larry clark - Profile on Academia.edu (original) (raw)

Papers by larry clark

Vertebrate wildlife damage management relates to developing and employing methods to mitigate aga... more Vertebrate wildlife damage management relates to developing and employing methods to mitigate against damage caused by wildlife in the areas of food production, property damage, and animal or human health and safety. Of the many management tools available, chemical methods (e.g., toxicants) draw the most attention owing to issues related to environmental burden, species specificity, and humaneness. Research and development focusing on RNA interference and gene drives may be able to address the technical aspects of performance goals. However, there remain many questions about regulation, environmental risk, and societal acceptance for these emerging biological technologies. Here we focus on the development and use of these biological technologies for use in vertebrate pest management and conservation (e.g., management of wildlife diseases). We then discuss the regulatory framework and challenges these technologies present and conclude with a discussion on factors to consider for enabling these technologies for pest management and conservation applications under a commercially applied framework.

Chemical irritation in birds: relationship between chemicalstructure of anthranilate and benzoic acid derivatives and repellency

Journal of Experimental Zoology

The Nest Protection Hypothesis: The Adaptive Use of Plant Secondary Compounds by the European Starling

ABSTRACT

Comparative Biochemistry and Physiology Part A: Physiology, 1993

Eight species of passerines were evaluated for their ability to form conditioned responses to odo... more Eight species of passerines were evaluated for their ability to form conditioned responses to odor stimuli. Only 5 species met training criteria and were tested for odor detection thresholds. 2. Detection thresholds were comparable to other passerines tested. Detection values were also similar to mammalian macrosmatic species, such as rats and rabbits. Thus, despite the poorly elaborated olfactory anatomy of passerines, these birds possess an adequate sense of smell. 3. Within the Passeriformes there is no correlation between olfactory acuity and relative size of the olfactory bulb. However, there is a correlation between acuity and olfactory bulb size across orders of birds. These latter observations are consistent with hypotheses correlating form and function.

Pest Management Science, 2002

Aerosolized essential oils and individual natural product Aerosolized essential oils and individu... more Aerosolized essential oils and individual natural product Aerosolized essential oils and individual natural product compounds as brown treesnake repellents compounds as brown treesnake repellents

The Journal of Wildlife Management, 2001

Wildlife managers need chemical repellents that are effective at deterring damage by birds, but t... more Wildlife managers need chemical repellents that are effective at deterring damage by birds, but these repellents must be environmentally and toxicologically safe. The number of commercially available bird repellents has been reduced because of concerns about environmental safety. Currently, there are 2 categories of avian repellents. Chemicals that are reflexively avoided by birds because they irritate the peripheral chemical senses are referred to as primary repellents. Chemicals that cause gastrointestinal illness and learned avoidance of ancillary sensory cues that are paired with the illness are known as secondary repellents. Secondary repellents most often identified as the most effective avian repellents are derived from synthetic agrichemical pesticides and generally are regulated against because of their toxicity and concerns about the consequences of adding them to the environment. Primary repellents are usually derived from natural products and human food and flavor ingredients, and their use as bird repellents has been promoted as fulfilling the need for environmentally safe repellents. However, primary repellents are considered to be less potent than secondary repellents. We found that if the primary repellent, methyl anthranilate, was delivered enterically in European starlings (Sturnus vulgaris), we could achieve the same level of repellency as with the secondary repellent, methiocarb. Equal repellent effects for the 2 chemicals were found despite differences in their mode of action. Also, birds given an enteric delivery of the primary repellent methyl anthranilate showed fewer signs of behavioral distress (e.g., immobility and regurgitation) relative to those birds given the secondary repellent, methiocarb. By redirecting the site of action of a primary repellent, we have shown the feasibility to optimally combine the potency levels of secondary repellents with the biological and environmental safety attributes of primary repellents, without sacrificing efficacy. Primary repellents may be converted to secondary repellents via gastrointestinal delivery, thus potentially increasing efficacy and economic viability of these chemicals. Formulations that mask the irritating qualities of primary repellents are needed so that the chemical will be freely consumed by the target animal and exert its effect in the gastrointestinal tract.

Aquaculture Research, 2006

The e¡ects of adding the nonlethal bird repellent methyl anthranilate (MA), at levels of 100 and ... more The e¡ects of adding the nonlethal bird repellent methyl anthranilate (MA), at levels of 100 and 1000 mg kg À1 , to ¢sh feed on the bioaccumulation and growth of juvenile (10 g) hybrid striped bass (Morone chrysops Â M. saxatilis) and juvenile (1g) African cichlid ¢sh Aulonocara jacobfreibergi were investigated under laboratory conditions. The bird repellent did not have any e¡ect on the ¢sh growth or survival over a period of 6 weeks. MA residues at low levels of 11.2 AE 2.6 mg g À1 were found in lipophilic tissues (liver) of MA-fed ¢sh. Control ¢sh, which had no MA added to their diet, had a much lower level of 0.6 AE 0.3 mg g À1 MA in their liver. Fish muscle was found to contain negligible MA residues, while the outer body surface mucus did not contain any MA. Following a 6-week depuration period, during which the previously MA-fed hybrid striped bass were fed a feed to which no MA was added, the levels of MA residues detected were reduced by one order of magnitude.

