#White-tailed deer and the science of yellow snownew research from wildlife ecologists at Michigan Technological University indicates that white-tailed deer may be making the soil in their preferred winter homes unfit to grow the very trees that protect them there.
Bryan Murray a Phd candidate at Michigan Tech and two faculty members Professor Christopher Webster and Assistant professor Joseph Bump studied the effects on soil of the nitrogen-rich waste that white-tailed deer
They compared eastern hemlock stands where deer congregated to stands where deer were fenced out and found a strong relationship between the amount of soil nitrogen from the deer's waste products
During cold northern winters deer seek out stands of evergreens with dense crowns such as eastern hemlock northern white cedar and balsam fir.
and blustery winds and to help deer hide from predators Murray explained. Deer instinctively seek deeryards
but their choice of location is passed knowledge from mother to fawn. Thus deeryards that are traditional favorites can harbor 100 deer
or more per square mile creating hotspots of high-nitrogen-content waste. Long ago before logging enabled the white-tailed deer to move further and further north
and before the deer population explosion more recently experienced the ecosystem stayed balanced because there were plenty of deeryards and fewer deer.
Now more deer are crowding into less winter cover shifting the dynamic balance of nature.
The Michigan Tech research demonstrates that the relationship of deer to their habitat is more complex than just the plants they eat Webster said.
Our hope is that by better understanding the links between habitat use and spatial patterning of resources
and plants in survivng hemlock stands we can identify sustainable management strategies for this critical resource.
It was fascinating to discover such complex interactions which have implications for sustainable management in a seemingly simple ecosystem Murray added Story Source:
and water we turned to large-scale industrial animal production systems and put high environmental pressure on land soils and biodiversity Krausmann points out.
#A grassy trend in human ancestors dietsmost apes eat leaves and fruits from trees and shrubs.
of grains grasses and meat and dairy from grazing animals. In four new studies of carbon isotopes in fossilized tooth enamel from scores of human ancestors and baboons in Africa from 4 million to 10000 years ago a team of two dozen researchers found a surprise
increase in the consumption of grasses and sedges--plants that resemble grasses and rushes but have stems and triangular cross sections.
For a long time primates stuck by the old restaurants--leaves and fruits--and by 3. 5 million years ago they started exploring new diet possibilities--tropical grasses
and sedges--that grazing animals discovered a long time before about 10 million years ago when African savanna began expanding Cerling says.
We see an increasing reliance on this new resource by human ancestors that most primates still don't use today.
when human ancestors began getting much of their grass by eating grass-eating insects or meat from grazing animals.
if they were pure herbivores or carnivores if they were eating fish which leave a tooth signal that looks like grass-eating
if they were eating insects or if they were eating mixes of all of these. Why Our Ancestor's Diets Matterthe earliest human ancestor to consume substantial amounts of grassy foods from dry more open savannas may signal a major and ecological and adaptive divergence from the last common ancestor we shared with African great apes
which occupy closed wooded habitats writes University of South Florida geologist Jonathan Wynn chief author of one of the new studies and a former University of Utah master's student.
Diet has long been implicated as a driving force in human evolution says Matt Sponheimer a University of Colorado Boulder anthropologist former University of Utah postdoctoral fellow
Human brains were larger than those of other primates by the time our Genus homo evolved 2 million years ago.
Hominins are humans their ancestors and extinct relatives that split from the other apes roughly 6 million years ago.
Cerling also wrote a study about baboon diets. Sponheimer wrote a fourth study summarizing the other three.
Animals eating C4 and CAM plants have enriched amounts of carbon-13. C3 plants include trees bushes and shrubs and their leaves and fruits;
and meat animals fed on C4 grasses and grains Cerling says. The highest human C3 diets today are found in Northern europe where only C3 cool-season grasses grow so meat animals there graze them not C4 tropical grasses.
The highest C4 diets likely are in Central america because of the heavily corn-based diet. If early humans ate grass-eating insects
or large grazing animals like zebras wildebeest and buffalo it also would appear they ate C4 grasses.
If they ate fish that ate algae it would give a false appearance of grass-eating because of the way algae takes up carbonate from water Cerling says.
and rhinos that browsed on C3 leaves it would appear they ate C3 trees-shrubs.
Small mammals such as hyrax rabbits and rodents would have added C3 and C4 signals to the teeth of human ancestors.
The Only Surviving Primates with a C4 Grass Dietcerling's second new study shows that
while human ancestors ate more grasses and other apes stuck with trees and shrubs two extinct Kenyan baboons represent the only primate genus that ate primarily grasses and perhaps sedges throughout its history.
when the baboons lived between 4 million and 2. 5 million years ago contradicting previous claims that they ate forest foods.
