Nova J. Silvy

Nesting Habitat of White-winged Doves in Urban Environments of Southern Texas

Changes in white-winged dove (Zenaida asiatica) distribution and habitat use have occurred in Texas since the 1940s. Breeding populations are now common in urban areas throughout Texas. These changes have resulted in unique challenges for monitoring populations in urban environments because of factors such as traffic, construction, and residential development. Delineating potential breeding habitat within urban areas may make surveys more efficient. Our objectives were to examine nest tree selection and identify habitat attributes associated with urban populations of white-winged doves. We...

Year
2008

Raccoon Abundance and Rio Grande Wild Turkey Production in Central Texas

Wildlife Outstanding Technical Paper

An understanding of spatial and temporal dynamics of wild turkey (Meleagris gallopavo) populations is essential in setting management goals. In central Texas, raccoon (Procyon lotor) populations have increased in recent years, causing concern that they may be limiting Rio Grande wild turkey (M. g. intermedia) production. We used two long-term data sets in central Texas to explore the relationship between raccoon abundance and Rio Grande wild turkey production at the regional, county, and local scale. We found no evidence that natural variation in raccoon abundance was associated with Rio...

Year
2004

An Evaluation of Sampling Methods for White-winged Dove Surveys in Urban Areas

Texas Parks and Wildlife Department (TPWD) has used auditory call counts annually since 1949 to monitor white-winged dove (Zenaida asiatica) populations in the Lower Rio Grande Valley of Texas. Recently, white-winged doves have been expanding their distribution, and now the largest populations occur in urban areas north of their historic south Texas range. It has become necessary to develop an urban survey method to better monitor these populations. We compared two call count sampling methods for surveying white-winged doves in urban environments (i.e., transects vs. grid-points in Austin...

Year
2004

Development of a Deer-guard Prototype for Florida Key Deer

Due to increased deer/vehicle collisions involving endangered Florida Key deer (Odocoileus virginianus clavium), the Florida Department of Transportation (FDOT) planned to fence a stretch of U.S. Highway 1 that crosses Big Pine Key, Florida. Public access roads, which would allow deer to enter the fenced portion of the highway, posed public and wildlife-related hazards. Currently there are no structures (deer guards) that are effective in preventing deer from entering access roads. Our purpose was to design, construct, and test a deer guard that would allow normal passage of vehicles while...

Year
2003

Brood-count Power Estimates of Rio Grande Turkey Production in Texas

Wildlife Outstanding Technical Paper

Brood counts are used frequently by state conservation agencies to estimate wild turkey (Meleagris gallopavo) recruitment. We performed power analyses for 25 years of Rio Grande Wild Turkey (M. g. intermedia; RGWT) brood-count data from five ecological regions of Texas in order to determine if these data had sufficient (1-b ?0.80) power to detect inter-annual and long-term changes in turkey production of 10%-20%, which we considered biologically meaningful. We then analyzed the data to determine trends in production. The analyses showed that a minimum annual sample of 200-500 turkey-group...

Year
2003

Animal Welfare-based Modification of the Rio Grande Wild Turkey Funnel Trap

The funnel trap has proven a safe (for handlers), efficient, low-manpower method of capturing Rio Grande turkeys (Meleagris gallopavo intermedia). Field biologists in Texas maintain that private ranchers accept this technique more readily than alternatives because it is passive and only requires one person. The impact of the technique on animal welfare, however, has not been addressed. In 2002, in the first year of an ongoing population ecology study, we trapped 46 turkeys using a standard walk in trap, and 40 more where a tarpaulin was slipped over the trap prior to removing birds. Using...

Year
2003

Relationships of Fur Market Conditions to Texas Quail Populations

Quail are declining throughout much of their range in the southeastern United States. The reason for this decline is unknown. However, the decline of fur prices during the late 1980s fueled a hypothesis that furbearer harvest has decreased, which in turn led to an increase in furbearer abundance, and a subsequent decrease in quail numbers. To evaluate this hypothesis, we attempted to correlate raccoon (Procycon lotor) fur prices, furbearer and raccoon harvest, and furbearer and raccoon abundance with abundance of northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata...

Year
2000

Use of Infrared-triggered Cameras and Monitors in Aquatic Environments

The use of infrared-triggered activity monitors in wildlife science has increased during recent years. In most cases, trail monitors are mounted to stationary objects. However, trail monitors in aquatic environments where change in elevation is necessary, because of varying water levels, curently restricts their use. In our study of Florida Key deer, we needed information on deer activities in areas influenced by tides. We developed an inexpensive device that allowed trail monitors to operate as tides changed. We propose that this device can expand the use of trail monitors to include...

Year
1999

Evaluating 2 Potential Limiting Factors for Relocated Turkeys in Texas

Relocated eastern wild turkeys (Meleagris gallopavo silvestris) have been increasing in northern Post Oak Savannah (POS) of Texas. However, it has been difficult to establish populations in the southern POS where mortality is high and reproductive success low. It has been proposed that high spring precipitation and high carnivore numbers account for poor population viability in the southern POS. We found that spring precipitation (1994-1995 nesting seasons) was not above the historic average (1950-1993), nor did unusually high rainfall events occur. These data suggest that spring...

Year
1999

Survival and Reproduction of Eastern Wild Turkeys Relocated into the Post Oak Savannah of Texas

Relocated (N = 76) eastern wild turkeys (Meleagris gallopavo silvestris) were released into the Post Oak Savannah of Texas in winters 1994 and 1995. Before release, each bird was fitted with a radio transmitter and numbered leg band. Mortality and reproduction were monitored through 1996 to determine survival and reproduction. First-year annual survival rates for gobblers and hens was 0.286 and 0.484, respectively. One of 4 study areas lost all gobblers within the first year. Mammalian predation (63.4%) was the primary cause of mortality. High post-release mortality was attributed to...

Year
1998