Happy halloween!

As a bat enthusiast this is definitely the time of year for celebrating the second most diverse order of mammals (second to rodents).

With over 1,200 species, bats do it all!

They are able to live in cold climates like Alaska and northern Europe but happily inhabit hot and dry deserts.

They fish, they echolocate, they fly, they eat insect pests, they pollinate and they disperse seeds to remote islands.

They find their babies amid colonies of thousands of other bat babies in the pitch black darkness of caves.

Even the blood eating ones have interesting behaviors like sharing meals!

Happy halloween!

What is a bat? Isn't it just a flying a rat?

Often people think bats are 'bugs,' birds, or rodents. Bats are certainly neither bugs (which as insects do not have an internal skeleton), nor are they birds which are actually related to dinosaurs. Instead like rodents bats are Mammals and do all sorts of mammal things like give birth to young they nurse. Additionally like other mammals they have hair, four-chambered hearts and different kinds of teeth. However, they are more closely related to us (Primates) or to a hedgehog (Eulipotophyla) then they are to a mouse. However the common assumption that they are mice or rats (Rodents) is reflected by the word for bats which in many languages includes reference to 'mouse' or 'rodent.' For example in German the word for bats is Fledermaus which literally translated means filtering mouse.

However, for a substantial period of time bats have been placed in their own Order (i.e. a taxonomic group) just like Rodents. The name of the Order bats are in is Chiroptera which means 'hand' and 'wing' based on the origins of their powered flight (see my evolution of flight post). Bats are further divided into two types which are referred to as Suborders. These two groups are the Megachrioptera and Microchiroptera.

Members of the Megachrioptera (a group of closely related species) are the largest bats. Mega is a Greek prefix meaning 'large' which refers to their large size. The species in this group are sometimes called flying foxes (see picture below to see their 'fox-like' faces) and are found in Australia and the South Pacific. Sometimes these bats are also called 'Fruit bats' given that nearly all of them rely entirely on fruit but this name is confusing because many Microchiroptera also eat fruit (for example my study species the Jamaican fruit bat and its relatives).

Microchriptera (aka 'Micro bats') however are generally small as their name suggests (Micro is a Greek prefix meaning 'small'). These closely related bats are usually very small but sometimes can be as large as small Megachiropterans. They are also nearly cosmopolitan in distribution (meaning they occur globally). They are found from the far north in places such as Alaska and Scandinavia to the extreme South such as South Africa, and Southern South America and are pretty much everywhere else between! An example of a Micro bat is shown below.

Microbats are much more diverse but both groups present amazing examples of the diversity of vertebrates as the only flying mammals!

*Images are from the American Society of Mammalogists website where you can access many other excellent photos of different mammals.

PhD Comics

Wonder what life is like for graduate students? I have to recommend this website: www.phdcomics.com. Recently this comic strip was even expanded into a film (see the website for details). Topics such as the 'Impostor Syndrome,' poorly attended office hours and modes of procrastination are all covered in both film and cartoon format.

The bats attacking hair myth (part 1)

A recent article from the Press Enterprise a Southern California newspaper presented once again the prevalent urban legend that bats attack people's hair.

A young girl in Lake Elsinore encountered a bat that was apparently sick due to an infection with rabies. This unfortunate incident was surely shocking for the unfortunate girl involved and her family. Hopefully the girl is recovering quickly from the event which is likely due to the immediate treatment she received. The remainder of this post does not argue that being bitten by any animal is not a potentially dangerous thing nor does it try to take away from what the poor-child involved experienced. However what it does focus on is the way the media responded. Reading responses to the article it was apparent that people were very concerned about the incident occurring again. Worrying about getting bit by a bat is unfounded as being bitten by a dog is exponentially more likely. This thought lead me to question if a rabid dog bit a 3 year old girl it would also appear in the news paper.

However, the fact remains that the article presented and focused on a reoccurring myth...bats attacking hair. This myth is what I would like to address. It simply is not true that bats 'go for' (i.e. seek out and attack) people's hair just as much as bats are not blind. It is however interesting that this is such a pervasive idea that it is even included in the header of the Press Enterprise article.

A prominent bat biologist Dr. Gary McCracken deals with this myth on the Bat Conservation International web page located here. I rather like Dr. McCracken's discussion of his own work with bats that has involved close contact during which he has not experienced bats 'attacking his hair'. Similarly, my dissertation research has all occurred in a cave that is FULL of bats and I have yet to have a bat become entangled in my medium length hair (i.e. longer than most men's hair). What is most likely is that bats near homes may be foraging at street lights for insects and in their focused hunting fail to 'correct' for larger non-food objects like humans that may be walking between them and their dinner. An additional tidbit (another myth) is the 'painful' nature of the rabies exposure vaccine. This concern is unwarranted as the vaccine is now less painful than vaccines for tetanus. Interesting is the Center for Disease Control (CDC) web site's reference to rabies exposure as a medical 'urgency' but not 'emergency'. Why is this? Generally because the shots are only administered after careful consultation with a doctor because you have a time-window within which to decide what to do.

