Concentrated animal feeding operations (CAFOs) are sometimes located in close proximity to fresh produce fields, both of which serve as easily accessible food and water sources for wild birds. When birds travel between these two areas, they have the potential to transfer pathogens from cattle, a documented source of enteric zoonotic foodborne pathogens, to fresh produce crops through fecal deposition. However, the presence of pathogens in wild birds is not a risk unless the birds or their fecal material come into contact with fresh produce crops. Therefore, the objective of this study was to determine if birds visiting CAFOs use flyways that cross fresh produce fields, thereby increasing the risk for contaminating fresh produce intended for human consumption. During 2014, birds trapped at a CAFO in southern Arizona were fitted with Lotek nano-coded radiotransmitters. Two receivers were placed at the CAFO and two receivers were placed in nearby fresh produce fields. A total of 103 birds were fitted with radiotransmitters, including 66 red-winged blackbirds, 21 Eurasian collared doves, 11 brown-headed cowbirds, four common ravens, and one European starling. Over four million data points were collected indicating the date, time, and bird ID number for each time a bird was recorded within 1 km of a receiver. Radiotelemetry results showed that birds travel regularly between the CAFO and fresh produce fields. Using PCR and culture techniques, 2 (1.9%) birds tested positive for Salmonella, and 5 (4.9%) tested positive for non-O157 Shiga toxin-producing Escherichia coli (STEC). During the same time period, Salmonella (4%), STEC O157 (16%), and non-O157 STEC (44.5%) were detected in 400 cattle fecal samples from the CAFO. Our results will aid in determining the pathogen risks that birds pose to fresh produce when they are frequent visitors to a CAFO and fresh produce fields.

Water quality standards for drinking water and recreational waters have long been based on the enumeration of faecal coliforms in the various water supplies, with 0 CFU Escherichia coli/100 ml for drinking water and <126 CFU generic E. coli/100 ml for recreational waters. Irrigation water will soon undergo the same scrutiny in the United States. For over 50 years the most probable number method has been used by laboratories to estimate the level of viable bacteria in a sample, but this method is labour intensive and slow, especially if large numbers of samples need to be tested. In this review, we describe some recent innovations in methods to enumerate enteric pathogens in water. These methods are based on different reasoning schemes that can be categorized as biosensors and nucleic acid-based methods. All the methods described here used natural water sources. Several were also used to survey the bacterial levels in naturally contaminated samples. The different methods vary in their limits of detection, ease of use, and potential portability. Some combine very good limits of detection with the ability to overcome technical challenges; however, there is considerable room for improvement, as none of the methods are without shortcomings.

Animal intrusion causes significant agricultural losses each year. Wild and domestic animals destroy crops by eating and trampling them, and can pose food safety risks due to the deposition of feces on or near the crops. Birds are one of the most challenging animals to keep out of agricultural fields. Growers try countless methods to deter them, including visual, auditory, tactile, and olfactory means. While some of these methods work some of the time, none provide stand-alone protection all the time. Recently there has been interest in developing technology-based solutions to deter nuisance birds in agricultural settings, while others are exploring more natural methods, including falconry. We provide a general overview of bird deterrent methods that are currently in use in agricultural settings, and explore options for novel methods. We found that very few independent scientific studies have been conducted to assess the efficacy of most bird deterrent methods. Ultimately, a multi-tiered approach using integrated pest management techniques will likely be most useful as it can be tailored to meet the needs of individual farmers. KEY WORDS: animal intrusion, birds, bird deterrent, falconry, integrated pest management, nuisance bird Proc. 28 th Vertebr. Pest Conf. (D. M. Woods, Ed.) Published at Univ. of Calif., Davis. 2018. Pp. 218-223. Table 1. Bird deterrents commonly used to protect fresh produce fields from nuisance birds.

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Authors' Contribution NM conceived and designed the study. NM and TM analysed the data and wrote the manuscript. PR improved the manuscript through valuable discussion and constructive comments. AA and SM participated in the fieldwork.

Consumption of produce contaminated with pathogens of fecal origin is the most common source of food borne illnesses. Current practice is to visually survey fields for evidence of fecal contamination, and to exclude problematic areas from harvest. Bird excrement is known to contain human pathogens, and is often not detectable in produce fields using current survey methods. The goal of this project was to identify parameters for optical detection of bird excrements to support development of instruments to be used to supplement existing visual surveys. Under daylight ambient conditions, results suggested that reflectance imaging at around 500–530 nm or 610–640 nm could be used to detect excrements from the three bird species tested. Images were acquired using ad hoc camera parameters; however, normalizing intensities for individual images at 525 nm and using a fixed detection threshold allowed detection of 100% of bird excrements with no false positives against the background that consisted of local soil and fresh romaine and spinach leaves. Similar results were obtained using fluorescence imaging. Fluorescent imaging was accomplished in a darkened room using 405-nm illumination. The largest consistent differences in intensity responses between excrements and the brightest non-excrement object in the background matrix occurred at around 550 nm. Results suggested that using reflectance or fluorescence imaging for detection of bird excrements could be a valuable tool for reducing risks of consuming contaminated produce. One possibility would be to incorporate appropriate reflectance imaging capabilities in drones under the control of the individuals currently conducting field surveys.