Intercropping switchgrass (Panicum virgatum) between tree rows within young pine (Pinus spp.) plantations is a novel method to generate lignocellulosic biofuel feedstocks within intensively managed forests. Intensively managed pine supports diverse avian assemblages potentially affected by establishment and maintenance of a biomass feedstock. I sought to understand how establishing switchgrass on an operational scale affects bird communities within intercropped plantations as compared to typical intensively managed loblolly pine (Pinus taeda) plantations. I conducted breeding bird point counts, nest searching and monitoring, and coarse woody debris (CWD) surveys following establishment of intercropped switchgrass stands (6 replicates), traditionally-managed pine plantations, and switchgrass-only plots (0.1 km2 minimum) in Kemper Co., MS from 2011 to 2013. I found establishment of intercropping did not affect downed CWD, but reduced standing snags and green trees. I detected 59 breeding bird species from 11,195 detections and modeled nest survivorship for 17 species. Neotropical migrants and forest-edge associated species were less abundant in intercropped plots than controls for two years after establishment, and more abundant in year three. Short distance migrants and residents were scarce in intercropped and control plots initially, and did not differ between these treatments in any year. Species associated with pine-grass habitat structure were less abundant initially in intercropped plots, but converged with pine controls in subsequent years. Switchgrass monocultures provided minimal resources for birds. There was no evidence supporting an effect of intercropping on songbird nest survivorship. I found evidence for dominance of one species, yellow-breasted chat (Icteria virens), over another, indigo bunting (Passerina cyanea) in competition for nest sites, which illustrates how songbirds competing for nest sites can coexist in sympatry without the dominant species driving subordinate competitors to local extirpation. This dissertation, and related publications, are among the earliest research on wildlife response to intercropping. Forest managers implementing intercropping within pine plantations where vertebrate conservation is a management priority should be aware of potential changes to snag-utilizing species from reductions in green trees and snags. Songbird populations may lag behind traditional management for up to two years following establishment of switchgrass. Intercropping neither positively nor negatively affected songbird nest survival.

There is an increasing interest in the use of autonomous recording units as an alternative survey method to point count surveys conducted by human observers; however, questions remain about whether or not these recording units perform similarly to point count surveys and produce valid, comparable results. The use of individual listeners to transcribe the acoustic data collected by autonomous recording units is a common method for the analysis of recorded acoustic data, but potential variability among transcribers raises questions about the standardization of listening protocols to decrease inconsistencies in transcription results. Autonomous recording units have been used to monitor birds in and around Brimfield State Forest in Brimfield, Massachusetts since 2012, after a tornado severely damaged a large area of the forest and surrounding properties. In 2016 and 2017, I conducted 71 10-minute point count surveys while simultaneously recording the survey with an autonomous recording unit in three habitat types in and around Brimfield State Forest in Brimfield, Massachusetts. I transcribed the acoustic data from the recordings and compared it to the results of the point count surveys to determine if autonomous recording units performed as well as point count surveys. To assess variability among listeners, four listeners transcribed the same sample of 30 recordings and a sub-sample of 6 of those recordings that were created during the 2014 field season using two different listening protocols. The first protocol instructed listeners to play each recording straight through without stopping, and the second protocol instructed listeners to stop and replay any part of the recording they needed to and also use outside sources to aid in species identification. I compared the number of species, individuals, distant individuals, and mean counts (uncorrected abundance), corrected abundance and detectability of focal species between both survey methods, among all listeners using both listening protocols, and where possible between habitat types to assess differences in method performance and listener variability. I tested for correlation between autonomous recording units and point counts using the uncorrected and corrected abundance estimates. The number of species and number of individuals detected did not differ between survey methods overall and for each habitat individually; however, in each habitat type, more individuals were classified as distant by autonomous recording units overall for all habitats. The number of species detected did not differ between listeners overall and for in each habitat using either listening protocol. The number of individuals and distant individuals detected differed significantly between listeners and within certain habitats using the first listening protocol. There were no differences in the number of species, individuals, or distant individuals detected overall between listeners using the second listening protocol, but there were significant differences in individuals and distant individuals detected between habitats by listeners. Corrected and uncorrected abundance estimates between autonomous recording units and point count surveys were highly correlated, and there were no differences in detection probabilities for the focal 23 species between survey methods and among habitat types. Only 2 out of 18 focal species indicated a significant difference in detection probability between listeners using both listening protocols. Based on the results of my study, I conclude that autonomous recording units perform at least as well as human observers conducting point count surveys, and that multiple listeners transcribing the same acoustic data do not show high levels of variation in the results of their transcriptions.