A well-made site hosted by the CDC for kids to learn more about rabies is hosted here.

Meanwhile, I am interested to learn more about how people reacted to this story and their own experiences relating to the myth that seems unlikely to go away anytime soon: that bats attack people's hair!

Fall bat events (updated year of the bat listing)

Below is an updated listing for October of events from around the world that relate to bats some in celebration of the Year of the Bat (2011)).
(In-progress, expect updates)

Australia, New Zealand, New Guinea, South Pacific Islands
31 October Australasian Bat night

Europe
France
26, 29 Oct. Bourges Chauve-souris expo at the Natural History Museum in Bourges.

Germany
3 Oct. Fledermaus Kreativ Wettbewerb (bat creativity contest to come up with art for the bat museum or Internet site.)

Sweden
23 Oct. Opening of Sweden's bat museum!

Switzerland
1 Oct. (Zurich) Long Sat. bat exhibit.

United Kingdom
21 Oct. Bats for building workers (workshop) Jersey Bat Group.

North America
Canada
26-29 Oct. North American Symposium on Bat Research (NASBR). Toronto, Canada. Chiropterologists will be meeting to discuss their research!

United States
Austin, Texas.
Anytime. Who knew? You can take river cruises to see the famous Congress Avenue Bridge bat colony emerge! So the next time you are in Austin check it out.

Bat souffle anyone? Milk assays in-progress

It has been some time (and then some) since I have posted anything but I figured a quick update about my current endeavours: bat milk analysis would get me back to posting more regularly. Besides classes start up tomorrow so I am back to my regular schedule and so too blogging.

Because I am interested in the costs of reproduction in bats I am also very interested in the quality of the milk bats produce. This is in part because lactation is arguably the most expensive task that mammals do! Females will deplete their fat stores and even start to break down their own skeletons to make milk for their young.

But here is the issue. Bats are MUCH smaller than cows.

So say I want to know the percentages of fat, sugar and protein or total calories in bat milk... I will need a LOT of milk or very specialized techniques to evaluate these components. This is where an amazing group of people come in one of which is Dr. Wendy Hood at Auburn who has developed methods to analyze very tiny volumes of milk!

Thank you Dr. Hood! So since last September I have worked off and on to develop my own versions of these tests using the methods and protocols of Dr. Hood.

My standard for all my tests (to be sure they are working) happens to be regular 'ol cow's milk. Luckily the values for all the parts of cow milk are all well known (thank you now to the USDA!) * see label above for an example.

The idea (one that takes more work than it sounds) is to get the same numbers for your cow milk as the contain of milk suggests... if you can do that your assays are working!

The parts I analyze are:

• dry mass (how much water is in the milk)


• fat


• carbohydrates (sugars like lactose) and


• protein

If you know these components you can calculate the amount of energy in your milk!

I will explain each of these in part but the bat souffle will be first so... keep posted!

Pitcher perfect- a strange mutualism

Carnivorous plants like the Venus flytrap capture insects and digest them to obtain protein (which is made up of Nitrogen). What could a bat and a carnivorous plant have in common? Recently, a group of German researchers demonstrated that these two organisms can develop a mutualistic association. (Mutualisms develop when both partners of a relationship gain something through their association with the other individual, many examples of which occur nature).

This fascinating study conducted in Brunei demonstrated that bats use pitcher plants as roosting sites and in turn the nitrogen rich feces (guano) from the bats fall into the pitcher of the plant where it like the insects the plant usually digests is incorporated into the plant's tissue.

The bat (woolly bats (Kerivoula hardwickii)) is provided with a place to live while the plant (areal pitcher plant (Nepenthes rafflesiana) gets its highly sought after nitrogen!

The precarious roosting location for the bats aside this fascinating study that uses both radio telemetry and stable isotope ecological methods reveals an unlikely relationship between carnivorous plants and bats.

The article:
Grafe, T. U., C.R. Schoener, G. Kerth, A. Junaidi, and M.G. Schoener. (2011). A novel resource-service mutalism between bats and pitcher plants. Biology Letters

Updated bat activies for May 2011 (year of the bat!)

An updated list of bat related activities around the world in May to celebrate the 'Year of the Bat'!



Unfortunately activities seem restricted to Europe for the time being...



