Demographic and spatial variables associated with spending time in nature during COVID-19 lockdowns.

To stop the spread of SARS-CoV-2 coronavirus (COVID-19) governments around the world implemented lockdowns restricting public travel. In the Australian state of Victoria, this included limiting permitted reasons for leaving home and restricting movements to within a 5 km radius of one's home. In 2020, we conducted a state-wide survey (N = 1024) of Victorians that coincided with a lockdown. We asked respondents where they had spent time in nature and how they perceived lockdowns affected the amount of time they spent in nature. We then considered demographic and spatial predictors of spending more or less time in nature. Women, younger people, and those living in areas with higher socio-economic status were likely to report spending more time in nature. Closer proximity of residents to parks and waterways and higher proportional area of native vegetation within a 1-km radius were also associated with more time in nature. Understanding how different groups were affected by restrictions on access to nature can help improve government management of crises like pandemics, including through urban planning for green space, supporting improved individual and societal resilience. We discuss the implications of our findings for improving access to nature during lockdowns as well as opportunities for a post-pandemic relationship with nature, particularly in urban settings.

Projecting biodiversity benefits of conservation behavior-change programs.

Biodiversity loss is driven by human behavior, but there is uncertainty about the effectiveness of behavior-change programs in delivering benefits to biodiversity. To demonstrate their value, the biodiversity benefits and cost-effectiveness of behavior changes that directly or indirectly affect biodiversity need to be quantified. We adapted a structured decision-making prioritization tool to determine the potential biodiversity benefits of behavior changes. As a case study, we examined two hypothetical behavior-change programs--wildlife gardening and cat containment--by asking experts to consider the behaviors associated with these programs that directly and indirectly affect biodiversity. We assessed benefits to southern brown bandicoot (Isoodon obesulus) and superb fairy-wren (Malurus cyaneus) by eliciting from experts estimates of the probability of each species persisting in the landscape given a range of behavior-change scenarios in which uptake of the behaviors varied. We then compared these estimates to a business-as-usual scenario to determine the relative biodiversity benefit and cost-effectiveness of each scenario. Experts projected that the behavior-change programs would benefit biodiversity and that benefits would rise with increasing uptake of the target behaviors. Biodiversity benefits were also predicted to accrue through indirect behaviors, although experts disagreed about the magnitude of additional benefit provided. Scenarios that combined the two behavior-change programs were estimated to provide the greatest benefits to species and be most cost-effective. Our method could be used in other contexts and potentially at different scales and advances the use of prioritization tools to guide conservation behavior-change programs.

Proyección de los beneficios para la biodiversidad obtenidos de los programas de cambios de comportamiento de conservación Resumen La pérdida de la diversidad biológica es causada por el comportamiento humano, pero existe incertidumbre sobre la efectividad que tienen los programas de cambio de comportamiento para otorgar beneficios a la biodiversidad. Para demostrar el valor que poseen, los beneficios para la biodiversidad y la rentabilidad de los cambios de comportamiento que afectan directa o indirectamente a la biodiversidad necesitan ser cuantificados. Adaptamos una herramienta de priorización de toma de decisiones estructurada para determinar el potencial de los beneficios para la biodiversidad obtenidos de los cambios de comportamiento. Como estudio de caso, examinamos dos programas hipotéticos de cambio de comportamiento, la jardinería silvestre y la contención de gatos, mediante la petición a expertos de considerar los comportamientos asociados con estos programas que directa o indirectamente afectan a la biodiversidad. Evaluamos los beneficios para el bandicut café (Isoodon obeselus) y el reyezuelo supremo (Malurus cyaeneus) mediante la obtención de estimaciones de expertos de la probabilidad de que cada especie persista en el paisaje con una gama establecida de escenarios de cambios de comportamiento en los cuales la aceptación de los comportamientos varió. Después comparamos estas estimaciones con un escenario de situación normal para determinar el beneficio relativo para la biodiversidad y la rentabilidad de cada escenario. Los expertos proyectaron que los programas de cambio de comportamiento beneficiarían a la biodiversidad y que los beneficios aumentarían con la creciente aceptación de los comportamientos deseados. También se pronosticó que los beneficios se acumularían mediante comportamientos indirectos, aunque los expertos estuvieron en desacuerdo sobre la magnitud del beneficio adicional proporcionado. Se estimó que los escenarios que combinaron los dos programas de cambio de comportamiento proporcionarían el mayor beneficio para las especies y serían los más rentables. Nuestro método podría usarse en otros contextos y potencialmente a diferentes escalas y fomenta el uso de herramientas de priorización para orientar a los programas de cambios en el comportamiento de conservación.

