le
the fastest animals and vehicles are neither the biggest nor the fastest over lifetime
a. bejan et al. 2018
http://dx.doi.org/10.1038/s41598-018-30303-1
hemimastigophora is a novel supra-kingdom-level lineage of eukaryotes
gordon lax et al. 2018
https://www.nature.com/articles/s41586-018-0708-8
body size downgrading of mammals over the late quaternary
felisa a. smith et al. 2018
http://dx.doi.org/10.1126/science.aao5987
total cat mojo: the ultimate guide to life with your cat
jackson galaxy 2017 9781524705268
the trainable cat: how to make life happier for you and your cat
john bradshaw and sarah ellis 2016 to read next
do similar foragers flock together? nonbreeding foraging behavior and its impact on mixed-species flocking associations in a subtropical region
harrison h jones et al. 2020
http://dx.doi.org/10.1093/auk/ukz079
In an analysis of nearly 100 North Florida flocks, Florida Museum of Natural History researchers found similar bird species were significantly more likely to flock together than hunt alone, working as a group to stay safe from predators while cruising the canopy in search of insects. Species kept competition within the flock low, however, by differentiating their foraging technique, their choice of hunting spot or the general distance they kept from a tree trunk.
In other words, think of flock dynamics like a K-pop band, said study lead author Harrison Jones.
“You have to be similar enough to the other members to get along as a group but specialized in some way: There’s the leader, the one who raps, the one who plays guitar,” said Jones, a doctoral student in the University of Florida’s department of biology. “It’s the same with birds. They hang out together because they share things in common, but they can’t share too much. If you’re so similar that you’re eating each other’s lunch, then you have a serious problem.”
North Florida’s winter flocking community is “probably the most complex in North America,” Jones said, featuring dozens of migratory species and a bevy of foraging opportunities. Still, the researchers were surprised to see how specialized the birds’ foraging habits were — a feature more reminiscent of the Amazon than North America.
The study documented previously unknown foraging behaviors in Florida, including the yellow-throated warbler’s habit of hanging sideways or upside down on palm fronds to feed on insects. Orange-crowned warblers probed the interior of dead leaves while pine warblers combed through air plants.
“These are very tropical features — not something I expected to see in a subtropical environment like Florida,” said study co-author Scott Robinson, Florida Museum Ordway Eminent Scholar and Jones’ adviser. Robinson has studied tropical bird species since 1977, with a focus on Central and South America. “Palm trees are not easy to feed from. It takes a very specialized bird using a specialized technique.”
Species that pick insects off live leaves and nab them in the air — the most common foraging techniques — were relatively abundant in mixed flocks. These included ruby-crowned kinglets, blue-gray gnatcatchers and pine warblers. But birds that hunt exclusively in harder-to-find material tended to be represented by a single member per flock. These specialists called repeatedly, as though to warn others of their kind “Hands off! This is my flock,” Jones said.
The diversity of Florida’s flocks ranged from three to 12 species and four to 36 individuals per flock. The researchers identified 14 species as regular participants in mixed flocks, with 10 species appearing in more than 80% of mixed flocks.
“We didn’t know birds were spending 80-90% of their time in these flocks,” Jones said. “It’s clear that this behavior is really important to their ecology and may explain why there’s so much partitioning of resources within the flock. They’re spending almost all their waking hours together.”
One-flock shopping
Mixed-species flocks only occur during winter, birds’ non-breeding season. Finding enough food in colder months is vital for birds, which must strike the right balance between putting on sufficient body fat to survive the night while staying lean enough to make a quick escape from a predator, Jones said.
Hunting insects as a group can be a life-saver. Flock members rely on sentinel species, which also direct the flock’s movements and pace, to sound the alarm if an owl or hawk swoops in. This allows the majority of birds in the flock to devote more attention to finding food. Traveling in numbers also lessens a bird’s chance of being the unlucky victim if a predator attacks.
In North Florida’s mixed-species flocks, tufted titmice and Carolina chickadees play the role of sentinels — “blabbermouth birds,” Jones said.
“They’re always giving little contact calls to one another as an ‘all clear,’” he said. “If they stop, everybody else is on edge. When they see a predator, they give an alarm call, and everybody in the flock will freeze.”
But these sentinel species don’t appear to be actively recruiting flock members, Jones said: “They’re just going about their business, and everyone else joins them.”
As with any good K-pop band, group choreography is key. Jones and his co-author and birding partner Mitchell Walters, also a UF doctoral student in biology, noticed mixed flocks were dominated by small, swift birds. Larger insect-eating birds, such as woodpeckers, often couldn’t keep up, joining temporarily but dropping behind when the flock moved on.
Birds that foraged in the understory, such as thrushes, didn’t flock at all.
To piece together the story of Florida’s mixed flocks, Jones and Walters, both seasoned birders, spent many hours in Gainesville’s upland hammocks, developing cricks in their necks as they stared into the canopy through their binoculars.
