Modeled mass of harvested males fluctuated more strongly, peaking well before median conception date and decreasing an average of 13.8% from seasonal peak to the end of hunting season. Harvest mass of prime-aged (5.5-7.5 years old) males began decreasing earliest in all regions, reflecting earlier participation in rut, and mass of older males always peaked earlier than younger males in the Delta and Thin Loess. In the LCP, projected peak male body mass did not correlate with age class and spacing between dates of peak mass was greatly truncated relative to other regions. Different patterns of mass change between the LCP and other regions may be explained by later breeding, greater overlap of rut-related and seasonal hypophagy, and lower nutritional plane. Models to correct body mass for harvest date should be specific to sex and age class and distinguish among adjacent populations with different mating season phenology. Ó 2017 The Wildlife Society.

Use of cast antlers to assess antler size variation in red deer populations: effects of mast seeding, climate and population features in Mediterranean environments

“…In addition, antler size relative to body size was found to be greater during years with favorable environmental conditions (Mysterud et al ., ). In particular, weight recovery after the rut (~25% of weight is lost during the rut; McMahon, ; Strickland et al ., ) and body size/condition at antler casting have been suggested to strongly correlate with allocation to antler growth (Hyvärinen, Kay & Hamilton, ; Muir et al ., ; Gaspar‐López et al ., ; Gómez et al ., ), although weight gain during antler development is also important (Gaspar‐López et al ., ). An example of high‐quality food after the rut is that provided by mast‐seeding trees (e.g.…”

Nutrition and ontogeny influence weapon development in a long-lived mammal

“…age classes than is often assumed, especially in comparison with lekking or haremdefending cervids(DeYoung et al 2009;Acker 2013;Turner et al 2016). Although the searching and tending strategy of older males requires a large investment of body reserves(Johns et al 1982, Strickland et al 2017, yearling males may obtain matings using low-energy, non-confrontational strategies(Sorin 2004;Holtfreter 2008; Jones et al 2011). This situation roughly corresponds to that of arthropod species with weapon or body size dimorphism that also exhibit morph-specific mating strategiesMoczek and Emlen 2000; Karino et al 2004;Zatz et al 2011).…”

“…). We adjusted body mass for the effect of harvest date using region-and age class-specific models to estimate harvest date-corrected mass (HDCM;Strickland et al 2017). We developed the ratio antler mass:body mass by dividing predicted antler mass (g) by HDCM (kg).…”

Seasonal flooding effects on deer in the Mississippi river batture

“…Although winter flooding apparently provided long‐term benefits from silt deposition, winter flooding did not negatively affect current‐year antler growth. The post‐rut period is a critical time for males, which commonly lose >20% of body mass during the mating season (Strickland et al , Foley et al ), and antler growth may be correlated with body condition during the period of initiation (Gaspar‐López et al , Gómez et al , Dryden ). Supplemental feeding is legal in Louisiana and Mississippi and may have been a factor mitigating flooding effects.…”

“…Although winter flooding apparently provided long-term benefits from silt deposition, winter flooding did not negatively affect current-year antler growth. The post-rut period is a critical time for males, which commonly lose >20% of body mass during the mating season (Strickland et al 2017, Foley et al 2018, and antler growth may be correlated with body condition during the period of initiation (Gaspar-López et al 2010, Gómez et al 2012, Dryden 2016 Figure 6. Long-term trends for A) harvest rate, B) yearling female dressed body mass (with SE bars), and C) proportion of property planted in soybeans for 61 properties in the Mississippi River Batture region, USA, 1994-2016.…”