Using long-term data for a reintroduced population to empirically estimate future consequences of inbreeding

Inbreeding depression is an important long-term threat to reintroduced populations. However, the strength of inbreeding depression is difficult to estimate in wild populations because pedigree data are inevitably incomplete and because good data are needed on survival and reproduction. Predicting future population consequences is especially difficult because this also requires projecting future inbreeding levels and their impacts on long-term population dynamics, which are subject to many uncertainties. We illustrate how such projections can be derived through Bayesian state-space modeling methods based on a 26-year data set for North Island Robins (Petroica longipes) reintroduced to Tiritiri Matangi Island in 1992. We used pedigree data to model increases in the average inbreeding level (F ) over time based on kinship of possible breeding pairs and to estimate empirically N_e/N (effective/census population size). We used multiple imputation to model the unknown components of inbreeding coefficients, which allowed us to estimate effects of inbreeding on survival for all 1458 birds in the data set while modeling density dependence and environmental stochasticity. This modeling indicated that inbreeding reduced juvenile survival (1.83 lethal equivalents [SE 0.81]) and may have reduced subsequent adult survival (0.44 lethal equivalents [0.81]) but had no apparent effect on numbers of fledglings produced. Average inbreeding level increased to 0.10 (SE 0.001) as the population grew from 33 (0.3) to 160 (6) individuals over the 25 years, giving a ratio of 0.56 (0.01). Based on a model that also incorporated habitat regeneration, the population was projected to reach a maximum of 331–1144 birds (median 726) in 2130, then to begin a slow decline. Without inbreeding, the population would be expected stabilize at 887–1465 birds (median 1131). Such analysis, therefore, makes it possible to empirically derive the information needed for rational decisions about inbreeding management while accounting for multiple sources of uncertainty.     

Historical and contemporary indigenous marine conservation strategies in the North Pacific

Strategies to reduce, halt, and reverse global declines in marine biodiversity are needed urgently. We reviewed, coded, and synthesized historical and contemporary marine conservation strategies of the Kitasoo/Xai'xais First Nation in British Columbia, Canada to show how their approaches work. We assessed whether the conservation actions classification system by the Conservation Measures Partnership was able to encompass this nation's conservation approaches. All first-order conservation actions aligned with the Kitasoo/Xai'xais First Nation's historical and contemporary marine conservation actions; hereditary chief management responsibility played a key role. A conservation ethic permeates Kitasoo/Xai'xais culture, and indigenous resource management and conservation existed historically and remains strong despite extreme efforts by colonizers to suppress all indigenous practices. The Kitasoo/Xai'xais's embodiment of conservation actions as part of their worldview, rather than as requiring actions separate from everyday life (the norm in nonindigenous cultures), was missing from the conservation action classification system. The Kitasoo/Xai'xais are one of many indigenous peoples working to revitalize their governance and management authorities. With the Canadian government's declared willingness to work toward reconciliation, there is an opportunity to enable First Nations to lead on marine and other conservation efforts. Global conservation efforts would also benefit from enhanced support for indigenous conservation approaches, including expanding the conservation actions classification to encompass a new category of conservation or sacredness ethic.     

Pacific Islanders’ understanding of climate change: Where do they source information and to what extent do they trust it?

Regional Environmental Change - The experience of environmental stress and attitudes towards climate change was explored for 1226 students at the University of the South Pacific, the foremost...     

Refinery evaluation of optical imaging to locate fugitive emissions

Fugitive emissions account for approximately 50% of total hydrocarbon emissions from process plants. Federal and state regulations aiming at controlling these emissions require refineries and petrochemical plants in the United States to implement a Leak Detection and Repair Program (LDAR). The current regulatory work practice, U.S. Environment Protection Agency Method 21, requires designated components to be monitored individually at regular intervals. The annual costs of these LDAR programs in a typical refinery can exceed US$1,000,000. Previous studies have shown that a majority of controllable fugitive emissions come from a very small fraction of components. The Smart LDAR program aims to find cost-effective methods to monitor and reduce emissions from these large leakers. Optical gas imaging has been identified as one such technology that can help achieve this objective. This paper discusses a refinery evaluation of an instrument based on backscatter absorption gas imaging technology. This portable camera allows an operator to scan components more quickly and image gas leaks in real time. During the evaluation, the instrument was able to identify leaking components that were the source of 97% of the total mass emissions from leaks detected. More than 27,000 components were monitored. This was achieved in far less time than it would have taken using Method 21. In addition, the instrument was able to find leaks from components that are not required to be monitored by the current LDAR regulations. The technology principles and the parameters that affect instrument performance are also discussed in the paper.     

