Impacts of the novel coronavirus SARS-CoV-2 on wildlife behaviour via human activities.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the pandemic of the coronavirus disease 2019 (COVID-19), resulting in a global lockdown in 2020. This stagnation in human activities ('anthropause') has been reported to affect the behaviour of wildlife in various ways. The sika deer Cervus nippon in Nara Park, central Japan, has had a unique relationship with humans, especially tourists, in which the deer bow to receive food and sometimes attack if they do not receive it.

Adaptive significance of light and food for a kleptoplastic sea slug: implications for photosynthesis.

Sacoglossan sea slugs can 'steal' chloroplasts from their algal food and use them for photosynthesis (kleptoplasty). Although it has been shown that light has positive effects on survival and body size retention of some sacoglossans likely through photosynthesis, it is unknown whether light affects their fitness components such as number of offspring or offspring size. Moreover, whether the effects of light extend over the sacoglossans' lifetime has been unexplored.

Defensive chemicals of neighboring plants limit visits of herbivorous insects: Associational resistance within a plant population.

Despite our understanding of chemical defenses and their consequences for plant performance and herbivores, we know little about whether defensive chemicals in plant tissues, such as alkaloids, and their spatial variation within a population play unappreciated and critical roles in plant-herbivore interactions. Neighboring plants can decrease or increase attractiveness of a plant to herbivores, an example of a neighborhood effect. Chemical defensive traits may contribute to neighborhood effects in plant-herbivore interactions.

Roles of the seasonal dynamics of ecosystem components in fluctuating indirect interactions on a rocky shore.

Accurately evaluating the strengths of direct (i.e., consumptive and non-consumptive) effects and indirect (density- and trait-mediated) interactions is crucial for understanding the mechanisms of the maintenance and dynamics of an ecosystem.

Early onset of spring increases the phenological mismatch between plants and pollinators.

Climate warming accelerates the timing of flowering and insect pollinator emergence, especially in spring. If these phenological shifts progress independently between species, features of plant-pollinator mutualisms may be modified. However, evidence of phenological mismatch in pollination systems is limited.

Demand-driven resource investment in annual seed production by a perennial angiosperm precludes resource limitation.

The limits on annual seed production have long been characterized as restriction by either pollination success or resource provision to seed development. This expected dichotomy between pollen and resource limitation is based on the assumption that reproductive resources are fixed, which is reasonable for semelparous species. In contrast, iteroparity can ease the constraints on reproductive output per breeding season, if resources can be either mobilized from past storage or borrowed against future performance.

Effects of defoliation and shading on the physiological cost of reproduction in silky locoweed Oxytropis sericea.

Background: The production of flowers, fruits and seeds demands considerable energy and nutrients, which can limit the allocation of these resources to other plant functions and, thereby, influence survival and future reproduction. The magnitude of the physiological costs of reproduction depends on both the factors limiting seed production (pollen, ovules or resources) and the capacity of plants to compensate for high resource demand.

Methods: To assess the magnitude and consequences of reproductive costs, we used shading and defoliation to reduce photosynthate production by fully pollinated plants of a perennial legume, Oxytropis sericea (Fabaceae), and examined the resulting impact on photosynthate allocation, and nectar, fruit and seed production.

Comparison of light harvesting and resource allocation strategies between two rhizomatous herbaceous species inhabiting deciduous forests.

Light conditions on the floor of deciduous forests are determined by the leaf dynamics of canopy trees and gap formation. Such spatiotemporal variations of light availability should affect the resource partitioning strategies of understory herbs. Although rhizomatous species are common in understory, relationships between rhizome structure, vegetative growth, and sexual reproduction are unclear in terms of carbon allocation.

Linkages between phenology, pollination, photosynthesis, and reproduction in deciduous forest understory plants.

Light availability in the understory of deciduous forests changes drastically within the growing season due to the foliage dynamics of canopy trees. Because flowering phenology, photosynthetic characteristics, and fruiting success respond to such strong seasonality in light availability, we hypothesized that understory plants in such ecosystems should describe distinct phenological groups or syndromes where "syndrome" is defined only as a set of characteristics that co-occur. To identify these phenological syndromes, we studied the flowering phenology, fruit or seed set, and photosynthetic characteristics for 18 perennial understory herbaceous species that differed in reproductive strategy over eight years in a deciduous forest in northern Japan.

Timing of canopy closure influences carbon translocation and seed production of an understorey herb, Trillium apetalon (Trilliaceae).

Background And Aims: The light availability on a temperate, deciduous-forest floor varies greatly, reflecting the seasonal leaf dynamics of the canopy trees. The growth and/or reproductive activity of understorey plants should be influenced by the length of the high-irradiance period from snowmelt to canopy closure. The aim of the present study was to clarify how spring-blooming species regulate the translocation of photosynthetic products to current reproduction and storage organs during a growing season in accordance with the changing light conditions.

A test of the effect of floral color change on pollination effectiveness using artificial inflorescences visited by bumblebees.

Floral color change has been recognized as a pollination strategy, but its relative effectiveness has been evaluated insufficiently with respect to other floral traits. In this study, effects of floral color change on the visitation pattern of bumblebees were empirically assessed using artificial flowers. Four inflorescence types were postulated as strategies of flowering behavior: type 1 has no retention of old flowers, resulting in a small display size; type 2 retains old flowers without nectar production; type 3 retains old flowers with nectar; and type 4 retains color-changed old flowers without nectar.

Floral color change in Weigela middendorffiana (Caprifoliaceae): reduction of geitonogamous pollination by bumble bees.

We examined the significance of retaining color-changed flowers in pollination success of Weigela middendorffiana through a single visit of bumble bees. Inner parts of flowers changed color with age from yellow to red. In an investigation of the mating system, duration of each color phase, reproductive ability of each of the color-phase flowers, and the effects of color-changed flowers on bumble bee behavior (1) flowers of this species were self-incompatible, (2) color-changed flowers provided little reward to pollinators and little residual reproductive ability, (3) the timing of floral color change was delayed with the progress of flowering season within individual plants, while the duration of the red phase shortened with the progress of flowering season, and (4) red-phase flowers did not attract bumble bees at a distance but did contribute to reducing the number of successive flower visits during a single stay within the plants.