William M. Giuliano

Response of birds to grazing of riparian zones

Livestock grazing of streams and associated riparian areas may negatively impact avian communities through direct disturbance and alteration of vegetation structure. We determined the effects of grazing on vegetation, avian abundance, species richness, and reproductive success on pasture streams and associated riparian habitats in southwest Pennsylvania. Bird counts, nest monitoring, and vegetation sampling were conducted on 12 pairs (grazed and control) of streams in 1996 and 10 pairs in 1997. Compared with control streams, grazed areas had lower avian species richness and abundance. Several wetland-and riparian-dependent species (e.g., common snipe [Gallinago gallinago], great blue heron [Ardea herodias], green-backed heron [Butorides striatus], belted kingfisher [Ceryle alcyon], and solitary sandpiper [Tringa solitatia]) were found more often or only on control areas. Although nest density was higher and nest destruction rates by livestock were lower on control streams, nest success (all species combined) was not affected by grazing. Avian communities in control areas appear to benefit primarily from improved vegetative cover and structure. Thus, management should focus on excluding livestock from such areas.

Predation on livestock by large carnivores in the tropical lowlands of Guatemala

Conflict with humans is a significant source of mortality in carnivore populations yet information on this issue is lacking for some areas where threatened carnivores such as the jaguar Panthera onca interact with humans. We interviewed cattle ranchers to examine patterns of predation on livestock by carnivores in the tropical lowlands of Guatemala and to determine if the ranchers applied management practices recommended to prevent such predation by large felids. Additionally, we compared ranches with and without attacks on livestock to determine whether ranch characteristics and landscape structure near ranches explains the variations in the occurrence of livestock predation by carnivores. Cattle losses to carnivores represented 0.7% of the cattle stock in all ranches surveyed. Jaguars were most often accused of livestock attacks (suggesting a negative perception of this felid in the area), followed by pumas Puma concolor and coyotes Canis latrans. Males and smaller cattle were most often attacked and general patterns of attacks on livestock were similar to sites previously studied in the neotropics. Landscape structure around ranches (e.g. forest cover, distance to forest, bodies of water and human settlements) best explained the probability of predation on livestock. Outreach programmes and conflict mitigation measures need to be implemented for those ranches that are distant from human settlements but near forest cover and water sources. The co-occurrence of predation by jaguars, pumas and coyotes is particular to Mesoamerica and conflict mitigation strategies proposed in studies elsewhere may need to be altered, and evaluated, to be effective in this region.

Lepidoptera-habitat relationships in urban parks

We examined the relationships among Lepidopteran species richness and relative abundance, field and park size, and herbaceous plant richness and cover in parks of New York, NY. Lepidopteran populations and habitats were quantified from 1 June–30 September 2002 in fields of 8 New York City (NYC) parks. We observed 42 species of Lepidoptera, with park size, field size, and plant species richness positively related to Lepidopteran abundance and species richness. Several plant species received heavy use and appeared to be important to Lepidoptera in this urban environment, particularly butterfly-bush (Buddleia davidii), mugwort (Artemisia vulgaris), knapweed (Centaurea maculosa), and clover (Trifolium spp.).

Short-term grazing exclusion effects on riparian small mammal communities

Abstract Grazing of livestock in streams and associated riparian habitats (hereafter referred to as riparian zones) may affect small mammal communities by influencing vegetation, water quality, and other site characteristics. To better understand these effects, we compared vegetation structure, and abundance and richness of small mammals in grazed riparian zones and similar areas where livestock had recently (1–2 years) been excluded in southwest Pennsylvania, 1998 and 1999. Mammalian species richness and abundance (all species combined, meadow voles [Microtus pennsylvanicus Ord], and meadow jumping mice [Zapus hudsonius Zimmermann]) were greater on sites where livestock had been excluded than grazed areas. These findings are likely the result of greater litter cover and increased vertical vegetation obstruction observed on these sites. Because small mammal communities respond quickly to relaxation of grazing in riparian zones, subsidy programs exist to partially pay for fencing, and landowners may potentially benefit from fencing these areas through improved water quality, erosion control, and livestock health, fencing may be an effective wildlife and grazing management tool.

Survival and Movements of Orphaned White-Tailed Deer Fawns in Texas

Harvest of females can be a controversial but necessary tool in managing white-tailed deer (Odocoileus virginianus) populations. Because little is known about the effects of female harvest on their orphaned fawns, we compared survival rates, home range area, and movement rates between fawns (7 M, 7 F) orphaned during early November, and unorphaned (4 M, 6 F) fawns for 11 months postorphaning. Distance moved during 3-6-hr periods (P = 0.498) and 21-27-br periods (P = 0.502) did not differ between orphaned and unorphaned fawns. However, compared with unorphaned fawns, orphaned fawns had smaller home ranges (95% minimum convex polygon [MCP]: 153 vs. 285 ha, P = 0.015, n = 23; 95% harmonic mean [HM]: 191 vs. 314 ha, P = 0.035, n = 23), and lower survival rates (0.79 vs. 1.00; P = 0.060, n = 24). Our results suggest early-season female deer harvest may negatively affect fawns, potentially reducing recruitment. Therefore, managers should carefully consider the timing of female harvests relative to management goals and harvest strategies.