EUROPE

Germany (Frankfurt)



11 May Nachtscwaermer-guided tour (Frakfurt Zoo)



18 May- Nachtscwaermer- guided tour (Frankfurt Zoo)



21 & 22 May- Experiencing bats (Frankfurt Zoo)



25 May- Lecture "night Flight- Fascinating bats" (Frankfurt Zoo)



UK

17 May Bat walk, Bryngarw County Park, Bridgend, South Wales



20May- 16 September Cambridge, 'Bat Safari' river tours

Back to field planing! (and milking bats)

Ah it is 'that time' again the birds are singing, the bees are buzzing and the bats are lactating! Yes, considering that the Artibeus were all pregnant (late-stage) during my mid-march visit if I plan on collecting milk it is time once again to schedule a trip to the field for the 'last' milk collection of my dissertation (assuming all going according to plan). This next trip my lab mate will accompany me which will be an added bonus. Now all that said I imagine one question came to mind rather quickly 'wait... milk bats?' Yes... this is actually not as difficult as it sounds. Basically the mother and pup are captured, kept away from each other for a short while (~1 hour) so she accumulates milk which is natural if the mother is away from her baby. (Also the mother and pup are accustomed to being separated from each other for longer periods of time because the baby that cannot fly must stay behind while its mother is out for several hours every night searching for food.) After about an hour, I inject the mother with a small amount of a hormone called oxytocin. Oxytocin increases milk let down (i.e. lactation) so this combined with what is essentially a miniature version of milking a cow allows me to collect milk from the female before letting her and her baby return to their roost. I then upon returning analyze many nutritional components in the milk (dry mass, protein, fat, and carbohydrate (sugar) content).

Flight (Part 2)

Continuing on the topic of flight... The physics of flight include 4 forces. 2 of these (in bold) are generated by the flying animal (in this case a bat) and 2 of them (drag and gravity) are natural properties that the animal must negotiate (fight) in order to fly. 1. Lift (i.e. upward force) 2. Thrust (i.e. forward force) 3. Drag (backward force (resistance)) 4. Gravity (i.e. downward force)

LIFT

The shape of wings causes air to move over the wing-surface in a unique way. Specifically, air flows faster over the upper curved surface of the wing and slower over the cupped (concave) surface. This causes negative pressure on the upper side of the wing and thus the wing begins to rise. In principle this is what happens when as a child you cupped your hand and played with the wind outside the open car window. Remember how the air would suddenly PUSH your hand upward? That is 'lift'! Additionally that is about the time you were reminded to not put your arms out the window.

Take home: the shape of wings (think of a bird or bat wing) is what causes air to move in a way that LIFTS the wing upward. The opposing force is gravity... without lift (like you or I flapping our arms, sorry to say but we are not going to generate sufficient lift) gravity 'wins' and we stay stuck to the ground. Gravity is complex for despite the fact that physicists can tell us its value (9.81 m/s2) how it 'works' and why it exerts force on objects was perplexing even to Einstein who wrote extensively on the topic. Incidentally, Einstein apparently also noted "Gravity cannot be held responsible for people falling in love." ______________ (I will insert an awkward pause here as you ponder that and why he might have felt it necessary to declare such a fact, if he made this statement in English or German and if it would have been funny regardless). Back to flight: The wings of bats are more flexible than birds because the wing itself is formed by a thin layer of skin rather than stiff feathers. However, birds are able to more easily change their wing area by moving their wings closer to their bodies because bats require the full extension of their 'fingers' i.e. the wing to have it function because of its thin nature. In searching for an analogy the best I have for you follows. This is similar in a way to how airplanes have rigid wings (like bird wings) while a para glider that uses a flexible surface (like a bats wings) is less able to change the shape of the 'wings' or they will loose lift.

THRUST

Basically thrust is the power from a wing-stroke that pushes back against air and results in a force propelling the animal FORWARD. Indeed to understand this idea you must remember that air is made up of molecules and is in actuality a fluid (like water). Thus there is indeed something to 'push upon'.

I will conclude for now and leave you with another Einstein quote as a 'token' physicist

"Science i nothing more than a refinement of everyday thinking".

I refer you to this much more comprehensive explanation of flight (here) and hope you find this topic interesting.

The evolution of flight (Part 1)

Many animals are able to fly and most of these are insects. However, when one stops to consider which vertebrates fly (vertebrates are animals with an internal skeleton including a spine and something resembling a spinal chord) only 3 main groups are able to fly.

These are: birds, Pterosaurs and bats.

The wing surface formed in 3 different ways one for each of these groups (see above).

Both bats and Pterosaurs used a wing-surface created by finger elongation (the 'pinkie' in Pterosaurs and all fingers elongated except the 'thumb' in bats).

Meanwhile, birds fly using a surface created by modified scales (feathers) and a strong series of arm and finger bones that are the result numerous bones fusing. Additional details are left out for brevity but are extremely interesting such as skeletal lightening in birds.

Pterosaurs are extinct and so only two extant flying vertebrate groups (extant = animals that are still alive today) are bats and birds. (What is a Pterosaur? Click here!)

Why did flight evolve?

