National Park Service

Controlling invasive wildlife species relies on the ability to efficiently remove individuals from the invaded environment. Thus, maximizing capture potential is of high interest, particularly for species that are difficult to capture. For invasive species such as the Argentine black and white tegu lizard ( Salvator merianae ), increasing attraction to traps could increase the probability of removal. While it has been established that S. merianae can be lured with a single chicken egg, the efficacy of increasing olfactory or visual cues to increase tegu captures has not been rigorously tested. To test this, we leveraged an ongoing National Park Service trapping effort near Everglades National Park. In 2023 and 2024, we randomly assigned traps to a control treatment (single real egg), increased olfactory and visual treatment (three real eggs), an increased visual plus standard olfactory treatment (one real egg and one decoy egg, or one real egg and two decoy eggs), or visual treatment only (three decoy eggs). We fitted Bayesian binomial models for tegu lizards and non-target species to the trapping data to assess how bait treatment, trap style, and trap location affected the daily probability of capture at a trap. Additionally, we fitted Bayesian linear models to test the effect of bait treatment on the size of tegus captured. We found that increasing the olfactory cue to three real eggs increased the probability of tegu capture, but not the probability of non-target species capture. Conversely, traps with one real egg and two decoy eggs increased the probability of non-target captures while reducing the probability of tegu captures. Trap style and trap location also had statistically significant effects. Bait treatment did not significantly influence the size of tegus captured; however, there was a weak effect suggesting juvenile and male tegus captured in traps with three real eggs were larger compared to traps with a single egg and two decoy eggs. Our results highlight potential improvements in tegu control methods that balance effective capture with minimizing non-target bycatch.

Abstract Rapids are common in steep rivers, often forming where flow transitions from supercritical (Froude number, Fr > 1) to subcritical ( Fr < 1) through a hydraulic jump. When upstream Fr is supercritical but close to 1, this transition may occur as an undular hydraulic jump, exhibiting a train of stationary waves downstream of the jump toe. Previous studies proposed a method to estimate discharge using only UHJ wave spacing and channel width combined with a wave dispersion equation for large water depths relative to the UHJ wavelength. This method is based on the hypotheses that, by their presence, UHJs indicate near‐critical flow conditions ( Fr 1) and that wave celerity c is equal to and opposite the cross‐sectionally averaged flow velocity U . However, these hypotheses have not been thoroughly tested. We used data from published UHJ flume experiments to test the hypotheses that Fr 1 and c = U , compare the deep‐water and general wave dispersion equations, and evaluate the accuracy of discharge estimates. In these experiments, the stationary waves exhibited shallow depths relative to wavelength and flow was subcritical ( Fr < 1) when averaged across multiple wavelengths. Additionally, wave celerity more closely approximated the surface flow velocity than U . By using a Fr representative of actual conditions and applying a coefficient to correct for , the accuracy of the discharge estimates improved. This finding suggests that the critical flow‐based method is robust and can produce reliable streamflow estimates if the remotely observed wave trains are correctly interpreted as UHJs, without requiring in situ measurements.

Baer's Pochard (Aythya baeri), a diving duck endemic to eastern Asia, has once experienced a significant population decline and was classified as "Critically Endangered" in 2012. However, the factors contributing to this decline remain poorly understood. Nest survival is a crucial demographic parameter that significantly influences avian population dynamics and is often correlated with various environmental factors and the breeding period. We conducted research on its breeding biology from 2019 to 2022, documenting a total of 108 nests with laying dates ranging from 25 April to 15 July. The nest success rate was 24.97%. Predation was the primary cause of nest failure, accounting for 44.66% of nest failures, followed by desertion (17.48%), flooding (7.77%), and egg collecting by local people (6.80%). The analysis of the factors affecting daily nest survival indicated that daily nest survival was positively correlated with the height above water and the distance to shore of mound where they nested, but negatively correlated with the laying date. We suggest that controlling nest predation, providing suitable nesting sites, and maintaining suitable water levels are crucial for ensuring the nesting success of Baer's Pochard.

Utah parks are attracting an increasing number of visitors due to the quality dark sky viewing opportunities. Despite increasing engagement in nighttime recreation, limited research exists on visitor interest in interpretation for dark skies in state and national parks. Nighttime visitors at nine Utah state and national park units certified as dark sky parks were surveyed to evaluate their preferences for dark sky-related interpretive topics and communication methods. Visitors expressed the strongest interest in astronomy and improving dark sky viewing, with ranger-led programs emerging as the most favored delivery method. National park visitors showed greater interest than state park visitors in self-guided learning formats such as interpretive displays and mobile apps for topics such as dark sky viewing/astronomy and viewing wildlife at night. These findings highlight the benefits of diverse, yet targeted communication strategies to improve visitor experiences of dark skies and foster stewardship of natural darkness in parks.

