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Evaluating population responses to management is a crucial component of successful conservation programs. Models predicting population growth under different management scenarios can provide key insights into the efficacy of specific management actions both in reversing population decline and in maintaining recovered populations. Bald eagle (Haliaeetus leucocephalus) conservation in the United States has seen many successes over the last 50 years, yet the extent to which the bald eagle population has recovered in Arizona, an important population within the Southwest region, remains an area of debate. Estimates of the species' population trend and an evaluation of ongoing nest‐level management practices are needed to inform management decisions. We developed a Bayesian integrated population model (IPM) and population viability analysis (PVA) using a 36‐year dataset to assess Arizona bald eagle population dynamics and their underlying demographic rates under current and possible future management practices. We estimated that the population grew from 77 females in 1993 to 180 females in 2022, an average yearly increase of 3%. Breeding sites that had trained personnel (i.e., nestwatchers) stationed at active nests to mitigate human disturbance had a 28% higher reproductive output than nests without this protection. Uncertainty around population trends was high, but scenarios that continued the nestwatcher program were less likely to predict abundance declines than scenarios without nestwatchers. Here, the IPM‐PVA framework provides a useful tool both for estimating the effectiveness of past management actions and for exploring the management needs of a delisted population, highlighting that continued management action may be necessary to maintain population viability even after meeting certain recovery criteria. [ABSTRACT FROM AUTHOR]

We compared abundance patterns and developed resource selection models for imperilled native southwestern (USA) fishes in the presence and absence of Black Bass (Micropterus spp.) to evaluate how fishes alter their selection for habitats when sympatric with a nonnative piscivore. We collected data using snorkel surveys and in‐stream habitat sampling in Fossil Creek (AZ), upstream (native fish only) and downstream (native and nonnative fish) of a fish barrier. The abundance of all Roundtail Chub (Gila robusta), small (≤127 mm total length [TL]; vulnerable to predation) Sonora Sucker (Catostomus insignis) and Speckled Dace (Rhinichthys osculus) was significantly reduced, but the abundance of both small and large (>127 mm TL; invulnerable to predation) Desert Sucker (Catostomus clarkii) was similar in sampling reaches with and without Black Bass. When sympatric with Black Bass, small Roundtail Chub increased their selection for riffles by 2.57 times and small Desert Sucker reduce their selection for pools by 6.90 times while also selecting for faster flow velocity and finer substrates in lotic mesohabitats. Large native fishes altered selection least, notwithstanding an increased selection for canopy cover in sampling reaches with Black Bass. Observed shifts in resource selection are consistent with predator avoidance strategies. Our study highlights the behavioural consequences of nonnative piscivores on native fish communities and stresses the importance of maintaining lotic mesohabitats as potential refugia for vulnerable native fishes when nonnative piscivores are present. [ABSTRACT FROM AUTHOR]

Objective: The Red Shiner Cyprinella lutrensis is one of the most prolific and ecologically destructive invasive fish species in the southwestern United States. The production and release of YY individuals as Trojan sex chromosome carriers can theoretically eradicate invasive fish populations by eventually eliminating phenotypic females. Methods: The YY individuals are typically produced through hormonally induced sex reversals and selective breeding of subsequently feminized males. We tested three dosages of estradiol‐17β (E2)‐treated diets (50, 100, and 150 mg of E2 per kg of diet) administered to sexually immature Red Shiner for various durations to determine their effectiveness at feminizing Red Shiner cohorts. Survival, growth, and gonadal development were assessed for each treatment. Result: All E2 treatments had minimal, if any, detrimental effects on the growth and gonadal development of Red Shiner. The 50‐mg dosage lasting from 2 to 120 days posthatch achieved a 100% feminization rate while using the lowest amount of E2; therefore, this dosage and treatment interval are recommended when attempting Red Shiner feminization under these rearing conditions. Feminization of males allowed for the spawning of neofemales (FXY) with wild‐type males (MXY), which resulted in the first putative YY Red Shiner. The YY verification crosses (n = 20) resulted in predominately male offspring (189 males/191 offspring) except for (1) an intersex individual from an MYY × FXX cross with two previtellogenic oocytes in its testis and (2) a single female that may have resulted from an inbred cross between an XY male and a YY female or from an unknown autosomal or environmental effect on sexual phenotype. Conclusion: More progeny tests with inbred and outbred crosses should be conducted to determine the prevalence of female offspring from YY individuals and how this may impact an eradication strategy featuring releases of YY Red Shiner. Impact statementThis research features the first production of Red Shiner with two Y sex chromosomes, which provides fisheries managers a new eradication strategy where releasing YY Red Shiner into an invasive population could theoretically skew the sex ratio toward 100% male, thus protecting the native fish that Red Shiner negatively impact. [ABSTRACT FROM AUTHOR]