There are two main thoughts about this. Basically either animals were able to flap and lift UP to escape predators etc. OR they were living in trees and started to glide from tree to tree (like 'flying' squirrels) also to catch food (insects) or avoid predators.

Regardless, the sky is (and was) full of potential food and once they were able to fly bats quickly filled a new niche (a niche is the ecological role of an animal generally relating to the food it eats). Both bats and birds were able to eat flying insects but bats as nocturnal animals compete with a fewer set of birds. Indeed this successful niche 'nocturnal insectivore' has since been radically expanded to include other more unusual food-types such as frogs or fish!

You can read more about the evolution of flight here.

Click here for cool videos of bats flying in slow motion.

For my next I will try to summarize the physics required for flight.

Can pregnant bats fly?

I happened upon the above question incidentally and thought perhaps it is a good one to address since I study reproductive bats and many people who do not study bats might have the same question!

(to the right is a photo of a Jamaican fruit-bat late in her pregnancy)

The simple answer is yes, bats fly while pregnant. That said it is very energetically costly for them and they become increasingly awkward as the pregnancy progresses. Indeed they may be more likely to be eaten by predators as they become slower and less-maneuverable.

Not only do they fly while pregnant, but bats give birth to pups that are much larger relative to the mom's size than human mothers give birth to! So, they are still flying when the developing baby is larger relative to the mother than a human would be walking around with.

After bats give birth (upside-down which is yet another difficulty) the mother will occasionally fly with her ever-growing baby (most bats only have one pup per pregnancy although some have twins and more rarely- triplets). The fortunate bats like Mexican free-tailed bats (Tadarida brasiliensis) or other cave dwelling bats usually leave their young in the roost while they forage but some less-fortunate bats may have to move their young nightly or semi-regularly if they inhabit less-permanent roosts.

So next time you hear a pregnant friend or family member saying how their back hurts or it is hard to get around you can tell them to cheer up and remind them they are lucky that they are not a pregnant bat!

Toothsome (more facts about biologists)

I have come to the conclusion and with increasing confidence that many biologists love to cook. Perhaps you are picturing them throwing some burgers on the grill or making killer chili.... no I mean that numerous biologists I know make on a semi-regular basis and with avid enthusiasm, fancy 4 course gourmet meals and exotic fare.

For example, BOTH of my collaborators in Mexico are involved in a 'gourmet club' that includes a group of several additional Mexican bat biologists who all alternate making and hosting gourmet fancy dinners. My adviser makes pies for fun and attempts to emulate her favorite dishes (generally carne asada comes into play). She may have learned this from an old committee member and bat-biologist of legend 'Mike' who attempts to dis-entangle the exact recipes from his favorite restaurants through rigours and I assume enjoyable experiments. My lab mate is addicted to the food network and is a good cook. Down the hall an undergraduate researcher brings in homemade meringue pies to lab meetings and makes special cheesecakes for birthdays. The field biologist Mike O'Farrell has published a cookbook on how to cook in the field. A favorite evolutionary biologist of mine- Hanna Kokko has a link on her lab page to her 'good food society' which seem very fun. (by the way...I remained strong and did not have a David Letterman trying to get Oprah on his show moment... but really Hanna if I am ever in town....). Even my friend Natalie, the coolest PhD holding biologist I know-who rock climbs and does field work in Alaska after being dropped off by a helicopter field-gear and all by a helicopter. But even cooler: she can fit her material world (mostly books, clothes and ski-gear) into the back of her truck (shes kind of like if Joni Mitchell and McGyver (to return to a recent post) had a daughter). Even she with her bohemian ways stunned me after years of freindship by making me dinner one night and wiping up an amazing and exotic salad (shes vegetarian but I love her anyway...) and admitted she loves to cook. (Mind you as the 'McGyver-esque soul' who's mother may have been a hippie, I imagine she only has one pot and uses it to make tofu stroganoff).

In sum is perhaps no surprise that biology departmental functions are a culinary joy as well as interestingly competitive when it comes to the 'best' stuffing or mashed potatoes.

Why do many biologists love to cook?

I have come up with several possible reasons but I think it has to do with two main things.

1. Cooking is a scientific process: meat turns brown etc. when you cook it in part because proteins are being denatured, bread rises because yeast produce gases, jelly 'sets' i.e. solidifies because a new chemical structure is forming a'la pectin. So there is the main and most obvious 'its because biologists are scientists and cooking is (if you want it to be) scientific.

