Mainland Colony Research Articles

Comparing three common nest survey methods, using double-crested cormorants as a proposed sentinel for monitoring plastic pollution in freshwater environments

Many bird species use plastic as nest-building material, and nest surveys represent a unique opportunity to monitor environmental plastic pollution. However, the current literature lacks consistent, repeatable methodologies, making comparison across studies challenging. This study evaluated three common nest survey methods to assess the use of nest debris: photographic assessment, visual assessment, and nest deconstruction. We applied these methods to double-crested cormorant nests (Nannopterum auritum) at two locations on Lake Ontario, Canada. We found that for this species, nest deconstruction yielded the greatest accuracy and detail for detecting debris abundance, type, and colour. Of the two non-invasive methods, visual surveys outperformed photographic surveys across all metrics assessed. In our mainland colony, 100% of nests contained debris based on visual assessment, while at our offshore colony only 37.4% of nests contained debris, suggesting that location influences nest debris for this species. We detected Personal Protective Equipment (PPE)-related debris in 20% of all nests across survey years at our mainland colony (2022 and 2023), representing the first time that PPE has been documented in the nests of this species and demonstrating that nest surveys can be a useful tool for capturing changes in an evolving pollution landscape. This study contributes evidence that double-crested cormorants may be a useful sentinel species for monitoring plastic pollution in understudied, freshwater environments. Our results also demonstrate that the chosen method can greatly impact the results of a nest survey, and careful consideration of methodology should be undertaken before implementing a nest survey to monitor plastic pollution.

Can island specialists succeed as urban pioneers? Pied imperial-pigeons provide a case study

Context Long-term viability of wildlife populations may be influenced by the adaptive or maladaptive nature of behavioural shifts. Yet, in the short term, implications of novel behaviour are often uncertain, as they were for a newly formed urban nesting colony of pied imperial-pigeons (PIPs) on the mainland coast of north-eastern Australia. It represented unprecedented behaviour, as most of PIPs, also known as Torresian imperial-pigeons, Ducula bicolor/spilorrhoa, breed colonially on remote small islands. Aims The present study would (1) determine whether aggregated mainland nesting continued, (2) evaluate reproductive success, (3) evaluate spatial distribution of nests and (4) explore possible association of reproductive success with predator presence and broad indicators of food availability. Methods With assistance from volunteers, we found mainland PIP nests and revisited them intermittently to monitor progress. We calculated quantitative estimates of nest survival by the Mayfield method and evaluated reproductive output in relation to environmental data from independent sources. Key results During the 2012, 2013 and 2014 breeding seasons, we recorded 436, 387 and 417 PIP nest events at the new mainland colony. Daily nest-survival rates declined progressively and estimated fledgling output decreased over successive seasons from 0.66 to 0.44 per nest event. The highest mainland output was below that estimated for an island PIP colony (0.78) on the basis of sparse prior data. Across potential foraging grounds, there was no negative change in land use and no widespread adverse weather to account for diminishing success. We identified important causes of nest failure among mainland nesting PIPs to be predation, predominantly by birds, and anthropogenic hazards, including tree pruning and collisions with vehicles and windows of buildings. Conclusions With ongoing exposure to these hazards, mainland nesting PIPs cannot be expected to increase productivity; hence, the new colony may be a short-term phenomenon. We infer that the historic success of PIP populations in Queensland stems from their selection of breeding sites on remote islands that are largely free of relevant predators and anthropogenic activity. Implications Future conservation of extant PIP abundance will depend crucially on protection of island breeding sites, because multiple hazards of mainland nesting make it an unfavourable alternative strategy.

Breeding male grey seals exhibit similar activity budgets across varying exposures to human activity

Human-wildlife interactions can be incidental or direct through activities such as wildlife tourism. In the presence of anthropogenic activities, some animals exhibit behavioural alterations such as increased vigilance or spatial displacement. Thus, chronic exposure could be adverse to individual fitness through loss of energy or time. Pinnipeds are exposed to human activities in the aquatic environment and on land, but the degree of exposure varies across a species’ geographic distribution. For example, breeding colonies of grey seals Halichoerus grypus along the mainland coast of England are exposed to anthropogenic disturbance in the forms of tourism and military activities; however, many offshore colonies are relatively undisturbed. Due to the recent expansion of mainland colonies, the impacts of human presence during the breeding season are of urgent interest for managers. Therefore, the aim of this study was to test for any behavioural adjustments associated with anthropogenic presence by comparing the activity budgets of individual male grey seals at a mainland colony with activity budgets from 2 isolated colonies. We found no evidence of differences in the male activity budgets for time spent in non-active behaviours across colonies, and of the 3 colonies, males on the mainland spent the least amount of time alert. This indicates that as capital breeders, selection for conservation of energy is potentially overriding short-term costs of local stressors or that males at the mainland colony have habituated to human presence. Our results demonstrate the importance of understanding species- and lifehistory-stage-specific selection pressures when considering management actions.

