Behavioral Ecology, Taxonomy, and Conservation Genetics of the Bahama Oriole (Icterus northropi)

In this dissertation, I examined the Bahama Oriole (Icterus northropi) at multiple scales, with the aim of developing a sound management plan for this critically endangered bird. In the first of five studies, I measured plumage variation among four allopatric populations of the former Icterus dominicensis complex in the Caribbean. Diagnosable plumage differences among populations contributed to the subsequent elevation of each of these populations (including northropi) to species status. In the second study, I examined molecular variation in subpopulations of 1. northropi on North Andros, Mangrove Cay, and South Andros, The Bahamas. I identified several patterns of genetic variation that will inform conservation planning. The third study explored the population status and breeding ecology of the Bahama Oriole. My estimates of 141- 254 individuals remaining globally contributed to an IUCN Red List designation as critically endangered. Orioles selected nesting trees that were significantly taller, less likely to have shrubs underneath, farther from cover, and with more palm trees nearby than randomly available palm trees. Lethal yellowing disease devastated coconut palms regionally on North Andros during the course of our study, but palms on South Andros and Mangrove Cay, where oriole density was higher, remained healthy. In the fourth study, I assessed the Bahama Oriole\u27s community-level relationships, including the relative densities of other avian species in three habitats (pine forest, coppice, and anthropogenic habitat), foraging strategies, and inter- and intraspecific social interactions. My findings indicate coppice is vitally important to resident, migrating, and wintering birds. Collectively, these studies identify key conservation priorities to save this critically endangered bird. In my final study, a literature review, I explored the ecological consequences of extinction in a well-studied insular model: the Hawaiian Islands avifauna. Five of six islands have significantly different trophic guild structure now than they did prior to the arrival of humans, due to a combination of extinction events and introduced bird species. Very few extinct bird species have been replaced by equivalent ecological substitutes in the present day avifauna, leading to coextinctions of dependent species. This research highlights the importance of preventing extinctions in the remaining global avifauna

Population size, distribution and habitat use of the Hawaiian Short-eared Owl (Asio flammeus sandwichensis) on O'ahu

Technical report prepared for the State of Hawaiʻi Department of Land & Natural Resources on population size, distribution and habitat use of the Hawaiian Short-eared Owl (Asio flammeus sandwichensis) on O'ahuThe Pueo (Asio flammeus sandwichensis), once common across the Hawaiian Islands, is currently state-listed as Endangered on O'ahu. The Pueo provides important ecosystem services by controlling population sizes of introduced rodents and preying on other introduced and native species, including birds and invertebrates. As the only native raptor that breeds on the main Hawaiian Islands, the Pueo plays an important role in top-down ecological regulation and is also valued by native Hawaiians and other Hawai'i residents. Although the Pueo has been recorded in a variety of vegetation types in the Hawaiian archipelago, key habitat selection variables are still unknown. In this study, we optimized a survey methodology to improve population estimates and define vegetation types important to population stability and we compared distribution among vegetation types and overall population densities of Pueo with other Short-eared Owl populations across the globe. Three different approaches were used: (a) standardized surveys by trained personnel; (b) citizen science reports of Pueo sightings submitted to an online portal www.pueoproject.com; and (c) citizen science reports to eBird www.ebird.org, a publicly available, well-established, and curated international online portal for submitting bird sighting reports. We collected more than 50 Pueo sightings in one year through the Pueo project online portal, while the eBird portal collected 43 reports in three decades. Information gathered through the citizen science portal was highly valuable for obtaining phenology and breeding event observations (nests, owlet locations, display flights), however, data collected in this manner were biased due to the lack of standard distribution of the observers, which hampered their usefulness for running distribution models or other population analyses. During the standardized surveys Pueo were observed on agricultural lands, wetlands, short grasslands and open native vegetation. Pueo were detected, on average, 23 minutes before twilight. Estimated densities ranged from 0 to 3.3 Pueo per 100 ha across vegetation types, with most detections occurring in open vegetation types, such as agricultural lands, grasslands, and wetlands. Based on observed densities, the population of Pueo inhabiting O'ahu was estimated at 807 individuals, with 95% confidence intervals of 8 to 2199. Densities obtained from standardized, randomized surveys are aligned with those studies targeting known Short-eared Owl populations with a high rate of occupancy, which does not seem to be the situation on O'ahu, especially if we consider the high level of threats that this species faces in Hawai'i and the observations of declining populations that local inhabitants have reported in person or submitted to the Pueo Project portal. Densities on O'ahu are probably similar to the ones reported in non-targeted, randomized and standardized studies, where owls occupy territories with high prey availability, but leave unoccupied low-prey-density territories. Based on this information, we consider the most likely population number to be on the lower end of the estimated range of possibilities