“By the end of the study, we started to recognize how each of these species has its own way of moving and foraging, its own personality — something birders often talk about,” Jones said. “In many ways, this study was inspired by talking to local birdwatchers and just going birding. They’ll say things like ‘Of course you only get one vireo per flock.’ And the science agreed.”
abstract Mixed-species flocks are ubiquitous in forest bird communities, yet the extent to which positive (facilitative) or negative (competitive) interactions structure these assemblages has been a subject of debate. Here, we describe the fine-scale foraging ecology and use network analysis to quantify mixed-species flocking interactions of an insectivorous bird community in hardwood forests of north-central Florida. Our goal was to determine if similarly foraging species are more (facilitation hypothesis) or less (competition hypothesis) likely to associate in flocks, and if foraging ecology can explain intraspecific abundance patterns within flocks. We quantified attack maneuvers, foraging substrate, and foraging microhabitat of all 17 common insectivorous species in these forests and characterized the composition of 92 flocks encountered. Flocking was important in our community; 14 of 17 species joined more than 5% of flocks, and 10 species had flocking propensities of over 0.80. Our results supported both hypothesized mechanisms structuring flock composition. Species had distinct, well-defined foraging niches during the nonbreeding season, but foraging niche overlap among flocking species was greater than expected by chance. Consistent with the facilitation hypothesis, we found that similarly foraging species were significantly more likely to associate in flocks, a result driven by lower association strengths in large-bodied woodpeckers. We found no evidence of assortment by foraging behavior, however, likely because foraging behavior and substrate use showed strong niche partitioning at the fine scale within our community. Intraspecific abundance patterns were significantly linked to foraging substrate use, with live leaf use correlated with high within-flock abundance and relative abundance at study sites. Species that specialized on comparatively less abundant substrates (tree trunks, epiphytes, dead leaves) joined flocks as singletons, showed lower relative abundance, and may exhibit nonbreeding territoriality. Our results highlight the importance of foraging substrate use and mixed-species flocks in structuring the nonbreeding ecology of migratory birds.
mutual visual signalling between the cleaner shrimp ancylomenes pedersoni and its client fish
eleanor m. caves et al. 2018
http://dx.doi.org/10.1098/rspb.2018.0800
wide-eyed glare scares raptors: from laboratory evidence to applied management
martine hausberger et al. 2018
http://dx.doi.org/10.1371/journal.pone.0204802
robots mediating interactions between animals for interspecies collective behaviors
frank bonnet et al. 2019
http://dx.doi.org/10.1126/scirobotics.aau7897
bees were located in Austria and the fish in Switzerland. Through robots, the two species transmitted signals back and forth to each other and gradually began coordinating their decisions. The study was published today in Science Robotics.
"We created an unprecedented bridge between the two animal communities, enabling them to exchange some of their dynamics," says Frank Bonnet, a researcher at EPFL's Mobile Robots Group (MOBOTS), which is now part of the school's Biorobotics Laboratory (BioRob). Researchers at MOBOTS have designed robots that can blend into groups of animals and influence their behavior. They have tested their robots on communities of cockroaches, chicks and, more recently, fish – one of these "spy" robots was able to infiltrate a school of fish in a circular aquarium and get them to swim in a given direction.
For this study, engineers took the fish experiment and went one step further, connecting the robot and school of fish with a colony of bees in a laboratory in Graz, Austria. There the bees live on a platform with robot terminals on each side which they naturally tend to swarm around.
The robots within each group of animals emitted signals specific to that species. The robot in the school of fish emitted both visual signals – in terms of different shapes, colors and stripes – and behavioral signals – like accelerations, vibrations and tail movements. The robots in the bee colony emitted signals mainly in the form of vibrations, temperature variations and air movements. Both groups of animals responded to the signals; the fish started swimming in a given direction and the bees started swarming around just one of the terminals. The robots in the two groups recorded the dynamics of each group, exchanged that information with each other, and then translated the information received into signals appropriate for the corresponding species.
"The robots acted as if they were negotiators and interpreters in an international conference. Through the various information exchanges, the two groups of animals gradually came to a shared decision," says Francesco Mondada, a professor at BioRob.
During the experiment, the two animal species "talked" to each other even though they were some 700 kilometers apart. The conversation was chaotic in the beginning, but eventually led to a certain amount of coordination. After 25 minutes, the animal groups were synchronized – all the fish swam in a counterclockwise direction and all the bees had swarmed around one of the terminals.
Swapping certain characteristics
"The species even started adopting some of each other's characteristics. The bees became a little more restless and less likely to swarm together than usual, and the fish started to group together more than they usually would," says Bonnet.
abstract Self-organized collective behavior has been analyzed in diverse types of gregarious animals. Such collective intelligence emerges from the synergy between individuals, which behave at their own time and spatial scales and without global rules. Recently, robots have been developed to collaborate with animal groups in the pursuit of better understanding their decision-making processes. These biohybrid systems make cooperative relationships between artificial systems and animals possible, which can yield new capabilities in the resulting mixed group. However, robots are currently tailor-made to successfully engage with one animal species at a time. This limits the possibilities of introducing distinct species-dependent perceptual capabilities and types of behaviors in the same system. Here, we show that robots socially integrated into animal groups of honeybees and zebrafish, each one located in a different city, allowing these two species to interact. This interspecific information transfer is demonstrated by collective decisions that emerge between the two autonomous robotic systems and the two animal groups. The robots enable this biohybrid system to function at any distance and operates in water and air with multiple sensorimotor properties across species barriers and ecosystems. These results demonstrate the feasibility of generating and controlling behavioral patterns in biohybrid groups of multiple species. Such interspecies connections between diverse robotic systems and animal species may open the door for new forms of artificial collective intelligence, where the unrivaled perceptual capabilities of the animals and their brains can be used to enhance autonomous decision-making, which could find applications in selective “rewiring” of ecosystems.
squid empire: the rise and fall of the cephalopods
danna staaf 2017 9781611689235
“the main driver of evolutionary diversity might have been diversity itself. As soon as new animals evolved, they altered and built on their surroundings and interacted with each other, creating a feedback loop of new niches for even newer animal forms to adapt into.”