Global agricultural intensification has caused large-scale wildlife declines, but agricultural lands that maintain natural habitats can support healthy wildlife populations and receive significant ecosystem services from these natural communities. However, how on-farm biodiversity results in beneficial ecosystem services is highly variable and is reported to differ among taxa and guilds. One group that has attracted attention for their potential beneficial role in reducing pest abundance are birds. Understanding the role of bird communities and individual species in pest control could be important for managing farms under a low intensity agroecological framework. In New England, farmers are increasingly applying low intensity agricultural practices, and these low intensity farms have high conservation value for bird communities. The value of bird communities to on-farm productivity, however, remains poorly understood. Therefore, we quantified the amount of insect pest control provided by birds to three important crops to New England farmers: brassicas (e.g., kale, broccoli), cucurbits (e.g., squash, cucumber), and Solanaceae (e.g., eggplant, potato). We also examined the role of different songbird species in the provision of pest control in this system. To determine the amount of pest control services provided by birds in this system, we conducted an exclusion experiment at nine low intensity farms in Franklin and Hampshire counties of Massachusetts. Birds were excluded from crops, and pest abundance and leaf damage were compared between exclusion plots and immediately adjacent control plots. In brassica crops, the abundance of imported cabbageworm (Pieris rapae) and diamondback moth (Plutella xylostella) were significantly reduced, while cabbage looper (Trichoplusia ni) was not significantly affected. In cucurbit crops, all life stages of squash bugs (Anasa tristis) were significantly reduced, though striped cucumber beetle (Acalymma vittatum) populations were not significantly changed. In Solanaceous crops, bird presence caused significantly larger populations of Colorado potato beetle (Leptinotarsa decemlineata) larvae, while the other life stages of Colorado potato beetle and aphids (superfamily Aphidoidea) were not significantly affected. Leaf damage was reduced by bird presence in all three crop types, though this effect was only significant for cucurbits. The varied effects of bird predation in different crop types highlights the need for crop-specific knowledge in applying agroecological pest management in New England. To determine the roles of different bird species in insect pest control, bird diets were studied at 11 low intensity farms in western Massachusetts. DNA metabarcoding was used to determine the frequency of crop pests and pest natural enemies in fecal samples collected from birds on each farm. We found evidence of pest species being consumed in 12.6% of the 737 total fecal samples collected, while pest natural enemies were present in 2.0% of samples. Among bird species, Gray Catbirds and Common Yellowthroats were determined to feed on crop pests significantly more frequently than Song Sparrows, while no bird species effect was found for natural enemy frequency. The only crop pest surveyed in our exclosure experiment which was present in fecal samples was Colorado potato beetle. Though birds preyed on Colorado potato beetle, they also preyed on two known predators of Colorado potato beetle eggs and larvae: Chrysopa oculata and Chrysoperla rufilabris. This provides evidence that the increase in Colorado potato beetle larvae we observed when birds were present was due to ecological release. Combined, our results show that birds provide important, though variable, insect pest control services on low intensity New England farms. Bird predation had primarily beneficial impacts on crops, suppressing abundance of several pest species and decreasing or minimally affecting leaf damage. The effects of bird predation on pest abundance and damage can be integrated into farm management to control insect pests without reliance on expensive, and sometimes damaging, outside inputs like pesticides. Promotion of woody, non-crop habitats on farms can promote species like Gray Catbirds and Common Yellowthroats that feed more frequently on insect pests. Management of New England farmlands for bird pest control may support healthy bird communities and improve agricultural output.