Both species went extinct perhaps due to competition from hooved grazing animals. Modern Theropithecus gelada baboons live in Ethiopia's highlands where they eat only C3 cool-season grasses.
Cerling notes that primate tropical grass-eaters--Theropithecus baboons and Paranthropus human relatives--went extinct
while human ancestors ate an increasingly grass-based diet. Why is an open question. Story Source:
#Threatened frogs palmed off as forests disappearoil palm plantations in Malaysia are causing threatened forest frogs to disappear paving the way for common species to move in on their turf scientists have revealed.
The study carried out by the Zoological Society of London (ZSL) describes how forests converted to palm oil plantations are causing threatened forest dwelling frogs to vanish resulting in an overall loss of habitat that is important for the conservation of threatened frog
Scientists travelled to Peninsular Malaysia where they spent two years studying communities of frog species in four oil palm plantations and two areas of adjacent forest.
The impact we observed is different from that observed previously for mammals and birds. Instead of reducing the number of species oil palm affects amphibian communities by replacing habitat suitable for threatened species with habitat used by amphibian species that are not important for conservation.
Amphibians are threatened the most vertebrates in the world with over 40%at risk of extinction.
The peat swamp frog (Limnonectes malesianus) is just one of the declining species threatened due to deforestation.
and if palm oil plantations continue to take over the peat swamp frog along with its forest home could be a thing of the past.
Existing practices in managing oil palm are not accommodating the highly threatened forest frog species in Malaysia
#Female moths use olfactory signals to choose the best egg-laying sitesfunctional calcium imaging in the antennal lobes of a female Manduca sexta moth:
whether the moths respond to (Z)- 3-hexenyl acetate or (E)- 2-hexenyl acetate. The odor of A z)- 3-isomer or A z)- 3/(E)- 2 ratio in favor of A z)- 3-isomer according to the odor bouquet of an unattacked plant guides ovipositing Manduca
females to plants that have yet been spared by herbivorous caterpillars. Copyright: Anna Spã¤the MPI Chem.
Ecol. Researchers at the Max Planck Institute for Chemical Ecology Jena Germany discovered that the ability of Manduca sexta moths to recognize changes in the profile of volatile compounds released by plants being attacked by Manduca caterpillars allows them to lay their eggs on plants that are less likely
to be attacked by insects and other predators and to avoid competing against other caterpillars of the same species for resources.
The results of field experiments and neurobiological studies were published now in the open access online journal elife.
elife May 14 2013 DOI: 10.7554/elife. 00421) Green leaf odorsplants have developed many different strategies to defend themselves against herbivorous animals particularly insects.
In addition to mechanical defenses such as thorns and spines plants also produce compounds that keep insects and other herbivores at bay by acting as repellents or toxins.
Some of these metabolites are produced on a continuous basis by plants whereas others--notably compounds called green-leaf volatiles--are produced mainly once the plant has been wounded
or repelling herbivores and indirect protection by attracting predators of the herbivores themselves. Attracting the enemies of the herbivoresthe hawkmoth Manduca sexta lays its eggs on various plants including tobacco and Sacred Datura plants (Datura wrightii.
Once the eggs have hatched into caterpillars they start eating the leaves of their host plant
and if present in large numbers these caterpillars can quickly defoliate and destroy the plant.
In an effort to defend itself the host plant releases green-leaf volatiles to attract various species of Geocoris predatory bugs that eat insect eggs and tiny larvae.
One of these green-leaf volatiles released by tobacco plants is known as (Z)- 3-hexenyl acetate
but enzymes released by M. sexta caterpillars'spit change some of these molecules into (E)- 2-hexenyl acetate
which has the same chemical composition but a different structure. The resulting changes in the volatile profile alerts Geocoris bugs to the presence of M. sexta caterpillars on the plant their potential prey.
Ideal conditions for Manduca offspringnow the scientists from the Max Planck Institute for Chemical Ecology show another interesting effect of the chemical odor conversion:
Just like Geocoris bugs adult female M. sexta moths are able to detect the changes in the green volatile profile emitted by Sacred Datura plants that have been damaged by M. sexta caterpillars.
This alerts the moths to the fact that Geocoris bugs are likely to predate eggs
and caterpillars on the plant and as a consequence the moths lay their eggs on unattacked plants.
Hereby they minimize the risk of newly laid eggs being eaten by the predators. Another positive effect is that the competition for resources with larvae that already feed on a plant is reduced.
Interdisciplinary Research: Ecology and Neurobiology The researchers also identified the neural mechanism that allows moths to detect the slightest changes in the volatile profile of plants that have already been attacked by caterpillars.