Does predation risk affect mating behavior? An experimental test in dumpling squid (Euprymna tasmanica).

INTRODUCTION: One of the most important trade-offs for many animals is that between survival and reproduction. This is particularly apparent when mating increases the risk of predation, either by increasing conspicuousness, reducing mobility or inhibiting an individual's ability to detect predators. Individuals may mitigate the risk of predation by altering their reproductive behavior (e.g. increasing anti-predator responses to reduce conspicuousness). The degree to which individuals modulate their reproductive behavior in relation to predation risk is difficult to predict because both the optimal investment in current and future reproduction (due to life-history strategies) and level of predation risk may differ between the sexes and among species. Here, we investigate the effect of increased predation risk on the reproductive behavior of dumpling squid (Euprymna tasmanica). RESULTS: Females, but not males, showed a substantial increase in the number of inks (an anti-predator behavior) before mating commenced in the presence of a predator (sand flathead Platycephalus bassensis). However, predation risk did not affect copulation duration, the likelihood of mating, female anti-predator behavior during or after mating or male anti-predator behavior at any time. CONCLUSIONS: Inking is a common anti-predator defense in cephalopods, thought to act like a smokescreen, decoy or distraction. Female dumpling squid are probably using this form of defense in response to the increase in predation risk prior to mating. Conversely, males were undeterred by the increase in predation risk. A lack of change in these variables may occur if the benefit of completing mating outweighs the risk of predation. Prioritizing current reproduction, even under predation risk, can occur when the chance of future reproduction is low, there is substantial energetic investment into mating, or the potential fitness payoffs of mating are high.

Multiple fitness benefits of polyandry in a cephalopod.

BACKGROUND: Sex differences in reproductive investment play a crucial role in sexual conflict. One intriguing aspect of sexual conflict is the evolution of female multiple mating (polyandry), particularly in systems where females receive no obvious direct benefits from males, and where mating is highly costly. Here, theory predicts that polyandrous females can increase their reproductive success by taking advantage of the genetic benefits of mating with multiple males. Cephalopods provide a model system for addressing this question, as all species mate multiply. Here we examine differences in reproductive success between monandrous, multiply mated (to the same male) and polyandrous female dumpling squid (Euprymna tasmanica). METHODOLOGY/PRINCIPAL FINDINGS: We mated females in the laboratory with two different males (polyandrous; controlling for mating order), or with a single male (monandrous). To control for mating frequency, we mated monandrous females either once (monandrous 1), or with the same male twice (monandrous 2), and measured reproductive success for each of the three treatments (polyandrous, monandrous 1, monandrous 2). Females mated to two different males produced eggs faster and had larger hatchlings relative to egg mass than females mated once with a single male. CONCLUSIONS/SIGNIFICANCE: The benefits of polyandry demonstrated here are the first, to our knowledge, in any cephalopod. These benefits may outweigh the significant costs associated with mating and help to explain how multiple mating has evolved (or is maintained) in this group.

Environmental deterioration increases tadpole vulnerability to predation.

Human-induced environmental change is occurring at an unprecedented rate and scale. Many freshwater habitats, in particular, have been degraded as a result of increased salinity. Little is known about the effects of anthropogenic salinization on freshwater organisms, especially at sublethal concentrations, where subtle behavioural changes can have potentially drastic fitness consequences. Using a species of Australian frog (Litoria ewingii), we experimentally examined the effects of salinization on tadpole behaviour and their vulnerability to a predatory dragonfly nymph (Hemianax papuensis). We found that tadpoles exposed to an ecologically relevant concentration of salt (15% seawater, SW) were less active than those in our freshwater control (0.4% SW). Tadpoles in elevated salinity also experienced a higher risk of predation, even though the strike rate of the predator did not differ between salt and freshwater treatments. In a separate experiment testing the burst-speed performance of tadpoles, we found that tadpoles in saltwater were slower than those in freshwater. Thus, it would appear that salt compromised the anti-predator response of tadpoles and made them more susceptible to being captured. Our results demonstrate that environmentally relevant concentrations of aquatic contaminants can, even at sublethal levels, severely undermine the fitness of exposed organisms.