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Abstract ObjectiveIn a southcentral Alaska stream system, we conducted a study to evaluate the effect of trap type (galvanized and nylon coated), bait type (salmon roe cured with and without sodium sulfite), and soak times (1 h and 24 h) on captures of juvenile salmon using Gee-style minnow traps. This was undertaken due to the limited research on this topic, aiming to determine how variations in methodology affected captures in juvenile salmon. MethodsWe employed a three-way fixed factorial design to sample 176 stream reaches (with a single trap in each each) from June 2021 to September 2021, capturing 296 Coho Salmon Oncorhynchus kisutch and 105 Chinook Salmon O. tshawytscha. ResultWe found an estimated 78% decrease in captures of Coho Salmon when nylon-coated traps were used instead of galvanized traps, and we found that trap type showed no effect on number of captures for Chinook Salmon. Additionally, we did not detect effects of bait type and soak time on the number of captures for either species. Not surprisingly, there was a positive relationship between Julian date and temperature with captures for both species. Additionally, for Coho Salmon, we found a quadratic relationship between water velocity and captures. ConclusionUnderstanding and accounting for these factors will help researchers to maximize trapping efficiency, standardize protocols, and determine the extent to which results are comparable across studies employing different methods.
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This content will become publicly available on June 1, 2026
Efficacy of baits and lures for weasel detection
Abstract Small mustelids are difficult to survey due to their low density and cryptic nature. Population status of North American weasels (Mustela erminea,Mustela nivalis, andNeogale frenata) are believed to be in decline, but there are no standardized monitoring protocols to evaluate their status. To support weasel monitoring, we compared the attractiveness of various combinations of baits and lures to weasels in sites located throughout the eastern and central USA. We baited a total of 122 clusters of 4 camera traps, across 14 states, with random combinations of 4 baits and 3 scent lures in the winters of 2022 and 2023. Cameras baited with meat were 3.5 times more likely to detect both short‐ and long‐tailed weasels on average (mean percentage of cameras detecting weasels: 20–30%) than those with scent lures (3–11%). Red meat was twice as effective at attracting short‐tailed weasels (50%) as chicken or cat food (20%; Z = 2.49,p < 0.01). While red meat marginally increased detections of long‐tailed weasels (21%) compared to chicken and cat food (19%), its effectiveness was influenced by whether the bait was stolen (Z = 2.08,p = 0.04). Additionally, long‐tailed weasels were detected in half the time when raw chicken was used (median days to detection: red meat = 39.5 days, raw chicken = 14.5 days). When salmon oil was added to meat bait, it increased the likelihood of detecting short‐tailed weasels and reduced the time to detection for both species. A variety of non‐target species stole meat bait during the survey, making the camera traps less effective. The addition of salmon oil may have allowed for continual attraction of weasels until stolen meat bait could be replenished. In summary, red meat was the best all‐purpose bait for weasels, although raw chicken is similarly effective for long‐tailed weasels, and the addition of salmon oil is helpful. We also recommend a specific bait enclosure design that was the most effective at minimizing theft of bait. We propose our baiting strategy can be used as a survey standard to evaluate the distribution and population status of weasels.
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- Award ID(s):
- 2206783
- PAR ID:
- 10621728
- Publisher / Repository:
- Wildlife Society
- Date Published:
- Journal Name:
- Wildlife Society Bulletin
- Volume:
- 49
- Issue:
- 2
- ISSN:
- 2328-5540
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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