Douglas H. Erwin, Marc Laflamme, Sarah M. Tweedt, et al., “The Cambrian Conundrum: Early Divergence and Later Ecological Success in the Early History of Animals,” Science 334, no. 6059 (2011): 1091–1097.
wild pollinators improve production, uniformity, and timing of blueberry crops
charles c. nicholson, taylor h. ricketts 2018
http://dx.doi.org/10.1016/j.agee.2018.10.018
The study, led by University of Vermont scientists, is the first to successfully reveal that wild bees improve not only blueberry quantities, but also size and other quality factors. It finds that wild bees provide major benefits for berry farmers, including: greater berry size (12%), quantity (12%), size consistency (11%), and earlier harvests -- by two and a half days.
"Other studies have explored bees' effects on blueberry yields, but this is the first to show that pollinators can improve the quality of crops as well," says Charles Nicholson, who led the study as a PhD student in UVM's Gund Institute for Environment and Rubenstein School of Environment and Natural Resources. The study is published in Agriculture, Ecosystems and Environment.
Of the nine berry farms studied across the state of Vermont, the researchers calculated that wild bees could boost production up to 36%, or roughly $136,000 per year, on one mid-sized berry farm alone. On other farms, researchers determined wild bees' potential benefits to production as roughly 6% on average.
"This study highlights the undervalued work that wild bees do," says Nicholson, noting that two-thirds of the world's most important crops benefit from bee pollination, including coffee, cacao (for chocolate) and many fruits and vegetables. "Without them farmers need to find pollination somewhere else, by paying high rental fees to bring in honeybees, for example."
The findings offer a farm-scale perspective to recent global estimates of wild bees' economic benefits in the billions, annually -- roughly equal to that of honeybees, with less associated costs.
Unique research location
Because honeybees visit Vermont blueberries much less often than in other blueberry growing regions, the Green Mountain State is a perfect location to isolate the value of wild bees to berry farmers, researchers say.
"Most pollination research occurs in regions awash in honeybees," says co-author Taylor Ricketts, Director of UVM's Gund Institute for Environment. "That makes it difficult to really see the job that wild bees can do for farmers."
The team painstakingly hand-pollinated blueberry plants in all nine research sites -- using electric toothbrushes to mimic the buzz pollination of bumblebees, and then painted the collected pollen on over blueberry 5,000 flowers with small brushes. They compared production on these flowers, which received near-perfect pollination, to the naturally pollinated branches. The difference between the two conditions revealed each farm's "pollination deficit," the amount by which production could be improved with an increase in wild pollinators.
"Many farmers don't realize they can be limited by not enough pollinators just like they can be limited by water or nutrients," says Nicholson.
This study highlights the importance of wild bees to global agriculture, yet the first study to map wild bees across the U.S. -- by Ricketts and colleagues -- suggests wild bees declined in abundance by 23% between 2008 and 2013, especially in key U.S. agricultural areas. Another Ricketts study recently found that climate change could reduce areas available for coffee production by 88% in Latin America, as well as the bees numbers available to pollinate coffee.
Another reason to protect wild pollinators -- for berry lovers, at least -- is that wild bees, especially bumblebees, are better at pollinating blueberries than honeybees. Bumblebees have evolved the ability to "buzz pollinate," vibrating blueberry flowers at a specific frequency to efficiently release showers of pollen. Honeybees are unable to do this, and must instead use less effective techniques to pry pollen from the flower.
What can farmers and policymakers do to protect wild bees? The UVM team has found that maintaining a high proportion of natural bee habitat around farms can help, as well as spraying less pesticides. Small actions by homeowners can help too, such as mowing less, planting native wildflowers, and putting out 'beeboxes,' which are like birdhouses, but for wild native bees.
"This study shows, yet again, that protecting wild bee populations offers important benefits to our agricultural economy," adds Ricketts. "Maintaining healthy ecosystems can be as important as providing fertilizer or water."
•Visits by wild bees improve quantity and quality of blueberry crops.
•Quantity improvements include larger fruit set and berry size.
•Quality improvements include increased berry uniformity and earlier harvest.
•Enhancing pollination by wild bee could improve farm revenues up to 36%, or $137,000/year.
•Farms vary widely in potential gains from enhancing pollinators.
