Zoology

Global effort 'needed to save migratory birds'

Scientists have called for a greater international collaborative effort to save the world's migratory birds, many of which are at risk of extinction due to loss of habitat along their flight paths.

More than 90 percent of the world's migratory birds are inadequately protected due to poorly coordinated conservation around the world, a new study published in the journal Science today reveals.

Led by the ARC Centre of Excellence for Environmental Decisions (CEED), the research found huge gaps in the conservation of migratory birds, particularly across China, India, and parts of Africa and South America.

This results in the majority of migratory birds having ranges that are well covered by protected areas in one country, but poorly protected in another.

"More than half of migratory bird species travelling the world's main flyways have suffered serious population declines in the past 30 years.

This is due mainly to unequal and ineffective protection across their migratory range and the places they stop to refuel along their routes," says lead author Dr Claire Runge of CEED and the University of Queensland.

"A typical migratory bird relies on many different geographic locations throughout its annual cycle for food, rest and breeding.

"So even if we protect most of their breeding grounds, it's still not enough -- threats somewhere else can affect the entire population," she says. "The chain can be broken at any link."

Dr Runge explains that these birds undertake remarkable journeys navigating across land and sea to find refuge as the seasons change, from endurance flights exceeding 10,000 kilometres by bar-tailed godwits to the annual relay of Arctic terns, which fly the equivalent of the distance to the moon and back three times during their lives.

Other examples include the sooty shearwater which flies 64,000 kilometres from the Falkland Islands to the Arctic, and the tiny blackpoll warbler, which flies for three days non-stop across open ocean from eastern Canada to South America.

The CEED study found that of 1,451 migratory bird species, 1,324 had inadequate protection for at least one part of their migration pathway. Eighteen species had no protection in their breeding areas and two species had no protection at all along their whole route.

For migratory bird species listed as threatened on the International Union for Conservation of Nature Red List by BirdLife International, less than three percent have sufficient protected areas.

"For example, the red-spectacled amazon - a migratory parrot of Brazil - is threatened by habitat loss," says Dr Stuart Butchart, Head of Science at BirdLife International and a co-author of the study.

"And yet less than four percent of its range is protected, and almost none of its seasonal breeding areas in southern Brazil are covered."

Amazona pretrei  |  Marie/Wikimedia Commons  [ CC BY-SA 2.0 ]

The team also examined over 8,200 areas that have been identified as internationally important locations for migratory bird populations.

They found that just 22 percent are completely protected, and 41 percent only partially overlap with protected areas.

"Establishing new reserves to protect the unprotected sites - and more effectively managing all protected areas for migratory species - is critical to ensure the survival of these iconic species," Dr Butchart said.

Co-author Associate Professor Richard Fuller of CEED says the results highlight an urgent need to coordinate protected area designation along the birds' full migration route.

"For instance, Germany has protected areas for over 98 percent of the migratory species that pass its borders, but fewer than 13 percent of its species are adequately protected across their global range.

"It isn't just a case of wealthy nations losing their migratory birds to a lack of protection in poorer nations. Many Central American countries, for example, meet the targets for more than 75 per cent of their migratory species, but these same species have less protected area coverage in Canada and USA."

While protected areas are usually designated by each country, collaborative international partnerships and inter-governmental coordination as well as action are crucial to safeguard the world's migratory birds.

"It won't matter what we do in Australia or in Europe if these birds are losing their habitat somewhere else - they will still perish. We need to work together far more effectively round the world if we want our migratory birds to survive into the future," Dr Fuller says.

Source University of Queensland

Citation C. A. Runge, J. E. M. Watson, S. H. M. Butchart, J. O. Hanson, H. P. Possingham, R. A. Fuller. Protected areas and global conservation of migratory birds. Science, 2015; 350 (6265): 1255 DOI: 10.1126/science.aac9180

This week in Zoology, Entomology and Science

It's been a very busy week in the world of zoology and entomology and science in general.

