As I’ve done every year for the last 15 years, I can now present the 2022 conservation / ecology / sustainability journal ranks based on my (published) journal-ranking method.
Although both the Clarivate (Impact Factor, Journal Citation Indicator, Immediacy Index) and Scopus (CiteScore, Source-Normalised Impact Per Paper, SCImago Journal Rank) values have been out for about a month or so, the Google (h5-index, h5-median) scores only came out yesterday.
This year’s also a bit weird from the perspective of the Clarivate ranks. First, Impact Factors will no longer be provided to three significant digits, but only to one (e.g., 7.2 versus 7.162). That’s not such a big deal, but it does correct for relative ranks based on false precision. However, the biggest changes are more methdological — Impact Factors now take online articles into account (in the denominator), so most journals will have a lower Impact Factor this year compared to last. In fact, of the 105 journals in the ecology/conservation/multidisciplinary category that have data for both 2021 and 2022, the 2022 Impact Factors are a median 15% lower than the 2021 values.
Another effect in play appears to have been the pandemic. The worst of the pandemic happened right during the assessment period, and I’m pretty sure this is reflected both in terms of the number of articles published (down a median of 10%) and total number of citations in the assessment period (down 7%) per journal.
But using my method, these changes a somewhat irrelevant because I calculate relative ranks, not an absolute score.
I therefore present the new 2022 ranks for: (i) 108 ecology, conservation and multidisciplinary journals, (ii) 28 open-access (i.e., you have to pay) journals from the previous category, (iii) 66 ‘ecology’ journals, (iv) 31 ‘conservation’ journals, (v) 43 ‘sustainability’ journals (with general and energy-focussed journals included), and (vi) 21 ‘marine & freshwater’ journals.
Have you ever watched a nature documentary and marvelled at the intricate dance of life unfolding on screen? From the smallest insect to the largest predator, every creature plays a role in the grand performance of our planet’s biosphere. But what happens when one of these performers disappears?
In this post, we delve into our recent article Estimating co-extinction risks in terrestrial ecosystems just published in Global Change Biology, in which we discuss the cascading effects of species loss and the risks of ‘co-extinction’.
But what does ‘co-extinction’ really mean?
Imagine an ecosystem as a giant web of interconnected species. Each thread represents a relationship between two species — for example, a bird that eats a certain type of insect, or a plant that relies on a specific species of bee for pollination. Now, what happens if one of these species in the pair disappears? The thread breaks and the remaining species loses an interaction. This could potentially lead to its co-extinction, which is essentially the domino effect of multiple species losses in an ecosystem.
A famous example of this effect can be seen with the invasion of the cane toad (Rhinella marina) across mainland Australia, which have caused trophic cascades and species compositional changes in these communities.
The direct extinction of one species, caused by effects such as global warming for example, has the potential to cause other species also to become extinct indirectly.
We’ve just published a new paper showing that young red kangaroos (Osphranter rufus) protected by the dingo-proof fence take more time to grow up than their counterparts on the other side, who quickly outgrow the risk of being a dingo’s next meal.
Published in the Journal of Mammalogy, our article led by Rex Mitchell also revealed that there are more young and female kangaroos inside the dingo-proof fence, showing that the fence impacts on different aspects of the red kangaroo’s life cycle.
Red kangaroos are one of the dingo’s favourite prey species, so it’s not surprising to find fewer of the smaller females and younger animals when there are more dingoes around. However, we didn’t expect that young animals inside the fence were lighter and smaller than those outside the fence. Read the rest of this entry »
The way that eels migrate along rivers and seas is mesmerising. There has been scientific agreement since the turn of the 20th Century that the Sargasso Sea is the breeding home to the sole European species. But it has taken more than two centuries since Carl Linnaeus gave this snake-shaped fish its scientific name before an adult was discovered in the area where they mate and spawn.
Even among nomadic people, the average human walks no more than a few dozen kilometres in a single trip. In comparison, the animal kingdom is rife with migratory species that traverse continents, oceans, and even the entire planet (1).