Are African penguins worth saving? The ecotourism value of the Boulders Beach colony

Populations of the African penguin Spheniscus demersus have decreased dramatically over the past century, due in part to competition for food with commercial fisheries, and the species is now endangered as a result. Economic arguments are used to favour fisheries over the needs of penguins, but penguins have direct value to the South African economy thanks to penguin-based tourism at several breeding colonies. We estimated the value of African penguins at the most important tourist site for African penguins: Boulders on the Cape Peninsula, South Africa. As a mainland colony close to Cape Town, Boulders is accessible to large numbers of visitors; gate revenues in 2009/2010 alone were R14.5 million (US$2 million). A zonal travel-cost analysis revealed an average consumer surplus among Cape Town residents of some R20 per visit. Penguin-based tourism thus forms an integral part of the R25 billion Western Cape tourism sector. Given that the future survival of this valuable resource is dependent, among others, on the availability of sufficient prey, competition with South Africa's purse-seine fishing fleet should be limited through management strategies that lessen the potential effects of fishing on prey available at the local scale.

Tuatara

Tuatara

The founding of a southern elephant seal colony

AbstractThe only large mainland colony of southern elephant seals (Mirounga leonina) is on Península Valdés, at 42°S, in Argentine Patagonia. Censuses of pups have been carried out regularly there since 1970, and the population grew five‐fold by 2010. Here we use Bayesian modeling tools to make rigorous estimates of the rate of population growth, r, and to estimate survival and recruitment parameters that could account for the growth, incorporating observation error across different census methods. In the 1970s, r= 8%/yr, but has slowed to <1%/yr over the past decade. Using explicit demographic models, we established that the high growth of the 1970s was consistent with adult and juvenile survival at the upper end of published values (0.87/yr adult female survival; 0.40 juvenile survivorship to age four); the decline in the rate of population growth from 1970 to 2010 can be described by density‐dependent reductions in adult and juvenile survival that fall well within published variation. Extrapolating empirical models of population growth rate backwards illustrates that the population could have been an established colony, with 100 pups born per year, between 1915 and 1945, consistent with qualitative observations prior to 1950. We conclude that the Valdés colony was founded by a few immigrants early in the 20th century and has been growing mostly by internal recruitment, with unknown density‐dependent processes causing a reduction in growth and stabilization at 15,000–16,000 pups born.

Early Modern Virginia: Reconsidering the Old Dominion (review)

Reviewed by: Early Modern Virginia: Reconsidering the Old Dominion Bradford J. Wood (bio) Early Modern Virginia: Reconsidering the Old Dominion. Edited by Douglas Bradburn and John C. Coombs. (Charlottesville: University of Virginia Press, 2011. Pp. ix, 350. $39.50 cloth) In the last four decades, historians of early America have moved towards giving Virginia the attention that is appropriate for Britain’s oldest, largest, and most important mainland colony. Scholarship shifted from New England to Virginia during the efflorescence of Chesapeake social and economic history during the 1970s and 1980s, but, unfortunately, work on Virginia waned by the 1990s. Now Douglas Bradburn and John Coombs have put together an impressive new collection of essays demonstrating that talented scholars are being drawn to the early history of the Old Dominion once again. Instead of collecting work focused on shared questions and methodological assumptions in the tradition of the Chesapeake School, Early Modern Virginia, which focuses on the seventeenth century, offers a much-broader sense of the range of topics and approaches available to scholars of colonial Virginia. However, the essays in Early Modern Virginia share high scholarly standards, a fresh and often critical perspective on the historiography, and careful attention to evidence that other scholars have sometimes neglected or simply taken for granted. Focusing on Virginia also enables a corrective to Chesapeake historiography that has at times concentrated disproportionately on Maryland. A brief review cannot do justice to all of the thought-provoking arguments in these essays. John Coombs’s contribution may get the most attention from many readers because it delves into debates about the origins of slavery in Virginia. Coombs provides convincing evidence that elite planters preferred slaves to indentured servants from an early date and certainly before Bacon’s Rebellion and the decline in the supply of servants. His coeditor, Douglas Bradburn, reconsiders the founding of Virginia in its often-neglected but pervasive religious context. Camilla Townsend examines the early years of Jamestown from the very different English, Spanish, and Powhatan perspectives. Victor Enthoven and Wim Klooster show [End Page 196] that Dutch commercial influence proved to be more important and more persistent in early Virginia than has been appreciated. Terri Snyder explores the experience of servant women through a careful and perceptive reading of court cases. In another especially valuable essay, Alec Haskell negotiates a middle position between interpretations that emphasize political deference and defiance by focusing on early-modern discourse about office. Philip Levy uses transitions in the landscape of Middle Plantation to argue for a more stable view of Virginia development. Edward Ragan offers a different view of Native Americans in early Virginia by focusing on the Rappahannocks, a people on the margins of Powhatan power. William Pettigrew places the early Virginia labor force within the context of imperial debates over the regulation of the slave trade. Lorena Walsh introduces the volume and carefully sets it within the tradition of the Chesapeake School, while Philip Morgan provides a magisterial conclusion, considering “The Future of Chesapeake Studies.” In sum, historians of seventeenth-century America should read and learn from Early Modern Virginia. Of course, no collection of essays could fully cover the history of colonial Virginia. Some readers will probably second-guess the editors’ decisions about what to include or exclude, and in many ways this volume may turn out to be only a starting point. If so, historians are likely to learn much more about the oldest British colony in America, even more than four hundred years after the arrival of the Susan Constant, Godspeed, and Discovery in the James River. Bradford J. Wood Bradford J. Wood is professor of history at Eastern Kentucky University in Richmond, Kentucky. His work focuses on the social and cultural history of colonial North Carolina. Copyright © 2012 Kentucky Historical Society