Here are some hand-picked snippets of stories that caught my attention in the last seven days, covering a range of topics including Chagas disease, the grasslands of Santa Cruz, sex determination in ants, flight stability in fruit flies, the etiquette of insect identification, monarch butterfly migrations, gifts for science geeks, "participation points", how ants avoid collisions, pollination is more than bees, describing new moth species, how trap-jaw ants jump, how parasitic tapeworms influence ants, replacing pesticides with plants' chemical defences, Sir David Attenborough's butterfly, co-authorships, fellowships, conserving Antarctica, building better and making the most of PhDs, and Neonicotinoids and butterfly declines.

 


New Report on Chagas Disease Causes Storm of Concern

There has been a great increase in concern, and spread of misinformation recently in response to a press release and policy paper earlier this month. The publication advocates for more research into Chagas disease, caused by a parasitic organism, Trypanosoma cruzi, carried by assassin bugs in the subfamily Triatominae. The result in social media especially has been the misidentification of nearly every indoor "bug" or assassin bug as a "kissing bug" carrying Chagas.

Trypanosoma cruzi crithidia  by Photo Credit:Content Providers(s): CDC/Dr. Myron G. Schultz - This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #613.Note: Not all PHIL images are public domain; be sure to check copyright status and credit authors and content providers.English | Slovenščina | +/−. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Trypanosoma_cruzi_crithidia.jpeg#/media/File:Trypanosoma_cruzi_crithidia.jpeg

Trypanosoma cruzi crithidia by Photo Credit:Content Providers(s): CDC/Dr. Myron G. Schultz - This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #613.Note: Not all PHIL images are public domain; be sure to check copyright status and credit authors and content providers.English | Slovenščina | +/−. Licensed under Public Domain via Commons - https://commons.wikimedia.org/wiki/File:Trypanosoma_cruzi_crithidia.jpeg#/media/File:Trypanosoma_cruzi_crithidia.jpeg

Source/read more Bug Eric



Through the Grasslands of Santa Cruz County

I love those grey-golden expanses of grass that role and wave under the low standing winter sun, and those mountain ranges with names like Mule and Mustang that cast their deep shadows. So when I had to deliver art work to my little Patagonia gallery (Creative Spirits Artists) I took my time on southbound Highway 83. I did not stop for every Hawk that perched on the power lines, but a whole heard of Pronghorns was too good. There were at least two dozens of them, grazing not too far from the road side.

Source/read more Arizona Beetles, Bugs, Birds and More



Sex Determination in Ants

Yin and Yang, Venus and Mars, the Moon and the Sun, however you want to describe it, becoming a female or a male can make a big difference in your life, and not just for human beings. Dr. Misato O. Miyakawa, a former post-doc at the Okinawa Institute of Science and Technology Graduate University (OIST) and Professor Alexander S. Mikheyev, leader of the Ecology and Evolution Unit have discovered the two ancient genetic components of sex determination in ants. This paper has just been published in PLOS Genetics

Source/read more Okinawa Institute of Science and Technology Graduate University

Citation Misato O. Miyakawa, Alexander S. Mikheyev. QTL Mapping of Sex Determination Loci Supports an Ancient Pathway in Ants and Honey Bees. PLOS Genetics, 2015; 11 (11): e1005656 DOI: 10.1371/journal.pgen.1005656



How Do Fruit Flies Maintain Flight Stability?

Have you ever wondered why insects move in the funky ways they do? Or how physical laws shape the design of animals' sensors and neural computation for locomotion?

Source/read more Newswise



Insect Identifications and Etiquette

I’ve been a student of insects for most of my life, and of the many aspects of entomology that interest me, field collecting and identification remain the most enjoyable. My interest in beetles first began to gel during my days at the university (despite a thesis project focused on leafhoppers), and early in my career I settled on wood-boring beetles (principally Buprestidae and Cerambycidae) as the taxa that most interested me. To say that species identification of these beetles can be difficult is an understatement, but I was fortunate to have been helped by a number of individuals — well-established coleopterists — who freely shared their time and expertise with me during my early years and pointed me in the right direction as I began to learn the craft.