The European eel (Anguilla anguilla) is an outstanding example. Adults migrate up to 5000 km from the rivers and coastal wetlands of Europe and northern Africa to reproduce, lay their eggs, and die in the Sargasso Sea — an algae-covered sea delimited by oceanic currents in the North Atlantic.
The European eel (Anguilla Anguilla) is an omnivorous fish that migrates from European and North African rivers to the Sargasso Sea to mate and die (18). Each individual experiences 4 distinct developmental phases, which look so different that they have been described as three distinct species (19): A planktonic, leaf-like larva (ilecocephalus phase) emerges from each egg and takes up to 3 years to cross the Atlantic. Off the Afro-European coasts, the larva transforms into a semi-transparent tiny eel (iiglass phase) that enters wetlands and estuaries, and travels up the rivers as it gains weight and pigment (iiiyellow phase). They remain there for up to 20 years, rarely growing larger than 1 m in length and 4 kg in weight (females are larger than males) — see underwater footage here and here. Sexual maturity ultimately begins to adjust to the migration to the sea: a darker, saltier, and deeper environment than the river. Their back and belly turn bronze and silver (ivsilver phase), respectively, the eyes increase in size and the number of photoreceptors multiplies (function = submarine vision), the stomach shrinks and loses its digestive function, the walls of the swim bladder thicken (function = floating in the water column), and the fat content of tissues increases by up to 30% of body weight (function = fuel for transoceanic travelling). And finally, the reproductive system will gradually develop while eels navigate to the Sargasso Sea — a trip during which they fast. Photos courtesy of Sune Riis Sørensen (2-day embryo raised at www.eel-hatch.dk and leptocephalus from the Sargasso Sea) and Lluís Zamora (Ter River, Girona, Spain: glass eels in Torroella de Montgrí, 70 cm yellow female in Bonmatí, and 40 cm silver male showing eye enlargement in Bescanó). Eggs and sperm are only known from in vitro fertilisation in laboratories and fish farms (20).
As larvae emerge, they drift with the prevailing marine currents over the Atlantic to the European and African coasts (2). The location of the breeding area was unveiled in the early 20th Century as a result of the observation that the size of the larvae caught in research surveys gradually decreased from Afro-European land towards the Sargasso Sea (3, 4). Adult eels had been tracked by telemetry in their migration route converging on the Azores Archipelago (5), but none had been recorded beyond until recently.
Crossing the Atlantic
To complete this piece of the puzzle, Rosalind Wright and collaborators placed transmitters in 21 silver females and released them in the Azores (6). These individuals travelled between 300 and 2300 km, averaging 7 km each day. Five arrived in the Sargasso Sea, and one of them, after a swim of 243 days (from November 2019 to July 2020), reached what for many years had been the hypothetical core of the breeding area (3, 4). It is the first direct record of a European eel ending its reproductive journey.
Eels use the magnetic fields in their way back to the Sargasso Sea and rely on an internal compass that records the route they made as larvae (7). The speed of navigation recorded by Wright is slower than in many long-distance migratory vertebrates like birds, yet it is consistent across the 16 known eel species (8).
Telemetry (6) and fisheries (14) of European eel (Anguilla anguilla). Eel silhouettes indicate the release point of 21 silver females in Azores in 2018 (orange) and 2019 (yellow), the circles show the position where their transmitters stopped sending signals, and the grey background darkens with water depth. The diagrams display the distance travelled and the speed per eel, where the circle with bold border represents the female that reached the centre of the hypothetical spawning area in the Sargasso Sea (dashed lines in the map) (3). Blue, green and pink symbols indicate the final location of eels equipped with teletransmitters in previous studies, finding no individual giving location signals beyond the Azores Archipelago (6). The barplot shows commercial catches (1978-2021) of yellow+silver eels in those European countries with historical landings exceeding 30,000 t (no data available for France prior to 1986), plus Spain (6120 t from 1951) — excluding recreational fishery and farming which, in 2020, totalled 300 and 4600 t, respectively (14). Red circles represent glass-eel catches added up for France (> 90% of all-country landings), Great Britain, Portugal, and Spain. Catches have kept declining since the 1980s. One kg of glass eels contains some 3000 individuals, so the glass-eel fishery has a far greater impact on stocks than the adult fishery.
