Is natural hatching asynchrony optimal? An experimental investigation of sibling competition patterns in a facultatively siblicidal seabird

In unpredictable environments, any tactic that enables avian parents to adjust brood size and, thus, energy expenditure to environmental conditions should be favoured. Hatching asynchrony (HA), which occurs whenever incubation commences before clutch completion, may comprise such a tactic. For instance, the sibling rivalry hypothesis states that the hierarchy among chicks, concomitant to HA, should both facilitate the adjustment of brood size to environmental conditions and reduce several components of sibling competition as compared to synchronous hatching, at both brood and individual levels. We thus predicted that brood aggression, begging and feeding rates should decrease and that older chick superiority should increase with HA increasing, leading to higher growth and survival rates. Accordingly, we investigated the effects of an experimental upward and downward manipulation of HA magnitude on behaviour, growth and survival of black-legged kittiwake (Rissa tridactyla) chicks. In line with the sibling rivalry hypothesis, synchronous hatching increased aggression and tended to increase feeding rates by parents at the brood level. Begging rates, however, increased with HA contrary to our expectations. At the individual level, as HA magnitude increased, the younger chick was attacked and begged proportionally more often, experienced a slower growth and a higher mortality than its sibling. Overall, the occurrence of energetic costs triggered by synchronous hatching both for parents and chicks, together with the lower growth rate and increased mortality of the younger chick in highly asynchronous broods suggest that natural HA magnitude may be optimal.     

Partial fertility and polyandry: a benefit of multiple mating hiding in plain sight?

Multiple mating is common in many socially monogamous birds and mammals, but why is still unclear. Fertility insurance is one the posited genetic benefits. However, this mechanism fails if females cannot detect male infertility before mating, and infertile sperm are equally capable of fertilizing eggs (e.g., fertilization occurs but is followed by early developmental arrest): multiple mating simply exchanges whole brood loss for partial brood loss with no difference in the overall proportion of failed offspring. However, I note here that these two options will rarely result in equivalent reproductive success: partial brood loss will generally result in more surviving offspring than whole brood loss vs. whole brood survival due to increasing per capita survival of offspring in smaller broods. A partial fertility strategy can yield benefits even in the extreme case where fertility is cryptic and defective sperm are capable of fertilizing eggs. Moreover, partial fertility will yield an added benefit to fertility insurance when the precedence of fertile over infertile sperm is incomplete.     

Symbiont shuffling during thermal bleaching and recovery in the sea anemone Entacmaea quadricolor

The sea anemone Entacmaea quadricolor simultaneously harbours multiple symbiont types from the genus Symbiodinium, while providing essential habitat for anemonefish. This anemone lives close to its upper thermal threshold and experiences bleaching under elevated temperature and light stress. Here, we determine whether E. quadricolor experienced a shuffling in the abundance of two genetically distinct symbiont types (Symbiodinium C25 and C3.25) during bleaching and recovery. Anemones were exposed to control (22.9 °C) or elevated temperature (28.5 °C) for 42 days, whereas for the following 75 days, all anemones were exposed to 22.9 °C. By day 47, a more pronounced bleaching occurred via symbiont expulsion in the elevated temperature treatment than the control, and the proportion of C25 to C25 + C3.25 increased by 6.2 and 13.2 % in the control and bleached anemones, respectively. The increased relative abundance of C25 to C3.25 after exposure to thermal stress may indicate that C3.25 performs poorly when temperature is elevated. Although no significant recovery in symbiont density was detected, a revival of the C3.25 genotype was found at day 117, which may indicate that it is either more competitive or has qualities that are beneficial to the symbiosis when thermal stress is no longer apparent. This work demonstrates the potential for this anemone species to shuffle its symbiont types in response to environmental change and could provide resilience during times of stress.     

A Probabilistic,Parcel‐Level Inundation Prediction Tool for Medium‐Range Flood Forecasting in Large Lake Systems

This study contributes a bathtub‐style inundation prediction model with abstractions of coastal processes (i.e., storm surge and wave runup) for flood forecasting at medium‐range (weekly to monthly) timescales along the coastline of large lakes. Uncertainty from multiple data sources are propagated through the model to establish probabilistic bounds of inundation, providing a conservative measure of risk. The model is developed in a case study of the New York Lake Ontario shoreline, which has experienced two record‐setting floods over the course of three years (2017–2019). Predictions are developed at a parcel‐level and are validated using inundation accounts from an online survey and flyover imagery taken during the recent flood events. Model predictions are compared against a baseline, deterministic model that accounts for the same processes but does not propagate forward data uncertainties. Results suggest that a probabilistic approach helps capture observed instances of inundation that would otherwise be missed by a deterministic inundation model. However, downward biases are still present in probabilistic predictions, especially for parcels impacted by wave runup. The goal of the tool is to provide community planners and property owners with a conservative, parcel‐level assessment of flood risk to help inform short‐term emergency response and better prepare for future flood events.     