Source/read more Beetles in the Bush



Seasonal monarch butterfly migrations may help lower infection levels

Seasonal migrations may help lower infection levels in wild North American monarch butterfly populations, according to a study published November 25, 2015 in the open-access journal PLOS ONE by Sonia Altizer from the University of Georgia, and colleagues.

Danaus plexippus  |  Kenneth Dwain Harrelson/Wikimedia Commons  [CC BY-SA 3.0]

Danaus plexippus | Kenneth Dwain Harrelson/Wikimedia Commons [CC BY-SA 3.0]

Source/read more Eureka Alert

Citation Sonia Altizer, Keith A. Hobson, Andrew K. Davis, Jacobus C. De Roode, Leonard I. Wassenaar. Do Healthy Monarchs Migrate Farther? Tracking Natal Origins of Parasitized vs. Uninfected Monarch Butterflies Overwintering in Mexico. PLOS ONE, 2015; 10 (11): e0141371 DOI: 10.1371/journal.pone.0141371



The Best Gifts of 2015 for Science Geeks

Want to find the perfect holiday gift for the science fan in your life? No need to experiment—we've done the research and selected some of the most electrifying goodies, from Plutonic pendants to mossy home décor, to fascinate your favourite brainiac.

  1. Pluto Pendant Necklace
  2. "Adventures in the Anthropocene"
  3. Women in Science Tee Shirts
  4. Planetary Glass Set
  5. Ernst Haeckel Science Illustration Pillows
  6. Marimo Moss Ball Light Bulb Terrarium
  7. Pandemic Legacy Board Game
  8. MEL Chemistry Sets
  9. Petrified Wood Cheese Tray
  10. Edison Touch Lamp

Source/read more Smithsonian Mag



Why I don’t use “participation” points

Do you think giving students “participation” points is a good idea? I don’t.

I’ve been promising for over two years that I’d be writing about why class credit for participation is a Bad Idea. So here’s the post!

People put “participation” points* in the syllabus for a variety of reasons. In my experience, professors count 5-10% of the total grade towards “participation,” and sometimes more. It seems that a student’s level of “participation” can make the difference of a whole letter grade, by making an otherwise-B into a C if a student gets a poor participation score, or can lift a B into an A if they get full credit for participation. In most of the syllabi I’ve reviewed, these participation points are rarely calculated quantitatively. A student could go into the final exam without having any idea what their participation grade is. That seems wonky, doesn’t it?

Source/read more Small Pond Science



Avoiding collision leads to common routes

Ants, when walking around in cluttered environments, are known to follow a limited number of common routes. Researchers show that similar routes emerge when an algorithm for collision avoidance, based on the apparent motion of obstacles, is combined with a target direction.

Source/read more Science Daily

Citation Olivier J. N. Bertrand, Jens P. Lindemann, Martin Egelhaaf. A Bio-inspired Collision Avoidance Model Based on Spatial Information Derived from Motion Detectors Leads to Common Routes. PLOS Computational Biology, 2015; 11 (11): e1004339 DOI: 10.1371/journal.pcbi.1004339


Pollination is more than bees

Other creatures visit more flowers than bees do, and may be almost as important in pollinating crops.

Romina Rader at the University of New England in Armidale, Australia, and her colleagues analysed data from 39 field studies of pollination by honey bees, other bees and other insects, including flies, beetles, moths and ants. They found that other insects carried out 25–50% of all visits to crop flowers. Although these 'non-bees' were less effective at pollinating on each visit, their increased visits made them roughly as effective as bees.

The contribution of different insect groups to flower visitation across the 37 crop studies for which visitation data were available. Crops are ordered, left to right, from mostly bee-dominated to mostly non-bee–dominated. (From Rader et al. 2015.)