Wright claimed that, instead of swiftly migrating for early spawning, eels engage in a protracted migration at depth. This behaviour serves to conserve their energy and minimises the risk of dying (6). The delay also allows them to reach full reproductive potential since, during migration, eels stop eating and mobilise all their resources to swim and reproduce (9).
Other studies have revealed that adults move in deep waters in daylight but in shallow waters at night, and that some individuals are faster than others (3 to 47 km per day) (5). Considering that (i) this fish departs Europe and Africa between August and December and (ii) spawning occurs in the Sargasso Sea from December to May, it is unknown whether different individuals might breed 1 or 2 years after they begin their oceanic migration.
Management as complex as life itself
The European eel started showing the first signs of decline at the end of the 19th Century (10, 11). In 2008, the species was listed as Critically Endangered by the IUCN, and its conservation status has since remained in that category — worse than that of the giant panda (Ailuropoda melanoleuca) or the Iberian lynx (Lynx pardinus).
Wildfires transform forests into mosaics of vegetation. What, where, and which plants thrive depends on when and how severely a fire affects different areas of a forest. Such heterogeneity in the landscape is essential for animal species that benefit from fire like woodpeckers.
The black-backed woodpecker (Picoides arcticus) lives in the coniferous forests of North America’s boreal-Mediterranean region. Thanks to a powerful and sharp bill, this bird can excavate nests inside the trunks of (mainly dead) trees, and those cavities will be re-used later by many species of birds, mammals, and invertebrates in fire-prone landscapes (22). The images show a male with the characteristic black plumage of his back that serves as camouflage against the dark bark of a dead tree three years after a wildfire in Montana (USA). Being omnivores, the diet of this bird largely relies on the larvae of woodboring coleoptera like jewell and longhorn beetles. These insects are abundant post-fire, the champion being the fire beetle (Melanophila spp.). The thorax of fire beetles is equipped with infrared-light receptors that can detect a wildfire from tens of kilometres away (23). These fascinating little beasts are the first to arrive at a burned forest and, of course, woodpeckers follow soon after. The preference of the blackbacked woodpecker for burned forests and their cryptic feathers and pyrophilic diet reflect a long evolutionary history in response to fires. Courtesy of Richard Hutto.
Anyone raised in rural areas will have vivid recollections of wildfires: the thick, ashy smell, the overcast sky on a sunny day, and the purring of aerial firefighters dropping water from their hanging tanks. The reality is that wildfires are natural events that shape biodiversity and ecosystem function (1) — to the extent that fire is intimately linked to the appearance and evolution of terrestrial plants (2). Since the Palaeolithic, our own species has used fire at will, to cook, hunt, melt metals, open cropland or paths, or tell stories in front of a hearth (3).
Where there are regular wildfires (fire-prone ecosystems), different areas of the landscape burn in different seasons and years under different weather patterns. Therefore, each region has a unique fire biography in terms of how frequently, how much, and how long ago wildfires occurred. All those factors interact will one another and with topography.
Thanks to the collaborative and evidence-driven foresight of my colleagues at PIRSA Biosecurity and Landscape Boards, I was recently involved in more research examining the most efficient, cost-effective, and humane ways to cull feral dear in South Australia. The resulting paper is now in review in NeoBiota, but we have also posted a pre-print of the article.
Feral deer are a real problem in Australia, and South Australia is no exception. With six species of feral deer in the country already (fallowDama dama, redCervus elaphus, hogAxis porcinus, chitalA. axis), rusaC. timorensis, and sambarRusa unicolor deer), fallow deer are the most abundant and widespread. These species are responsible for severe damage to native plants, competition with native animals, economic losses to primary industries (crops, pastures, horticulture, plantations), and human safety risks from vehicle collisions. Feral deer are also reservoirs and vectors of endemic animal diseases and have the potential to transmit exotic animal diseases such as foot-and-mouth. If left uncontrolled, within 30 years the economic impacts of feral deer could reach billions of dollars annually.