Previous studies have shown that it is possible for juvenile songbirds to learn songs through listening to prerecorded songs played back to them. What is not known however, is how this will differ from normal learning, both on neural level as well as on the bird as whole. In this project we have taken data from playback experiments and attempted to measure the differences in neuron spiking activity across two different contexts. Firstly, when the bird is only listening to playback recordings and secondly when the bird is listening to playback recordings on the same day as listening to a live tutor. We analysed the spiking activity with several different methods in order to establish a distinction between these contexts that could be seen across birds and across trials. The methods include analysing joint spiking events as binary spike trains, the Fano factor across trials as well as the variability of the spike rate. Our hypothesis was that the birds would learn more effectively on days when exposed to a live tutor, therefore, the playback days would show much higher and much more varied spiking data. From our results we found many cases when this hypothesis is true. However, it does not hold true for each of the birds, as some are offered similar results in either context. Therefore we believe that further study would be required to get conclusive results. Although, our results tend to favour the tutoring days it is only suggestive that this shows evidence of better learning. / Tidigare studier har visat att det är möjligt för unga sångfåglar att lära sig sånger genom att lyssna på förinspelade läten som spelas upp för dem. Vad som dock inte är känt är hur detta sätt kommer att skilja sig, jämfört med normalt lärande, både på neural nivå och på fågeln som helhet. I detta projekt har vi tagit data från ett uppspelningsexperiment och försökt mäta skillnaderna neuronspikande aktiviteter i två fall. I det första fallet lyssnar fågeln bara på inspelad fågelsång och i det andra fallet lyssnar fågeln på inspelad fågelsång samma dag som den lyssnar på en vuxen fågel som mentor. Vi analyserade spikningsaktiviteten med flera olika metoder för att finna en skillnad mellan dessa fall, som kan ses både mellan fåglar och mellan ollika försök. Metoderna inkluderar analys av gemensamma spikinghändelser som binära spiktåg, Fanofaktorn över försöken samt variationen i spikhastigheten. Vår hypotes var att fåglarna skulle lära sig mer effektivt på dagar när de utsattes för en vuxen fågel som mentor, därför skulle uppspelningsdagarna visa mycket högre och mycket mer varierad spikdata. Från våra resultat fann vi att i många fall där hypotesen är sann. Men den stämmer inte för alla fåglarna eftersom några fåglar hade liknande resultat för båda fallen. Därför tror vi att ytterligare studier krävs för att få tydliga resultat. Dock så tenderar våra resultat att gynna mentordagarna, även om det bara antyder att detta visar på bättre lärande.

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Solitary Vireos (Vireo solitarius alticola) were studied on an extensive mature forest landscape in 1994 and on three sites harvested using the group selection method in 1995. Pairing success was 88% on the unharvested site in 1994, however it was lower on the harvested sites in 1995 (53.8%). Low reproductive success was observed in both years (12% and 22% respectively). In 1995, the amount of opening within a 200 meter radius of the first observation point of a male was positively related to pairing success (p<0.05). This suggests that females may be cueing in on the increased number of shrubs in and around openings. / Master of Science

Agriculture and, more recently, oil and gas development have contributed to extensive degradation and loss of temperate grasslands. I investigated the landscape-scale effects of oil and gas development, and roads, on grassland birds in southern Alberta using abundance, clutch size and nesting success data collected from 2010-2014. I estimated: (i) the distance at which there are effects of edge, and effects of shallow gas well density, using piecewise regressions; (ii) the locations and extent of habitat affected by infrastructure for obligate grassland species– Baird’s Sparrow (Ammodramus bairdii), Chestnut-collared Longspur (Calcarius ornatus) and Sprague’s Pipit (Anthus spragueii); and generalist species – Clay-colored Sparrows (Spizella pallida), Horned Lark (Eremophila alpestris), Savannah Sparrow (Passerculus sandwichensis), Vesper Sparrow (Pooecetes gramineus) and Western Meadowlark (Sturnella neglecta), and (iii) the total area affected by wells and roads. My findings suggest that the effects of roads, overall, extended to further distances than edge effects associated with natural gas wells, obligate species had more habitat affected by infrastructure than generalist species and shallow gas wells affected more habitat than did oil wells, due to their greater density on the landscape. Additionally, obligates, on average, were negatively affected by proximity to edge where as generalists were more productivity closer to edge. Reducing fragmentation caused by roads, minimizing the spread of non-native vegetation and management of cattle around gas wells could improve habitat quality for these focal species. / February 2016