2. However, I think there is another reason (this is at least how I explain to myself at my sudden affection for cooking). Much of biology is comprised of incomplete days and tasks. Many days you go to the office and read articles to gain knowledge or attend meetings to question it. Some days you write proposals. After several days of proposal tweaks you send it off and wait to see if you get funding. Meanwhile, on another day, you work on getting permits for your research. Days pass and you wait for the permits and if you are lucky you've heard back from granting agency. If you are even more lucky you were funded. More days and you wait on your permits and meanwhile you order your lab supplies and continue to wait. You secure your permits and supplies and start your work. Probably something about your research does not work the first time... you wait. Days and days you may work to perfect an assay to make sure it works before you use your valuable samples that took days and days to collect. Then for days and days you run samples. Days and days you run your statistics (only after days of entering data). You start to make some conclusions and spend a few days talking to others about your results. You spend days or months writing up your results. You send them to co-authors and wait to hear back. You make changes and send the written results to a journal and wait for their decision. So on and so on. This is obviously the less-glamorous version of biology and truly I am happy to be in academia however... with time answering the 'what did you get done today' question wears on a person.

So indeed, most days you do not come home and think 'gee I am so glad I cured cancer and saved the polar bears today.' In fact more likely you don't even think 'Gee I am so glad I finished that side project on why pika prefer grasses over shrubs today'. Nope. So what do you do?

While members of M*A*S*H told jokes and made bootlegged gin in their tents and Zorba the Greek would say 'now... we dance' -my advice?

Now you cook.

Why? When you start you have nothing but....

But then you finish and when you finish you have (hopefully) something delicious to share with your loved ones or at least to eat while you read or watch TV. Suddenly when someone asks "what did you get done today?" you can reply- "I checked e-mail, made a graph, ordered some pipette tips and made stuffed mushrooms and cheese souffle with rhubarb cobbler for desert."

And who can argue with that?

Argentinian ants and yes...a bat would eat that

Possibly the worst (at least most boring) B-movie of all time 'THEM' (view trailer here)

Yesterday I awoke to find my depressed cat gloomily staring at a trail ... make that a carpeting of Southern California's bane; Argentinian ants swarming her food. To those not familiar with these little ants, they are a terrible pest in kitchens throughout the Los Angeles area and this is for a biological nuance the exhibit. Linepithema humile occur in South Africa, Europe, Australia, Japan and The US but originated in Argentina, Uruguay, Paraguay and Southern Brazil, and in 2009 it was discovered that these little ants are part of a super colony spanning from Japan to the Americas and that because of extreme genetic similarities their hydro-carbons which are used by ants to identify enemy ant colonies (such as the same species but a competitor for a clumped food-source say a chunk of candy-bar) were the same between colonies. Thus, separate colonies of Argentinian ants recognize each other as 'kin'. This means that instead of attacking neighboring colonies they join forces as a 'family unit.' Indeed, they join forces and harass innocent cats and soil the previously clean and well-functioning kitchen of many an innocent resident.

They do not just harass humans, these ants are also blamed for the decline of horned lizards in Southern California. While conducting what has become a nearly ritualistic 'wiping out of the ant-attack' which involves several trail washing bouts followed by waiting for them to be convinced the item of interest is truly gone before replacing my cat's food now sitting in a moat she is clearly intimidated by, I contemplated what pay-back might these ants... i.e. what animals eat ants. I will be honest, I really truly like ants and respect them as some of the most interesting animals to embrace sociality. But really... what might keep these little ants in check before they re-group and plan their next attack?

Indeed many mammals have specialized diets focused entirely on what to me seems a non-appetizing fare. These include ant-eaters, pangolins, aardvarks and well I suspect you saw this one coming: bats! Yes bats.

Some bats, I will assume some very desperate ones at that, eat ants. In an article by Eran Levin, Yoram Yom-Tov and Anat Barnea published in Naturwissenschaften in 2008 it was noted that in Israel, female Greater mouse-tailed bats (Rhinopoma microphyllum) are able to 'afford' the expensive task of lactation by adding ants to their diets during periods of ant swarms! (Ant swarms occur when female and male ants hatch and leave their natal nests to mate and for the female to find a new location to establish a colony). During these times of plentiful ants up to 90% of the bats diets include these unsavory treats. Perhaps my favorite part of the article was the pitiful photo of a bat with an dis-articulated ant heat stuck to it's lip (below right).

Mouse-tailed bats in a colony (photo form Arkive)

So if i were to suggest a timely sci-fi B movie, (of better quality relative to 'THEM' pictured above, which I must say is the most boring 'attack of the killer....(fill in blank but make sure it is larger than usual and relentless)' movie, which is especially surprising considering that THEM features giant killer-ants which seems like a winning plot-line) it would involve mutant bats released from a sealed cave that opened during a recent earthquake. These bats would wipe-out the Argentinian super colony of ants of Southern California or at least keep the kitchens and cat food bowls of residents ant-free!

The value of bats in monitary form no-less than $3 billion dollars and counting

Today I was sent a link to an interesting new article about the value of bats from an economic standpoint. This recent SCIENCE article (summary link here) suggests that bats may be worth at least $3 billion dollars per year in the services they provide (free of charge I am left to assume but if they started charging bats would be rolling in cash to say the least!)

