Weather and Age Ratios of Northern Bobwhites in South Texas

Understanding the effects of weather on quail reproduction in semiarid environments requires simultaneous consideration of temperature and precipitation data. Therefore, we used neural modeling to assess the interactive effects of summer (Jun–Aug) temperatures (monthly means of daily maxima) and seasonal precipitation (totals) on age ratios (juvenile/adult) of northern bobwhites (Colinus virginianus) in south Texas based on data collected during 1940–97 (n = 35, 23 years missing). Age ratios increased with June temperature. Ratios were insensitive to mean maximum daily temperature in July up to 36 C, when they began to decline rapidly. Ratios were insensitive to August temperatures. Ratios increased in an asymptotic manner with fall (Sep–Nov), spring (Mar–May), and summer precipitation, and were least sensitive to fall precipitation and most sensitive to spring precipitation. Based on our analysis, temperature and precipitation influenced bobwhite production in a complex, nonlinear manner that seemed to contain thresholds and asymptotes. Low temperatures can ameliorate the negative effects of drought, and high temperatures can suppress the positive effects of precipitation. The apparent asymptotic effect of precipitation, given temperature, illustrates that assumed linearity between precipitation and production may lead to errors of interpretation and expectation for production in a particular year

Hunters and Their Perceptions of Public Access: A View from Afield

Declining hunter participation threatens cultural traditions and public support for conservation, warranting examination of the forces behind the downward trajectory. Access to lands for hunting, an often-cited reason for non participation, may play a critical role in the retention and recruitment of hunters. Meeting the access needs of a diverse hunting constituency requires understanding how hunters use and perceive access opportunities, particularly public-access sites. Given that perceptions of access are entirely place based and degrade with time, traditional postseason survey methods may fail to adequately quantify the value of public access to the hunting constituency. To overcome the potential limitations of postseason surveys, we conducted on-site assessments of hunter perceptions of habitat quality, game abundance, ease of access, and crowding as well as whether the experience met the hunters’ expectations and their likelihood to return to hunt. Over 3 y, we interviewed 3,248 parties of which 71.5% were hunting. Most parties (65.9%) reported having no private access within the region of Nebraska where they were interviewed. Parties (67.6%) were largely limited to two or fewer hunters, most of whom were adult males (84.3%) who were, on average, 41.2 y old. The perception of public-access sites was generally positive, but 43.1% of parties indicated that game abundance was below average despite 59.2% of parties seeing game and 37.3% harvesting at least one animal. Similar to other explorations of hunter satisfaction, we found game abundance, and in particular harvest success, had the most consistent relationship with hunter perception of public access. By surveying multiple types of hunters across sites that encompass a range of social and ecological conditions, we gained a broader understanding of how hunters perceive public access in real time, which will help to inform future management decisions to foster and improve public-access programs

CHAPTER THIRTEEN- Habitat Selection and Brood Survival of Greater Prairie-Chickens

The Greater Prairie-Chicken (Tympanuchus cupido pinnatus) is a species that may benefit from conversion of crop ground to grassland through the Conservation Reserve Program (CRP). CRP grasslands could provide nesting and brood-rearing habitat, an important component of population persistence. Managers and policymakers currently lack evidence of CRP’s relative contribution to populations of Greater Prairie-Chicken. We used radiotelemetry to mark females (n =100) in southeast Nebraska, in a landscape which had \u3e15% of land area enrolled in CRP. We examined macrohabitat and microhabitat selection of brood-rearing females (n=36) using discrete choice models, and examined the variability in brood survival using logistic exposure models. Brood-rearing females selected locations inside cool-season CRP grasslands at higher rates than rangeland, but did not select cropland. At a vegetation level, brood-rearing locations had more bare ground and forb cover than random points. However, landcover and vegetation did not affect survival rates of broods; variation in daily brood survival was best explained by temporal effects such as hatch date and brood age. Our results suggest that CRP grasslands provide acceptable broodrearing habitat, and managers should encourage land owners to create habitat with high forb content and an open understory. Broods in our study had low survival rates to 21 days (0.59; 95% CI: 0.41, 0.77), which may explain the low juvenile/ adult ratio observed in hunter-killed birds in the region. Disturbance of CRP fields to increase bare ground and forb cover may improve their value to Greater Prairie-Chicken broods

