Radio Frequency Identification (RFID) technology has been broadly applied in the biological sciences to yield new insights into behavior, cognition, population biology, and distributions. RFID systems entail wireless communication between small tags that, when stimulated by an appropriate radio frequency transmission, emit a weak, short-range wireless signal that conveys a unique ID number. These tags, which often operate without a battery, can be attached to animals such that their presence at a particular location can be detected by an RFID reader. This paper describes an RFID data-logging system that can serve as the core for a wide variety of field and laboratory applications for monitoring the activities of individual animals. The core electronics are modeled on an Arduino circuit board, which is a hobbyist electronics system. Users can customize the hardware and software to accommodate their needs. We demonstrate the utility of the system with cursory descriptions of three real-world research applications. The first is a large-scale deployment that was used to examine individual breeding behaviors across four local populations of Wood Ducks. The second application employed an array of RFID-enabled bird feeders that allowed for tests of spatial cognition. Third, we describe a nest-box monitoring system that both records visits from breeding birds and administers experimental treatments, such as increasing temperature or playing audio recordings, in accordance to the presence/absence of individual birds. With these examples we do not attempt to relate details with regard to research findings; rather our intent is to demonstrate some of the possibilities enabled by our low-cost RFID system. Detailed descriptions, design files, and code are made available by means of the Open Science Framework.

The dynamics of predator-prey interactions vary enormously, due both to the heterogeneity of natural environments and to wide variability in the sensorimotor systems of predator and prey. In addition, most predators pursue a range of different types of prey, and most organisms are preyed upon by a variety of predators. We do not yet know whether predators employ a general kinematic and behavioral strategy, or whether they tailor their pursuits to each type of prey; nor do we know how widely prey differ in their survival strategies and sensorimotor capabilities. To gain insight into these questions, we compared aerial predation in 4 species of libelluid dragonflies pursuing 4 types of dipteran prey, spanning a range of sizes. We quantified the proportion of predation attempts that were successful (capture success), as well as the total time spent and the distance flown in pursuit of prey (capture efficiency). Our results show that dragonfly prey-capture success and efficiency both decrease with increasing size of prey, and that average prey velocity generally increases with size. However, it is not clear that the greater distances and times required for capturing larger prey are due solely to the flight performance (e.g., speed or evasiveness) of the prey, as predicted. Dragonflies initiated pursuits of large prey when they were located farther away, on average, as compared to small prey, and the total distance flown in pursuit was correlated with initial distance to the prey. The greater initial distances observed during pursuits of larger prey may arise from constraints on dragonflies' visual perception; dragonflies typically pursued prey subtending a visual angle of 1°, and rarely pursued prey at visual angles greater than 3°. Thus, dragonflies may be unable to perceive large prey flying very close to their perch (subtending a visual angle greater than 3-4°) as a distinct target. In comparing the performance of different dragonfly species that co-occur in the same habitat, we found significant differences that are not explained by body size, suggesting that some dragonflies may be specialized for pursuing particular types of prey. Our results underscore the importance of performing comparative studies of predator-prey interactions with freely behaving subjects in natural settings, to provide insight into how the behavior of both participants influences the dynamics of the interaction. In addition, it is clear that gaining a full understanding of predator-prey interactions requires detailed knowledge not only of locomotory mechanics and behavior, but also of the sensory capabilities and constraints of both predator and prey.

Environmental changes caused by urbanization and noise pollution can have profound effects on acoustic communication. Many organisms use higher sound frequencies in urban environments with low-frequency noise, but the developmental and evolutionary mechanisms underlying these shifts are less clear. We used a common garden experiment to ask whether changes in minimum song frequency observed 30 years after a songbird colonized an urban environment are a consequence of behavioral flexibility or canalized changes that occur early in development. We captured male juvenile dark-eyed juncos (Junco hyemalis thurberi) from two recently diverged populations (urban and mountain) soon after they reached independence (aged 25-40 days), raised them in identical indoor aviaries, and studied their songs at an age of three years. We found that the large population difference in minimum frequency observed in the field persisted undiminished in the common garden despite the absence of noise. We also found some song sharing between the common garden and natal field populations, indicating that early song memorization before capture could contribute to the persistent song differences in adulthood. These results are the first to show that frequency shifts in urban birdsong are maintained in the absence of noise by genetic evolution and/or early life experiences..

Anthropogenic noise is a ubiquitous feature of the American landscape, and is a known stressor for many bird species, leading to negative effects in behavior, physiology, reproduction, and ultimately fitness. While a number of studies have examined how anthropogenic noise affects avian fitness, there are few that simultaneously examine how anthropogenic noise impacts the relationship between parental care behavior and nestling fitness. We conducted Brownian noise playbacks for 6 h a day during the nesting cycle on Eastern Bluebird (Sialia sialis) nest boxes to investigate if experimentally elevated noise affected parental care behavior, nestling body conditions, and nestling stress indices. We documented nest attendance by adult females using radio frequency identification (RFID), and we assessed nestling stress by measuring baseline corticosterone levels and telomere lengths. Based on the RFID data collected during individual brood cycles, adult bluebirds exposed to noise had significantly higher feeding rates earlier in the brood cycle than adults in the control group, but reduced feeding rates later in the cycle. Nestlings exposed to noise had higher body conditions than the control nestlings at 11 days of age, but conditions equalized between treatments by day 14. We found no differences in nestling baseline corticosterone levels or nestling telomere lengths between the two treatment groups. Our results revealed that noise altered adult behavior, which corresponded with altered nestling body condition. However, the absence of indicators of longer-term effects of noise on offspring suggests adult behavior may have been a short-term response.