The article 'Economic Importance of Bats in Agriculture' by Boyles, Cryan, McCracken and Kunz was published in Science this month (331: 6025, April 2011) (for link click HERE). A figure (above) from Boyles et al. 2011 (SCIENCE) illustrates the worth of insectivorous bats with warmer (redder) colors indicating higher financial worth relative to cooler colors (yellow) in the US.

Indeed, the bat-services discussed in the article are focused on those of pest-control by insectivorous bats. Because insectivorous bats must eat many insects every night to maintain their high metabolic demands they are responsible for maintaining lower agricultural pests that would otherwise destroy crops. Thus bats are able to save farmers costs in pesticide use. As the horrific White Nose Syndrome moves gradually westward we can hope these services will still be performed by hungry bats in the West not yet impacted by the disease. However, the Eastern bat populations have been drastically reduced in size and we might expect to see an increase need for pesticides in the near-future. Hopefully, funding of research projects aimed and limiting the spread of this disease will increase as the NSF and other funding agencies evaluate the importance of insectivorous bats in North America. This article focuses on the potential impact of White Nose Syndrome bats but it is worth recalling that world-wide bats provide many economically important services.

I would speculate the monetary value of bats in general supersedes that speculated by the authors of the article given other important services provided by bats such as pollination of plants including agaves that result in tequila in the tropics. Furthermore, the dispersal of seeds of remote islands and after hurricanes is another important bat-service. Regardless, the focus of the article is to make people aware of White-Nose Syndrome as something very scary that can impact us all even if we are not bat enthusiasts. I commend the authors for their article that will hopefully help inform the public and legislators while enticing them with considerations of the economic importance of bats.

big bat, little bat, how big are bats?

As far as mammals go bats are on average on the small end of the spectrum. The smallest bat is the bumblebee bat (Craseonycteris thonglongyai) that weighs less than a penny (~2 grams). This rivals the Eurasian pygmy shrew (Sorex minutus) which weighs roughly 2.5 grams, for 'smallest mammal' status. Being a bat biologist I think that the winner is this small little species that lives in Thailand and Burma and is featured in the children's book below that might be of interest to some people.

One of the largest bats is the Large flying fox (Pteropus vampyrus) with wingspans of 1.5 meter (~7 foot) and weighing 1.5 kilograms (3 pounds). Flying Foxes live in Australia and the tropical areas of South-east Asia.

All members of this genus called 'flying foxes' are large and are known for their expressive 'dog-like' faces. These bats eat fruit and are important seed dispersers. Indeed their diets lead to the spread of seeds and consequent growth of fruit trees on distant islands that are easily reached by these large flying fruit-enthusists.

Read more about the conservation issues faced by the Large flying fox due to it being hunted for food (here).

An interesting video about another flying fox species the Grey-headed flying fox can be seen by clicking here.

Additionally, several books about flying foxes are available including the children's story book below.

I would like to direct encourage people to learn abou an amazing organization called the Lubee Bat Conservancy which is based in Florida that aims to conserve biological diversity though the conservation of 'plant-visiting' bats. Bats are extremely important for the pollination, and seed dispersal plants require for their successful establishment. You can read more about Lubee and see amazing photos of the bats housed there by clicking on the link here. If you live in Florida you may consider taking a tour of Lubee to see all of the various fruit bats including flying foxes that are housed there.

types of field-biologists OR duct tape and imported plastic rings

Interesting fact; field gear tends to quickly define what kind of biologist you are. There are about 3-4 categories of field-biologists with occasional hybrids in-between.

1. You could be the nifty REI-type biologist with various field gear made with the newest and fanciest wizz-bang technology including new GPS units with colored screens and probably some form of blue-tooth, SPF and bug-repellent infused clothing, fancy tents, camp chairs that make have foot-rests, thermo-imaging technology, solar panels and of course a solar powered espresso maker. I think anyone who uses those fancy tree-canopy cranes for their research would automatically be in this group.

2. There are the old school biologists with field gear resembling a turn of the century expedition to deepest Africa. These biologists can be recognized by pre 1980 technology in well kept containers, binoculars and a classic field notebook in tow, and inevitably a coffee-peculator that they know exactly how to use, old well-worn coolers from the 1960s or 1970s. Perhaps we could consider these guys 'steam punk' biologists.

I think Jane Goodall (above) would fit into this category.

3. 'Old school' biologists can be easily confused with a similar type that I would call the Woodie-Guthrie /cowboy biologists. These are easily distinguished by (yes ok obvious) a cowboy hat or well worn cap but may also be noted by well worn boots, flannel shirts, field work conducted comfortably while wearing some old blue-jeans, a compass and topo map, and of course a green Stanley thermos. The coffee in a Woodie-Guthrie biologist's thermos incidentally is made one of two ways: the peculator method (above) or cowboy style by throwing some grounds into boiling coffee and then adding cold water prior to drinking to make the grounds drop to the bottom *cool trick right? Indeed, these last two kinds of biologists are full of cool tricks like how to cook a meal in a tin can using the sun, or how to noose a lizard with dental-floss and a stick. Ok and yes... many of my ways of defining these groups are their modes of coffee preparation and for that I apologize but it does hold true to a decent extent.

