Caudal Distraction by Rat Snakes (Colubridae, Elaphe): a Novel Behavior Used when Capturing Mammalian Prey

Caudal movement in snakes may serve either a predatory (e.g., caudal luring) or defensive (eg., rattling, aposematism) function. I describe a new behavioral pattern of tail movement in snakes. Gray rat snakes (Elaphe obsoleta spiloides) foraging on small mammals (Mus domesticus) moved their tails in an erratic, whiplike fashion after detecting their prey in the vicinity. The thrashing movement in the horizontal plane was audibly and visually obvious, resulting in displacement of leaf litter around the tail. All subjects displayed the behavior, but not in all foraging episodes. Shorter durations of caudal distraction resulted in greater predator success during the 1st attempt at prey capture. Caudal distraction may facilitate prey capture by gray rat snakes by direction the attention of prey away from the approaching head of the snake

A Survey of Anuran Breeding Activity in Illinois, 1986-1989

tAmphibian populations have been declining worldwide, with several documented specie extinctions in the past two decades. Although monitoring population health can presen challenges, surveys of breeding choruses are relatively effective methods for assessing populations and population trends of many frog and toad species. We analyzed data from breeding chorus surveys conducted throughout Illinois from 1986 to 1989. Of the 20 species native to Illinois, 9 were stable or increasing during the survey period whereas the trends for other species were either inconsistent or indicated a decline in population size. To better assess population trends for Illinois frogs, we advocate re establishment and regular monitoring of choruses, and improved training for volunteers who conduct the surveys

Demographics of a Geographically-Isolated Population of Threatened Salamander (Caudata: Ambystomatidae) in Central Illinois

Amphibian populations that use small isolated wetlands are often small in size, susceptible to stochastic extinction processes, and have little to no contact with other populations. One can ascertain the persistence of such populations only by obtaining data that allow the prediction of future changes in population’s size, and propensity to achieve a sustainable number of individuals. The number of metamorphosing larvae leaving a pond predicts the viability of a salamander population, and thus, the number recruited into the terrestrial adult population. The Jefferson Salamander, Ambystoma jeffersonianum, is a listed threatened species in Illinois, occurring at fewer than 15 ponds statewide. In 2004 and 2005, individuals at an isolated breeding pond in Lincoln Trail State Recreation Area (LTSRA) were captured using a drift fence-pitfall trap array. Once captured, we determined sex, measured snout-vent length, and using a unique combination of toe clips, marked the salamanders. We also determined the number of egg masses, average percentage of successfully hatched eggs, and number of juveniles leaving the pond. We incorporated this information into a matrix for a stage-based population model. Model simulations predicted that on average, the population at the LTSRA pond would persist for four more years, with survivorship from larvae to juvenile being the most important parameter. Increasing survivorship during the larval period increased abundance as well as average persistence time. Active management at the breeding pond to increase the time available for successful metamorphosis might facilitate persistence of the salamander at this site

The Foraging Ecology of the Gray Rat Snake (Elaphe Obsoleta Spiloides)-Visual Stimuli Facilitate Location of Arboreal Prey

We examined the responsiveness of adult gray rat snakes to avian prey in enclosures that simulated natural habitat conditions. Subjects searched for arboreal nest contents in the presence or absence of a bird model flown so as to simulate avian provisioning behavior. In the absence of the model, gray rat snake latency to capture prey was over 92 % greater than when searching for nest contents with the model. Snakes responded to model flight by turning their heads in the direction of its movement. We conclude that gray rat snakes perceive relatively distant visual cues from prey, and that nest provisioning (activity localized around a nest) may facilitate snakes correctly choosing to ascend trees that contain active nests and ignoring those that do not

Risk stratification and targeted neuroprotection in Parkinson disease utilising the glucocerebrosidase pathway