Animal pollination is an important input to the global food system, affecting 2/3 of crops and worth more than $100 billion annually. Mounting evidence of pollinators’ importance, and of their decline worldwide, has prompted efforts to conserve and restore wild bees within agricultural regions. To date, however, research on the value of wild pollinators has focused largely on crop productivity per se and on intensely managed landscapes. Here, we combine field experiments, bee observations, and economic methods to estimate the impact of wild pollinators on the quantity and quality of blueberry crops within a low intensity agricultural landscape in Vermont, USA. Visits by wild bees reduced pollination limitation and increased seed set by up to 92%, fruit mass 12%, and fruit set 12%. Visitation also increased the uniformity of fruit size by up to 11% and advanced the timing of harvest by 2.5 days, both of which can increase crop value. For five out of six groups of wild bees, increased visits improved seed set relative to hand-pollinated controls. The potential economic value of relieving pollen limitation (and therefore improving fruit set and fruit mass) varied widely among farms. On most, production could increase 1–6% (representing $500-$4000 per year in additional revenue), but the maximum increase was 36% (representing $137,000 per year). Conserving wild pollinator communities, therefore, can increase crop quantity, quality, and farm revenue, but some farmers will benefit more than others. Farm-specific studies and recommendations are needed to best inform local and regional management decisions.
wild african drosophila melanogaster are seasonal specialists on marula fruit
suzan mansourian et al. 2018
http://dx.doi.org/10.1016/j.cub.2018.10.033
"The ancestors of the flies in our fruit bowls lived in southern Africa. About 10,000 years ago they moved in with their neighbours: humans. Their offspring then colonised the world. It's actually quite awesome," says Marcus Stensmyr, senior lecturer at Lund University.
It was in the forests of what is now Zambia and Zimbabwe that the researchers after several years of searching have found clues to the background of the fruit fly, Drosophila melanogaster. Within science, it has been perhaps the most studied organism ever, but even so no-one had ever discovered them in the wild, or uncovered where they came from.
With the help of traps, Marcus Stensmyr and colleagues from Lund and the University of Wisconsin-Madison succeeded in capturing fruit flies in the African forests. Traps close to marula fruit were quickly filled with flies, while traps at other locations remained empty or only attracted a few flies.
The researchers already knew that overripe, rotten, citrus fruits are the fruit flies' favourite in the fruit bowl. They therefore tested what the flies preferred in the wild: marula or citrus. The answer: marula. They got the same results when testing fruit flies in other parts of the world, flies that had never previously been anywhere near marula.
"At home in the kitchen the flies feast on whatever is starting to rot in the fruit bowl, even though they like citrus fruits best. In the wild they are far more picky, they prefer marula fruit," says Marcus Stensmyr.
"They are drawn to particular aromatic substances from marula that activate receptors on the antennae. When these are activated, it's a sign that it's a good place to lay eggs."
However, marula have not only been liked by fruit flies through the millennia. Archaeological finds have shown that the San people, one of the indigenous tribes in the investigated area, have had a special relationship with marula fruit throughout history. In one cave, archaeologists found more than 24 million walnut-sized marula pips.
The researchers' conclusion is that the San people's love of marula fruit explains why the fruit flies moved in with people long ago. Over time the flies adjusted to living inside and became increasingly tolerant to ethanol in rotten fruit.
"The fly has developed into a generalist that eats and breeds in all sorts of fruit. But originally it was a real specialist that only lived where there was marula fruit," concludes Marcus Stensmyr.
abstract •Wild African D. melanogaster are seasonally associated with marula fruit
•Marula is the likely ancestral host of D. melanogaster
•Marula odor activates a key odorant receptor that shows signs of regional adaptation
•Marula use may have driven the switch to human commensalism
Although the vinegar fly Drosophila melanogaster is arguably the most studied organism on the planet, fundamental aspects of this species’ natural ecology have remained enigmatic 1. We have here investigated a wild population of D. melanogaster from a mopane forest in Zimbabwe. We find that these flies are closely associated with marula fruit (Sclerocarya birrea) and propose that this seasonally abundant and predominantly Southern African fruit is a key ancestral host of D. melanogaster. Moreover, when fruiting, marula is nearly exclusively used by D. melanogaster, suggesting that these forest-dwelling D. melanogaster are seasonal specialists, in a similar manner to, e.g., Drosophila erecta on screw pine cones 2. We further demonstrate that the main chemicals released by marula activate odorant receptors that mediate species-specific host choice (Or22a) [3, 4] and oviposition site selection (Or19a) 5. The Or22a-expressing neurons—ab3A—respond strongly to the marula ester ethyl isovalerate, a volatile rarely encountered in high amounts in other fruit. We also show that Or22a differs among African populations sampled from a wide range of habitats, in line with a function associated with host fruit usage. Flies from Southern Africa, most of which carry a distinct allele at the Or22a/Or22b locus, have ab3A neurons that are more sensitive to ethyl isovalerate than, e.g., European flies. Finally, we discuss the possibility that marula, which is also a culturally and nutritionally important resource to humans, may have helped the transition to commensalism in D. melanogaster.
treatable condition could be mistaken for schizophrenia or bipolar disorder
https://www.sciencedaily.com/releases/2017/12/171213130504.htm
anti-nmda receptor encephalitis in the polar bear (ursus maritimus) knut
h. prüss et al. 2015
http://dx.doi.org/10.1038/srep12805
fish reproductive-energy output increases disproportionately with body size
diego barneche et al. 2018
http://dx.doi.org/10.1126/science.aao6868
‘who’s a good boy?!’ dogs prefer naturalistic dog-directed speech
alex benjamin, katie slocombe 2018
http://dx.doi.org/10.1007/s10071-018-1172-4
hippos (hippopotamus amphibius): the animal silicon pump
schoelynck, j., subalusky et al. 2019
http://dx.doi.org/10.1126/sciadv.aav0395
Wild hippos have a unique lifestyle: at night they eat dozens of kilograms of fresh grass in the savannahs. Most of their days they spend relaxing together in rivers or lakes, far away from enemies and protected from the burning sun. While chilling in the water, however, their digestion becomes active. Thus, enormous quantities of hippo poo enter the water.