Each organism has a limit of tolerance to cold and hot temperatures. So, the closer it lives to those limits, the higher the chances of experiencing thermal stress and potentially dying. In our recent paper, we revise gaps in the knowledge of tolerance to high temperatures in cold-blooded animals (ectotherms), a diverse group mostly including amphibians and reptiles (> 16,000 species), fish (> 34,000 species), and invertebrates (> 1,200,000 species).
As a scientist, little is more self-realising than to write and publish a conceptual paper that frames the findings of your own previous applied-research papers. This is the case with an opinion piece we have just published in Basic and Applied Ecology1 — 10 years, 4 research papers2-5 [see related blog posts here, here, here and here], and 1 popular-science article6 after I joined the Department of Biogeography and Global Change (Spanish National Research Council) to study the thermal physiology of Iberian lizards under the supervision of Miguel Araújo and David Vieites.
Iberian lizards for which heat tolerance is known (varying from 40 to 45 °C)
[left, top to bottom] Iberian emerald lizard (Lacerta schreiberi, from Alameda del Valle/Madrid) and Geniez’s wall lizard (Podarcis virescens, Fuertescusa/Cuenca), and [right, top to bottom] Algerian sand racer (Psammodromus algirus, Navacerrada/Madrid), Andalusian wall lizard (Podarcis vaucheri, La Barrosa/Cádiz), Valverde’s lizard (Algyroides marchi, Riópar/Albacete), and Cyren’s rock lizard (Iberolacerta cyreni, Valdesquí/Madrid). Heat-tolerance data deposited here and used to evaluate instraspecific variation of heat tolerance3,4. Photos: Salvador Herrando-Pérez.
In our new paper, we examine how much we know and what areas of research require further development to advance our understanding of how and why the tolerance of ectotherm fauna to high environmental temperature (‘heat tolerance’ hereafter) varies within and across the Earth’s biomes. We focus on data gaps using the global database GlobTherm as a reference template (see Box 1 below).
Our three main tenets
1. Population versus species data: Most large-scale ecophysiological research is based on modelling one measurement of heat tolerance per species (typically representing one population and/or physiological assay) over hundreds to thousands of species covering broad geographical, phylogenetic, and climatic gradients.
But there is ample evidence that heat tolerance changes a lot among populations occupying different areas of the distribution of a species, and such variation must be taken into account to improve our predictions of how species might respond to environmental change and face extinction.
The Faculty for Mathematics and Natural Sciences of Humboldt-Universität zu Berlin (HU Berlin), Geography Department, has an open position for a tenure-track professorship in Conservation and Development.
Starting as soon as possible. This is a Junior Professorship (W1 level, 100%) with a tenure track to a permanent professorship (W2 level, 100%). To verify whether the individual performance meets the requirements for permanent employment, an evaluation process will be opened not later than four years of the Junior Professorship. Tenure track professors at the HU Berlin are expected to do research and teaching, as well as to be active in university administration, in the promotion of young scientists, and in acquiring leadership and management skills. The concrete requirements out of the framework catalogue will be specified in the course of the appointment process.
We seek candidates with an outstanding research record in biodiversity conservation and sustainable development, with experience in working in the Global South. Successful candidates are rooted in conservation science and must have a doctoral degree in conservation science, development geography, environmental science, political ecology or related fields. We expect a demonstrated ability to work interdisciplinary, across the social and natural sciences to understand conservation challenges and and develop solutions.
We seek individuals with the vision, leadership and enthusiasm to build an internationally recognised research program. We expect collaboration with other research groups at the department, at HU Berlin and beyond, and a commitment to promoting a positive, diverse, and inclusive institutional culture. Experience in translating conservation science into action and/or work at the science/policy interface are beneficial.
We offer a tenure-track position in an international, young and vibrant department with an excellent scientific and education track record. The successful candidate will join an interdisciplinary group of faculty focused on human-environment relations, global change, and sustainability.
The salary will be according to W1 level, and after successful tenure evaluation W2 level. Employment at HU Berlin offers all benefits of the German public service system, including health insurance, an attractive pension plan, and social benefits.
Flooding in the Murray-Darling Basin is creating ideal breeding conditions for many native species that have evolved to take advantage of temporary flood conditions. Led by PhD candidate Rupert Mathwin, our team developed virtual models of the Murray River to reveal a crucial link between natural flooding and the extinction risk of endangered southern bell frogs (Litoria raniformis; also known as growling grass frogs).