Annals of the New York Academy of Sciences, 1987

Chemical treatment of the olfactory epithelium can impair the sense of smell in two ways: product... more Chemical treatment of the olfactory epithelium can impair the sense of smell in two ways: production of a selective hyposmia or of general hyposmia. We have reported the former in tiger salamanders conditioned to respond to two odorants, cyclohexanone and dimethyldi~ulfide.'.~ An example of the latter can be seen in the results of ap

Journal of Experimental Biology, 2004

SUMMARY Using digital fluorescence imaging, we determined the effects of methyl anthranilate (MA)... more SUMMARY Using digital fluorescence imaging, we determined the effects of methyl anthranilate (MA), an avian irritant, and capsaicin (CAP), a mammalian irritant, on intracellular calcium ([Ca2+]i) in chicken trigeminal neurons. Concentration–response functions indicated that the threshold for inducing increases in [Ca2+]i was higher for CAP (30 μmol l–1) than for MA (10 μmol l–1). The maximum magnitudes of [Ca2+]iin response to MA and CAP were compared after normalization to 40 mmol l–1 KCl. At equal concentrations (300 μmol l–1), trigeminal neurons responded with a greater change in[Ca2+]i to MA (78% of KCl) than to CAP (43% of KCl). Furthermore, at 300 μmol l–1, 48% of neurons responded to MA whereas only 16% responded to CAP. The increases in[Ca2+]i induced by both MA and CAP were dependent upon extracellular calcium. While the calcium responses to MA were also dependent on extracellular sodium, responses to CAP were not. There were separate but overlapping populations of neurons ...

1987 AnimBehav (Clark olfaction starling)

Short Communications TABLE 2. Weight changes (g) of 11 Screech Owls between spring and fall-winte... more Short Communications TABLE 2. Weight changes (g) of 11 Screech Owls between spring and fall-winter. [Auk, Vol. 96 Spring Fall-winter Sex Date captured (weight) Date captured (weight) Wt. gain Male 05-14-75 (150) 10-29-75 (180) +30 Male 04-15-76 (145) 10-30-75 (180) +35 Male 05-18-78 (170) 12-28-77 (185) + 15 Male 04-24-75 (160) 02-22-77 (165) +5 Male 05-04-76 (185) 02-22-77 (150) a-35 Female 05-11-78 (205) 12-05-78 (225) + 20 Female 05-14-76 (160) 12-28-77 (200) +40 Female 05-22-75 (190) 02-21-77 (220) +30 Female 04-24-76 (180) 02-21-77 (190) + 10 Female 05-04-76 (180) 02-22-77 (185) +5 Unknown 05-06-76 (205) 01-01-75 (220) + 15 Mean males 156.2 177.5 +21.3 Mean females 183.0 204.0 + 21.0 a Banded as adult on i May 1967, was at least 103A yr old and in poor condition; excluded from mean for males. the extremely cold winter of 1977-78, which included deep snow, five dead Screech Owls were found. No dead owls were found in 1975-76 or 1976-77 when the boxes were checked in the spring. Eighteen and 15 pairs nested successfully in the 150 nest boxes in 1976 and 1977, respectively. The number declined to 6 in 1978 (6 in 150 boxes, or 4%) following the severe winter; this is the lowest percentage recorded since the study began in 1944 (VanCamp and Henny 1975). It appears that a fall weight gain is important to the Screech Owl, but in spite of the weight gain, extreme weather conditions, which tend to occur irregularly, can still pose a hardship for this species near the northern edge of its breeding range in Ohio. The manuscript was improved by the reviews of Vivian M. Mendenhall and Anne R. McLane. LITERATURE CITED EARHART, C. M., & N. K. JOHNSON. 1970. Size dimorphism and food habits of North American owls.

Zoologicheskiĭ zhurnal

The reproductive success of laboratory rats (Rattus norvegicus) housed at different distances (2,... more The reproductive success of laboratory rats (Rattus norvegicus) housed at different distances (2, 20, and 80 m) from a predator (Lynx lynx) was investigated. Virgin female (n = 120) and male (n = 40) rats of an outbred laboratory population were used for the experiments. Groups of rats (I male and 3 females) were housed in standard cages in close proximity to the predator. Litter size, sex ratio. number of alive pups, number of placental scars and corpora lutea were counted; pre- and post-implantation losses were calculated for each female. The reproductive success of females calculated as a number of alive pups per female was much higher in both control groups (20 and 80 m) than in both test groups (2 and 2 m). Equal numbers of corpora lutea in all groups but different numbers of placental scars between the control and test groups indicated a higher pre-implantation loss in the experimental groups. The post-implantation loss was also higher in both test groups. The total loss (calc...