"Hippos differ from other large grazing animals in the savannah," explains biologist Jonas Schoelynck from the University of Antwerp, the first author of the study. "The nutrients in the excrements of most grazers largely end up back in the savannah again, where they are reabsorbed by the plants. This is not the case with hippos: they act as a kind of nutrient pump from the land to rivers and lakes." In the study now published, researchers around Schoelynck and Frings show that this pumping function can be crucial for life in water. The results come from an expedition to the nearly four hundred kilometre long Mara River in the Masaai Mara Nature Reserve in Kenya.
Hippo excrements examined in the lab
"The grass that hippos eat contains silicon," explains Jonas Schoelynck. "The grass absorbs this silicon from the groundwater. It gives it the strength it needs, protects it from disease and, to a limited extent, from grazing by small animals." Patrick Frings from the Geochemistry of the Earth's Surface Section of the GFZ analysed the isotopic composition of silicon in samples of plants, water and hippo excrements in the laboratory. This type of analysis provides a kind of chemical fingerprint of a sample substance. "The isotope analysis enabled us to reconstruct the transport path of the silicon," explains Frings.
The researchers showed that a large part of the silicon in the Mara River was transported there via hippos. In the investigated area in southwest Kenya, the grazing animals absorbed a total of 800 kilograms of silicon per day through the plants they ate. 400 kilograms per day ended up in the water via excretion of hippo faeces. Through various ecological mechanisms, the hippos' silicon contribution influences over 76 percent of the total silicon transported along the Mara River, according to calculations by the researchers. Hippos are therefore a key factor in the biogeochemical silicon cycle of certain areas.
"Our results are completely new," says Patrick Frings of the GFZ. "So far, it has not been assumed that grazing wild animals could have such an influence on the transport of silicon from land to lakes. This process is crucial for the entire land-water ecosystem. In the past, however, it has simply been overlooked."
A world without hippos
According to the researchers, silicon is vital for certain organisms such as diatoms. These unicellular algae live in the water, produce oxygen and form the basis of the food chain in many water ecosystems. If a lack of silicon occurs, the diatomaceous algae population can collapse, with harmful consequences for the entire food web in the lake or river concerned, the researchers say.
The number of hippos in Africa has been drastically reduced in recent years due to hunting and loss of habitats and their function as animal silicon pumps has thus been partially lost, say the researchers. In recent decades, up to ninety percent of hippos in Africa have become extinct. "Lake Victoria, into which the Mara River flows, can survive for several decades with its current silicon supply," says Jonas Schoelynck. "But in the long run there is probably going to be a problem. If the diatoms do not get enough silicon, they are replaced by pest algae, which have all sorts of unpleasant consequences, such as a lack of oxygen and the associated death of fish. And fishing is an important source of food for the people of Lake Victoria.
abstract While the importance of grasslands in terrestrial silicon (Si) cycling and fluxes to rivers is established, the influence of large grazers has not been considered. Here, we show that hippopotamuses are key actors in the savannah biogeochemical Si cycle. Through a detailed analysis of Si concentrations and stable isotope compositions in multiple ecosystem compartments of a savannah-river continuum, we constrain the processes influencing the Si flux. Hippos transport 0.4 metric tons of Si day−1 by foraging grass on land and directly egesting in the water. As such, they bypass complex retention processes in secondary soil Si pools. By balancing internal processes of dissolution and precipitation in the river sediment, we calculate that hippos affect up to 76% of the total Si flux. This can have a large impact on downstream lake ecosystems, where Si availability directly affects primary production in the diatom-dominated phytoplankton communities.
parabens and their metabolites in pet food and urine from new york state, united states
rajendiran karthikraj et al. 2018
http://dx.doi.org/10.1021/acs.est.7b05981
the olfactory basis of orchid pollination by mosquitoes
chloé lahondère et al. 2020
http://dx.doi.org/10.1073/pnas.1910589117
And without that sense of smell, mosquitoes could not locate their dominant source of food: nectar from flowers.
“Nectar is an important source of food for all mosquitoes,” said Jeffrey Riffell, a professor of biology at the University of Washington. “For male mosquitoes, nectar is their only food source, and female mosquitoes feed on nectar for all but a few days of their lives.”
Yet scientists know little about the scents that draw mosquitoes toward certain flowers, or repel them from others. This information could help develop less toxic and better repellents, more effective traps and understand how the mosquito brain responds to sensory information — including the cues that, on occasion, lead a female mosquito to bite one of us.
