Rove beetles (Staphylinidae) in Ontario soybean-hedgerow agroecosystems were surveyed in 2009-2010 to identify common, widespread species and assess their potential biological control of Soybean Aphid and Bean Leaf Beetle. The spatiotemporal distributions, habitat use, and co-occurrence of staphylinids with soybean pests were studied to provide a framework for future agroecological studies of biocontrol services in soybean. A taxonomic review of the Staphylinina (Staphylinidae: Staphylininae) (‘large rove beetles’) for the geographic area of study was conducted and identification keys were created to assist in future staphylinid research. Common soybean staphylinids were generally exotic, penetrated field interiors, utilized hedgerow habitat outside the growing season and co-occurred with pest populations during vulnerable life stages. Several species exhibited nocturnal activity in soybean foliage. Biocontrol of overwintering Soybean Aphid and Bean Leaf Beetle populations in hedgerows by staphylinids may occur in buckthorn canopies and leaf litter, respectively.

Food habits for yellow perch Perca flavescens were compared using current and previous diet studies from southern Lake Michigan index sites. Yellow perch were not gape limited but size-selective in consumption of the newly established round goby Neogobius melanostomus. Ingested fish ranged from 7 to 47% of the yellow perch's total length and 2 to 53% of their gape. Currently, yellow perch diets are dominated in volume by fish/fish products (85%), which is double from previous studies. Utilization of zooplankton and insect prey items in the yellow perch diet has decreased to <1% by volume in 2002, contrasting with previous consumption of 4 to 20% and 5 to 17%, respectively, from previous studies during 1971-1993. Yellow perch are exhibiting opportunistic, generalist feeding strategy that incorporates both exotic and native prey items, allowing the population to use multiple prey items with the changing prey base in Lake Michigan. / Department of Biology

Masters of Science / African brown house snakes (Boaedon capensis) are widely thought to be dietary specialists that predominantly consume rodents. Given their ubiquitous distribution, these snakes potentially play an important role in controlling rodent populations throughout their range. However, the full extent of the diet of this species remains poorly quantified, and the proportional importance of mammals to their diet is speculative. Moreover, little is known regarding intraspecific dietary variation of these snakes. In recent years, a dearth of reports of B. capensis feeding, particularly from novel information-sharing streams available through social media, suggests that the diet of these snakes may be broader than previously thought. B. capensis are not rodent specialists as amphibians (3%), birds (12%), and reptiles (38%) collectively comprise a significant proportion of their diet. There was no evidence for sexual size dimorphism or dietary variation between adult males and females. However, significant differences in morphology and prey utilisation between adults and juveniles indicate an ontogenetic shift in diet from small lizards to larger, and more diverse prey. Variation in climate and time of year did not affect diet. Importantly, the diet of B. capensis as presented by museum data vastly differed compared to literature and community science reports. In particular, the proportional use of reptiles differed across sources (museum data = 6%; community science data = 27%). Overall, my findings reiterate the importance of examining multiple sources of information when characterizing the diet of species, as these multiple sources provide different result outcomes.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: In surveys carried out on poultry farms in the Western Cape Province, South Africa, the larvae of the flies Musca domestica L., Fannia canicularis (L.) and Leptocera sp. were found to be numerous. The majority of M domestica larvae and the mite Proctolaelaps sp. were recovered from manure with temperatures between 20 and 26°C while the larvae of F. canicularis and Leptocera sp. were mostly found between 14 and 22°C. Predominant predatory arthropods in the manure were the histerid Carcinops pumilio (Erichson), the staphylinid Philonthus sordidus (Gravenhorst) and the mite Macrocheles muscaedomesticae (Scopoli). These had a manure temperature tolerance of between 12 and 31°C. Macrocheles muscaedomesticae and P. sordidus preferred fresh manure, whilst C pumilio preferred aged manure. Therefore these two predators could complement one another in integrated pest management programmes. From a study of the vertical