Neurobiological studies of the moth brain revealed that E-and Z-odors lead to different activation patterns.
The two isomers of hexenyl acetate activated different regions in the antennal lobe of the moth (see images above.
This suggests that the female moths have isomer-specific receptors and neurons on their antennae says Bill Hansson director of the institute.
The combination of such neurological experiments and ecological field studies are very promising and may provide further insights into odor-guided behavior of insects in nature and agriculture.
New plant protection strategiesa similar behavioral pattern is known from potato beetles (Leptinotarsa decemlineata. An artificial application of (Z)- 3-or (E)- 2-hexenol (E)- 2-hexanal or 1-hexanol to potato plants lead to a disoriented behavior observed in egg-laying potato beetles.
On the basis of these results plant protection strategies seem possible which utilize artificial odor application
in order to deter ovipositing insects from field crops and thereby reduce insect infestation. Mclennan/AO/JWK Story Source:
The above story is provided based on materials by Max Planck Institute for Chemical Ecology. Note: Materials may be edited for content and length.
Journal Reference a
#Songbirds may give insight to nature vs. nurtureon June 3rd Jove will publish a research technique that allows neural imaging of auditory stimuli in songbirds via MRI.
The technique developed by Dr. Annemie Van der Linden and her laboratory at the University of Antwerp in Belgium will be one of the first published in Jove Behavior a new section of the video journal that focuses on observational and experimental techniques that seek to understand human and animal
Species of animals that are more vocal in their expression like macaques parrots or the zebra finch used in the Jove article are unique as they provide a landscape for scientists to study song acquisition storage and regurgitation.
Results from these test subjects provide strong parallels and insights to human language acquisition. The birds are also much easier to maintain
and study in laboratories than other vocal animals like apes. By utilizing a high-resolution functional magnetic resonance imaging apparatus (fmri) Dr. Van der Linden
and her colleagues can image the brains of live birds in a noninvasive environment. MRI is used widely with human beings
which makes any findings derived from songbirds highly applicable to working with the human brain. Until recently fmri in small animals was focused mainly on rats
and to a lesser extent on mice Dr. Van der Linden explains. Thus far songbird brains have been studied using electrophysiological and histological techniques.
However these approaches do not provide a global view of the brain and do not allow repeated long-term developmental measurements.
Using the songbird model and MRI as an in vivo tool allows us to answer many questions related to learning language and neuroendocrinological plasticity.
The Van der Linden laboratory hopes to use this technique to conduct experiments that be done with humans.
For example they are able to see how language acquisition may be different between animals raised in isolation
and animals raised socially or between genetically modified songbirds and naturally occurring ones. Results of these trials will allow researchers to gain insight into genetic and social components of behavior bringing insight to the Nature vs.
Nurture debate. This article is a milestone for Jove as it is one of the first articles in the new Jove Behavior journal section.
The expansion will mark Jove's eighth journal section after the recent additions of Jove Chemistry and Applied Physics.
and reproduce behavioral experiments such as bird fmri techniques as described in Dr. Van der Linden's article which are both novel and technically complex.
and provide greater insight into both animal and human cognition. Proud to be included in this significant new section Dr. Van der Linden says MRI imaging techniques should in the near future lead to major conceptual advances in the study of how the brain changes behavior
Understanding how ecosystems respond to climate variability is a priority in a fast changing globe says Marten Scheffer who leads the research program on tipping points.
and if these young seedlings grow fast enough to escape from herbivores then woodlands can expand. With our analysis of satellite data we could now assess how general this response is.
In its perfect crystalline form graphene (a one-atom-thick carbon layer) is the strongest material ever measured as the Columbia Engineering team reported in Science in 2008--so strong that as Hone observed it would take an elephant balanced on a pencil to break through a sheet
#The scoop on bird poop: Evolving diversity of microbial life in bird gutsgut bacteria are known to have a central role both in human and in animal health.
Animals acquire different bacteria as they age but how the microbial communities in the bodies of wild animals change over time is understood not well.
Wouter Van dongen and colleagues at the Vetmeduni Vienna have examined the gastrointestinal bacteria of chick and adult black-legged kittiwakes.
Surprisingly the microbial assemblages of chicks and adults generally differ greatly with only a few types of bacteria in common.
The findings have recently been published in the journal BMC Ecology. Gastrointestinal bacteria are important for digestion immune functions and general health.
& Diversit Biologique (EDB) Toulouse and from the US Geological Survey Anchorage to study the cloacal bacterial assemblies of black-legged kittiwakes (Rissa tridactyla).