Riffell’s team, which includes researchers at the UW, Virginia Tech and UC San Diego, has discovered the chemical cues that lead mosquitoes to pollinate a particularly irresistible species of orchid. As they report in a paper published online Dec. 23 in the Proceedings of the National Academy of Sciences, the orchid produces a finely balanced bouquet of chemical compounds that stimulate mosquitoes’ sense of smell. On their own, some of these chemicals have either attractive or repressive effects on the mosquito brain. When combined in the same ratio as they’re found in the orchid, they draw in mosquitoes as effectively as a real flower. Riffell’s team also showed that one of the scent chemicals that repels mosquitoes lights up the same region of the mosquito brain as DEET, a common and controversial mosquito repellent.
Their findings show how environmental cues from flowers can stimulate the mosquito brain as much as a warm-blooded host — and can draw the mosquito toward a target or send it flying the other direction, said Riffell, who is the senior author of the study.
The blunt-leaf orchid, or Platanthera obtusata, grows in cool, high-latitude climates across the Northern Hemisphere. From field stations in the Okanogan-Wenatchee National Forest in Washington state, Riffell’s team verified past research showing that local mosquitoes pollinate this species, but not its close relatives that grow in the same habitat. When researchers covered the flowers with bags — depriving the mosquitoes of a visual cue for the flower — the mosquitoes would still land on the bagged flowers and attempt to feed through the canvas. Orchid scent obviously attracted the mosquitoes. To find out why, Riffell’s team turned to the individual chemicals that make up the blunt-leaf orchid’s scent.
“We often describe ‘scent’ as if it’s one thing — like the scent of a flower, or the scent of a person,” said Riffell. “Scent is actually a complex combination of chemicals — the scent of a rose consists of more than 300 — and mosquitoes can detect the individual types of chemicals that make up a scent.”
Riffell describes the blunt-leaf orchid’s scent as a grassy or musky odor, while its close relatives have a sweeter fragrance. The team used gas chromatography and mass spectroscopy to identify dozens of chemicals in the scents of the Platanthera species. Compared to its relatives, the blunt-leaf orchid’s scent contained high amounts of a compound called nonanal, and smaller amounts of another chemical, lilac aldehyde.
Riffell’s team also recorded the electrical activity in mosquito antennae, which detect scents. Both nonanal and lilac aldehyde stimulated antennae of mosquitoes that are native to the blunt-leaf orchid’s habitat. But these compounds also stimulated the antennae of mosquitoes from other regions, including Anopheles stephensi, which spreads malaria, and Aedes aegypti, which spreads dengue, yellow fever, Zika and other diseases.
Experiments of mosquito behavior showed that both native and non-native mosquitoes preferred a solution of nonanal and lilac aldehyde mixed in the same ratio as found in blunt-leaf flowers. If the researchers omitted lilac aldehyde from the recipe, mosquitoes lost interest. If they added more lilac aldehyde — at levels found in the blunt-leaf orchid’s close relatives — mosquitoes were indifferent or repelled by the scent.
Using techniques developed in Riffell’s lab, they also peered directly into the brains of Aedes increpitus mosquitoes, which overlap with blunt-leaf orchids, and a genetically modified strain of Aedes aegypti previously developed by Riffell and co-author Omar Akbari, an associate professor at UC San Diego. They imaged calcium ions — signatures of actively firing neurons — in the antenna lobe, the region of the mosquito brain that processes signals from the antennae.
These brain imaging experiments revealed that nonanal and lilac aldehyde stimulate different parts of the antenna lobe — and even compete with one another when stimulated: The region that responds to nonanal can suppress activity in the region that responds to lilac aldehyde, and vice versa. Whether this “cross talk” makes a flower attractive or repelling to the mosquito likely depends on the amounts of nonanal and lilac aldehyde in the original scent. Blunt-leaf orchids have a ratio that attracts mosquitoes, while closely related species do not, according to Riffell.
“Mosquitoes are processing the ratio of chemicals, not just the presence or absence of them,” said Riffell. “This isn’t just important for flower discrimination — it’s also important for how mosquitoes discern between you and I. Human scent is very complex, and what is probably important for attracting or repelling mosquitoes is the ratio of particular chemicals. We know that some people get bit more than others, and maybe a difference in ratio explains why.”
The team also discovered that lilac aldehyde stimulates the same region of the antenna lobe as DEET. That region may process “repressive” scents, though further research would need to verify this, said Riffell. It’s too soon to tell if lilac aldehyde may someday be an effective mosquito repellant. But if it is, there is an added bonus.
“It smells wonderful,” said Riffell.
abstract Mosquitoes are important vectors of disease and require sources of carbohydrates for reproduction and survival. Unlike host-related behaviors of mosquitoes, comparatively less is understood about the mechanisms involved in nectar-feeding decisions, or how this sensory information is processed in the mosquito brain. Here we show that Aedes spp. mosquitoes, including Aedes aegypti, are effective pollinators of the Platanthera obtusata orchid, and demonstrate this mutualism is mediated by the orchid’s scent and the balance of excitation and inhibition in the mosquito’s antennal lobe (AL). The P. obtusata orchid emits an attractive, nonanal-rich scent, whereas related Platanthera species—not visited by mosquitoes—emit scents dominated by lilac aldehyde. Calcium imaging experiments in the mosquito AL revealed that nonanal and lilac aldehyde each respectively activate the LC2 and AM2 glomerulus, and remarkably, the AM2 glomerulus is also sensitive to N,N-diethyl-meta-toluamide (DEET), a mosquito repellent. Lateral inhibition between these 2 glomeruli reflects the level of attraction to the orchid scents. Whereas the enriched nonanal scent of P. obtusata activates the LC2 and suppresses AM2, the high level of lilac aldehyde in the other orchid scents inverts this pattern of glomerular activity, and behavioral attraction is lost. These results demonstrate the ecological importance of mosquitoes beyond operating as disease vectors and open the door toward understanding the neural basis of mosquito nectar-seeking behaviors.