Wildlife species that rely on early successional habitat are showing long-term region-wide declines, including songbirds such as Eastern Towhee (Pipilo erythrophthalmus), Field Sparrow (Spizella pusilla), Blue-winged Warbler (Vermivora cyanoptera), Golden-winged Warbler (Vermivora chrysoptera), Prairie Warbler (Setophaga discolor), and Brown Thrasher (Toxostoma rufum). All six species are listed as Species of Greatest Conservation Need on a majority of the New England state's Wildlife Action Plans and in 2011, the Golden-winged Warbler was placed under review for federal listing. In areas where vegetation structure is actively maintained in early successional stages, such as powerline rights-of-way (ROWs), there is an opportunity to provide habitat over long time frames. This study focused on habitat use by six early successional bird species in the Champlain Valley in Vermont along powerline ROWs. Thirty sites that included potential habitat were established. During the breeding season, trained citizen scientist volunteers spot-mapped species distribution patterns along transects. Focal habitat use by individuals was mapped during timed field observations (n=83). Vegetation species composition and structure was evaluated within 1m2 vegetation plots across each site (n=965). Logistic regression models of study species' abundance patterns and focal habitat use were compared using Akaike's information criterion (AIC). Surrounding landscape composition, vegetation species composition and vegetation structure had the greatest influence on species abundance and focal habitat use based on best-fit models. All species occurrence, except Blue-winged Warbler and Brown Thrasher, decreased with greater development and fragmentation in the surrounding landscape. While the covariates that influenced habitat use patterns by the species were similar, the effect size and direction of influence varied. These results suggest that a universal management approach for shrubland songbird habitat would not support a broad range of species. The findings from this study determined species-specific habitat preferences that can improve management practices to benefit these declining species.

In migratory vertebrates, the optimal timing of successive life history stages is relatively inflexible. As a result, life history trade-offs that occur during breeding may influence individual success in subsequent stages because there is little time to mitigate negative costs that are incurred, or because the onset of subsequent stages is delayed. In migratory songbirds, understanding how breeding events carry over to influence individual success has been challenging because individuals are difficult to track once breeding is complete. I studied an island breeding population of migratory Savannah sparrows (Passerculus sandwichensis) and tracked individuals from breeding up until the onset of autumn migration. In Chapter 1, I investigated the effects of early life events on body condition during the pre-migratory period and first year apparent survival. I found that juveniles fledging from larger broods were in poorer condition at fledging, had lower fat stores prior to migration, and had lower first year apparent survival. In Chapter 2, I examined the effects of life history trade-offs made by adults during breeding on pre-migratory body condition and annual apparent survival. I did not find evidence for a trade-off between reproductive effort or date of breeding completion with annual apparent survival or body condition during the pre-migratory period, but instead found that adults with the highest reproductive effort and later dates of breeding completion were more likely to survive until the following year. In Chapter 3, I examined the effect of timing of breeding completion and fledging on the date of fall migration. I found that both variables had strong positive effects on date of departure. Together, my results suggest that successful migration in juveniles is influenced by early life events, but that any potential costs incurred by adults during the breeding season likely has little influence on survival during migration.

The three Pycnonotus bulbuls endemic to Africa, P. barbatus, P. nigricans and P. capensis, occupy mutually exclusive distributions in southern Africa. These species are closely related and appear to occupy very similar ecological niches, only in different regions. Using a multifaceted approach, this study attempts to explain the ecology of this species complex. All three species show similar physiological responses to temperature extremes, and are therefore unlikely to be directly limited by environmental temperature. However, their distributions are highly correlated to a complex of environmental variables, particularly winter minimum temperatures, the coefficient of variation in mean annual rainfall, and the seasonality of rainfall. This combination of environmental parameters can be used to predict the distributions of at least one of the species, P. nigricans, accurately. An analysis of the vocalizations and behaviour of the three species revealed that, whilst P. capensis has a number of recognizably different vocalizations, those of P. barbatus and P. nigricans are very similar. The three have nearly identical behaviours, particularly courtship and pre-copulatory behaviours. The mate recognition systems of the three are therefore extremely similar. P. barbatus is territorial during the breeding season, and exhibits highly structured-variation in male territorial song at the level of the local neighbourhood. The literature pertaining to song dialects is reviewed, and a new hypothesis is postulated to explain song-matching in terms of neighbour/stranger discrimination and the possible existence of cooperative territory defence. A survey of the eastern Cape region, where all three species come into contact, showed that extensive hybridization is taking place between each species pair. Phenotypically, this hybridization is restricted to narrow hybrid zones, that are considered to be stable in both time and place. The evolutionary and ecological significance of these zones to the distributions of the species is discussed, and it is proposed that the zones are maintained by selection acting on differentially-adapted genomes along an environmental gradient.