Terrestrial Activity in Pitheciins (Cacajao,Chiropotes, and Pithecia)

Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc.     

Evolution of parental care in Phodopus: Conflict between adaptations for survival and adaptations for rapid reproduction

SYNOPSIS. Two species of dwarf hamsters are used to developa model of the proximate and ultimate selective forces leadingto the evolution of parental care strategies. One species, Phodopuscampbelli, has been studied extensively as a socially monogamous,biparental species; the other, P. sungorus, rears its youngwithoutmale assistance. The cold, arid habitat occupied by both species has selectedfor shape, insulation, and physiology that provide toleranceof extremely cold ambient temperatures and enhance survivalwhen water availability is limited. At the same time, the smallbody size and highly seasonal environment have selected forrapid maturation and the most compressed reproductive cycleknown in a mammal. Rapid reproduction increases water demandsfor milk production and further stresses water balance becausematernal hyperthermia demands increased evaporative heat loss.Thus, in Phodopus habitat, rapid reproduction requires heattolerance and water availability, which conflict with adaptationsfor survival. In the habitat of P. sungorus, predictable rains allow a breedingseason and females rear litters alone. In P. campbelli, wateravailability is insufficient for solitary reproduction. Instead,male presence alleviates thermoregulatory, and thus water balance,stresses on the female. The result is improved pup survivaland growth. Therefore, an ‘ultimate’ reason forbiparental care in P. campbelli is its harsh environment, anda ‘proximate’ reason is a need to reduce maternalwater demand. Results confirm that independent physiologicalconstraints, in addition to constraints on energy or time investment,can be essential selective pressures in the evolution of mammaliansocial organization and behavior.     

Evaluation of Bear Rub Surveys to Monitor Grizzly Bear Population Trends

Abstract: Wildlife managers need reliable estimates of population size, trend, and distribution to make informed decisions about how to recover at-risk populations, yet obtaining these estimates is costly and often imprecise. The grizzly bear (Ursus arctos) population in northwestern Montana, USA, has been managed for recovery since being listed under the United States Endangered Species Act in 1975, yet no rigorous data were available to evaluate the program's success. We used encounter data from 379 grizzly bears identified through bear rub surveys to parameterize a series of Pradel model simulations in Program MARK to assess the ability of noninvasive genetic sampling to estimate population growth rates. We evaluated model performance in terms of 1) power to detect gender-specific and population-wide declines in population abundance, 2) precision and relative bias of growth rate estimates, and 3) sampling effort required to achieve 80% power to detect a decline within 10 years. Simulations indicated that ecosystem-wide, annual bear rub surveys would exceed 80% power to detect a 3% annual decline within 6 years. Robust-design models with 2 simulated surveys per year provided precise and unbiased annual estimates of trend, abundance, and apparent survival. Designs incorporating one survey per year require less sampling effort but only yield trend and apparent survival estimates. Our results suggest that systematic, annual bear rub surveys may provide a viable complement or alternative to telemetry-based methods for monitoring trends in grizzly bear populations.     

Development of Immunodeficiency of Pituitary Dwarf Mice

Autosomal recessive pituitary dwarf mutants of the Snell-Baggand Ames mouse strains develop severe immunodeficiency of thethymus-dependent (T cell) system which frequently leads to afatal wasting syndrome. The ontogenetic development of the Tcell system is already subnormal soon after birth as evidencedby diminished responsiveness of thymus and spleen cells to phytohemagglutininand concanavalin A. The immunodeficiency of the dwarf mouseis a consequence of defective pituitary influences which willcause (i) an inadequate production of immunocompetent cellsdue to a central developmental defect primarily affecting thethymus, and (ii) the inability of immunocompetent cells to undergoa rapid and efficient antigen-induced proliferation and differentiationinto antibody-forming cells. The lack of epinephrine-inducedstimulation of adenylate cyclase activity in dwarf spleen andthymus cells suggests that the impaired lymphoid cell proliferationin dwarf mice may be due to inadequate stimulation of cyclicAMP production.     

THE EFFECT OF VARIATIONS IN CALCIUM SUPPLY, PH VALUE AND NITROGEN CONTENT OF NUTRIENT SOLUTIONS ON THE RESPONSE OF LETTUCE AND RED CLOVER TO MOLYBDENUM

Lettuce and red clover were grown in nutrient solutions with varied calcium supply, pH value, and nitrogen content, and the response to molybdenum compared under each set of conditions.
The calcium requirement was greater in solutions at pH 4-4 than at 6-3, but the quantity of calcium supplied did not affect the response of the plant to molybdenum. Growth was best in the more acid of a range of solutions from pH 4-2 to 8-2 in spite of a rapid levelling up to a pH between 6 and 7, but with the possible exception of the solution at pH 8-3, the need for molybdenum was unaffected by the reaction of the medium. When the calcium supply and/or the initial pH value of the solution was varied, the effect of molybdenum was most pronounced in the largest plants.
When the nitrogen supply was deficient, lettuce showed a slower response to molybdenum than when it was plentiful. With both inoculated or uninoculated clover the reverse was true. This difference in behaviour is explained on the assumption that lettuce has a smaller requirement for molybdenum than clover.
In both lettuce and clover the percentage nitrate-nitrogen in the dry matter of the shoot was higher when molybdenum was not supplied, but the total nitrogen content was increased in the case of lettuce only. At any level of nitrogen supplied, 5 or 10 p.p.m. molybdenum was of no more benefit than o-i p.p.m. though the liability to damage from toxicity was possibly greater when nitrogen was plentiful.     