The Red Shiner Cyprinella lutrensis is of increasing management interest as an invasive species that negatively impacts many native fishes throughout North America. Trojan sex chromosome (TSC)‐carrying individuals could theoretically control invasive fish populations by skewing the sex ratio to 100% male. The efficacy of TSC‐based control programs requires an understanding of a population's sex determination system, yet such information is lacking for Red Shiner. We used single‐digest restriction site‐associated DNA sequencing to discover sex‐linked single‐nucleotide polymorphisms (SNPs), and we conducted a series of breeding experiments to uncover the sex determination system. All candidate sex‐linked SNPs that fit our selection criteria exhibited a pattern of male heterogamety. We developed two sex‐identification (sex‐ID) marker assays, XY_248 and XY_170, which showed phenotype–genotype concordance scores of 77.00% and 84.35%, respectively. These sex‐ID markers exhibited relatively high phenotype–genotype concordance in females (XY_248 = 96.30%; XY_170 = 98.61%), which allowed for selective breeding of phenotypically feminized genetic males. We observed a 3:1 male : female sex ratio in spawns from feminized males crossed with wild‐type males, indicative of a male heterogametic sex determination system (i.e., XY male/XX female). The discovery of a male heterogametic sex determination system, in combination with our two markers, increases the likelihood of developing an effective TSC eradication strategy for invasive Red Shiner populations. [ABSTRACT FROM AUTHOR]

While most carnivore populations are declining worldwide, some species are successfully living in human‐modified landscapes. For example, coyotes (Canis latrans) have expanded their range across North America and into many urban areas making it important to understand factors influencing broad‐scale patterns of occurrence. We used citizen science data in the form of coyote observations by archery deer hunters from throughout the state of Illinois to evaluate factors affecting coyote detection and occupancy. Our statewide participant‐level occupancy estimate (0.63) was 58% greater than our naïve occupancy estimate (0.40) while detection probability was <0.25, highlighting the importance of using modeling frameworks that account for imperfect detection when modeling occupancy of cryptic species with low detection rates. Time period (AM/PM) had the largest effect on detection of coyotes, with detections greater in the AM. The number of hours hunted (analogous to effort) also impacted coyote detection, with more hours hunted increasing coyote detections. In contrast, none of the landscape covariates examined had strong effects on coyote occupancy. While coyote ubiquity and generalist habitat use may at least partially explain our results, we suspect it also is because the landscape covariates were measured at the county level, as more precise participant location data were unavailable, whereas participants effectively surveyed a much smaller area. Since scale affects the strength and direction of species‐habitat relationships, this scale mismatch is likely an important limitation when using many sources of citizen scientist observations to infer species‐habitat relationships for widespread generalist species when precise participant location data are unavailable. [ABSTRACT FROM AUTHOR]

The article discusses the factors affecting the accuracy of triangulated radio telemetry locations of eastern Indigo snakes (Drymarchon couperi). Topics discussed include use of multiple metrics to evaluate triangulation accuracy, precision of beacon tests on triangulation accuracy, and correlation between estimated distance and ellipse area.