Long-Distance Dispersal of a Female Cougar in a Basin and Range Landscape

Abstract: We used Global Positioning System technology to document distance, movement path, vegetation, and elevations used by a dispersing subadult female cougar (Puma concolor) through the fragmented habitat of the Intermountain West, USA. Over the course of 1 year, female number 31 moved 357 linear km, but an actual distance of 1,341 km from the Oquirrh Mountains, Utah to the White River Plateau, Colorado, constituting the farthest dispersal yet documented for a female cougar. This cougar successfully negotiated 4 major rivers and one interstate highway while traversing portions of 3 states. Our data suggest that transient survival, and therefore total distance moved, may be enhanced when dispersal occurs during the snow-free season due to low hunting pressure and greater access to high elevation habitats. Long-distance movements by both sexes will be required for the recolonization of vacant habitats, and thus inter-state management may be warranted where state boundaries do not coincide with effective dispersal barriers.     

Elevated CO2 mitigates chilling-induced water stress and photosynthetic reduction during chilling

Bean, cucumber and corn plants were grown in controlled-environment chambers at 25/18 °C day/night temperature and either ambient (350 μmol mol^?1) or elevated (700 μmol mol^?1) CO₂ concentration, and at 20–30 d after emergence they were exposed to a 24 h chilling treatment (6.5 ± 1.5 °C) at their growth CO₂ concentration. Whole-plant transpiration rates (per unit leaf area basis) during the first 3 h of chilling were about 26,28 and 13% lower at elevated than at ambient CO₂ for bean, cucumber and corn, respectively. The decline in leaf water potential (ψ_L) and visible wilting of bean and cucumber during chilling were significantly less at elevated than at ambient CO₂. Corn ψ_L was not significantly affected by chilling, and corn did not exhibit any other symptoms of chilling-induced water stress. Leaf osmotic potentials (measured before chilling only) of bean and cucumber were more negative at elevated than at ambient CO₂, and the corresponding calculated leaf turgor potentials were significantly higher at elevated than at ambient CO₂. Leaf relative water content (RWC) during chilling at ambient CO₂fell to 62 and 48% for bean and cucumber, respectively. RWC during chilling at elevated CO₂ was never below 79% for bean or 63% for cucumber. Corn RWC was not measured. After 24 h of chilling at ambient CO₂, net photosynthetic rate (P_N) reductions were 83, 89 and 24% for bean, cucumber and corn, respectively. P_N reductions during chilling were less at elevated CO₂: 53, 40 and 4% for bean, cucumber and corn, respectively. At ambient CO₂, none of the species fully recovered to pre-chilling P_N, but at elevated CO₂ both bean and corn recovered fully. The average percentage leaf area with visible leaf damage due to chilling was 20.6 and 9.6% at ambient and elevated CO₂, respectively, for bean, and 32.4 and 23.6% at ambient and elevated CO₂, respectively, for cucumber. Corn showed no significant permanent leaf damage from chilling at either CO₂ concentration. These results indicate that cucumber was most sensitive to chilling as imposed in this study, followed by bean and corn. The results support the hypothesis that, at least in young plants under controlled-environment conditions, elevated CO₂ improves plant water relations during chilling and can mitigate photosynthetic depression and chilling damage. The implications for long-term growth and reproductive success in managed and natural ecosystems will require testing of this hypothesis under field conditions.     

The Effect of Molybdenum upon the Nitrogen Metabolism of Anabaena cylindrica: II. A More Detailed Study of the Action of Molybdenum in Nitrate Assimilation

Molybdenum-deficiency in Anabaena cylindrica results in a decreaseof all the organic nitrogen fractions determined analyticallywith the exception of amide which occurs at approximately thesame concentration irrespective of the molybdenum status. Molybdenum-rich,nitrogen-starved cells assimilate nitrate to protein rapidlyin the dark; similarly treated molybdenum-deficient cells rapidlyreduce nitrate to ammonia and amide, but the further synthesisto peptides and proteins proceeds very slowly. The rate of endogenousrespiration is higher in deficient than in normal cells, butthe rate of glycolysis is lower. No period of adaptation isrequired, after the addition of molybdenum to deficient cells,before normal nitrogen metabolism commences. Glucose, acetate,fumarate, succinate, and citrate are respired by normal anddeficient cells in the dark. Acetate has no effect on nitratereduction, glucose stimulates the reduction for a short period,while fumarate (and probably succinate) and, somewhat less efficiently,citrate, stimulate reduction in both normal and deficient cellsand enable the deficient cells to assimilate nitrate completelyto protein. It would seem that, in the absence of molybdenum,there is an insufficient supply of hydrogen and/or energy donorsto permit complete nitrate assimilation.     