Southern bell frogs are one of Australia’s 100 Priority Threatened Species. This endangered frog breeds during spring and summer when water levels increase in their wetlands. However, the natural flooding patterns in Australia’s largest river system have been negatively impacted by expansive river regulation that some years, sees up to 60% of river water extracted for human use.
Our latest paper describes how we built computer simulations of Murray-Darling Basin wetlands filled with simulated southern bell frogs. By changing the simulation from natural to regulated conditions, we showed that modern conditions dramatically increase the extinction risk of these beloved frogs.
The data clearly indicate that successive dry years raise the probability of local extinction, and these effects are strongest in smaller wetlands. Larger wetlands and those with more frequent inundation are less prone to these effects, although they are not immune to them entirely. The models present a warning — we have greatly modified the way the river behaves, and the modern river cannot support the long-term survival of southern bell frogs.’
Following my annual tradition, I present the retrospective list of the ‘top’ 20 influential papers of 2022 as assessed by experts in Faculty Opinions(formerly known as F1000). These are in no particular order. See previous years’ lists here: 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, and 2013.
Climate change is one of the main drivers of species loss globally. We know more plants and animals will die as heatwaves, bushfires, droughts and other natural disasters worsen.
But to date, science has vastly underestimated the true toll climate change and habitat destruction will have on biodiversity. That’s because it has largely neglected to consider the extent of “co-extinctions”: when species go extinct because other species on which they depend die out.
Our new research shows 10% of land animals could disappear from particular geographic areas by 2050, and almost 30% by 2100. This is more than double previous predictions. It means children born today who live to their 70s will witness literally thousands of animals disappear in their lifetime, from lizards and frogs to iconic mammals such as elephants and koalas.
But if we manage to dramatically reduce carbon emissions globally, we could save thousands of species from local extinction this century alone.
Ravages of drought will only worsen in coming decades. CJA Bradshaw
An extinction crisis unfolding
Every species depends on others in some way. So when a species dies out, the repercussions can ripple through an ecosystem.
For example, consider what happens when a species goes extinct due to a disturbance such as habitat loss. This is known as a “primary” extinction. It can then mean a predator loses its prey, a parasite loses its host or a flowering plant loses its pollinators.
A real-life example of a co-extinction that could occur soon is the potential loss of the critically endangered mountain pygmy possum (Burramys parvus) in Australia. Drought, habitat loss, and other pressures have caused the rapid decline of its primary prey, the bogong moth (Agrotis infusa).
In a newly announced partnership with Texas biotech company Colossal Biosciences, Australian researchers are hoping their dream to bring back the extinct thylacine is a “giant leap” closer to fruition.
Scientists at University of Melbourne’s TIGRR Lab (Thylacine Integrated Genetic Restoration Research) believe the new partnership, which brings Colossal’s expertise in CRISPR gene editing on board, could result in the first baby thylacine within a decade.
The genetic engineering firm made headlines in 2021 with the announcement of an ambitious plan to bring back something akin to the woolly mammoth, by producing elephant-mammoth hybrids or “mammophants”.
But de-extinction, as this type of research is known, is a highly controversial field. It’s often criticised for attempts at “playing God” or drawing attention away from the conservation of living species. So, should we bring back the thylacine? We asked five experts.
As is my tendency, I like to wade carefully into other disciplines from time to time to examine what components they can bring to the conservation table. I do not profess any sort of expertise when I do so, but if I require a true expert for research purposes, then I will collaborate with said experts.
I often say to my students that in many ways, the science of sustainability and conservation is more or less resolved — what we need now is ways to manage the human side of the problems we face. The disciplines that deal with human management, such as psychology, economics, political science, and sociology, are mainly pursuits of the humanities (have I just argued myself out of a job?).
On the topic of human psychology, I think most people involved in some way with biodiversity conservation often contemplate why human societies are so self-destructive. Even in the face of logic and evidence, people deny what’s going on in front of their eyes (think anti-vaxxers, climate-change denialists, etc.), so it should be no wonder why many (most?) people deny their own existential threats. Yet, it still doesn’t seem to make much sense to us until we put the phenomenon into a psychological framework.