a longitudinal study of phenotypic changes in early domestication of house mice
madeleine geiger et al. 2018
http://dx.doi.org/10.1098/rsos.172099
electric fields elicit ballooning in spiders
erica l. morley, daniel robert 2018
https://doi.org/10.1016/j.cub.2018.05.057
feather mites play a role in cleaning host feathers: new insights from dna metabarcoding and microscopy
jorge doña et al. 2019
http://dx.doi.org/10.1111/mec.14581
vane-dwelling feather mites do not eat feathers. Rather, they feed mainly on fungi and bacteria that get caught in or grow on the feathers."
There are more than 2,500 species of feather mites that live inside the hollow quills of feathers, in the fluffy down, and on the vanes of wing and tail feathers. Until this study, vane-dwelling mites have often been assumed to be parasitic, like feather lice, which are harmful to birds.
Alongside undergraduate student Arnika Oddy-van Oploo, Proctor conducted a rigorous investigation of what vane-dwelling feather mites eat. The pair examined the gut contents of 1,300 individual mites representing 100 different species, collected from 190 bird species. Co-authors augmented these data with genetic analyses of the diets of a smaller number of feather mites.
"Their diets indicate that they are either harmless commensals or possibly even beneficial mutualists that clean their hosts' feathers of pathogenic microbes," explained Proctor. "This may explain why birds have often been observed to be heavily laden with feather mites and have plumage that's in excellent condition."
The discovery may have implications for those who work with wild birds. "This information could also influence those who take care of wild birds in captivity, such as rehabilitation or in zoos, where birds are typically treated with chemicals to remove lice, which can also remove the potentially helpful feather mites," said Proctor.
abstract Parasites and other symbionts are crucial components of ecosystems, regulating host populations and supporting food webs. However, most symbiont systems, especially those involving commensals and mutualists, are relatively poorly understood. In this study, we have investigated the nature of the symbiotic relationship between birds and their most abundant and diverse ectosymbionts: the vane‐dwelling feather mites. For this purpose, we studied the diet of feather mites using two complementary methods. First, we used light microscopy to examine the gut contents of 1,300 individual feather mites representing 100 mite genera (18 families) from 190 bird species belonging to 72 families and 19 orders. Second, we used high‐throughput sequencing (HTS) and DNA metabarcoding to determine gut contents from 1,833 individual mites of 18 species inhabiting 18 bird species. Results showed fungi and potentially bacteria as the main food resources for feather mites (apart from potential bird uropygial gland oil). Diatoms and plant matter appeared as rare food resources for feather mites. Importantly, we did not find any evidence of feather mites feeding upon bird resources (e.g., blood, skin) other than potentially uropygial gland oil. In addition, we found a high prevalence of both keratinophilic and pathogenic fungal taxa in the feather mite species examined. Altogether, our results shed light on the long‐standing question of the nature of the relationship between birds and their vane‐dwelling feather mites, supporting previous evidence for a commensalistic–mutualistic role of feather mites, which are revealed as likely fungivore–microbivore–detritivore symbionts of bird feathers.
oust the louse: leaping behaviour removes sea lice from wild juvenile sockeye salmon oncorhynchus nerka
e.m. atkinson et al. 2018
http://dx.doi.org/10.1111/jfb.13684
sudden collapse of a mesopredator reveals its complementary role in mediating rocky reef regime shifts
jenn m. burt et al. 2018
http://dx.doi.org/10.1098/rspb.2018.0553
active host response to algal symbionts in the sea slug elysia chlorotica
cheong xin chan et al. 2018
http://dx.doi.org/10.1093/molbev/msy061
using its own blood to digest food
hemocyanin facilitates lignocellulose digestion by wood-boring marine crustaceans
katrin besser et al. 2018
http://dx.doi.org/10.1038/s41467-018-07575-2
Gribble are small marine invertebrates that have evolved to perform an important ecological role eating the abundant supplies of wood washed into the sea from river estuaries.
They can also be something of a marine menace, consuming the wood of boats and piers and causing considerable damage in the process.
Until now, the question of how gribble break through lignin -- the highly resistant coating that wraps around the sugar polymers that compose wood -- has been a mystery.
The team of scientists, led by the University of York, studied the hind gut of gribble, and discovered that Hemocyanins -- the same proteins that make the blood of invertebrates blue -- are crucial to their ability to extract sugars from wood.
The discovery brings researchers a step closer to identifying cheaper and more sustainable tools for converting wood into low carbon fuel -- a promising alternative to fossil fuels like coal and oil.