The contribution of different insect groups to flower visitation across the 37 crop studies for which visitation data were available. Crops are ordered, left to right, from mostly bee-dominated to mostly non-bee–dominated. (From Rader et al. 2015.)

Source/read more Nature

Citation Romina Rader, Ignasi Bartomeus, Lucas A. Garibaldi, Michael P. D. Garratt, Brad G. Howlett, Rachael Winfree, Saul A. Cunningham, Margaret M. Mayfield, Anthony D. Arthur, Georg K. S. Andersson, Riccardo Bommarco, Claire Brittain, Luísa G. Carvalheiro, Natacha P. Chacoff, Martin H. Entling, Benjamin Foully, Breno M. Freitas, Barbara Gemmill-Herren, Jaboury Ghazoul, Sean R. Griffin, Caroline L. Gross, Lina Herbertsson, Felix Herzog, Juliana Hipólito, Sue Jaggar, Frank Jauker, Alexandra-Maria Klein, David Kleijn, Smitha Krishnan, Camila Q. Lemos, Sandra A. M. Lindström, Yael Mandelik, Victor M. Monteiro, Warrick Nelson, Lovisa Nilsson, David E. Pattemore, Natália de O. Pereira, Gideon Pisanty, Simon G. Potts, Menno Reemer, Maj Rundlöf, Cory S. Sheffield, Jeroen Scheper, Christof Schüepp, Henrik G. Smith, Dara A. Stanley, Jane C. Stout, Hajnalka Szentgyörgyi, Hisatomo Taki, Carlos H. Vergara, Blandina F. Viana, and Michal Woyciechowski. Non-bee insects are important contributors to global crop pollination. PNAS, November 2015 DOI: 10.1073/pnas.1517092112



Get to know them faster: Alternative time-efficient way to describe new moth species

Having collected thousands of moth and butterfly species from across Costa Rica, famous ecologist Daniel Janzen, University of Pennsylvania, and his team were yet to find out many of their names. When they sought help from Dr. Gunnar Brehm, the taxonomist realised he needed too much time to describe species in the framework of an extensive revision of the genus, especially as there are still only a few biologists skilled to do this.

Source/read more Eureka Alert

Citation Gunnar Brehm. Three new species of Hagnagora Druce, 1885 (Lepidoptera, Geometridae, Larentiinae) from Ecuador and Costa Rica and a concise revision of the genus. ZooKeys, 2015; 537: 131 DOI: 10.3897/zookeys.537.6090



Trap-Jaw Ant Jumps with Its Legs or Its Mandibles

Trap-jaw ants have powerful mandibles that they use to capture and crush prey, and to fling themselves from danger. Now new research shows that a species of trap-jaw ant jumps with its legs, a previously unseen jumping behaviour, rather than its jaws. The discovery makes this species, Odontomachus rixosus, the only species of ant that can jump with either its legs or its mandibles.

Odontomachus rixosus  |  Bernard Dupont./Flickr  [ CC BY-SA 2.0 ]

Odontomachus rixosus | Bernard Dupont./Flickr [CC BY-SA 2.0]

Source/read more Entomology Today



Parasitic tapeworm influences the behaviour and lifespan of uninfected members of ant colonies

Aggressive behaviour of entire ant colony reduced / Lifespan of uninfected nest-mates curtailed but increased in infected ants.

Ants are quite often infected by parasites. For example, tapeworms use ants as intermediate hosts for a part of their development phase before they complete their life cycle in their main host. Researchers at Johannes Gutenberg University Mainz (JGU) have now discovered that such parasites not only change the appearance and behaviour of infected ants but also have an effect on the behaviour of uninfected members of the colony. The overall aggressiveness of an ant colony diminishes if it contains members who are infected with a parasite. The investigations being undertaken by a team of Mainz-based evolutionary biologists headed by Professor Susanne Foitzik are designed to uncover the effects that parasites have on animal societies and to find out how the parasites manipulate the behaviour of their hosts in order to better survive. Their findings have recently been published in Proceedings of the Royal Society B.