Population genetics and the effects of a severe bottleneck in an ex situ population of critically endangered Hawaiian tree snails

As wild populations decline, ex situ propagation provides a potential bank of genetic diversity and a hedge against extinction. These programs are unlikely to succeed if captive populations do not recover from the severe bottleneck imposed when they are founded with a limited number of individuals from remnant populations. In small captive populations allelic richness may be lost due to genetic drift, leading to a decline in fitness. Wild populations of the Hawaiian tree snail Achatinella lila,a hermaphroditic snail with a long life history, have declined precipitously due to introduced predators and other human impacts. A captive population initially thrived after its founding with seven snails, exceeding 600 captive individuals in 2009, but drastically declined in the last five years. Measures of fitness were examined from 2,018 captive snails that died between 1998 and 2012, and compared with genotypic data for six microsatellite loci from a subset of these deceased snails (N5335), as well as live captive snails (N5198) and wild snails (N592). Surprisingly, the inbreeding coefficient (Fis) declined over time in the captive population, and is now approaching values observed in the 2013 wild population, despite a significant decrease in allelic richness. However, adult annual survival and fecundity significantly declined in the second generation. These measures of fitness were positively correlated with heterozygosity. Snails with higher measures of heterozygosity had more offspring, and third generation offspring with higher measures of heterozygosity were more likely to reach maturity. These results highlight the importance of maintaining genetic diversity in captive populations, particularly those initiated with a small number of individuals from wild remnant populations. Genetic rescue may allow for an increase in genetic diversity in the captive population, as measures of heterozygosity and rarified allelic richness were higher in wild tree snails

Conservation taxonomy of the Greater Antillean Oriole (Icterus dominicensis): diagnosable plumage variation among allopatric populations supports species status

Allopatric populations, such as those present on islands, pose special challenges to identifying taxonomic boundaries which can be practically addressed using diagnostic criteria. To assess the taxonomic and, hence, conservation status of the four island populations of the Greater Antillean Oriole (Icterus dominicensis), we examined 156 male specimens of I. dominicensis for six discrete and three continuous plumage characters. The four island populations proved to be 100% diagnosable. Icterus d. northropi differed from all other taxa by having the greatest extent of yellow on the venter (non-overlapping with other taxa). Icterus d. portoricensis was distinguished from all other taxa by the presence of a black upper rump (yellow in other taxa) and the least extent of yellow on the rump (non-overlapping with other taxa). Icterus d. melanopsis and I. d. dominicensis were fully discriminated from I. d. northropi and I. d. portoricensis by the aforementioned characters and from each other by upper-tail covert color (black and ≥ 50% yellow, respectively). Our findings support recent studies suggesting that the four island groups represent distinct allospecies consistent with interpretations of both the phylogenetic and evolutionary species concepts. With elevation to full species, conservation priorities need to be revisited, particularly for the critically endangered Bahamas taxon (I. d. northropi)

Interactive/Transmedia Storytelling As Cultural Narrative: Stories Of Family, Place And Identity