Electronic devices are frequently used for field ecological research (e.g. Allan et al., 2018; Marvin et al., 2016). In many cases these devices are left in the field for weeks or months at a time. For example, passive acoustic monitoring devices (e.g. Wildlife Acoustics) are designed to continuously record soundscapes for months; trail cameras have opened a new realm of animal research (O'Connell, Nichols, & Karanth, 2010), and the use of radio frequency identification (RFID) to track movement and behaviour of animals is on the rise (Bridge et al., 2019). The expanding capabilities of small computing units, such as the Arduino (Ivrea, Italy) or Raspberry Pi

Climate change is increasing aridity in grassland and desert habitats across the southwestern United States, reducing available resources and drastically changing the breeding habitat of many bird species. Increases in aridity reduce sound propagation distances, potentially impacting habitat soundscapes, and could lead to a breakdown of the avian soundscapes in the form of loss of vocal culture, reduced mating opportunities, and local population extinctions. We developed an agent‐based model to examine how changes in aridity will affect both sound propagation and the ability of territorial birds to audibly contact their neighbors. We simulated vocal signal attenuation under a variety of environmental scenarios for the south, central semi‐arid prairies of the United States, ranging from contemporary weather conditions to predicted droughts under climate change. We also simulated how changes in physiological conditions, mainly evaporative water loss (EWL), would affect singing behavior. Under contemporary and climate change‐induced drought conditions, we found that significantly fewer individuals successfully contacted all adjacent neighbors than did individuals in either the contemporary or predicted climate change conditions. We also found that at higher sound frequencies and higher EWL, fewer individuals were able to successfully contact all their neighbors, particularly in drought and climate change drought conditions. These results indicate that climate change‐mediated aridification may alter the avian soundscape, such that vocal communication no longer effectively functions for mate attraction or territorial defense. As climate change progresses, increased aridity in current grasslands may favor shifts toward low‐frequency songs, colonial resource use, and altered songbird community compositions.

21Environmental changes caused by urbanization and noise pollution can have profound 22 effects on acoustic communication. Many organisms use higher sound frequencies in 23 urban environments with low-frequency noise, but the developmental and evolutionary 24 mechanisms underlying these shifts are less clear. We used a common garden 25 experiment to ask whether changes in minimum song frequency observed 30 years 26 after a songbird colonized an urban environment are a consequence of behavioral 27 flexibility or canalized changes that occur early in development. We captured male 28 juvenile dark-eyed juncos (Junco hyemalis thurberi) from two recently diverged 29 populations (urban and mountain) soon after they reached independence (aged 25-40 30 days), raised them in identical indoor aviaries, and studied their songs at an age of 31 three years. We found that the large population difference in minimum frequency 32 observed in the field persisted undiminished in the common garden despite the absence 33 of noise. We also found some song sharing between the common garden and natal field 34 populations, indicating that early song memorization before capture could contribute to 35 the persistent song differences in adulthood. These results are the first to show that 36 frequency shifts in urban birdsong are maintained in the absence of noise by genetic 37 evolution and/or early life experiences. 38 39 40 41 42 Introduction 43Anthropogenic noise can alter the biology of diverse animal taxa at organismal, 44 population, and even community scales [1][2][3][4][5][6][7]. In particular, the low frequency 45 background noise often associated with urbanization can interfere with animal 46 communication and has been associated with changes in acoustic signals that improve 47 sound transmission [8, 9]. One such change that is widely observed in urban 48 environments is increased minimum frequency of acoustic signals, which may be an 49 adaptation to overcome the masking effects of low-frequency noise [10][11][12][13][14][15][16]. Our 50 understanding of the developmental and evolutionary mechanisms that may underlie 51 such changes in acoustic signaling remains limited [9,[17][18][19][20][21][22]. Species such as oscine 52 songbirds that learn their songs are of particular interest due to the potential for cultural 53 evolution and other forms of behavioral plasticity, which can facilitate rapid change in 54 response to anthropogenic noise [23][24][25]. 55Several non-mutually exclusive hypotheses have been proposed to explain 56 changes in song frequency in urban environments [9, 26], including short-term plasticity, 57 ontogenetic effects (early experience), and evolutionary change across generations. 58The plasticity hypothesis argues that frequency shifts are the result of behavioral 59 flexibility in response to the presence or absence of a noise stimulus. Some studies in 60 oscine songbirds have found evidence supporting plasticity either through rapid 61 increases in minimum song frequency [18, 22, 27, 28] or switching to...

Supplemental feeding is a common anthropogenic influence on wildlife which, dependent on natural food availability, can have positive or negative effects on physiological condition. For example, animals may respond negatively to supplemental feeding if the artificial food source increases disease exposure or there may be negative consequences from removal of a supplemental food source. We manipulated supplemental food availability in a wild population of eastern bluebirds Sialia sialis to examine the influence on body mass, physiological metrics and nesting success. Adult and nestling bluebirds were randomly assigned to one of three feeding groups. The first treatment group received mealworm Tenebrio molitor larvae inside nest boxes throughout the breeding attempt, the second treatment group received mealworms from nest completion until nestlings hatched, and the third treatment group received no supplementation. We collected blood samples from adults and nestlings to quantify bacterial killing ability, corticosterone levels and heterophil to lymphocyte ratios. As measures of nesting success, we quantified hatching success and fledging success. Supplement group tended to impact nestling mass near fledging; however, neither the physiological metrics nor the nesting success metrics differed significantly among experimental groups. Our results suggest eastern bluebird supplementation is largely neutral with the exception of its removal at the time of hatching, at least when natural food sources are abundant. Bird feeding by hobbyists may attract birds to locations with available nesting sites without demonstrably negative or positive effects, unless practiced inconsistently during breeding.