Source/read more Johannes Gutenberg University Mainz

Citation Sara Beros, Evelien Jongepier, Felizitas Hagemeier, Susanne Foitzik. The parasite's long arm: a tapeworm parasite induces behavioural changes in uninfected group members of its social host. Proceedings of the Royal Society B: Biological Sciences, 2015; 282 (1819): 20151473 DOI: 10.1098/rspb.2015.1473



Chemicals That Make Plants Defend Themselves Could Replace Pesticides

Chemical triggers that make plants defend themselves against insects could replace pesticides, causing less damage to the environment. New research published in Bioorganic & Medicinal Chemistry Letters identifies five chemicals that trigger rice plants to fend off a common pest – the white-backed planthopper, Sogatella furcifera.

We used the relative induction of GUS activity as a screening tool for identifying new chemical elicitors that induce resistance in rice to the white-backed planthopper  Sogatella furcifera . (From He et al. 2015.)

We used the relative induction of GUS activity as a screening tool for identifying new chemical elicitors that induce resistance in rice to the white-backed planthopper Sogatella furcifera. (From He et al. 2015.)

Source/read more Elsevier

Citation Xingrui He, Zhaonan Yu, Shaojie Jiang, Peizhi Zhang, Zhicai Shang, Yonggen Lou, Jun Wu. Finding new elicitors that induce resistance in rice to the white-backed planthopper Sogatella furcifera. Bioorganic & Medicinal Chemistry Letters, 2015; 25 (23): 5601 DOI: 10.1016/j.bmcl.2015.10.041



New Butterfly Species Named after Sir David Attenborough

Add another item to the list of insects that have been named after the British naturalist and filmmaker David Attenborough. Last year a 20-million-year-old pygmy locust was named after him, as was a new species of beetle.

Now, for the first time, a butterfly has been named after him. It’s a black-eyed satyr that it is known only from lowland tropical forests of the upper Amazon basin in Venezuela, Colombia, and Brazil. In fact, Euptychia attenboroughi has such a restricted distribution that all of its known sites lie within 500 kilometres from each other in the northwest of the upper Amazon basin.

Source/read more Entomology Today



Researchers wrestle with co-authorship

The prickly topic of how to assign credit to scientists flares up on social media.

Questions of paper authorship have been plaguing scientists on social media recently. Who should come first? And who deserves to be listed at all? When it comes to papers with numerous authors, the publishing process can get messy. For instance, when Dorothy Bishop, a psychologist at the University of Oxford, UK, found herself trying to review a paper blemished with mistakes, she tweeted:

Source/read more Nature



Fellowships are the future

Postdocs need a level of autonomy to get the best out of their position, say Viviane Callier and Jessica Polka.

Much scientific research could not function without postdocs. They do the research outlined in a grant — moving the work of the principal investigator (PI) forward, producing papers and helping to win grants. Yet too many postdocs end up doing work that does not benefit their scientific and intellectual development. They are shut out of developing ownership of a research programme, a step that is crucial for launching the next stage of their career.

Source/read more Nature



Conservation: It is rational to protect Antarctica

We are dismayed that the international commission that oversees the Convention on the Conservation of Antarctic Marine Living Resources has voted against establishing marine protected areas (MPAs) around Antarctica for the fifth consecutive time. These MPAs are designed to protect wildlife hotspots of world significance.

Source/read more Nature



How to build a better PhD

There are too many PhD students for too few academic jobs — but with imagination, the problem could be solved.

“Since 1977, we've been recommending that graduate departments partake in birth control, but no one has been listening,” said Paula Stephan to more than 200 postdocs and PhD students at a symposium in Boston, Massachusetts, in October this year.

Source/read more Nature



Make the most of PhDs

The number of people with science doctorates is rapidly increasing, but there are not enough academic jobs for them all. Graduate programmes should be reformed to meet students’ needs.