Ichthyophthirius multifiliis (Ciliophora) Invasion of Gill Epithelium1

The sequence of morphologic events associated with Ichthyophthirius rnultifliis invasion of gill epithelium began in the theront with differentiation of secretory mucocysts and the perforatorium. After escaping from the cyst the theront, which stained intensely with Mallory' stain, sought a host. As it approached the host epithelium, the contents of the mucocysts were discharged, enveloping the ciliate in sticky material, which made initial contact with the host epithelium. Rapid penetration by the theront caused disruption of one or more host cells and resulted in a focal necrosis associated with the anterior margin of the ciliate. Within five minutes postexposure, the parasite completed its invasion of the epithelial layer and stained less intensely. The remnants of host cells disrupted during its entry surrounded the trophont until they were ingested by the parasite. Within 40 min postexposure, synthetic activity of the parasite appeared to increase as evidenced by an abundance of organelles, particularly ribosomes and crystalline mucocysts. At this point, the overlying host epithelium appeared normal.     

Factors which influence female crickets' (Acheta domesticus) phonotactic and sexual responsiveness to males

ABSTRACT. Removal of the corpora allata from sexually responsive Acheta domesticus females exhibiting direct, positive phonotaxis resulted in a decline of the directionality of phonotaxis and sexual responsiveness to males for the 3-day testing period. Phonotaxis and sexual responsiveness were restored to the level before allatectomy after topical treatment with JH III. Sexually and phonotactically responsive females, given Precocene I or II showed no change in phonotactic orientation or sexual responsiveness. Females were isolated from males just prior to the imaginal moult. After 3 weeks of isolation (1 2.5 weeks following the imaginal moult) they showed significantly better phonotaxis to the calling song than did females that had been fully exposed to males, or those which had only olfactory exposure to males. There were no significant differences among the groups in their copulatory readiness when placed directly in contact with males. Mating caused a reduction in the phonotaxis of females. Females on the day of imaginal moult responded negatively to the calling song. This negative response disappeared on the day following the imaginal moult and did not re-appear in older females. Topical application of JH III or the synthetic analogue, ZR 515 caused females to become phonotactically positive in response to the calling song on the day of, or the day following the imaginal moult.     

Factors influencing stream chemistry in catchments on Prince of Wales Island, Alaska

1. Factors influencing the water chemistry of streams were evaluated for remote catchments on Prince of Wales Island, Alaska, a high-latitude geologically diverse landscape. 2. We evaluated the hypothesis that weathering rates of dominant geological formations of catchments would be the major factor influencing the water chemistry of streams. 3. Catchments were compared by synoptic sampling of stream and cave waters, mapping to define the distribution of geological formations, and laboratory studies of rock weathering. 4. Carbonation was identified as the major mechanism influencing the weathering of rocks. High Pco ₂ levels of cave and upwelling waters in streams suggested CO₂, supplied by soil respiratory processes, was the major factor controlling the concentration of dissolved CO₂, carbonic acid dissociation, and H⁺ replacement of cations on rock surfaces. 5. Additional evidence of carbonation included the relationship between HCO₃^1– and Ca²⁺ + Mg²⁺ (r² = 0.95) for low- and high-alkalinity waters. The relationship suggested that the high-alkalinity waters were associated with the weathering of calcareous rocks. Waters with high alkalinities (> 1254 μeq l^–1), pH (> 7.0), Ca : Mg ratios (> 6.0.) and saturation values for Ca²⁺ (SI_c = –0.59–0.06) indicated that karst (limestone) formations with calcite minerals were the major sources of calcium (> 1266 μeq l^–1). Waters with the lowest alkalinity, pH, HCO₃^1– and cation concentrations were associated with granodiorite (igneous) rocks. Laboratory studies substantiated these findings, with weathering being highest when waters contacted Heceta and Bay of Pillars limestone formations and lowest with igneous rocks. 6. Weathering of rocks, and possibly soils, appeared to be facilitated by surface and subsurface movements of CO₂ and water through fractured karst formations, and water availability in rain-dominated forests. The proximity of the sea and sulphur in marine aerosols and rainfall, and sulphate reacting with water, may also supply hydrogen ions to weathering reactions. 7. This study provides a basis for developing a better understanding of the influences of surface–subsurface geological and hydrological factors, and climatic conditions, on stream chemistry and biota in high-latitude ecosystems.