cross-sectional profile of the manure cone it was clear that the larvae of the prey species M domestica and F. canicularis and predator P. sordidus distinctly occupy the crest of the manure cone. The succession of arthropods in accumulating poultry manure and the effect of manure height on their numbers was studied. The prey species M domestica and F. canicularis were the first colonizers followed by the predators P. sordidus and M muscaedomesticae. Carcinops pumilio was a late colonizer. The numbers of M domestica and F. canicularis larvae were negatively correlated with the increase in manure height whilst the numbers of the predators C pumilio and M muscaedomesticae were positively correlated with this. The total developmental time of C pumilio from egg to adult emergence at 30°C was 20.5 days. Two larval instars were recorded. The immature stages sustained about 50% mortality before adult emergence. Carcinops pumilio adults can live up to 130 days at 30°C and had a Type I survivorship curve. The intrinsic rate of natural increase (rm) was 0.064943 and net reproduction rate (Rs) was 20.191.The rate of oviposition was directly proportional to body size and weight. Increase in density had a dampening effect on fecundity and led to an increase in developmental time. Thus density will be a critical factor in any mass rearing programme for this predator of fly larvae. In addition, an increase in density stimulated the dispersal of C. pumilio. A crowding level of 50 C. pumilio adults per 200ml container resulted in the least dispersal which did not exceed 2.5% per day, compared with up to 24.0% at a crowding level of 400. The predation rate of flies by C. pumilio in the laboratory decreased with an increase in predator density, but increased with an increase in starvation. Starvation had no effect on predation rate of M muscaedomesticae. A technique exploiting Drosophila melanogaster Meig. as a source of prey was successfully developed for rearing C. pumilio, which could be of commercial value. Drosophila melanogaster appeared to be an ideal candidate as a source of prey for mass rearing C. pumilio due to its short developmental time of about ten days. It is also inexpensive and easy to breed, and has a very high biotic potential. Carcinops pumilio that were fed on artificial diet had a prolonged developmental time and increase in weight, and laid fewer eggs than those fed on natural diet. C. pumilio completed its development on the artificial diet and both the F, and F2 generations fed on an artificial diet were able to lay eggs. This could be the first step towards finding an artificial diet that would allow continuous rearing of C. pumilio and their availability at all times for utilization in the biological control of houseflies. / AFRIKAANSE OPSOMMING: In opnames wat op pluimveeplase in die Westelike Kaapprovinsie, Suid-Afrika uitgevoer is, is gevind dat die vliegsoorte Musca damestica L., Fannia canicularis (L.) en Leptacera sp. volop is. Die meeste van die M. damestica larwes en die myt Practalaelaps sp. is versamel in hoendermis met temperature tussen 20 en 26°C en die larwes van Ficanicularis en Leptacera tussen 14 en 22°C. Die volopste predatoriese arthropode in die mis was die histerid Carcinaps pumilia Erichson, die staphylinid Philanthus sardidus (Gravenhorst) en die myt Machrascheles muscaedamesticae (Scopoli). Hulle temperatuurtoleransie in die mis was tussen 12 en 31°C. Machrasceles muscaedamesticae en P. sardidus het vars mis verkies, terwyl C. pumilio voorkeur aan ouer mis gegee het. Gevolglik behoort hierdie twee predatore mekaar te komplementeer in programme van ge-integreerde plaagbestuur. In Studie van die vertikale deursnee-profiel van die miskeel het duidelik getoon dat die prooispesies M. damestica en en F canicularis en die predator P. sardidus in die kroon van die miskeel voorkom. Die opeenvolging van die arthropode in die ophopende hoendermis en die invloed van mishoogte op hulle getalle is bestudeer. Die prooispesies M damestica en F canicularis was die eerste koloniseerders, gevolg deur die predatore P. sardidus en M muscaedamesticae. Carcinaps pumilia was In laat koloniseerder. Die getalle van die larwes van M damestica en F. canicularis was negatief gekorreleer met die toename in mishoogte terwyl die getalle van die predartore C. pumilia en M. muscaedamesticae positief daarmee gekorreleer was. Die totale ontwikkelingstyd van C. pumilia van eier tot die volwassene se verskyning was 20.5 dae by 30°C. Twee larwale instars is gevind. Die onvolwasse stadia het 50% mortaliteit ondergaan voor die verskyning van die volwassenes. Die volwassenes van C. pumilia kan tot 130 dae lank by 30°C lewe en het In Tipe 1 oorlewingskurwe