It is hard to argue against the idea that a workforce should be highly educated. The media, politicians and universities all believe that a scientific background will not only benefit individuals, but also drive science, innovation and the economy. As a result, the number of people entering higher education in the sciences and engineering has been on the rise for decades. Between 1995 and 2012, the Organisation for Economic Co-operation and Development reported an overall increase in university graduation rates of 22 percentage points. In the same time frame, the PhD production rate has doubled, even though PhDs account for only a small percentage of higher-education graduations.

Source/read more Nature



Neonicotinoid pesticides linked to butterfly declines in the UK

The use of neonicotinoid pesticides may be contributing to the decline of butterflies in the UK, a new study by the Universities of Stirling and Sussex in partnership with Butterfly Conservation and the Centre for Ecology and Hydrology has revealed.

Thymelicus lineola  |  Korall/Wikimedia Commons  [ CC BY-SA 3.0 ]

Thymelicus lineola | Korall/Wikimedia Commons [CC BY-SA 3.0]

Source/read more University of Stirling

Citation Andre S. Gilburn, Nils Bunnefeld, John McVean Wilson, Marc S. Botham, Tom M. Brereton, Richard Fox, Dave Goulson. Are neonicotinoid insecticides driving declines of widespread butterflies? PeerJ, 2015; 3: e1402 DOI: 10.7717/peerj.1402

Leatherback sea turtles choose nest sites carefully, study finds

OK, so I know this isn't about insects, but my blog is titled Zoological Musings and not Entomological Musings, after all, so I'm allowed to diversify...

Leatherback turtles are near and dear to my heart because the very first essay I wrote at university was on this species (by my own choosing), and I scored a nifty little High Distinction for my hard work! I had to choose an animal that would be negatively affected by climate change and an animal that would benefit. I chose the cane toad for the latter. There seemed to be so much information about polar bears and then I came across Dermochelys coriacea and was immediately won over.

This was my introduction:

Many environmental scientists agree that, over the next hundred years or so, global temperatures will increase as a result of greenhouse gas emissions. Estimates vary, however, between less than 1°C and up to 8°C (Davenport 1997). How different species will be affected by this climate change will also vary, in that some may benefit while others could be impacted negatively. The worldwide population of the critically-endangered leatherback turtle (Dermochelys coriacea) is likely to be adversely affected by climate change, by way of growing rates of egg clutch feminisation, erosion of nesting sites and changes in ocean currents (IUCN 2009). While the invasive species the cane toad (Bufo marinus) might be positively affected by this warming trend, as a result of an expansion of suitable habitats for living, foraging and breeding, particularly in Australia (Kearney et al. 2008).

I remember being so anxious about getting my essay results. It was during the first-year Biology intensive school - my very first - and the Professor had just given the entire class a very stern talking to about plagiarism and indicated that many students had been pinged for not citing their sources correctly or at all. Those students would find a plagiarism notice attached to the front of their essay and would have to meet with the first-year advisor to discuss it.

It was nerve-wracking. I was sure I'd followed all the advice correctly, but it was my first essay after all. Needless to say, I was thrilled when I picked up my paper and saw 97% pencilled in the top corner. Phew! That moment really set the scene for the rest of my degree.

So, yeah, leatherback turtles are pretty special to me. Cane toads not so much...

Dermochelys coriacea  |  FWS/Wikimedia Commons  [ CC BY 2.0 ]

Dermochelys coriacea | FWS/Wikimedia Commons [CC BY 2.0]

Evaluating Environmental and Climatic Influences on Nesting in Leatherback Sea Turtles (Dermochelys coriacea) in St. Kitts, West Indies

CHAMPAIGN, Ill. — The enormous, solitary leatherback sea turtle spends most of its long life at sea. After hatching and dispersing across the world’s oceans, only the female leatherbacks return to their natal beaches to lay clutches of eggs in the sand. A new study offers fresh insights into their nesting choices and will help efforts to prevent the extinction of this globally endangered giant of the sea, researchers said.