The bacteria in the cloaca are known to be similar to assemblages deeper within the gastrointestinal tract so the researchers examined samples from the cloaca of birds at different ages to look indirectly at gut bacteria.
Flushing bacteriato obtain bacterial samples the researchers flushed the birds'cloacae by gently infusing a salt solution into the cloacae and collecting the liquid.
The bacterial diversity in the cloaca of each bird could be estimated with the aid of molecular genetic techniques.
and thus to draw a clear picture of how bacterial communities in bird guts change as the birds age.
From a youthful hodgepodge to a stable communitythere turned out to be a great variety of bacterial species in the guts of kittiwake chicks
Given that chicks share the nest with their parents and eat food that is regurgitated by the parents we expected the level of bacterial sharing to be a lot higher.
The scientists'findings suggest that young birds are susceptible to many species of bacteria that pass through their gut.
As the animals mature the number of bacterial species decreases. Particular groups of bacteria that stay ultimately form a stable community.
The differences may correlate with changes in the birds'gut chemistry over time or with changes in diet
Further studies are needed to determine the causes and consequences of the variation in the bacterial assemblages in guts of wild birds.
and stages of milk production from the fertilizer used to grow the animal's feed to waste disposal of packaging after consumer use.
The greenhouse gases were measured as carbon dioxide equivalents and included methane refrigerants and other gases that trap radiation.
The largest contributors were feed production enteric methane--gas emitted by the animal itself --and manure management.
#Human activity echoes through Brazilian rainforestthe disappearance of large fruit-eating birds from tropical forests in Brazil has caused the region's forest palms to produce smaller less successful seeds over the past century researchers say.
and evolutionary models to determine that the absence of large seed-dispersing birds in the area was the main reason for the observed decrease in the palm's seed size.
The pervasive fast-paced extirpation of large vertebrates in their natural habitats is very likely causing unprecedented changes in the evolutionary trajectories of many tropical species. In general researchers estimate that human activity such as deforestation
and sugar cane plantations and were no longer capable of supporting large-gaped birds or those whose beaks are more than 12 millimeters wide such as toucans and large cotingas.
In undisturbed patches of forest on the other hand large-gaped birds still make their homes and palms continue to produce large seeds successfully dispersed by the birds they say.
Small seeds are more vulnerable to desiccation and cannot withstand projected climate change explained Galetti.
But small-gaped birds such as thrushes that populate the fragmented patches of forest are unable to swallow
and disperse large seeds. As a result of this impaired dispersal palm regeneration became less successful in the area with less-vigorous seedlings germinating from smaller seeds.
and displaced many large bird populations in the region triggered a rapid evolution of forest palms that resulted in smaller less successful seeds.
Long periods of drought and increasingly warmer climate (as predicted by climate model projections for South america) could be particularly harmful to tropical tree populations that depend on animals to disperse their seeds.
About 80 percent of the entire Atlantic rainforest biome remains in small fragments according to the researchers and the successful restoration of these habitats critically depends on the preservation of mutualistic interactions between animals and plants.
#More at-risk bird species in Brazilian forest than previously thoughtin a study published today in the journal PLOS ONE a team of researchers led by NJIT Associate professor Gareth Russell has applied a novel method for linking large-scale habitat
Our goal was to assess the extinction risk for bird species in the Atlantic Forest of Brazil a global'hotspot'of bird diversity said Russell.
The current study applied this metric to 127 forest-dependent passerine birds inhabiting the Atlantic Forest of Brazil an area that has lost over 90 percent of its original forest.
or even how to get around outside the hive. Before they can forage they must learn how to navigate a changing landscape
and the detection of novelty in vertebrates also kicks into high gear in the brains of honey bees
This gene is the insect equivalent of a transcription factor found in mammals. Transcription factors regulate the activity of other genes.
and neuroscience and director of the Institute for Genomic Biology at the University of Illinois. And finding that it's Egr with all that this gene is known to do in vertebrates provides another demonstration that some of the molecular mechanisms underlying behavioral plasticity
because previous research in animals had linked changes in gut flora to changes in affective behaviors.
and those fatty acids are deposited into the fat of the animal said Hans-Henrik Stein study co-author
or look pretty attract insect pollenators so they are not generally important allergens because their pollen is not airborne.
and flowering trees like the Bradford pear and Crabapple but they are not typically allergens as they rely on insects instead of the wind to carry their pollen.
Bug and weed killers, solvents may increase risk of Parkinsons diseasea large analysis of more than 100 studies from around the world shows that exposure to pesticides
or bug and weed killers and solvents is associated likely with a higher risk of developing Parkinson's disease.
