Much can be at stake depending on the choice of words used to describe citizen science, because terminology impacts how knowledge is developed. Citizen science is a quickly evolving field that is mobilizing people's involvement in information development, social action and justice, and large-scale information gathering. Currently, a wide variety of terms and expressions are being used to refer to the concept of 'citizen science' and its practitioners. Here, we explore these terms to help provide guidance for the future growth of this field. We do this by reviewing the theoretical, historical, geopolitical, and disciplinary context of citizen science terminology; discussing what citizen science is and reviewing related terms; and providing a collection of potential terms and definitions for 'citizen science' and people participating in citizen science projects. This collection of terms was generated primarily from the broad knowledge base and on-the-ground experience of the authors, by recognizing the potential issues associated with various terms. While our examples may not be systematic or exhaustive, they are intended to be suggestive and invitational of future consideration. In our collective experience with citizen science projects, no single term is appropriate for all contexts. In a given citizen science project, we suggest that terms should be chosen carefully and their usage explained; direct communication with participants about how terminology affects them and what they would prefer to be called also should occur. We further recommend that a more systematic study of terminology trends in citizen science be conducted.

The number of wildlife-vehicle collisions has an obvious value in estimating the direct effects of roads on wildlife, i.e. mortality due to vehicle collisions. Given the nature of the data-species identification and location-there is, however, much wider ecological knowledge that can be gained by monitoring wildlife roadkill. Here, we review the added value and opportunities provided by these data, through a series of case studies where such data have been instrumental in contributing to the advancement of knowledge in species distributions, population dynamics, and animal behaviour, as well as informing us about health of the species and of the environment. We propose that consistently, systematically, and extensively monitoring roadkill facilitates five critical areas of ecological study: (1) monitoring of roadkill numbers, (2) monitoring of population trends, (3) mapping of native and invasive species distributions, (4) animal behaviour, and (5) monitoring of contaminants and disease. The collection of such data also offers a valuable opportunity for members of the public to be directly involved in scientific data collection and research (citizen science). Through continuing to monitor wildlife roadkill, we can expand our knowledge across a wide range of ecological research areas, as well as facilitating investigations that aim to reduce both the direct and indirect effects of roads on wildlife populations.

The rates of oxygen consumption by embryos of antarctic echinoderms (Acodontaster hodgsoni, Odontaster validus, Psilaster charcoti, and Sterechinus neumayeri) were compared to the biomas (ash-free dry organic weight) of the egg of each species. These species could survive for months to years (range: 10 months to 5 years) by relying solely on the reserves present in the egg. However, certain species did not use any of the egg's reserves during early development. Embryonic stages of O. validus (a species with planktotrophic larvae) did not decrease in lipid, protein, or total biomass during the first 35 days of development. During the first 42 days of development, embryos of A. hodgsoni (a species with lecithotrophic development) used protein as an energy source. For both species lipid composed 40 to 50% of egg biomass, but was not used as an energy reserve. Larvae of O. validus have a high-affinity transport system for amino acids dissolved in seawater (K1 = 1.3 {mu}M for alanine). The rate of alanine transport from a low concentration (50 nM) could supply 32% of the larva's metabolic needs. This is a 10-fold higher input to metabolism than was determined (3% at 50 nM) for larvae of a temperate asteroid, Asterina miniata. Larvae of antarctic echinoderms live in an environment where the food supply is low for most of the year. Relative to their metabolic rates, antarctic larvae have larger energy stores and planktotrophic larvae have higher nutrient transport capacities when compared to larvae from temperate regions. These physiological differences allow antarctic larvae to survive for long periods without particulate food.

High traffic volume is one of the main contributors to wildlife-vehicle collision (WVC) and wildlife mortality on roads. Government shelter-in-place (SIP) orders have been used to help mitigate the spread of COVID-19, resulting in unprecedented reductions in global traffic volumes. Using traffic and collision data from four US states (California, Idaho, Maine, and Washington), we investigated changes in total WVC, following the state and local SIP orders. From mid-March to mid-April 2020, these orders have resulted in up to 71%, 63%, 73%, and 72% reduction in driving, as measured by vehicle miles traveled (VMT), in CA, ID, ME, and WA respectively. The daily WVC rates from the 4 weeks prior to SIP orders going into effect, to the 4 weeks after, declined 34%, with 21, 36, 44, and 33% declines for CA, ID, ME, and WA, respectively. For mountain lions ( Puma concolor) in CA, there was a 58% decline in mortality during the traffic reduction. The changes in WVC from 1 month pre-SIP orders to 1 month post-order only occurred in 2020 and not 2015, 2016, 2017, 2018, or 2019, suggesting that the reductions were associated with the reductions in traffic. The measured declines in WVC reversed in ME and WA during May, June and July 2020, paralleling reversals in traffic volumes. A 34% reduction in WVC would potentially equate to 10s of millions fewer vertebrates killed on US roadways during one month of traffic reduction, representing an unintentional conservation action unprecedented in modern times.

Fertilin, a sperm protein of the metalloprotease/disintegrin/cysteine-rich (MDC) family, plays a critical role in sperm-egg binding in mammals. Peptides corresponding to the disintegrin domain of fertilin and antibodies against fertilin have been shown to inhibit mammalian sperm-egg binding and fusion. A protein from the same family, xMDC16, was recently cloned from frog (Xenopus laevis) testis and was found to be involved in frog sperm-egg binding. Here we report that xMDC16 is localized predominantly on the posterior surface of egg jelly-activated sperm, and peptides from the disintegrin domain of this protein activate eggs when applied near the egg surface. Egg activation was dependent on (1) specific amino acid residues (KTX); (2) the presence of divalent cations, but not external Ca2+ alone; and (3) voltage across the egg plasma membrane. This is the first demonstration of egg activation in vertebrates by the surface application of a peptide derived from a sperm surface protein, supporting a model for egg activation that involves a signal transducing receptor for sperm in the egg's plasma membrane.