gehad. Die intrinsieke tempo van natuurlike toename (rm) was 0.064943 en die netto reproduksietempo (Rs) 20.191. Die tempo van eierlegging was in direkte verhouding tot die liggaamsgrootte en massa. Toename in digtheid het 'n onderdrukkende effek op vrugbaarheid gehad en tot 'n toename in ontwikkelingstyd gelei. Digtheid sal dus 'n kritieke faktor wees III emge program van massateling vir hierdie predator van vlieglarwes. Daarmee saam het 'n toename in digtheid die verspreiding van C. pumilio gestimuleer. By 'n digtheid van 50 C. pumilio volwassenes per houer het die verspreiding nie 2.5% oorskrei nie, in vergelyking met tot 24.0% by 'n dightheid van 400. Die predasietempo van vliee deur C. pumilio in die laboratorium het afgeneem met 'n toename in predatordigtheid, maar toegeneem met 'n toename in verhongering. Verhongering het nie 'n invloed gehad op die predasietempo van M. muscaedomesticae nie. 'n Tegniek met Drosophila melanogaster Meig. as bron van prooi in die teling van C pumilio is suksesvol ontwikkel en dit kan van kommersiele waarde wees. Dit blyk dat D. melanogaster ideaal kan wees as 'n bron van prooi in die massateling van Cpumilio vanwee sy kort ontwikkkelingstyd van ongeveer tien dae. Die spesies is ook goedkoop en maklik om te teel, en het 'n baie hoe biotiese potensiaal.Care inops pumilio wat op 'n kunsmatige dieet gevoed het, het 'n verlengde ontwikkelingstyd en gewigstoename gehad, en het minder eiers gele as die wat op 'n natuurlike dieet gevoed het. C. pumilio het sy lewensloop op die kunsmatige dieet voltooi en beide die FJ en F2 generasies wat op die kunsmatige dieet gevoed het, was in staat om eiers te Ie. Dit kan die eerste stap wees in 'n poging om 'n kunsmatige dieet te vind wat dit sal moontlik maak om C. pumilio aaneenlopend te teel sodat dit deurlopend beskikbaar kan wees vir gebruik in die biologiese beheer van huisvliee,

New and emerging diseases in human and animal populations appear to be predominately associated with generalist pathogens that are able to infect multiple hosts. Carnivores are susceptible to a wide range of these pathogens and can act as effective samplers of their vertebrate prey, which are important reservoirs of many emerging diseases. This thesis evaluates the utility of carnivores as sentinels for pathogens present in their prey by exploration of four selected pathogen-prey-sentinel combinations in three rural study sites of varying habitat in northern England and Scotland over a twenty-two month period (2007-2009). Selected pathogens were Coxiella burnetii, Leptospira spp., Encephalitozoon cuniculi, and rabbit haemorrhagic disease virus (RHDV), selected prey species were wild rodents and rabbits, and selected carnivores were foxes, domestic cats and corvids. Seroprevalence to C.burnetii, Leptospira spp and E.cuniculi was assessed using adapted or novel test methodologies to enable their use for multiple mammalian species, however these were not applicable to corvids. RHDV seroprevalence was not assessed due to low acquisition of rabbit samples. Overall, seroprevalence to all three pathogens was significantly higher in predators than prey, at 24.2% and 12.4 % for C.burnetii, 22.73% and 1.95% for Leptospira spp and 39.06% and 5.31% for E.cuniculi in predator and prey species respectively. A similar pattern was found in all study areas and was consistent irrespective of individual prey or predator species, although serological evidence of exposure to E.cuniculi was not detected in domestic cats in any area. A semi-quantitative assessment of the time and financial costs of the study approach and application to hypothetical examples indicates that sampling carnivores is a much more costeffective approach to pathogen detection than sampling prey. The results indicate that carnivores can act as useful sentinels for broad-scale detection of pathogen presence and relative levels of prevalence in prey and predator populations. Careful selection of predator species and methods of sample acquisition are necessary to maximise their utility, and issues associated with diagnostic test performance and validation must also be acknowledged. Suggestions are made as to how this principle might be applied to future surveillance programmes. In addition, the study is the first report on the seroprevalence of C.burnetii, Leptospira spp and E.cuniculi in multiple wildlife species (field voles, bank voles, wood mice, foxes), the first detection of antibodies to C. burnetii in wildlife and cats, the first detection of antibodies to L mini, L hardjo prajitno and L hardjo bovis in wild rodents, and to L mini in cats, and the first detection of antibodies to E.cuniculi in wild rodents and foxes in the UK.