For the analysis researchers reviewed 104 studies that looked at exposure to weed fungus rodent or bug killers and solvents and the risk of developing Parkinson's disease.
The research found that exposure to bug or weed killers and solvents increased the risk of developing Parkinson's disease by 33 to 80 percent.
and domesticated plants and animals constitutes a fundamental threat to the well-being and even the survival of humankind warns the founding Chair of a new global organization created to narrow the gulf between leading international biodiversity scientists and national policy-makers.
When a breed population falls to about 1000 animals it is considered rare and endangered. Causes of genetic erosion in domestic animals are the lack of appreciation of the value of indigenous breeds
and their importance in niche adaptation incentives to introduce exotic and more uniform breeds from industrialised countries and product-focused selection.
The decline in the diversity of crops and animals is occurring in tandem with the need to sharply increase world food production
#Bechsteins bat is more Mediterranean than originally thoughtalthough the Bechstein's bat is regarded as a Euro-Siberian species a study by researchers in the UPV/EHU's Department of Zoology
and Animal Cell biology has revealed that the historical transformation of part of its original habitat rather than bioclimatic reasons could be responsible for this distribution.
The Bechstein's Bat (Myotis bechsteinii) has a broad distribution: from the Iberian peninsula to the Caucasus in the East and as far as southern Scandinavia in the north.
More flexible in the Mediterraneanin the Atlantic as well as Mediterranean domain the observations were consistent with the data available on the ecology of the species. M. bechsteinii prefer roosts carved out by woodpeckers in the trunks of living oak trees located inside the forest
and degradation of the forestry systems can have on the populations of forestry specialists like the Bechstein's bat.
#Monkey teeth help reveal Neanderthal weaningmost modern human mothers wean their babies much earlier than our closest primate relatives.
and from monkeys at the California National Primate Research center at the University of California Davis. Using the new technique the researchers concluded that at least one Neanderthal baby was weaned at much the same age as most modern humans.
Just as tree rings record the environment in which a tree grew traces of barium in the layers of a primate tooth can tell the story of
what age it was weaned said Katie Hinde professor of human evolutionary biology at Harvard university and an affiliate scientist at the UC Davis Primate Center.
and behavior among rhesus macaques at UC Davis. The team was able to determine exact timing of birth
By studying monkey teeth and comparing them to center records they could show that the technique was accurate almost to the day.
The technique opens up extensive opportunities to further investigate lactation in fossils and museum collections of primate teeth.
Yet recent investigations of wild chimpanzees have shown that the first molar eruption occurs toward the end of weaning.
By applying these new techniques to primate teeth in museum collections we can more precisely assess maternal investment across individuals within species as well as life history evolution among species Hinde said.
#Research aims for insecticide that targets malaria mosquitoesin malaria-ridden parts of Africa mosquito netting protects people from being infected
now a University of Florida entomologist wants to improve the netting by coating it with insecticide toxic only to mosquitoes.
The insecticide would work by interfering with an enzyme found in the nervous systems of mosquitoes and many other organisms called acetylcholinesterase.
If the enzyme can't do its job the mosquito begins convulsing and dies. The research team's goal is to develop compounds perfectly matched to the acetylcholinesterase molecules in malaria-transmitting mosquitoes he said.
A simple analogy would be that we're trying to make a key that fits perfectly into a lock Bloomquist said.
but only in target species. Malaria is spread by mosquitoes in the Anopheles genus notably Anopheles gambiae native to Africa.
The disease is common in poor communities where homes may not have adequate screens to keep flying insects out.
Malaria is caused by microscopic organisms called protists which are present in the saliva of infected female mosquitoes and transmitted when the mosquitoes bite.
Initial symptoms of the disease can include fever chills convulsions headaches and nausea. In severe cases malaria can cause kidney failure coma and death.
Bloomquist and colleagues at Virginia Tech where the project is based are trying to perfect mosquito-specific compounds that can be manufactured on a large scale
and applied to mosquito netting and surfaces where the pests might land. It will take at least four to five years before the team has developed
and tested a compound enough that it's ready to be submitted for federal approval Bloomquist said.
Though they were less toxic to mosquitoes than commercial products the experimental compounds were far more selective indicating researchers are on the right track he said.
The compounds we're using are not very toxic to honeybees fish and mammals but we need to refine them further make them more toxic to mosquitoes
and safer for nontarget organisms he said. Funding for the project came from a five-year $3. 6 million grant from the National Institute of Allergy and Infectious diseases part of the National institutes of health.
In Florida malaria was a significant problem in the early 20th century transmitted by native Anopheles mosquitoes.
The disease has been curtailed greatly via mosquito-control practices but even today cases are reported occasionally in the Sunshine state.
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011