A Documentary History of Naples: Ancient Naples, Chapter Two - From Parthenope to Neapolis

The early history of Naples is traced, from prehistory to the eve of the Samnite Wars. Founded on recent archaeological discoveries and a close reading of the texts documenting the city's founding, this chapter presents a fresh interpretation of the motives and events underlying the Greek foundation of the earliest mainland colony on the Bay of Naples, Parthenope, the subsequent founding of Neapolis nearby, and the arrival of the Athenians at Neapolis in the mid-fifth century BCE. The Samnite invasion of the 420s BCE, and its influence over the subsequent development and ethnic identity of Neapolis, is also considered.

Population size, breeding success and provenance of a mainland colony of Little Penguins (Eudyptula minor)

Although most Little Penguins (Eudyptula minor) breed on offshore islands, several small colonies occur on the mainlands of New Zealand and Australia, including mainland Tasmania. Unlike island colonies, most mainland colonies have declined over recent decades, several having gone extinct. A mainland colony of Little Penguins in North Harbour, Sydney, Australia, was monitored over three consecutive breeding seasons (2002–03 to 2004–05). The number of known nesting pairs was 49–56 per annum. The mean number of eggs laid per pair (2.45), eggs hatched per pair (1.84), fledglings produced per pair (1.71), hatching success (0.72) and breeding success (0.70) were among the highest reported from Australian colonies. Underlying these figures was a particularly high proportion of pairs that double-brooded (14–31% per annum, mean 24%). Fledging mass as a percentage of mean adult mass (103%) was also high. Together, these results suggest that food at the North Harbour colony was abundant during the period of study. Fledglings first returned to the colony at 1–4 years of age and first bred at 2–4 years of age. The recruitment rate of fledglings produced at the North Harbour colony was up to 15%, much higher than that recorded elsewhere. Banding recoveries (1997–2005) show that the North Harbour colony contains a substantial number of immigrants that have come from as far afield as Phillip Island, 761 km south of Sydney. Individuals banded at North Harbour have been recovered as far away as Sydenham Inlet, Victoria, 485 km to the south. The mixed provenance of the North Harbour population demonstrates that it is not isolated, either demographically or genetically, from other colonies in south-eastern Australia.

Stable isotopic (δ15N, δ13C) analysis of wood in trees growing in past and present colonies of burrow‐nesting seabirds in New Zealand. I. δ15N in two species of conifer (Podocarpaceae) from a mainland colony of Westland petrels (Procellaria westlandica), Punakaiki, South Island

Marine nitrogen (N) has been traced into terrestrial and freshwater food chains at petrel (Aves: Procellariiformes) colonies on the South Island of New Zealand, but the effects of N or other marine‐derived nutrients on the productivity of mainland forests are unknown. Mean ring widths in matai (Prumnopitys taxifolia; n = 3) and rimu (Dacrydium cupressinum; n = 2) trees growing in a Westland petrel (Procellaria westlandica) colony were 0.9–1.4 mm yr–1, similar to ring widths reported elsewhere. However, series of much wider rings in cores showed that trees in a petrel colony can experience periods of accelerated growth. δ15N values of whole wood were, at 3.2–11.1%, significantly enriched in comparison to other temperate forest trees. The highest δ15N values were at the cambial and pith ends of different cores, so isotopic fractionation during N remobilisation is unlikely to have been significant. The radial extent of 15N enrichment suggests that petrels have bred at the site since at least the mid 18th century.

