winkler extraction and pitfall traps method mahon

Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Variation in Baiting Intensity Among CO2- Baited Traps Used to Collect Hematophagous Arthropods Bait-station indices should not be conducted near research sites that employ similar bait when both produce a tangible reward for the animals. Bears may have become habituated to the bait on trap lines and incorporated it as a regular food source. We found that population trends inferred from bait-station visits in areas that also were trapped with bait were biased high and that bias increased over time. We modeled probability of bait stations being visited by bears on trapped and untrapped lines to estimate the effect baited trapping had on visitation rates. Because the same baits were used for both trapping and bait station lines, we hypothesized that visitation rates of bears to bait stations established in proximity to baited trap lines would differ from rates at bait stations that were not associated with baited trap lines. Baited bear trapping also took place in the sanctuary during those years, and some trap lines coincided with bait-station lines. In the Pisgah Bear Sanctuary, bait-station surveys were conducted in most years from 1983 to 2000 to follow trends over time in the black bear (Ursus americanus) population. Indices of relative abundance allow managers and researchers to examine changes in population size over time or compare relative population sizes in different areas. The Silphidae and Histeridae were more abundant in the maple forest, whereas the Hydrophilidae and Ptilidae were more abundant in the fir forest.Įffects of trapping with bait on bait-station indices to black bear abundanceīrongo, L.L. Strong differences in species assemblages were also observed between the southern maple and fir forest sites. For the beetles caught in the meat- baited traps (majority of captures), decreases in abundance and species richness were observed from south to north along the fir forest transect, with evidence of decreasing specific diversity as measured by the Shannon index of diversity. All Histeridae, Hydrophilidae, Scarabaeidae, and Silphidae were identified to species to examine specific diversity variation among sites. Meat- baited pitfall traps caught nearly 15 times as many beetles as dung- baited traps. A total of 8,511 beetles were caught and identified to family level, 95.7% of which belonged to families with known coprophilous or necrophagous behavior. Beetle abundance was estimated using a sampling design comprising replicated pitfall traps baited with red deer meat or dung in each site. We studied selected assemblages of coprophilous and necrophagous beetles in Quebec along a 115-km north-south transect in three balsam fir (Abies balsamea (L.) Miller) forest sites and in a fourth forest site dominated by sugar maple (Acer saccharum Marshall), close to the southern fir site. The presence and abundance of beetles exploiting such resources are influenced by various ecological factors including climate and forest cover vegetation. Vertebrate dung and carrion are rich and strongly attractive resources for numerous beetles that are often closely linked to them. Selected beetle assemblages captured in pitfall traps baited with deer dung or meat in balsam fir and sugar maple forests of central Quebec.īrousseau, Pierre-Marc Cloutier, Conrad HÃ©bert, Christian

Winkler extraction and pitfall traps method mahon