Aggressiveness of breeding territorial honeyeaters corresponds to seasonal changes in nectar availability

Summary On the east coast of Australia, new holland and white-cheeked honeyeaters experience huge seasonal changes in nectar availability over their breeding periods. I observed breeding males of both species to determine whether levels of territorial aggressiveness varied with these changes in nectar availability. I watched individual males repeatedly and assessed their aggressiveness by recording their responses to birds that came within 30 m of them. Almost all attacks were on unfamiliar birds; males never attacked their mates or offspring and rarely attacked other birds that were resident in the area. Intruders were most likely to be attacked if they were conspecifics, if they landed rather than flying by, and if they came near the centers of males' territories. Taking into account the types, behaviors, and locations of intruders, there were pronounced seasonal changes in the probability of an intruder being attacked by a territorial male. Males were least aggressive when nectar was abundant, suggesting that territorial aggression could be at least partially a response to scarcity of nectar. Seasonal changes in aggressiveness were not accounted for by breeding cycles or by changes in frequency of intrusions.     

Dry and heat stress affects H2S production of Salmonella on selective plating media

The pH of Salmonella pre-enrichment media can become acidic (pH 4.0–5.0) when feeds/ingredients are incubated for 24?h. Salmonella in feed that have been stressed by heat and desiccation exhibit different pH tolerances than non-stressed cultures. Acidic conditions can result in cell injury/death and affect biochemical pathways. In this study, eight serotypes of Salmonella were grown in sterile meat and bone meal that was subjected to desiccation and heat stress. Cultures of non-stressed and stressed isolates were subsequently exposed to acidic pH from 4.0 to 7.0 in 0.5?pH increments (3 replicates/pH increment) in citrate buffer. At 6 and 24?h, serial dilutions were plated in duplicate on XLT-4 (xylose lysine tergitol-4) agar. Four serotypes showed an impaired ability to decarboxylate lysine on XLT-4. This inability to decarboxylate lysine was dependent on isolate, stress status, and incubation time. When the isolates’ ability to decarboxylate lysine was examined using biochemical tests, cultures were found to be able to decarboxylate lysine with the exception of S. Infantis. This suggests that XLT-4 contains a biochemical stressor(s) which affects the rate of decarboxylation by these Salmonella. These results suggest that acidic conditions may influence the detection and confirmation of Salmonella in feed.     

Predatory behavior and prey selection by army ants in a desert-grassland habitat

Summary Colonies of Neivamyrmex nigrescens conduct extensive nocturnal raids on other ants and termites in the desert-grassland of Arizona-New Mexico. We collected quantitative data on several aspects of raiding to pinpoint differences due to colony size and behavioral phase. In the nomadic phase, colonies began raiding at sunset and continued until dawn. Larger colonies covered more area, discovered more prey sites, and collected more booty than smaller colonies, but there were no systematic changes in raid intensity over the course of the nomadic phase. In the statary phase, raiding occurred less frequently and was less intense when it occurred; however, at the end of this phase, raiding was similar to nomadic phase raids in extent, duration, and booty captured. N. nigrescens preyed exclusively on termites and ants, and appeared to select certain species of Pheidole in preference to other ants. Pheidole was the most abundant genus, but was preyed upon twice as often as expected based on relative colony density. Pheidole attempted to avoid predation by fleeing or defending their nest, but rarely succeeded. Because they are about the same size as army ants and lack defensive chemicals, Pheidole made comparatively easy prey. N. nigrescens ignored or was repelled by other ants (Pogonomyrmex, Novomessor, Iridomyrmex, Myrmecocystus) during the early summer, when Pheidole was abundant; however, in late summer when Pheidole was less available, the army ants preyed upon Novomessor cockerelli. N. harrisi raided in close proximity to N. nigrescens, but preyed exclusively on Solenopsis xyloni. Selection of prey and partitioning of resources are now indicated in several army ant species; these processes have probably been important factors in the evolution of the ants' predatory behavior.