Hemocyanins are a group of proteins better known for their role in transporting oxygen in invertebrates in a similar way to haemoglobin in animals. While haemoglobin binds oxygen through its association with iron atoms, giving blood its red colour; hemocyanins do this with copper atoms producing a blue colour.
Oxygen is a highly reactive chemical, and gribble have harnessed the oxidative capabilities of hemocyanins to attack the lignin bonds that hold the wood together.
The research, which involved teams from the Universities of York, Portsmouth, Cambridge and Sao Paulo, has revealed that treating wood with hemocyanins enables more than double the amount of sugar to be released -- the same amount that can be released with expensive and energy consuming thermochemical pre-treatments currently used in industry.
Professor Simon McQueen-Mason, from the Department of Biology at the University of York, who led the research team, said: "Gribble are the only animal known to have a sterile digestive system. This makes their method for wood digestion easier to study than that of other wood-consuming creatures such as termites, which rely on thousands of gut microbes to do the digestion for them."
"We have found that Gribble chew wood into very small pieces before using hemocyanins to disrupt the structure of lignin. GH7 enzymes, the same group of enzymes used by fungi to decompose wood, are then able to break through and release sugars."
With pressure mounting for global action to be taken on climate change, many countries are rapidly trying to de-carbonise by switching to renewable energy sources such as biofuels.
Woody plant biomass is the most abundant renewable carbon resource on the planet, and, unlike using food crops to make biofuels, its use doesn't come into conflict with global food security.
Co-author of the paper, Professor Neil Bruce, from the Department of Biology, said: "In the long term this discovery may be useful in reducing the amount of energy required for pre-treating wood to convert it to biofuel.
"The cellulase-enhancing effect of the haemocyanin was equivalent to that of thermochemical pre-treatments used in industry to allow biomass hydrolysis, suggesting new options for bio-based fuel and chemicals production."
Lead author of the report, Dr Katrin Besser, added "it is fascinating to see how nature adapts to challenges and this discovery adds to evidence that haemocyanins are incredibly versatile and multi-functional proteins."
internet cat flap
non-internet non—microchip pet bowl
sureflap non-internet microchip feeder
sureflap non-internet cat door
the rise and fall of the dinosaurs: a new history of a lost world
steve brusatte 2018 to read next
animals race and multiculturalism
luis cordeiro-rodrigues 2017
blowfish’s oceanopedia: 291 extraordinary things you didn’t know about the sea
tom hird 2017
spineless; the science of jellyfish and the art of growing a backbone
juli berwald 2018
book of animal ignorance: everything you think you know is wrong
john mitchinson 2008
wicked bugs: the louse that conquered napoleon’s army and other diabolical insects
amy stewart 2011
the beachcomber’s companion
anna marlis burgard & jillian ditner 2018
the humane economy; how innovators and enlightened consumers are transforming the lives of animals
wayne pacelle 2016
the everything guide to anatomy and physiology
kevin langford 2015
the truth about animals: stoned sloths, lovelorn hippos, and other tales from the wild side of wildlife
lucy cooke 2018
the ascent of birds: how modern science is revealing their story
john reilly 2018
humankind: solidarity with nonhuman people
timothy morton 2017
wild lives: leading conservationists on the animals and the planet they love
lori robinson 2017
spirals in time: the secret life and curious afterlife of seashells
helen scales 2015
eye of the shoal: a fishwatcher’s guide to life, the ocean and everything
helen scales 2018
natural nutrition for cats
kymythy schultze 2008
other minds: the octopus, the sea, and the deep origins of consciousness
peter godfrey-smith 2016
human: the science behind what makes us unique
michael gazzaniga 2008
behave: the biology of humans at our best and worst
robert m. sapolsky 2017
being salmon, being human: encountering the wild in us and us in the wild
martin lee mueller 2017
the inner life of animals : love, grief, and compassion : surprising observations of a hidden world
peter wohlleben 2017
the secret life of whales
micheline jenner 2017
you are here: why we can find our way to the moon, but get lost in the mall
colin ellard 2009
spirals in time: the secret life and curious afterlife of seashells
helen scales 2015
the secret lives of backyard bugs: discover amazing butterflies, moths, spiders, dragonflies, and other insects!
judy burris, wayne richards 2011
never home alone: from microbes to millipedes, camel crickets, and honeybees, the natural history of where we live
rob dunn 2018
the secret language of cats: how to understand your cat for a better, happier relationship
susanne schotz 2018
what cats want: an illustrated guide to truly understanding your cat
yuki hattori 2020 unread
dragon pearl
yoon ha lee 2019
varjak paw
sf said 2003
kent
narrow flat faced brush made from beech wood and filled with pure white bristle
kentbrushes.com/lg3
johnlewis.com/kent-narrow-grooming-hairbrush/p84414
brush cleaner
kentbrushes.com/lpc2
tease apart knots using fingertips, brush out fur that has been shed. keep brushing sessions shortish to avoid tactile overstimulation
may need to cut off knots that are too set (e.g. dried mud or poo)
approximates effect of (mother’s relatively) large cat tongue
we use a “set” grooming station, if catty moves to the “station” on top of the chair nearest the brush kept on the mantlepiece, then we begin brushing. this is similar to a cleaning–wrasse’s cleaning station