My apologies here to actual psychologists if I oversimplify or otherwise make mistakes, but the following explanation has done a lot for me personally in my own journey to understand this conundrum. It is also a good way to teach others about why there is so much reticence to fixing our environmental problems.
The idea is a rather simple one, but it requires a little journey to appreciate. Let’s pop back to the 1970s with the publication of Ernest Becker’s The Denial of Death, for which he won the Pulitzer Prize in 1974 (ironically, two months after his own death). In this book, Becker examined the awareness of death on human behaviour and the strategies that we have developed to mitigate our fear of it. This particular quote sums it up nicely:
This is the terror: to have emerged from nothing, to have a name, consciousness of self, deep inner feelings, and excruciating inner yearning for life and self expression — and with all this yet to die
Ernest Becker in The Denial of Death (1973)
The upshot is that we have evolved a whole raft of coping mechanisms to this personal existential dread. Some engage in overly hedonic pursuits to numb the anxiety; others try to “tranquillise themselves with the trivial”, essentially ignoring the terror, while others still manage the dread through religion and the hope of an existence beyond the mortal.
Now that Clarivate, Google, and Scopus have recently published their respective journal citation scores for 2021, I can now present — for the 14th year running on ConvervationBytes.com — the 2021 conservation/ecology/sustainability journal ranks based on my journal-ranking method.
Like last year, I’ve added a few journals. I’ve also included in the ranking the Journal Citation Indicator (JCI) in addition to the Journal Impact Factor and Immediacy Index from Clarivate ISI, and the CiteScore (CS) in addition to the Source-Normalised Impact Per Paper (SNIP) and SCImago Journal Rank (SJR) from Scopus.
I therefore present the new 2021 ranks for: (i) 106 ecology, conservation and multidisciplinary journals, (ii) 27 open-access (i.e., you have to pay) journals from the previous category, (iii) 64 ‘ecology’ journals, (iv) 32 ‘conservation’ journals, (v) 43 ‘sustainability’ journals (with general and energy-focussed journals included), and (vi) 21 ‘marine & freshwater’ journals.
Remember not to take much notice if a journal boasts about how its Impact Factor has increased this year, because these tend to increase over time anyway What’s important is a journal’s relative (to other journals) rank.
I’ll preface this post with a caveat — the data herein are a few years old (certainly pre-COVID), so things have likely changed a bit. Still, I think the main message holds.
That last observation is important because there are really two main ways to quantify a country’s environmental performance. First, there is its relative environmental damage, which essentially means what proportion of its own resources a country has pilfered or damaged. This type of measure standardises the metrics to account for the different areas of countries (e.g., Russia versus Singapore) and how much of, say, forests, they had to start with, and what proportion of them they have thus far destroyed.
Looking at it this way, small countries with few large-scale industries came out in the lead as the least-damaged environmentally — the least environmentally damaged country according this metric is Cape Verde (followed by Central African Republic, Swaziland, Niger, and Djibouti).
However, another way to look at it is how much of the overall contribution to the world’s environmental damage each country is responsible, which of course implies that the countries with the highest amounts of resources damaged in absolute terms (i.e., the biggest, most populous ones) disproportionately contribute more to global environmental damage.
Using this absolute metric, the countries with the greatest overall damage are Brazil (largely due to the destruction of the Amazon and its other forests), the USA (for its greenhouse-gas emissions and conversion of its prairies to farmland), and China (for its water pollution, deforestation, and carbon emissions). On the flip side, this means that the smallest countries with the fewest people are ranked ‘better’ because of their lower absolute contribution to the world’s total environmental damage.
Looking more closely at how countries do relative to each other using different and more specific measures of environmental performance, the best-known and most-reported metric is the ecological footprint. This measures the ecological ‘assets’ that any particular population of people requires to produce the natural resources it consumes and to absorb its wastes.
Nearly a decade ago (my how time flies*), I wrote a post about the guaranteed failure of government policies purporting no-extinction targets within their environmental plans. I was referring to the State of South Australia’s (then) official policy of no future extinctions.