Generalist predators can contribute to vital ecosystem services by potentially inducing trophic cascades as natural enemies of pests in agroecosystems. As the human population of the world gets larger, we need to produce more food on ever-smaller swaths of available land relying on ecosystem services, in the form of pest control, that may contribute to agricultural sustainability. Teasing apart the exact trophic linkages between predators and prey is a vital first step and essential to uncovering which predators are inducing trophic cascades and should be enhanced through conservation biological control. Combined with ecological experimentation, the main tool used throughout my research to identify trophic linkages is molecular gut-content analysis. I began by investigating mass sampling techniques and found they do not cause contamination in gut-content analysis and may be a simple method for collecting large numbers of cryptic predators for use in determining trophic linkages. Additionally, my research uncovered trophic interactions between stink bugs and generalist predators at multiple scales. Overall, I successfully designed molecular methods to investigate relationships between agricultural pests and generalist predators. A multi-year field study uncovered low predation on stink bug pests in contrast to previous research suggesting that generalist predators were contributing highly to biological control. This research highlights the need for replicated studies before making broad conservation biological control decisions. Although generalist predators were not consuming stink bugs in large numbers, my field cage study showed evidence of superfluous killing by spiders on adult stink bugs, highlighting the need to combine ecological studies with molecular methods to understand consumptive and non-consumptive effects on prey items. Gut-content analysis showed no evidence of consumption, but the field cage study allowed me to uncover the complicated relationships between spiders and stink bugs. In addition, I showed an invasive species can be detected in new areas through molecular gut-content analysis of predators before other sampling methods.

This thesis is about the dynamics of eastern grey kangaroo (Macropus giganteus) populations and their food supplies in temperate grasslands of south-eastern Australia. It is based on the study of three populations of eastern grey kangaroos inhabiting �warm dry�, �cold dry�, and �warm wet� sites within the Southern Tablelands climatic region. After a pilot survey and methods trial in early 2001, the main period of study was from August 2001 to July 2003. The study populations were found to have the highest densities of any kangaroo populations, 450 to 510 km-2. Their density was the same at the end of the two year study period as at the beginning, in spite of a strong decline in herbage availability due to drought. The eastern grey kangaroo populations were limited according to the predation-sensitive food hypothesis. Fecundity, as the observed proportion of females with late pouch young in spring, was high, in spite of the high kangaroo density and restricted food availability. Age-specific fecundity of a kangaroo sample shot on one of the sites in 1997 to avert starvation was the highest reported for kangaroos. Thus, limitation acted through mortality rather than fecundity. Population growth rate was most sensitive to adult survival but the demographic rate that had the greatest effect in practice was mortality of juveniles, most likely sub-adults. The combination of high fecundity with high mortality of immatures would provide resilience to low levels of imposed mortality and to fertility control. The normal pattern of spring pasture growth was not observed in the drought conditions and few of the recorded increments of growth were of the magnitude considered typical for sites on the southern and central tablelands. Temperature was necessary to predict pasture growth, as well as rainfall, over the previous two months. The best model of pasture growth (lowest AICc) included negative terms for herbage mass, rainfall over the previous two months, and temperature, and a positive term for the interaction between rainfall and temperature. It accounted