We tested the bird aversive properties of methyl anthranilate, yucca extracts, and Xanthoxylum sp... more We tested the bird aversive properties of methyl anthranilate, yucca extracts, and Xanthoxylum spp. extracts in one-and two-bottle drinking assays that used European starlings (Sturnus vulgaris). In one-and two-bottle tests, methyl anthranilate proved to be the more potent stimulus in producing an avoidance response. Starlings avoided consuming Xanthoxylum and yucca only in the two-bottle tests. Previous studies showed that yucca was a good adjuvant in stabilizing lipophilic compounds in water. Starlings did not avoid binary mixtures of methyl anthranilate and yucca differently from what would be expected if they were only responding to the solution's methyl anthranilate content. However, yucca enhanced the aversive qualities of Xanthoxylum. The ability to identify mode of action for repellency and synergistic combinations of chemicals derived from natural products for use in repellent mixtures is an important aspect of the development of cost-effective, environmentally safe repellents for use in conflict resolution between humans and wildlife.

Human food flavor additives as bird repellents: I. Conjugated aromatic compounds

Pesticide Science, 1999

ABSTRACT Avian repellents derived from natural products and human food flavorants may be less exp... more ABSTRACT Avian repellents derived from natural products and human food flavorants may be less expensive to register under United States environmental pesticide registration requirements. However, one difficulty faced by workers attempting to target repellents for development is the need to screen large numbers of compounds for activity, as well as consideration of formulation and environmental constraints. In this study, we compare the bird repellent activity of aldehyde-based human food additives and compare the levels of activity with our previously elucidated model for structure–activity relationships (SAR) for bird repellents. We find that a previously elucidated SAR model for identifying acetophenone and anthranilate bird repellents is applicable to predicting the activity of aromatic aldehyde flavorants as well. In particular, of the nine flavorants tested, four, benzaldehyde, cinnamaldehyde, o-tolualdehyde, and o-anisaldehyde, warrant further consideration as bird repellents.L© 1999 Society of Chemical Industry

International Biodeterioration & Biodegradation, 2000

The identi®cation of new chemical repellents for wildlife damage management is impeded by the nee... more The identi®cation of new chemical repellents for wildlife damage management is impeded by the need to perform cumbersome and expensive behavioral tests. Here, we report the development of in vitro cell culture methods to increase the speed and eciency of repellent screening while reducing costs, as well as the number of animals necessary for research. Our methods exploit the fact that eective primary repellents depend on the stimulation of pain receptors. We cultured trigeminal nociceptors (pain receptors) from Norway rat (Rattus norvegicus, laboratory strain), white leghorn chicken (Gallus gallus), coyote (Canis latrans), white-tailed deer (Odocoileus virginianus) and Canada goose (Branta canadensis), and then applied digital¯uorescence microscopy to measure changes in intracellular calcium (an index of cellular activation) in response to applications of known and eective repellents. Capsaicin, bradykinin and acetylcholine were more eective stimuli for rat, coyote, and deer neurons than cells from chicken.

Because of their numbers and close association with humans and agriculture. the role of blackbird... more Because of their numbers and close association with humans and agriculture. the role of blackbirds in disease transmission has been of concern. Unfortunately fear systematic and quantit3tir.e studies have been carried out that bear on this issue. We review the extant literature on zoonases xnd oathoeens of aericultural concern where there is documented evidcnce for the . " involvement of blzckbirds and starlings. It is clear that blackbirds can exacerbate levels of risk for failures in agricultural biosecurity and human health. To what degree these levels of risk are raised is largelv unknown and should be the focus of future . studies because this information will prove vital in the assessment of management options.

Journal of Experimental Zoology, 1990

A passerine bird, the European Starling Sturnus vulgaris, demonstrated a seasonal ability to resp... more A passerine bird, the European Starling Sturnus vulgaris, demonstrated a seasonal ability to respond to odor cues. Cardiac conditioned responses were most evident when birds were in breeding condition. Once birds were in nonbreeding condition, responding to odors all but ceased. For birds in breeding condition, threshold sensitivity to the odor cyclohexanone was comparable to levels reported for nonpasserine birds (0.3% vapor saturation or 3.778 x 1014 molecules/ ml). In contrast, the threshold level during the postreproductive phase of the annual cycle was 10% vapor saturation (1.256 X 10l6 moleculesiml), a level high enough to implicate the trigeminal system as the modality mediating chemosensory perception. The strong cyclic responding pattern suggests links between photoperiodically controlled endocrine production, breeding behavior, and olfactory sensitivity.