Hunters and Their Perceptions of Public Access: A View from Afield

Declining hunter participation threatens cultural traditions and public support for conservation, warranting examination of the forces behind the downward trajectory. Access to lands for hunting, an often-cited reason for non participation, may play a critical role in the retention and recruitment of hunters. Meeting the access needs of a diverse hunting constituency requires understanding how hunters use and perceive access opportunities, particularly public-access sites. Given that perceptions of access are entirely place based and degrade with time, traditional postseason survey methods may fail to adequately quantify the value of public access to the hunting constituency. To overcome the potential limitations of postseason surveys, we conducted on-site assessments of hunter perceptions of habitat quality, game abundance, ease of access, and crowding as well as whether the experience met the hunters’ expectations and their likelihood to return to hunt. Over 3 y, we interviewed 3,248 parties of which 71.5% were hunting. Most parties (65.9%) reported having no private access within the region of Nebraska where they were interviewed. Parties (67.6%) were largely limited to two or fewer hunters, most of whom were adult males (84.3%) who were, on average, 41.2 y old. The perception of public-access sites was generally positive, but 43.1% of parties indicated that game abundance was below average despite 59.2% of parties seeing game and 37.3% harvesting at least one animal. Similar to other explorations of hunter satisfaction, we found game abundance, and in particular harvest success, had the most consistent relationship with hunter perception of public access. By surveying multiple types of hunters across sites that encompass a range of social and ecological conditions, we gained a broader understanding of how hunters perceive public access in real time, which will help to inform future management decisions to foster and improve public-access programs

Assessing Landscape Constraints on Species Abundance: Does the Neighborhood Limit Species Response to Local Habitat Conservation Programs?

<div><p>Landscapes in agricultural systems continue to undergo significant change, and the loss of biodiversity is an ever-increasing threat. Although habitat restoration is beneficial, management actions do not always result in the desired outcome. Managers must understand why management actions fail; yet, past studies have focused on assessing habitat attributes at a single spatial scale, and often fail to consider the importance of ecological mechanisms that act across spatial scales. We located survey sites across southern Nebraska, USA and conducted point counts to estimate Ring-necked Pheasant abundance, an economically important species to the region, while simultaneously quantifying landscape effects using a geographic information system. To identify suitable areas for allocating limited management resources, we assessed land cover relationships to our counts using a Bayesian binomial-Poisson hierarchical model to construct predictive Species Distribution Models of relative abundance. Our results indicated that landscape scale land cover variables severely constrained or, alternatively, facilitated the positive effects of local land management for Ring-necked Pheasants.</p></div

The evaluation of the predictive performance of the Ring-necked Pheasant fitted and the corrected species distribution models.

<p>Standardized predicted values of Ring-necked Pheasant abundance compared to observed abundance values from an independent dataset collected in 2012 indicated that both the original spatial model (A) and the corrected spatial model (B) perform well. Data points are identified in blue, where the intensity of points is reflected by the color shade (dark blue = high intensity, and light blue = low intensity). The solid black line represents the fitted least-squares regression line and the two dashed lines represent the 95% confidence intervals. The dotted line identifies where a perfect fit would occur between predicted pheasant abundance and observed abundance.</p

The final 30×30-m resolution predicted Ring-necked Pheasant species distribution model for Nebraska based on the corrected fitted land cover and topographic variables.

<p>The range of predicted values was divided into ten categories based on an equal area approach, whereas each color class represents 10% of the area within the entire species distribution model. Classifying the relative predicted abundance values using this approach allows users to pinpoint the top 10% of the areas within the Nebraska that contain the highest predicted abundance (bright red), which is useful in management planning and implementation.</p

The relationships between Ring-necked Pheasant abundance and the proportion of land cover types within a 5 km radius.

<p>Ring-necked Pheasant populations respond positively to the proportion of row crop agriculture and small grains within the landscape (5 km radius), but negatively to the proportion of trees in the landscape. Solid line represents land cover relationships and the dashed lines represent the 95% credible intervals predicted out to the maximum range we observed during the study.</p

Pairwise Spearman’s ranked correlation Rho statistics for land cover variables.

<p>Pairwise Spearman’s ranked correlation Rho statistics for land cover variables.</p

The fitted and corrected relationships between Ring-necked Pheasant abundance and crop types in the surrounding landscape.

<p>Fitted relationships for Ring-necked Pheasant counts indicated a positive response to small grains and row crops in the landscape (dark line), but failed to predict pheasant response in areas containing a higher proportion of either cover class located outside of the study region. The range of data values used to fit the relationship between Ring-necked Pheasant abundance and row crop is 0.00–0.75 and a mean of 0.25. The range of data values used to fit relationship between Ring-necked Pheasant abundance and small grains is 0.0–0.45 and a mean of 0.08. Assuming that too much row crop or small grains in the landscape is detrimental to pheasants, dashed lines represent the corrected relationships used to create the final spatial model of Ring-necked Pheasant abundance in Nebraska.</p