Mouthpart and foregut ontogeny in larval, postlarval, and juvenile spiny lobster, Panulirus argus Latreille (Decapoda, Palinuridae)

The spiny lobster Panulirus argus has a life cycle consisting of a long-term (～9-12 months) planktonic larval period with 11 larval stages (the phyllosoma), a short (<1 month?) planktonic-to-benthic transitional postlarval stage (the puerulus), and benthic juvenile and adult phases. The mouthparts and foregut during these stages were examined and described by means of scanning electron microscopy (SEM) in an investigation of the species' developmental morphology, diet, and ecology. The phyllosoma mouthparts close to the esophagus are the labrum, mandibles, paragnaths, and first maxillae. The second maxillae and first and second maxillipeds are increasingly distant from the esophagus as the larva develops. The pair of asymmetrical mandibles bear many teeth and spines, and the molar processes form what appears to be an intricate toothed shear. The mandibles remain similar throughout the phyllosoma stages. During the molt into the puerulus, the mouthparts are greatly changed, and the second maxilla and the three maxillipeds join the other mouthparts near the esophagus. However, the transformation appears incomplete, and many of the mouthparts are not fully formed until the molt to juvenile completes their development. The phyllosoma foregut lacks a gastric mill and has but one chamber. In addition, the first two stages lack a gland filter. During the molt to puerulus, the foregut is greatly changed and subsequently is similar to typical decapod foreguts in having an anterior cardiac and posterior pyloric chamber. Only rudimentary internal armature is present. Following the molt to juvenile, the foregut is quite similar to that of the adult, which exhibits a substantial gastric mill. The 11 phyllosoma stages were separated into two groups (group A = stages 1-5, group B = stages 6-11) on the basis of changes in both mouthpart and foregut morphology. The puerulus has never been observed to feed. Nothing was observed in our investigations that would prevent feeding, though both mouthpart and foregut development appeared incomplete. The mouthpart and foregut structures of larval, postlarval and juvenile P. argus differ widely, possibly reflecting the extreme modifications for different habitats found among these life phases.     

Using Vaginal Implant Transmitters to Aid in Capture of Mule Deer Neonates

Abstract: Estimating survival of the offspring of marked female ungulates has proven difficult in free-ranging populations yet could improve our understanding of factors that limit populations. We evaluated the feasibility and efficiency of capturing large samples (i.e., >80/yr) of neonate mule deer (Odocoileus hemionus) exclusively from free-ranging, marked adult females using vaginal implant transmitters (VITs, n = 154) and repeated locations of radiocollared females without VITs. We also evaluated the effectiveness of VITs, when used in conjunction with in utero fetal counts, for obtaining direct estimates of fetal survival. During 2003 and 2004, after we placed VIT batteries on a 12-hour duty cycle to lower electronic failure rates, the proportion that shed ≤ 3 days prepartum or during parturition was 0.623 (SE = 0.0456), and the proportion of VITs shed only during parturition was 0.447 (SE = 0.0468). Our neonate capture success rate was 0.880 (SE = 0.0359) from females with VITs shed ≤ 3 days prepartum or during parturition and 0.307 (SE = 0.0235) from radiocollared females without VITs or whose implant failed to function properly. Using a combination of techniques, we captured 275 neonates and found 21 stillborns during 2002-2004. We accounted for all fetuses at birth (i.e., live or stillborn) from 78 of the 147 females (0.531, SE = 0.0413) having winter fetal counts, and this rate was heavily dependent on VIT retention success. Deer that shed VITs prepartum were larger than deer that retained VITs to parturition, indicating a need to develop variable-sized VITs that may be fitted individually to deer in the field. We demonstrated that direct estimates of fetal and neonatal survival may be obtained from previously marked female mule deer in free-ranging populations, thus expanding opportunities for conducting field experiments. Survival estimates using VITs lacked bias that is typically associated with other neonate capture techniques. However, current vaginal implant failure rates and overall expense limit broad applicability of the technique.     

Evaluating Mule Deer Body Condition Using Serum Thyroid Hormone Concentrations

ABSTRACT Body condition of ungulates is a determinant of fecundity and survival rates. Ultrasonography and body condition scoring techniques allow reliable estimation of body fat but may not be feasible to employ in some circumstances. A reliable blood chemistry index for assessing relative condition of different ungulate populations or groups would be useful in ongoing population monitoring programs. We provided a nutrition supplement (treatment) to a group of free-ranging mule deer (Odocoileus hemionus) during 2 consecutive winters in southwest Colorado. In late February each year, we evaluated whether percent body fat and serum concentrations of total thyroxine (T4), total triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) were higher among treatment deer than an adjacent group of deer that did not receive treatment (control). As a corroborative analysis, we modeled body fat as a function of thyroid hormone concentrations and morphometric variables. Estimated body fat of treatment deer averaged 12.3% (SE = 0.327), whereas estimated body fat of control deer averaged 7.0% (SE = 0.333) during the 2 winters of study. Concentrations of T4 and FT4 averaged 48.07 nanomole/L (SE = 3.80) and 12.61 picomole/L (SE = 1.04) higher, respectively, in treatment deer than control deer. Our optimal model of estimated body fat included T4, T4², FT4, and deer chest girth (%FAT = −4.8015 − 0.0946 × T4 + 0.000603 × T4² + 0.1474 × FT4 + 0.1426 × chest girth, R² = 0.609). Serum thyroid hormones effectively discerned treatment deer from control deer and were related to estimated body fat. Ultrasound and body condition scoring should be used to estimate body fat whenever possible. However, in cases where only a blood sample can be obtained, we documented potential utility of T4 and FT4 during late winter for evaluating relative body condition of mule deer.