In summary, zero- (or no-) extinction targets at best demonstrate a deep naïvety of how ecology works, and at worst, waste a lot of resources on interventions doomed to fail.
4. Climate change will also guarantee additional (perhaps even most) future extinctions irrespective of Australian policies.
I argued that no-extinction policies are therefore disingenuous to the public in the extreme because they sets false expectations, engender disillusionment after inevitable failure, and ignores the concept of triage — putting our environment-restoration resources toward the species/systems with the best chance of surviving (uniqueness notwithstanding).
Bees are essential for pollination, but their critical function can be perturbed by pesticides. The detrimental effects of those chemicals accumulate through a bee’s life, and become stronger if females cannot collect pollen from wildflowers.
Our childhood experiences partly determine our health, personality, and lifestyle when we are adults, and our experiences accumulate over time. Accumulation also occurs in any living being and can explain why some populations and species adapt to their environments better than others.
Migratory birds are a clear example. Thousands can travel to their breeding grounds after wintering elsewhere, and those coming from regions laden with resources (e.g., food, shelter, water) will have a greater reproductive success than those that migrated from resource-poor regions (1). In ecology, these ‘carry-over’ effects can take place between seasons, but also across the different phases of the life cycle of a plant or animal (2).
From larvae to adults
Clara Stuligross and Neal Williams have studied the carry-over effect of pesticides on the blue orchard beeOsmia lignaria in California (3). Instead of the typical hives constructed by the honey bee (Apis mellifera), solitary blue orchard bees make lines of brood cells with mud partitions, glued into holes and crevices of branches and trunks from fallen trees (see videos here, here, & here).
Carnivores are essential components of trophic webs, and ecosystem functions crumble with their loss. Novel data show the connection between calcareous reefs and sea otters under climate change.
Trophic cascade on the Aleutian Islands (Alaska, USA) linking sea otters (Enhydra lutris) with sea urchins (Strongylocentrotus polyacanthus) and calcareous reefs (Clathromorphum nereostratum). With males weighting up to 50 kg, sea otters have been IUCN-catalogued as Endangered since 2000. The top photo shows a male in a typical, belly-up floating position. The bottom photo shows live (pinkish) and dead (whitish) tissue on the reef surface as a result of grazing of sea urchins at a depth of 10 m. Sea otters are mesopredators, typically foraging on small prey like sea urchins, but their historical decline due to overhunting unleashed the proliferation of the echinoderms. At the same time, acidification and sea-water warming have softened the skeleton of the reefs, allowing for deeper grazing by sea urchins that eliminate the growth layer of living tissue that give the reefs their pinkish hue. Large extents of dead reefs stop fixing the excess in carbonic acid, whose carbon atoms sea water sequesters from the atmosphere enriched in carbon by our burning of fossil fuels. Photos courtesy of Joe Tomoleoni taken in Moss Landing – California, USA (otter), and on the Near Islands – Aleutian Archipelago, Alaska (reef).
For most, the decisions made by people we have never met affect our daily lives. Other species experience the same phenomenon because they are linked to one another through a trophic cascade.
A trophic cascade occurs when a predator limits the abundance or behaviour of its prey, in turn affecting the survival of a third species in lower trophic levels that have nothing directly to do with the predator in question (1).
Sea otters (Enhydra lutris) represent a text-book example of a trophic cascade. These mustelids (see video footage here and here) hunt and control the populations of sea urchins (Strongylocentrotus polyacanthus), hence favouring kelp forests — the fronds of which are eaten by the sea urchins.
Removing the predator from the equation should lead to more sea urchins and less kelp, and this chain of events is exactly what happened along the coasts of the North Pacific (2, 3). The historical distribution of sea otters once ranged from Japan to Baja California through the Aleutian Islands (see NASA’s photo from space, and documentary on the island of Unimak), a sub-Arctic, arc-shaped archipelago including > 300 islands between Alaska (USA) and the Kamchatka Peninsula (Russia), extending ~ 2000 kilometres, and having a land area of ~ 18,000 km2.