4. But there remains a final group and a group to which I admit I belong and I call this the duct-tape biologist. These are the biologists that have rigged nearly the entirely of their gear from odds and ends. They could make you a centrifuge from a drill or tube and piece of string. Their tents do not sit on pre-made foot prints but cut pieces of tarps. They do their field work sitting on the ground or on a nice rock or log. A decent portion of their gear is second-hand, hand-made or corner-store purchased and they make their coffee by pouring hot water through a canvass sock (trust me a topic that I will expand on at another time). Their field attire is hodge podge and can cover the range of looks above but only mixed-and matched leading to an overall-effect of Pippi Longstockings or McGyver. Come to think of it McGyver, which I have recently learned is a Spanish verb, would have made an excellent field-biologist.

So why are there these differences in types of biologists? For one it depends on what the person is studying or doing. If you are studying flight or biomechanics of animals you are likely an REI biologist because frankly you cannot Jerry-rig a high-speed video camera. If you do something considered 'classic biology' like behavioral observations of animals you may or may not find yourself more like the 2nd type of biologist in the field with just your eyes, binoculars and a notebook. If your work involves tracking (radio tracking etc.) animals you may be more of a Woodie-Guthrie type transversing the landscape as hobo-esque scientist.

Indeed in light of 'what you do dictates which of these types you may be categorized as' I have found that there are some things that you simply cannot buy... for example a bat traps in general cannot be purchased by typing 'bat trap' into an Amazon search engine. So some McGyver action must be used. I also cannot just search 'bat feces collection pans' and consequently I have become a duct-tape addict. In fact thanks to modern times I have decided to embrace my dependence by purchasing various colors under the valid excuse that hot-pink or yellow duct tape is easier to track down in a dark cave than the classic silver variety. Several people have suggested Duct tape may be a good sponsor for my research and I couldn't agree more (in the photo to the left you can see my bat nets with orange duct tape and my feces collection traps that while you cannot see from the photo are also held together by duct tape).

However there are some surprising things you cannot easily rig no-matter how much duct tape. I could not for the life of me 'make' a syringe or a pesola for that matter (a little scale for weighing things). For me the quintessential example of something unexpected that one must buy is that of little plastic bands with numbers to mark individual bats. I have found myself not only ordering fancy little plastic rings with special numbers for each bat but dependant on ordering them from a company in the United Kingdom! So I guess when you need something special it quickly becomes a narrow market. Are we really surprised that there is only one company known for making little rings with numbers to mark birds and bats? Probably not.

A Mexican Jamaican fruit bat unaware (I assume) that it is wearing a necklace a numbered bead imported from England via the United States.

Disney doesn't really do bats or do they?

So after a fun-filled day with my brother and nephew at Disneyland I started wondering about the role of bats at Disneyland. There are plenty of rides with hippos, lions, birds (a la' Tiki Tiki Tiki room), rides with raccoons, I saw about 4-5 skunks amid other creatures but what about bats? For those of you that know about hidden Mickeys (there is one hidden Mickey on every ride and various ones throughout the park) I decided to investigate the hidden bats of Disneyland and here is what I have found....

While walking into the Indiana Jones ride, there are bats in the 'archaeological site.' In fact they even come with a sign ! In fact the sign was a nice one asking passersby to not disturb the bats! Thanks Mickey! Meanwhile the fussing and buzzing of 'bats' can be heard as you casually enter the ride to explore the Temple of the Forbidden Eye with Indy. Pirates of the Caribbean also has its share of bats at the end of the ride keeping Captain Jack Sparrow company. Never mind that they have glowing eyes (bat eyes do not glow interesting concept however!) On Big Thunder Mountain (a roller coaster ride with a wild west theme) some bats can be seen in a mine!

So why do we care? I would suggest that if one was to spend some time looking though movies Disney or otherwise that bats are used to convey a feeling. Be it that you are entering a cave or mine, that it is night-time, or in other cases that things are 'creepy'. (An interesting association that maybe has less to do with bats and more that we are generally a little more frightened at night and in dark places than in actuality afraid of bats). What if bats went extinct, such as many species of bats in the Eastern US are now close to doing? These Eastern bats are in very serious trouble due to White Nose Syndrome. So while many people may not consciously notice the bats in these rides, or while watching movies it would be a tragedy if future generations no-longer knew them as actual animals and they entered the realm of 'fantasy' together with the spunky mice and talking duck we all grew up with.