The Sugar Industry and the Abolition of the Slave Trade, 1775–1810

Caribbean historian Selwyn H. H. Carrington’s painstaking and exhaustive archival research in the Caribbean and England over the last 30 years has finally culminated in the publication of his new book. In it he discusses the critical decline of the sugar plantation economy in the British West Indies followed by the outbreak of the American Revolution. In the foreword, Colin Palmer discusses the importance of Carrington’s work in Caribbean historiography. Lowell J. Ragatz’s The Fall of the Planter Class, 1763–1833 (1929) first argued that the economic decline of the British Caribbean preceded the abolition of the slave trade (1807). Ragatz’s thesis was elaborated further by Eric Williams in his classic Capitalism and Slavery (1944). Indeed, Carrington’s book has been written largely as a reaffirmation of this “decline-and-abolition thesis,” which was challenged and opposed by our contemporaries, most notably Seymour Drescher in his Econocide: British Slavery in the Era of Abolition (1977).The book’s first four chapters discuss external factors of the West Indian sugar plantation economy from the pre–American Revolutionary period until after 1775. The author first discusses the establishment of the agro-export monoculture economy in the British Caribbean. The region depended on the metropolis, which imported most of their superior sugar, as well as on the British colonial mainland, which imported their rum and secondary crops while supplying them with foodstuffs and lumber. The outbreak of the American Revolution ended the seemingly well-balanced trade between the West Indes and the former British mainland, and the British government’s increasingly restrictive policy for the regulation of the West Indes trade further deteriorated the plantation economy of the Caribbean colonies. The middle part of the book is “chiefly concerned with internal issues” (p. 7); Carrington assesses the continued growth of planters’ debts at the end of the eighteenth century, despite their efforts at amelioration on individual plantations. The last four chapters analyze the continued decline in the colonial Caribbean economy between 1789 and 1810; the author demonstrates that the economy was in constant decline despite the seeming adjustments during and after the Haitian Revolution. Carrington accordingly concludes that the abolition of the slave trade was by no means the cause of the decline in the Caribbean sugar plantation economy.Carrington successfully presents a complex series of historical events in which important historical actors, both external and internal, took distinctive actions for their economic self-interests. Externally, England, after having lost its mainland colony, did not protect the sugar economy of her Caribbean colonies. Internally, the colonial elite continued to lose their economic power, and the colonial societies began to observe new problems. The steam engine and other technological innovations were not introduced in the West Indies until the sugar economy was in decline. Whereas Caribbean planters tried to resolve their financial problems by importing more female slaves for reproduction and by hiring their slaves out for wage earning, slaves themselves took advantage of the shaky plantation economy to find and create new and better socioeconomic opportunities. Some even managed to purchase their freedom. Their decisions and actions clearly illuminate the breakdown of slave society from inside, through the personal negotiations of power between the powerful (the absentee planters) and the powerless (the enslaved). This reader wonders if these middle chapters might have been developed into a separate monograph, which could appeal to a wide range of scholars and students of slavery and emancipation in the Americas.It should also be noted that the author tends to be repetitive in his arguments, and he does not discuss the abolition of the slave trade to any great extent. Furthermore, despite his statement that his study “has been fertilized by modern scholarship through historical investigation” (p. 10), his bibliography includes only a handful secondary works published after 1990. One wonders if that merely reflects a lack of interest in the topics this book deals with. Nonetheless, this book is clearly a valuable contribution to Caribbean history, studies of New World slave systems, the transatlantic slave trade, and emancipation, as well as to the growing field of Atlantic history. It will be well appreciated by historians who specialize in the economic history of major slave societies of the Americas. Carrington is also to be praised for his meticulous use of an amazing quality and quantity of primary sources, including abundant plantation papers that have never been presented before.

Burrow occupancy and productivity at coastal sooty shearwater (Puffinus griseus) breeding colonies, South Island, New Zealand: can mark - recapture be used to estimate burrowscope accuracy?