OBJECTIVES: Glucocerebrosidase mutations represent genetically the most significant risk factor for Parkinson disease, however their penetrance is incomplete and variable such that only a minority of glucocerebrosidase mutation carriers will develop Parkinson disease. In this thesis I aimed to investigate the basis for this incomplete penetrance, to identify indices which may be used to predict Parkinson disease conversion amongst glucocerebrosidase mutation carriers and to test a putative neuroprotective drug designed to modify the glucocerebrosidase pathway. METHODS: In chapter 2 we used meta and joint analyses to calculate the odds ratio of developing Parkinson disease with individual glucocerebrosidase mutations. In chapter 3 we prospectively assessed a cohort of glucocerebrosidase mutation carriers without Parkinson disease for prodromal signs of Parkinsonism. In chapter 4 we sought to extend the scope, scale and sustainability of this study by producing a prototype study to assess these patients remotely through the internet. In chapter 5 we investigated whether novel imaging (PET using the PK-1195 and DAT ligands), serum (alpha synuclein, tau and inflammatory markers) and urine (hypothesis generating screen) could be used to predict PD conversion. In chapter 6 we used single cell calcium imaging in a primary neuronal mouse model carrying the N370S glucocerebrosidase mutation to investigate whether deranged calcium homeostasis might be the basis for the selective vulnerability of dopaminergic neurons in glucocerebrosidase mutation carrying cells. In chapters 7 and 8 we present optimisation and preliminary data from AiM PD, a phase II, open label, non placebo controlled trial of ambroxol, a small molecular chaperone of the glucocerebrosidase enzyme. RESULTS: Chapter 2: We derived quantifiable estimates of Parkinson disease risk for 84GG, E326K N370S, L444P, D409H, RecNcil as well as important data relating to the ethnic distribution of these mutations. Chapter 3: The University of Pennslyvannia smell identification test and Montreal cognitive assessment scores of glucocerebrosidase mutation carriers were worse than those of controls. There is a clustering effect amongst glucocerebrosidase mutation carriers whereby poor scores in these assessments and the Beck’s depression index seemed to be present together in a subset of participants. Chapter 4: We show the rapsodi portal is able, using validated assessments, to detect Parkinson disease features. Preliminary data shows cognitive deficits amongst Glucocerebrosidase mutations carriers exist compared to controls. Chapter 5: PK11195 signal is increased in the substantia nigra of glucocerebrosidase mutation carriers compared to controls and this signal increase correlates with olfactory loss. Serum alpha synuclein levels in glucocerebrosidase carriers correlate with the number of severe (neuronopathic) mutations and a risk score derived from prospective assessment of prodromal Parkinson disease features. The hypothesis generating urine proteomics screen identified a number of potential markers of Parkinson disease conversion including elements of the IgG kappa light chain. Chapter 6: We found no evidence of deranged calcium homeostasis Chapter 7: The glucocerebrosidase enzyme activity assay has been optimised to be reproducibly used in cerebrospinal fluid samples in our hands. The optimal time to carry out the assay to prevent degradation of activity following freezing is within 2 weeks of collection. In vitro addition of ambroxol to control CSF at physiologically relevant concentrations caused a 50% reduction in activity levels, due presumably to anatagonistic binding to the active site of the enzyme. Chapter 8: Preliminary results show that ambroxol delivers a statistically significant increase in leucocyte glucocerebrosidase activity amongst glucocerebrosidase mutation carriers with Parkinson disease. These patients seem to have worse features of non motor Parkinson disease symptoms than idiopathic Parkinson disease cases. CONCLUSIONS: Our results collectively suggest it may be feasible to stratify risk of Parkinson disease conversion amongst glucocerebrosidase mutation carriers on the basis of genetic, clinical, imaging and biochemical indices. Moreover they suggest that ambroxol has potential as a neuroprotective agent in Parkinson disease

Radio Telemetry and Post-Emergent Habitat Selection of Neonate Box Turtles (Emydidae: Terrapene Carolina) in Central Illinois

Although factors influencing turtle offspring prior to nest emergence have received considerable attention by researchers (Gutzke and Crews 1988; Janzen et al. 2000; Packard and Packard 1987), the activity of neonates following their emergence from the nest is poorly understood (but see Burger 1976; Butler and Graham 1995; Keller et al. 1997). Previous field research has produced valuable information on several aspects of neonate ecology for several species (Brewster and Brewster 1991; Butler and Sowell 1996; Janzen 1993). However, a thorough understanding of life history patterns for many species is absent, and some existing information is conflicting (e.g., Congdon et al. 1999; Janzen et al. 2000). The lack of knowledge is primarily due to the cryptic nature of neonates and various logistical problems associated with studying small animals in the field. Recent advances in radio telemetry technology such as decreased transmitter size and increased battery life facilitate tracking small neonate turtles for a longer duration. We studied nest dispersal and habitat use in neonate box turtles using a relatively new, very small radio transmitter. Few studies have been conducted using telemetry on neonate turtles (e.g., Butler et al. 1995), and none has focused on nest dispersal and habitat use of neonate box turtles. The study was conducted at Rhodes-France Boy Scout Reservation (RFBSR) located in western Shelby County, Illinois, USA (39°19\u27N; 89°02\u27W), from March to April 2002. Two nests were located by radio tracking gravid female turtles during summer 2001 (Flitz 2003). The nests were sited in relatively open areas next to a tree stump in a grassy field and at the edge of a fire trail (see Flitz 2003 for more description). Nest disturbance was prevented by using excluder devices, made of hardware cloth of 0.6 cm2 mesh and 30 cm diameter with walls buried 15 cm into the ground, around the nest until the end of the 2001 activity season. Upon hatching and emergence, neonate turtles from both nests (clutch sizes were 4 and 5, respectively) were collected, brought to our laboratory and allowed to overwinter in an outdoor enclosure (1.5 x 1.5 m) under ambient conditions. Each turtle was marked with a unique series of notches in the marginal scutes. This facilitated identification and placement back at the proper nest site the following spring

Thermoregulation of Male Elaphe Spiloides in an Agriculturally-Fragmented Forest in Illinois

Anthropogenic forest fragmentation increases the amount of edge habitat. Although edges are harsh environments for many native species, ratsnakes often prefer this habitat. We examined thermoregulatory effectiveness of Central Ratsnakes (Elaphe spiloides) using forest edges preferentially to determine if edge preference is driven by increased thermoregulatory efficiencies. Six male subjects were located every 1-2 days using radio-telemetry and temperature sensitive transmitters. Subjects did not thermoregulate more efficiently in edges than in forest. Snakes were thermoconformers in both habitat types suggesting edge preference might be driven by other factors