Consumption-based accounting of CO2 emissions in the sustainable development Goals Agenda

In 2017 the paper ‘The Sustainable Development Oxymoron: Quantifying and Modelling the Incompatibility of Sustainable Development Goals’ was published, showing that there is a conflict between socio-economic development goals and ecological sustainability goals using cross-country time-series data. The authors looked at production-based CO2 emissions to measure and model the 13^th SDG goal addressing climate change. Their models showed that production-based CO2 emissions were stalling or even decreasing in rich countries, which suggests that other countries are also likely to see stalling and decrease in their CO2 emissions once they become rich. However, this conclusion can be challenged when accounting for consumption-based CO2 emissions rather than production-based CO2 emissions. In this follow-up paper, we re-run some of the analyses performed in the original paper making use of consumption-based CO2 emissions. The analysis confirms the inherent SDG conflict between socio-economic and ecological SDGs. But, this new analysis demonstrates that from a consumption perspective the trend of stalling or decreasing CO2 emissions is reversed, with natural depletion costs being exported to poorer countries. Despite this new perspective on CO2 emissions, the conflict between SDG goals can still be avoided by making investments in public health, education and renewable energy, as suggested in the original paper.     

Hunger and food allocation among nestlings of facultatively siblicidal ospreys

Summary Previous studies of food allocation among nestlings of siblicidal birds have focussed on the proximate link between food and aggression. However, food sharing among sibs (and brood reduction) need not involve aggression. Here I examine the role of hunger (defined operationally in terms of the amount of food eaten recently) within the broader framework of passive and aggressive food-sharing among nestlings of facultatively siblicidal ospreys (Pandion haliaetus). Feeding among brood members was hierarchical; senior, dominant sibs ate more when hungry, leaving a smaller residual share of food for junior sibs. Senior sibs did not become more generous at large meals (i.e., the prospect of a large meal did not quell the selfish tendencies of senior sibs). That individuals ate more when hungry indicates a proximate link between food and the allocation of resources among siblings. Overall, aggression was infrequent and seemed to be used when junior sibs contested food allocation at meals. Aggression was diminished and food allocation was skewed toward the junior sib in broods with artificially exaggerated hatching intervals, suggesting that senior sibs were more generous when their dominant status was not threatened.Offprint requests to the present address     

The Airline Lifesaver: a 17-year analysis of a technique to prompt the delivery of a safety message

INTRODUCTION: The Airline Lifesaver (AL) is a 13.3 cm x 9.8 cm card any passenger can deliver to the attendant of a commercial airline in order to prompt the delivery of an important safety message. In particular, the AL requests the following safety--belt reminder be added to the regular announcements given at the end of the flight-"Now that you have worn a seat belt for the safest part of your trip, the flight crew would like to remind you to buckle-up during your ground transportation." METHOD: The AL card was handed to 1,258 flight attendants over a 17-year period and compliance with the request for the safety message was systematically tracked. Slightly more than one-third of the AL cards (n=460) included an incentive for making the announcement. RESULTS: Without the incentive, compliance to give the buckle-up reminder was 35.5% of 798 flights. With the incentive, compliance was significantly higher (i.e., 53.3%). IMPACT: The validity of the AL intervention is discussed with regard to its: (a) relevance to cognitive dissonance and consistency theory, and (b) broad-based applicability as a component of community-wide efforts to facilitate a safety-focused culture. The 17-year study also demonstrated a practical and cost-effective application of a behavior-based incentive program.     

Increasing the safety of children's vehicle travel: from effective risk communication to behavior change

INTRODUCTION: When installed and used correctly, child safety seats reduce the risk of fatal injury by 71% for infants and 54% for toddlers. However, four out of five safety seats are unintentionally misused. Yet, parents fail to participate in safety-seat checks and other child seat interventions aimed at correcting misuse. METHOD: Such lack of participation is the focus of this article, which argues that most caregivers are na?ve to their own vulnerability for misusing their child's seat. Research on risk perception is discussed as a guide to understanding both the high misuse rate and the lack of participation in interventions designed to correct this public safety problem. RESULTS AND IMPACT: A comprehensive intervention plan that incorporates risk communication techniques for maximum parental participation is proposed that includes three essential components: (a) establishing community locations for parents to turn for safety seat advice, (b) making these locations well known to the public, and (c) increasing caregivers' perceptions of risk of misusing their children's seats.     

Living dangerously: driver distraction at high speed

Recent research indicates that cell phone use can distract drivers from safe vehicle operation. However, estimates of the prevalence of cell phone use while driving have been limited to daytime hours and low-speed roadways. This paper describes the results of a study to estimate rates of cell phone use and other distractions by examining approximately 40,000 high-quality digital photographs of vehicles and drivers on the New Jersey Turnpike. The photographs, which originally were collected as part of a separate study, were taken both during the day and during the night and at different locations across the span of the Turnpike. A radar gun linked to the camera recorded the speeds of vehicles as they passed. This provided us with the speeds of every vehicle photographed, and allowed us to determine population counts of vehicles. A panel of three trained coders examined each photograph and recorded the presence of cell phone use by the drivers or any other distracting behavior. Demographic information on the driver was obtained during previous examinations of the photographs for an unrelated study. A rating was considered reliable when two out of the three coders agreed. Population estimates (and confidence intervals) of cell phone use and other distractions were estimated by weighting the cases by the inverse probability of vehicle selection. Logistic regression was used to predict cell phone use from demographic and situational factors. The results indicated that the most frequent distraction was cell phone use: 1.5% of the drivers on the Turnpike were using cell phones compared to the 3 to 4% use rates reported in the National Occupant Protection Use Survey (NOPUS) surveys conducted during the daytime on lower speed roadways. The Turnpike survey indicated that cell phones were used less on weekends and at night, and when the driver was exceeding the speed limit or had a passenger in the car.