Breeding colonies of sooty shearwaters ('muttonbird', tïtï, Puffinus griseus) on mainland New Zealand have declined in recent years. New data on burrow occupancy and colony productivity for seven sooty shearwater breeding colonies on the coast of Otago, New Zealand for the 1996–97 and 1997–98 breeding seasons are presented and analysed as part of a five-year data set. Detection of a burrow's occupants using a fibre-optic burrowscope may underestimate absolute occupancy rates, but is still of value in the analysis of trends. Detection probabilities estimated by the novel use of mark–recapture models corresponded with those of previous studies of the technique's accuracy. Mainland declines are associated with a lack of control of introduced mammalian predators at most mainland colonies superimposed on a global pattern of decline in the species' abundance. Large numbers of recovered carcasses and an absence of burrow activity at two small mainland colonies show the decline to extinction of these colonies over the five years of collecting data. At one mainland colony with intensive predator control, survival rates and parameter variances are comparable with those found on a predator-free offshore island. All other mainland colonies showed negligible breeding success. There was a significant positive relationship between egg survival and an index of relative adult survival, with an apparent threshold below which few eggs hatch. Adult survival during the breeding season is likely to be the most important parameter in maintaining a colony's viability.

ESTABLISHMENT, GROWTH AND CONSERVATION OF A MAINLAND COLONY OF JACKASS PENGUINS SPHENISCUS DEMERSUS AT STONY POINT, BETTY'S BAY, SOUTH AFRICA

Summary Whittington, P.A., Hofmeyr, J.H. & Cooper, J. 1996. Establishment, growth and conservation of a mainland colony of Jackass Penguins Spheniscus demersus at Stony Point, Betty's Bay, South Africa. Ostrich 67: 144–150. Following the discovery of a single pair of Jackass Penguins Spheniscus demersus nesting on the mainland at Stony Point, Western Cape Province, South Africa (34 22S 18 53E) in 1982, a colony developed and has since been regularly monitored. Numbers of nests increased to 35 in 1986, until a leopard Panthera pardus severely reduced the size of the colony. Numbers subsequently rose again to a total of 139 nests in 1990, but fell to 57 in 1993. This decrease was probably due to predation by mammals. Following the use of a trap and translocation of the animals caught, the colony increased again in 1995 and 1996. Productivity of the colony was insufficient for it to be self-sustaining, and it therefore presently represents a population sink.

Status, Dispersion, and Population Changes of the Least Tern in Coastal Mississippi

Least Terns (Sterna antillarum) nest on barrier island and mainland beaches, on dredged spoil, and on large flat, gravel-covered rooftops in coastal Mississippi. Barrier island populations seem to be limited to small colony sizes to deter avian and mammalian predators. Mainland colony sites may be abandoned within a year or two as a result of vegetative succession, but sites where wind, waves, or human management prevents vegetative succession are inhabited year-after-year. As a result of development of a broad man-made beach, beach maintenance outside of the breeding season and protection during the breeding season, and a highway that selects heavily against predators crossing it to reach tern colonies, some Least Tern colonies on the Mississippi coast support 3000+ nests each year. Factors affecting Least Tern populations and the history of habitat changes and conservation efforts are discussed. At a time when stories of negative impacts of human activities on birds are commonplace, and while other Least Tern site. Many populations of the Least Tern (Sterna antillarum) are considered threaten- ed or endangered by human developments or disturbance. The California population (S. a. browni) is federally listed as en- dangered (Greenwalt 1980) and the interior United States population is being consider- ed for listing as endangered (Sidle 1984). In sharp contrast, Least Tern populations on the Mississippi Gulf Coast seem to be thriving. Least Terns generally arrive on the Mississippi coast in early April, have begun egg-laying as early as 28 April (1978, Judy Toups, pers. comm.) and often a few are still feeding small young during the first week in August (Jackson et al. 1979). In recent years, colonies have included several thousand nests. In this paper we summarize past and present distribution and popula- tion changes of the Least Tern in Mississip- pi and relate the species' changing status to habitat changes and conservation efforts.

Interchange complexes in Italian populations of Reticulitermes lucifugus Rossi (Isoptera: Rhinotermitidae)

In six Italian populations of the rhinotermitid Reticulitermes lucifugus there is a diploid complement of 2n=42 with no visible sex chromosome difference between male and female reproductives. The first male meiotic division in this species is, however, characterised by the presence of inter-change multiples. Thus males from three mainland colonies at Udine, Tombolo and Barberino, as well as a Sicilian colony (Polizzi), are regularly heterozygous for a single translocation chain (C) multiple of IV (2n=19II+ C IV). A fourth mainland colony (Squinzano) proved to be polymorphic. Here, three of the six males analysed regularly formed 21 bivalents; two further males had nineteen bivalents and a chain of four multiple while a sixth male had a predominance of meiocytes with 19 bivalents and a chain of four together with a small number of cells with 18 bivalents and a chain of six multiple. Finally a sixth colony from Sardinia (Sennori) was characterized by larger multiple configurations involving chains or rings of eight.