A report of the new findings appears in the Journal of Herpetological Medicine and Surgery.

“Leatherbacks are the largest of the sea turtles: The males can grow to more than 1,800 pounds and the females are 600 to 800 pounds,” said University of Illinois veterinary clinical medicine professor Dr Mark Mitchell, who led the study. Mitchell also edits the journal in which the study appears.

Some leatherbacks migrate up to 7,000 miles between their hatching and feeding areas, with females making return trips to lay eggs every two or three years.

“Their ability to get back to their natal beaches without some GPS tracker to show them where to go is pretty impressive,” Mitchell said.

Veterinary clinical medicine professor Dr. Mark Mitchell and his colleagues studied the nesting habits of leatherback sea turtles.

The researchers focused on leatherback sea turtles nesting on St. Kitts, an island in the West Indies southeast of Puerto Rico. The team wanted to know what factors influence where and when the leatherbacks lay their eggs. The information will help conservation efforts and improve the ecotourism experience, Mitchell said.

Other studies of sea turtles suggest that characteristics of the sand, the slope of the beach and proximity to vegetation contribute to the success or failure of nests, but “no study has tried to determine what factors cause female leatherback sea turtles to dig a nest in a particular spot, or what factors contribute to when they come up to nest,” the researchers wrote.

“They don’t nest every year, but when they do nest, they’ll often lay multiple clutches,” Mitchell said. “Sometimes they’ll ‘false crawl,’ which means if they’re not happy with something, they’ll go back into the water and come back another time. One of the concerns that we had was that maybe the reason they sometimes leave the beach without laying has something to do with the beach itself.”

To determine whether this was so, the team tracked leatherback sea turtles’ behavior on St. Kitts during the 2008 nesting season, from May through July. This meant walking a 4-kilometre stretch of natal beach every night between 8 p.m. and 8 a.m. looking for turtles. The researchers kept track of air and water temperatures, humidity, wind speed, the lunar phase, cloud cover, the tides, and levels of natural and artificial light. They also studied the sand in the nest sites and in two control sites per nest, measuring its temperature, pH, conductivity, moisture content and grain size. In total, data were collected for 27 leatherback nests and dozens of control sites.

“We found that the places the turtles select are different from other places along the same beach where they didn’t lay their eggs,” Mitchell said. “They tend to nest in sand with a slightly higher pH and a milder conductivity than sand taken at the same depth from the control sites. The leatherback nests are in a sand that allows itself to be highly compact.”

Conductivity is in part a measure of the wetness of the sand, Mitchell said.

“They don’t want the nest to become over-saturated because that could lead to the death of the hatchling. It also can’t be too dry,” he said. “We also saw that the females like to lay when the moon is closer to full and when cloud cover is low, which probably is based on light.”

Some turtles will start to dig one or two nests before finding a spot where they’ll lay their eggs, Mitchell said.

“Maybe they’re picking up on the coarseness of the sand and how well it will pack to ensure that their nest chamber is going to stay structured,” he said.

Human encroachment on leatherback nesting sites, in the form of beachfront construction and sand mining, is a major threat to the animals’ continuation as a species. The researchers saw evidence of both on the shores of St. Kitts, Mitchell said.

Mitchell hopes that a better understanding of the leatherbacks’ nesting habits will increase the likelihood that ecotourists will show up when the turtles are nesting. This would boost ecotourism and incentives to protect the turtles’ nesting habitat, he said.

By Diana Yates

Source University of Illinois at Urbana-Champaign

Citation Mark A. Mitchell. Evaluating Environmental and Climatic Influences on Nesting in Leatherback Sea Turtles (Dermochelys coriacea) in St. Kitts, West Indies. Journal of Herpetological Medicine and Surgery, 2015; DOI: 10.5818/15-01-035.1