If cinema and television are considered the dominant storytelling vehicles of the twentieth century, helping to shape and reflect the social, political and cultural sensibilities of that era, then the emerging characteristics of twenty-first century storytelling are digital; interactive; networked; playful; mobile; social; processual; immersive; and convergent. This chapter explores migrant narratives and identity formation through the vehicle of immersive; participatory; user-driven; multi-platform; and interactive documentary. What emerges is a new, evolving literacy in response to emerging storytelling technologies. Through describing two transmedia projects in which they are personally involved, the authors also provide a glimpse of an emerging ecology of storytelling through which a new vocabulary is evolving. This vocabulary assigns a different role to participants who are both immersed in the narrative discourse and actively engaged in the storytelling itself

Environmental drivers of seasonal shifts in abundance of wild pigs (Sus scrofa) in a tropical island environment

Four raster datasets are included that were developed using data derived from game camera traps. These data were used as inputs in a species distribution modeling approach using environmental correlates (please find more detailed information in the referenced publication). The resulting raster datasets are a relative abundance index (0 - 100) of feral pigs on Maui using seasonal (Fall and Spring) and combined annual data as well as an averaged ensemble model using seasonal outputs. For those interested in a single model that best represents average pig distribution please use the averaged ensemble model (Maui_pig_ensemble_distribution.tif). *Please note: Additional raster datasets for feral goat (Maui_feralgoats_distribution.tif) and Axis deer (Maui_axisdeer_distribution.tif) distributions are included but are currently unpublished data. Please reach out should you have any questions.Background: Non-native wild pigs (Sus scrofa) threaten sensitive flora and fauna, cost billions of dollars in economic damage, and pose a significant human–wildlife conflict risk. Despite growing interest in wild pig research, basic life history information is often lacking throughout their introduced range and particularly in tropical environments. Similar to other large terrestrial mammals, pigs possess the ability to shift their range based on local climatic conditions or resource availability, further complicating management decisions. The objectives of this study were to (i) model the distribution and abundance of wild pigs across two seasons within a single calendar year; (ii) determine the most important environmental variables driving changes in pig distribution and abundance; and (iii) highlight key differences between seasonal models and their potential management implications. These study objectives were achieved using zero-inflated models constructed from abundance data obtained from extensive field surveys and remotely sensed environmental variables. Results: Our models demonstrate a considerable change in distribution and abundance of wild pigs throughout a single calendar year. Rainfall and vegetation height were among the most influential variables for pig distribution during the spring, and distance to adjacent forest and vegetation density were among the most significant for the fall. Further, our seasonal models show that areas of high conservation value may be more vulnerable to threats from wild pigs at certain times throughout the year, which was not captured by more traditional modeling approaches using aggregated data. Conclusions: Our results suggest that (i) wild pigs can considerably shift their range throughout the calendar year, even in tropical environments; (ii) pigs prefer dense forested areas in the presence of either hunting pressure or an abundance of frugivorous plants, but may shift to adjacent areas in the absence of either of these conditions; and (iii) seasonal models provide valuable biological information that would otherwise be missed by common modeling approaches that use aggregated data over many years. These findings highlight the importance of considering biologically relevant time scales that provide key information to better inform management strategies, particularly for species whose ranges inc

A comparison of abundance and distribution model outputs using camera traps and sign surveys for feral pigs

Two raster datasets are included that were developed using data derived from game camera traps (Oahu_pigcam_distribution.tif) and visual sign surveys (Oahu_pigsign_distribution.tif). These data were used as inputs in a species distribution modeling approach using environmental correlates (please find more detailed information in the referenced publication). The resulting raster datasets are a relative abundance index (0 - 100) of feral pigs on Oʻahu.Species distribution models play a central role in informing wildlife management. For models to be useful, they must be based on data that best represent the presence or abundance of the species. Data used as inputs in the development of these models can be obtained through numerous methods, each subject to different biases and limitations but, to date, few studies have examined whether these biases result in different predictive spatial models, potentially influencing conservation decisions. In this study, we compare distribution model predictions of feral pig (Sus scrofa) relative abundance using the two most common monitoring methods: detections from camera traps and visual surveys of pig sign. These data were collected during the same period using standardised methods at survey sites generated using a random stratified sampling design. We found that although site-level observed sign data were only loosely correlated with observed camera detections (R2 ¼ 0.32–0.45), predicted sign and camera counts from zero-inflated models were well correlated (R2 ¼ 0.78–0.88). In this study we show one example in which fitting two different forms of abundance data using environmental covariates explains most of the variance between datasets. We conclude that, as long as outputs are produced through appropriate modelling techniques, these two common methods of obtaining abundance data may be used interchangeably to produce comparable distribution maps for decision-making purposes. However, for monitoring purposes, sign and camera trap data may not be used interchangeably at the site level