for 13% more of the variation in the data than did the simpler model of the type used by Robertson (1987a), Caughley (1987) and Choquenot et al. (1998). However this was only 63% of total variation. Re-evaluation of the model based on measurements of pasture growth in more typical (non-drought) conditions is recommended. Grazing had a powerful influence on the biomass of pasture due to the high density of kangaroos. This is a marked difference to many other studies of the type which have been conducted in semi-arid environments where rainfall dominates. The offtake of pasture by kangaroos, as estimated on the research sites by the cage method, was linear on herbage mass. It was of greater magnitude than the more exact estimate of the (curved) functional response from grazedowns in high�quality and low�quality pastures. The widespread recognition of three forms of functional response is inadequate. Both the theoretical basis, and supporting data, have been published for domed, inaccessible residue, and power forms as well (Holling 1966; Noy-Meir 1975; Hassell et al. 1976, 1977; Short 1986; Sabelis 1992). Eastern grey kangaroos had approximately the same Type 2 functional response when consuming either a high quality artificial pasture (Phalaris aquatica), or dry native pasture (Themeda australis) in autumn. Their functional response rose more gradually than those published for red kangaroos and western grey kangaroos in the semi-arid rangelands, and did not satiate at the levels of pasture available. This gradual behaviour of the functional response contributes to continuous stability of the consumer-resource system, as opposed to discontinuous stability. The numerical response was estimated using the ratio equation, assuming an intrinsic rate of increase for eastern grey kangaroos in temperate grasslands of 0.55. There is indirect evidence of effects of predation in the dynamics of the kangaroo populations. This is demonstrated by the positive relationship between r and kangaroo density. Such a relationship can be generated by predation. A desirable future task is to compile estimates of population growth rate and simultaneous estimates of pasture, in the absence of predation, where kangaroo population density is changing, so that the numerical response can be estimated empirically. The management implications arising from this study are numerous and a full account would require a separate report. As one example, kangaroos in these temperate grasslands are on average smaller, eat less, are more numerous, and are more fecund, than would be predicted from other studies (e.g. Caughley et al. 1987). Thus the benefit of shooting each kangaroo, in terms of grass production, is less, or, in other words, more kangaroos have to be shot to achieve a certain level of impact reduction, and the population will recover more quickly, than would have been predicted prior to this study. Secondly, of much importance to managers, the interactive model which can readily be assembled from the products of Chapters 4, 5 and 8, can be used to test a range of management options, and the effect of variation in weather conditions, such as increased or decreased rainfall. For example, the model indicates that commercial harvesting (currently under trial in the region), at the maximum level allowed, results in a sustainable harvest of kangaroos, but does not increase the herbage mass, and only slightly reduces the frequency of crashes when herbage mass falls to low levels. (To demonstrate this with an ecological experiment would require an extremely large investment of research effort.) However, an alternative �national park damage mitigation� formula, which holds kangaroo density to about 1 ha-1, is predicted to increase herbage mass considerably and to reduce the frequency of crashes in herbage mass, but these effects would be achieved at the cost of having to shoot large numbers of kangaroos. Thus, aside from many specific details of kangaroo ecology, the knowledge gained in this study appears to have useful potential to illustrate to managers the dynamic properties of a resource-consumer system, the probabilistic nature of management outcomes, and the consequences of particular kangaroo management proposals.