Predicting Cattle Rancher Wildlife Management Activities: An Application of the Theory of Planned Behavior

Integrating wildlife management into routine livestock operations has become a priority of many wildlife conservation agencies and nongovernmental organizations because grazing lands occupy more than one-third of the United States. We surveyed 1,093 beef cattle ranchers by mail to predict cattle rancher intentions to consider wildlife management in routine cattle management activities. We framed our survey using the theory of planned behavior, whereby attitudes, subjective norms, and perceived behavioral controls explain behavioral intent. Our results indicated that attitudes and subjective norms best explained rancher intentions. Wildlife agency personnel and program planners can apply these results to design new or increase participation in existing cattle rancher wildlife conservation assistance programs by fostering positive attitudes regarding the integration of wildlife management in routine cattle operations and targeting key social groups of the ranching and conservation communities.

Ruffed Grouse Nest Success and Habitat Selection in the Central and Southern Appalachians

Abstract Ruffed grouse (Bonasa umbellus; hereafter, grouse) populations in the central and southern Appalachians are experiencing declines, which may be linked to deteriorating recruitment. Because nest success is an important component of recruitment, understanding the influence of habitat on nest success is important for developing regional grouse management strategies. Therefore, our objectives were to determine grouse nest success rates, characterize nest site selection, and identify habitat characteristics associated with successful nests in this region. From 1995 to 2002, we located 234 nests, of which 147 (63%) were successful (≥1 egg hatched). We characterized habitat at 167 of these nests and compared successful and unsuccessful nests using logistic regression and Akaikes Information Criterion (AIC). Similarly, we characterized nest site selection by pairing 73 nests with 1–8 nearby systematic sites and conducting a matched-pairs logistic regression followed by AIC. Eleven of 25 candidate models of nest success were supported; distance to a road or opening, ground cover, deciduous canopy cover, coarse woody debris, and basal area were increasingly important predictors of nest success. Increases in basal area, coarse woody debris, and deciduous canopy cover improved the odds of nest success. Alternatively, greater amounts of ground cover and increased distance to a road or opening decreased the odds of a nest being successful. The two supported models of habitat selection were basal area with coarse woody debris and basal area alone. Odds of a habitat being selected increased with both variables. Selection of these habitat elements likely reflects the tendency for females to nest at the base of large trees, stumps, or logs, which can reduce their exposure to predators and seems to improve nest success. Increased ground cover may reduce the females ability to detect a predator and increase the susceptibility of a nest. We recommend managers ensure coarse woody debris is available for nest sites, particularly when logging operations (e.g., clearcuts, thinnings) remove a high proportion of the standing basal area.

Effect of border-edge cuts on birds at woodlot edges in Southwestern Pennsylvania

Many edge- and shrub-nesting bird species have exhibited population declines in the United States over the last 30 years, despite increasing abundance of edge habitat. Declines may be related to quality of edge habitat, rather than quantity. Border-edge cuts are a management technique used to modify existing edge habitat by creating a shrub transitional zone 15-40 m in width at the forest-field edge. To determine if the increased shrub growth in border-edge cuts affected edge-nesting birds, we tested the hypotheses that bird communities in border-edge cuts versus uncut edges have (1) greater abundance and species richness, and (2) greater nest success. We conducted line transect bird counts and nest searches in 12 pairs of border-edge cuts (2-3 yr old) and uncut edges. Border-edge cuts had greater horizontal (P = 0.008) and vertical (P < 0.001) cover than uncut edges. Avian abundance was higher in border-edge cuts than in uncut edges (P = 0.034), but species richness did not differ (P = 0.596). Of 60 bird species recorded, 13 were found only in border-edge cuts, and 23 were found only in uncut edges. Border-edge cuts supported more shrub- and edge-nesting species, while uncut edges contained more woodland species. There was no difference in Mayfield nest-success probabilities between the 2 edge types (P = 0.337). Evidence at depredated nests suggested snakes were the primary nest predators. Border-edge cuts may provide habitat for some declining populations of avian shrubnesting species in Pennsylvania, but evidence of effects on reproductive success was inconclusive.

Effects of Token Financial Incentives on Response Rates and Item Nonresponse for Mail Surveys

Self-administered mail questionnaire surveys are commonly used by human dimensions of wildlife researchers, but nonresponse error and item nonresponse can decrease questionnaire data quality. By using token financial incentives, researchers can increase response rates and reduce error. We surveyed two random samples of 500 Georgia cattle ranchers to conduct an incentive experiment by giving one group a

Avian Community Response to Grazing Intensity on Monoculture and Mixed Florida Pastures

1 Jefferson coin and the other nothing. The financial incentive increased the response rate by nine percentage points. The incentive reduced nonresponse error for ethnicity but not other demographic or ranch characteristic variables. Item nonresponse for sensitive questions about income and threatened or endangered species and other more benign questions about demographics, crop damage, songbirds, deer, and turkey were also unaffected by the incentive. Token financial incentives can be a cost-effective way to increase wildlife survey response rates and increase data quantity and quality.