Population status, habitat dependence, and reproductive ecology of Bahama Orioles: a critically endangered synanthropic species.

Recent elevation of critically endangered Bahama Orioles (Icterus northropi) to species status promptedustoevaluate theirpopulation status,habitatuse,andbreedingecology.Fromsurveys,weestimatedthat at least 141 to 254 individuals remain globally, with 90 to 162, 24 to 44, and 27 to 48 individuals remaining on North Andros Island, Mangrove Cay, and South Andros Island, The Bahamas, respectively. Orioles were observed nesting exclusively in anthropogenic habitat (residential and agricultural land), but home ranges also included nearby pine forest and coppice (dry broadleaf forest). Most nests (40 of 46, or 87%) were in nonnative coconut palm (Cocos nucifera), with native Sabal palmetto and Thrinax morrisii, and an introduced Brassaia actinophylla also used. Trees selected by orioles for nesting were significantly taller, less likely to have shrubs underneath, further from cover, and had more palm trees nearby than randomly selected palm trees. Three of eight nests with known contents were parasitized by Shiny Cowbirds (Molothrus bonariensis). Lethal yellowing disease recently devastated coconutpalmsandreducedthenumberoforiolesonNorthAndros,butpalmsonMangroveCayandSouthAndros remain healthy. The juxtaposition of anthropogenic habitat to suitable native habitats may be more important than any single factor for Bahama Orioles, especially for breeding adults and fledged young. Conservation of coppice habitat, at high risk for agricultural and residential development, is crucial for survival of this critically endangered synanthropic species

Breeding phenology and daily activity of the Hawaiian Short-eared Owl (Asio flammeus sandwichensis) on O'ahu

A technical report prepared for the State of Hawaiʻi Department of Land & Natural Resources on breeding phenology and daily activity of the Hawaiian Short-eared Owl (Asio flammeus sandwichensis) on O'ah

Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico

We examined organic-walled dinoflagellate cysts from one 210Pb-dated sediment core and 39 surface sediment samples from the northern Gulf of Mexico to determine the relationship between nutrient enrichment and cyst assemblages in this region characterized by oxygen deficiency. The core spans from 1962 to 1997 and its sampling location is directly influenced by the Mississippi River plume. Surface sediments were collected in 2006, 2007, 2008, and 2014 and represent approximately 1 to 4 years of accumulation. A total of 57 cyst taxa were recorded, and four heterotrophic taxa in particular were found to increase in the top section (1986–1997) of the core—Brigantedinium spp., cysts of Archaeperidinium minutum, cysts of Polykrikos kofoidii, and Quinquecuspis concreta. These taxa show a similar increasing trend with variations in US fertilizer consumption and Mississippi River nitrate concentrations, both of which increased substantially in the 1970s and 1980s. The same four heterotrophic taxa dominated dinoflagellate cyst assemblages collected near the Mississippi River Bird’s Foot Delta where nutrient concentrations were higher, especially in 2014. We propose that these cyst taxa can be used as indicators of eutrophication in the Gulf of Mexico. A canonical correspondence analysis (CCA) supports this proposition. The CCA identified sea-surface nutrient concentrations, sea-surface temperature, and sea-surface salinity as the most important factors influencing the cyst assemblages. In addition, cysts produced by the potentially toxic dinoflagellates Pyrodinium bahamense and Lingulodinium polyedrum were documented, but did not appear to have increased over the past 50 years