Humans tend to mark their presence and thus their lands by naming charismatic places such as mountains, canyons, rivers, and lakes. Toponyms is the term for marking places with names. In doing so, cultural groups claim the lands and the recognition of their presence through names in their language and behaviors reflecting their culture. When other cultures occupy these lands, they similarly mark them with their own place names, thus replacing earlier names and evidence of occupation. A conflict of toponyms occurs when one cultural group uses their power to maintain a superior attachment to the land. This chapter uses six toponym ethnographic studies to understand the origins of debates between Native American and settler colonial peoples in North American. Research findings from these studies define both the importance of toponyms to cultural groups and possible resolution of heritage conflicts. All studies have been reviewed and approved for public use for place interpretations, visitor education, and culturally appropriate management by funding agencies and participating Native American tribes and Pueblos.

Northern red-backed voles (Clethrionomys rutilus) are an important species in the boreal forest ecosystem, both as herbivores and as a key food source for many mammalian and avian predators. They exhibit dramatic inter- and intra-annual population fluctuations, for which causes are not entirely known. We monitored northern red-backed vole densities in Denali National Park and Preserve through time with the goal of examining how environmental factors influenced density over time. Using a 30-year record of mark-recapture data, we used spatially explicit capture-recapture methods to estimate autumn and early summer densities each year. We assessed cyclic patterns in density, variation in amplitude, and any periodicity of population fluctuations using post hoc linear modeling. We found that the vole population appeared to be cyclic with a 2-4 year period, although the pattern varied somewhat among sampling sites. Our results indicated an association between white spruce (Picea glauca) seed production and vole density, implying white spruce seeds were either an important source of food during winter seasons, or that the environmental triggers that promote high seed fall were also associated with increased vole density. We also found a negative effect of an autumn harshness index, indicating winter conditions play a role in vole density in the following season. Finally, we found evidence of a negative density-dependent relationship between autumn and early summer. Together, these findings suggest a system in which density dependence and cyclic relationships are irregular but highly influential, with environmental effects capable of enhancing or moderating their impact. Continued monitoring of voles, alongside more thorough assessments of environmental conditions, may provide additional insight into the complex population dynamics of this species.

Under the current global biodiversity crisis, there is a need for automated and noninvasive monitoring techniques that can gather large amounts of data cost-effectively at various ecological scales, from local to large spatial scales. These data can then be analyzed to inform stakeholders and decision-makers. One such technique is passive acoustic monitoring, which is commonly coupled with automatic identification of animal species based on their sound. Automated sound analyses usually require the training of sound detection and identification algorithms. These algorithms are based on annotated acoustic datasets which mark the occurrence of sounds of species inside sound recordings. However, compiling large annotated acoustic datasets is time-consuming and requires experts, and therefore, they normally cover reduced spatial, temporal, and taxonomic scales. This data paper presents WABAD, the World Annotated Bird Acoustic Dataset for passive acoustic monitoring. WABAD is designed to provide the public, the research community, and conservation managers with a novel and globally representative annotated acoustic dataset. This database includes 5047 min of audio files annotated to species-level by local experts with the start and end time and the upper and lower frequencies of each identified bird vocalization in the recordings. The database has a wide taxonomic and spatial coverage, including information on 91,931 vocalizations from 1192 bird species recorded at 72 recording sites in 29 recording locations (mainly countries) and distributed across 13 biomes. WABAD can be used, for example, for developing and/or validating automatic species detection algorithms, answering ecological questions, such as assessing geographical variations on bird vocalizations, or comparing acoustic diversity indices with species-based diversity indices. The dataset is published under a Creative Commons Attribution 4.0 International license that permits redistribution and reuse on the condition that the original work is properly credited.

Subarctic floodplains are “hotspots” of biological productivity, diversity, and cross-trophic habitat quality embedded in otherwise relatively unproductive ecosystems. Broad-scale and rapid changes to the discharge regime, biogeochemistry, and seasona

Yellowstone cutthroat trout Oncorhynchus virginalis bouvieri in Yellowstone Lake are the focus of intensive conservation efforts due to the threat of predation by invasive lake trout Salvelinus namaycush. Suppression gillnetting has reduced the abundance of predatory lake trout, and the Yellowstone cutthroat trout population is recovering. Long-term monitoring indicates the size structure of the population shifted following lake trout invasion, suggesting that reproductive demographic rates of Yellowstone cutthroat trout may have changed. Length at 50% probability of maturity, as assessed using histological analysis of gonadal tissue, was 479 mm (95% confidence interval [CI] 467-490 mm) for females and 406 mm (95% CI 386-430 mm) for males, compared to 330 mm for males and females historically. Currently, age at 50% probability of maturity is 6.6 for females and 5.4 for males. The rate of skipped spawning was 3% for females and 38% for males. Mean absolute fecundity was 2897 ovarian follicles/individual at present compared to 1141 ovarian follicles/individual before lake trout invasion. Mean relative fecundity was 2157 ovarian follicles/kg. This research illustrates the plasticity in the reproductive strategies of fishes as a result of an invasive species. Understanding the reproductive biology of fish populations is vital for effective fisheries management, and these results are integral to a population model that can be used to develop new conservation benchmarks for Yellowstone cutthroat trout.