The endangered willow flycatcher (Empidonax traillii) breeds in mountain meadows in the Sierra Nevada, which have been intensively modified, especially reducing meadow wetness, which favors easy access for mammalian predators to reach nesting areas in the meadow interior. High nest predation frequency is one of the main factors for willow flycatcher and other passerines? populations decline. I conducted trapping in wet and dry areas on 10 meadows in May?August of 2007 and 2008 to identify the assemblage of potential mammalian nest predators. I compared the predator activity between wet and dry areas of the meadows and determined the relationship between predator activity with vegetation and hydrology of the meadows. In 2008, I used radio-telemetry on deer mice (Peromyscus maniculatus) and yellow-pine chipmunks (Tamias amoenus) to determine their movement patterns across wet and dry areas, and between forest and meadow. My results showed that chipmunks? and squirrels? activity was restricted almost to dry areas. The activity of yellow-pine chipmunks was 96% and 97% higher in dry versus wet areas in 2007 and 2008, respectively. Voles, mice, and shrews were active in both site types. Voles (Microtus spp.) and shrews (Sorex spp.) were in general more active in wet areas versus dry areas in 2007. Deer mice were equally active in both site types in 2007 and more active in wet areas in 2008. Between years, predators were 68% more active in wet areas in 2007 compared to 2008, and similarly 52% more active in dry areas. Radio-tagged deer mice used the forest and the meadow and were more common in dry areas, whereas yellowpine chipmunks used more the forest than the meadows and were active only in dry areas. Passerines nesting in drier areas are exposed to a larger assemblage of potential predators and are more likely to be predated. My results suggest that increasing the proportion of inundated areas in the meadows would help reduce predator activity (especially chipmunks and squirrels) and consequently nest predation, helping increase flycatcher numbers. In addition, wetter conditions will favor an increment in food availability for flycatchers and an increment in willow cover, which consequently will provide more nesting substrate and will help increase nest concealment.

Predation is the leading cause of nest failure in songbirds. My study identified nest predators of black-capped vireos and white-eyed vireos, quantified the activity of potential predator species, examined the relationships between vegetation and nest predators, and examined the relationship between nest predation and parasitism by brown-headed cowbirds. In 2008 and 2009 I monitored black-capped and white-eyed vireo nests on privately-owned properties in Coryell County and black-capped vireo nests on Kerr WMA in Kerr County and at Devils River State Natural Area in Val Verde County (2009 only). I monitored vireo nests using a video camera system to identify predators and nest fate. I also collected at-nest vegetation measurements including nest height, distance to nearest habitat edge, and nest concealment. Additionally, I sampled potential predator activity at a subset of black-capped vireo and white-eyed vireo nests in Coryell County using camera-trap bait stations and herptofaunal traps. I monitored 117 black-capped vireo nests and 54 white-eyed vireo nests. Forty-two percent of black-capped vireo and 35% of white-eyed vireo nests failed due to predation. I recorded >10 total predator species and 37 black-capped vireo and 15 white-eyed vireo nest predation events. Snakes (35%) and cowbirds (29%) were the most frequently identified nest predators; however, major predator species varied by location. I observed no significant relationship between nest fate (fledge vs. fail) and nest concealment or distance to edge for either vireo species. Nest height, concealment and distance to edge may relate to predator species in Coryell Co. for snake species, and Kerr for avian species. Additionally, I observed no difference between the predator activity and the fate of the nest. Both vireos have multiple nest predator species. Additionally, multiple cowbird predations demonstrate this species may have multi-level impacts on vireo productivity, even with active cowbird management. Vegetation structure and concealment may also affect predator species. However, the activity of other predator species near active nests may not negatively affect nest success.

M. Tech. Nature Conservation / The influence of predation on ungulates is most commonly measured through the direct lethal effects of predators. However, indirect effects of predation risk may alter prey behaviour and survival. The introduction of a pack of African wild dogs (Lycaon pictus) into the Northern Tuli Game Reserve, Botswana, allowed various indirect responses of ungulates to predation risk to be investigated. The study focused on predation pressure and its effects on ungulate activities during the denning period of the wild dogs, and on how the distribution and density of prey and lions influenced wild dog movement patterns in both the denning and non-denning period.