Abstract Pig heart citrate synthase has been estimated to have a molecular weight of 96,000 and sedimentation coefficient 6.2 S. The presence two similar subunits is indicated by equilibrium studies viscosity measurements in 7.0 m guanidine containing 0.1 mercaptoethanol. Further evidence for obtained from the number peptides produced tryptic digestion enzyme. pure enzyme, specific activity 180 units per mg protein, an absorbance index (E1 cm1% at 280 nm) 17.8. turnover calculated be 17,000...

AbstractIn species that provide parental care, parents will sometimes cannibalize their own young (i.e., filial cannibalism). Here, we quantified the frequency of whole-clutch cannibalism in a giant salamander (eastern hellbender; Cryptobranchus alleganiensis) has experienced precipitous population declines with unknown causes. We used underwater artificial nesting shelters deployed across gradient upstream forest cover to assess fates 182 nests at 10 sites over 8 years. found strong...

The objective was to evaluate the impacts of a complex environment and stocking density on Ross 708 broiler chicken behaviors. Eight pens contained either high complexity (HC) or low (LC) environments, (HD) (LD) density. Through focal-animal sampling, frequency duration behaviors were recorded continuously for 5 min at two timepoints one day in weeks 2, 4, 7. Birds active 30% observed time, with birds showing more activity HC compared LC. spent time preening foraging than LC pens, which...

Abstract Detecting declines and quantifying extinction risk of long‐lived, highly fecund vertebrates, including fishes, reptiles, amphibians, can be challenging. In addition to the false notion that large clutches always buffer against population declines, imperiled status long‐lived species often masked by debt, wherein adults persist on landscape for several years after populations cease viable. Here we develop a demographic model eastern hellbender ( Cryptobranchus alleganiensis ), an...

Citrate lyase from Klebsiella aerogenes inactivated by reaction in the presence of substrate or treatment with hydroxylamine can be reactivated acetic anhydride only if its sulfhydryl groups are reduced. Alkaline hydrolysis pure citrate yields about 3 mol phosphopantothenate per enzyme.

Abstract In conservation science, metapopulation models are frequently used to explore the spatial dynamics of organisms, and ultimately guide management decisions for threatened endangered species. Pond‐breeding amphibians often touted as a classic example structure. However, empirical assessment this assumption is lacking many species owing prohibitively high costs movement studies. Our aim was use spatially explicit occupancy evaluate in an amphibian. First, dynamic, occupancy‐based were...

Survival rates are known to vary over the course of an individual's lifetime and among individuals within a population. Quantifying natural variability in survival is crucial when scaling up infer dynamics populations. Using ten years mark–recapture data from two adjacent wetlands on Florida Panhandle, we investigated individual temporal Reticulated Flatwoods Salamanders (Ambystoma bishopi). Our objectives were 1) provide first estimates for species, 2) evaluate relationship between body...

Understanding how natural selection determines species’ life histories can reveal their resilience or sensitivity to anthropogenic changes. For example, the safe harbor hypothesis posits that will favor maximize time spent in safest stages; a second theoretical prediction suggests species with complex growth potential of stage relative its safety. Amphibians exhibit histories, diversity developmental strategies occurring across taxa. Many involve complete elimination particular stage, and...

The presence of locally abundant wildlife raises questions about natural regulation and ecological consequences overpopulation. We sought to establish precise information population size, structure, productivity examine the role in a closed tule elk (Cervus elaphus nannodes) at Point Reyes National Seashore, California, USA. estimated an instantaneous exponential growth rate 0.19 with adjusted R 2 = 0.98 during 1998, 20 years after were introduced. annual survival for adult cows nearly 0.95....

The prevalence of studies that discern the drivers animal migrations is increasing exponentially, in line with raised concerns over climate-driven shifts phenological patterns. Amphibians breed ephemeral wetlands are particularly vulnerable owing to stochastic nature their breeding habitat and high survival reproductive costs associated untimely migrations. Knowledge effects climatic cues on timing amphibian migration phenologies required understand potential consequences climate change...

Abstract The field of conservation has seen a shift in focus from monitoring trends census population size to ‘effective’ size. Numerous genetic methods exist for estimating effective size, resulting uncertainty among practitioners as which are most appropriate when conducting assessments or evaluating recovery efforts. Demographic approaches offer promising avenue provide link between and using life‐history information, but rarely do studies have all three sources data (genetic,...

Abstract Population viability analyses (PVAs) represent a key component of many recovery plans for threatened and endangered species. Demography links the processes that affect individuals to population‐level patterns, hence projections constructed from demographic data are most common tools PVAs. We size‐structured integral projection model (IPM) United States federally Reticulated Flatwoods Salamander, Ambystoma bishopi , evaluate influences on population growth predict efficacy future...

Individual growth rates are intrinsically related to survival and lifetime reproductive success hence, key determinants of population growth. Efforts quantify age-size relationships hampered by difficulties in aging individuals wild populations. In addition, species with complex life-histories often show distinct shifts that cannot be readily accommodated traditional modelling techniques. Amphibians characterized rapid larval growth, cessation prior metamorphosis, resumption the adult stage....

We present a joint effort at Virginia Tech between research group in the Department of Fish and Wildlife Conservation Data Services University Libraries to improve data management for long-term ecological field projects Florida Panhandle. Consultative support from played an integral role development training curriculum. Emphasizing importance quality workers beginning this curriculum was vital part its success. Also critical success group's investment time work with systems. compare case...

Virtually all natural community assemblages are dominated by a handful of common species. Dominant species can exert negative impacts on biodiversity through competitive exclusion, and thus there is strong incentive to understand imbalances in composition, changes dominance hierarchies time, mechanisms coexistence. Pond-breeding amphibians that utilize ephemeral wetlands provide an excellent opportunity evaluate theoretical predictions composition stochastic environments. One the most...

Modeling population dynamics in response to various threats or potential management actions has become an increasingly common aspect of conservation programs for imperiled species. However, these models typically require a detailed understanding demographic processes that are often challenging quantitatively assess. We combined data from the published literature (n = 4) with collected preserved specimens 6) model relationship between female body size and clutch Ambystoma cingulatum (Frosted...

The evolution of vertebrate life histories has been fuelled by key transitions among water and land. Life history diversity evolves according to the interplay predation on juveniles adults, physical properties environment, developmental context each lineage. selection pressures environment dictate which life-history strategies persist over evolutionary time render certain impossible. Despite well-recognized shifts in selective accompanying environments, conditions driving innovation its...

<title>Abstract</title> The objective was to assess the impact of environmental complexity on affective state (anxiety) in fast- and slow-growing broilers (<italic>Gallus gallus domesticus</italic>) as they gain weight. Six hundred fast-growing (Ross 708; “fast-growers”) 600 (Hubbard Redbro Mini; “slow-growers”) were raised 24 pens with simple (standard; SE) or complex (permanent temporary enrichments; CE) environments. birds/pen underwent attention bias test day 23 (fast-growers only),...