But the fur trade during the 18th and 19th centuries brought the species to the brink of extinction, down to < 2000 surviving individuals (4). Without otters, sea urchins boomed and deforested kelp ecosystems during the 20th Century (5). Now we also know that this trophic cascade has climate-related implications in other parts of the marine ecosystem.
Underwater bites
Doug Rasher and collaborators have studied the phenomenon on the Aleutian Islands (6). The seabed of this archipelago is a mix of sandy beds, kelp forests, and calcareous reefs made up of calcium and magnesium carbonates fixed by the red algae Clathromorphum nereostratum. These reefs have grown at a rate of 3 cm annually for centuries as the fine film of living tissue covering the reef takes the carbonates from the seawater (7).
While you have little choice these days about posting your data and code online when you publish, here are some things to consider when contemplating putting potentially sensitive data online (modified excerpt from The Effective Scientist).
Of course, there are many different types of ‘sensitive’ information that might accompany the more basic quantitative measurements of your datasets, with perhaps the most common being personal details of any human subjects. For example, if you are a medical researcher and your data are derived primarily from living human beings undergoing some procedure, trial, or intervention, then clearly you are bound by your human ethics approvals not to publish information like names, addresses, or anything that could be used to identify the subjects in your sample. In fact, human ethics approvals generally prohibit any sort of public accessibility to medical data that has personal information included; thus, the scientists concerned are being pulled in two different directions — keeping their subjects’ personal information out of the hands of the public, while still making the data available to other scientists.
There are ways around this, such as publishing only generic information online (i.e., by excluding personal identifiers) that could then be linked to the more sensitive data via unique identifiers. In these cases, any other researcher requiring the additional information would have to seek specific permission from the primary researchers, pending additional human-ethics approvals.
Last week, researchers at the University of Melbourne announced that thylacines or Tasmanian tigers, the Australian marsupial predators extinct since the 1930s, could one day be ushered back to life.
The thylacine (Thylacinus cynocephalus), also known as the ‘Tasmanian tiger’ (it was neither Tasmanian, because it was once common in mainland Australia, nor was it related to the tiger), went extinct in Tasmania in the 1930s from persecution by farmers and habitat loss. Art by Eleanor (Nellie) Pease, University of Queensland. Centre of Excellence for Australian Biodiversity and Heritage
Advances in mapping the genome of the thylacine and its living relative the numbat have made the prospect of re-animating the species seem real. As an ecologist, I would personally relish the opportunity to see a living specimen.
The announcement led to some overhyped headlines about the imminent resurrection of the species. But the idea of “de-extinction” faces a variety of technical, ethical and ecological challenges. Critics (like myself) argue it diverts attention and resources from the urgent and achievable task of preventing still-living species from becoming extinct.
The rebirth of the bucardo
The idea of de-extinction goes back at least to the the creation of the San Diego Frozen Zoo in the early 1970s. This project aimed to freeze blood, DNA, tissue, cells, eggs and sperm from exotic and endangered species in the hope of one day recreating them.
The notion gained broad public attention with the first of the Jurassic Park films in 1993. The famous cloning of Dolly the sheep reported in 1996 created a sense that the necessary know-how wasn’t too far off.
The next technological leap came in 2008, with the cloning of a dead mouse that had been frozen at –20℃ for 16 years. If frozen individuals could be cloned, re-animation of a whole species seemed possible.
After this achievement, de-extinction began to look like a potential way to tackle the modern global extinction crisis.
A recent paper, co-authored with the late Paul Ehrlich, reveals that the global human population has surpassed Earth’s sustainable capacity. It highlights the dire implications for food security, climate stability, and wellbeing. The study underscores that immediate changes in consumption and population management are crucial for a sustainable future.
Using animals as sport symbols reflects the integration of biodiversity into cultural identity and the transmission of collective values. This raises the possibility that the economic muscle of the sport industry could translate its symbolic capital into tangible commitments to biodiversity conservation. Those who have had the privilege of travelling in remote areas might have…
Under the sea where there is little or no light, the foraging, communication, and orientation of whales and many other marine animals depend on sound. But increasing human activity has transformed the soundscape of seas and oceans. This change affects the behaviour of species and presents challenges in managing a problem of global scale. Many…
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