Disney and other similar companies hold an amazing potential power for educating kids and the public in general. Happily, I was able to find a blurb about bats from Disney at this site (here).

Disney does fund research and I am curious to know if any of it has been directed at these little cave and night creatures particularly our friends in the Eastern US and those such as charismatic Flying Foxes. As we progress through 2011, the year of the bat here's hoping!

The bats that vamp... VAMPIRES

(an example of a Mythical vampire above and an actual (and rather cute) vampire bat to the right!)

While considering what to write about today and part of me was excited to go on some of my favorite bats- the sucker footed-bats that recently to my dismay were demonstrated to not really BE sucker-footed (long story... don't worry I'll get to this topic soon enough!) But then I thought that maybe that would be jumping ahead and skipping one of the classics.... vampire bats! (Leave it to me to skip the classics! My apologies)!

Did you know there are 3 kinds of vampire bats? When I say 3 kinds I mean 3 species. These are: the common vampire (Desmodus rotundus) (below you can see a common vampire bat on a cave wall), the Hairy-legged vampire (Diphylla ecaudata) (a face of which you can see to the right with its big eyes), and the White-winged vampire (Diaemus youngi). These bats are unique among all bats in that they are the only species that derive their entire diets from blood. Just to get those numbers straight out of the nearly 1100 bat species 3 are vampire bats. That's not very many. Indeed most bats eat insects or fruit and not blood. A diet of blood is actually fairly difficult because blood does not have all the usual components of a balanced diet and is also full of water meaning these animals need special digestive organs to be able to manage eating blood.

So for those vampire literature affectionados out there it is of note that vampire bats are from the 'New World' i.e. the Americans while most of our classic 'vampire' mythology comes from Europe ('Old World'). Vampires also do not 'suck' blood. They simply bite their host and lap up the blood that drips as a result of the wound. Indeed vampire bats have a very special saliva that prevents clotting (what happens when you develop a scab and you stop bleeding) so that they have a little longer to 'eat' before the wound closes. This special saliva has been researched by scientists and is now used in hospitals in cases where doctors need to prevent clotting in human patients! (Pending future post!...)

While vampire bats may SEEM scary they are quiet nice bats and even share food and are excellent mothers. We do not have vampire bats in the US with the exception of some places in Southern Texas.

Vampire bats are interesting for many reasons but also receive a bad reputation due to their diets. (Click here for a video from Animal Planet).

Other blood-feeding animals that are much more common than vampire bats:

• Ticks (see my 'tick' post)
• Mosquitoes (video)
• Bed bugs
• Fleas
• Leeches

and the less common but incredibly cool

• Vampire finch (click here for a video)!

Year of the bat

You may have heard of the year of the rat but have you heard of the year of the bat?

Aimed at increasing public awareness of the importance of bats United Nations Environmental Programe, Bat Conservation International, Conservation of Populations of Migratory Species of Wild Animals and Eurobats.org have named 2011 'the Year of the Bat!' Please go to http://www.yearofthebat.org/ if you would like to find out more!

Specifically find out what bat researchers near you are trying to do to help conserve bats by clicking here.

Next week in Mexico (March 26 and 27)

Bosques a Media Luna (click here)

In Australia (9th of April)

Bat box building workshop (click here)

Germany (1-3 April)

Bats between Nature and culture (click here)

Ticked at ticks and 'a day in the life of a tick'

Ok lets get this straight... I am a biologist and I love animals furry, scaly or otherwise. Because I prefer to study animals in the wild I am technically (in most regards a least) a field-biologist at heart. I have done most of my research in places that the average camping enthusiast would not immediately volunteer to venture- places like the Sonoran desert in July or August or the Chihuahan desert during monsoon season. So I am okay with many of the trials and tribulations of field-life: no electricity, sleeping on the ground often without a tent, no showers, avoiding cacti, snakes and flash floods. However... I have a confession. I hate ticks. No really I think they are horrible horrible little animals. Why? Let me just give you a visual depiction of how I view ticks:
I have been bit, stung and harassed by a variety of insects ranging from acacia ants, wasps, Velvet 'ants', to mosquitoes, even one time being bit by a mosquito literally ON my eyelid waking and being met with looks of terror from my fellow field-workers at my Quasimodo-esque appearance. However, I can count on one hand (or at least that was the case until my last trip to the field) the number of ticks I had had the dis-pleasure to encounter. I had convinced myself that my record: one Colorado tick and one Panama tick was due to a genetically coded body chemistry derived from my father's apparent mosquito-repelling composition. This idea was just fine for me- I have to admit that on both previous tick-encounters I had to be literally pinned down during the ridiculously belabored and meticulous process of tick removal...

How do you remove a tick and why should you care?
Carefully... very carefully with heat or something else to provide encouragement to back out of its position and pull its head (see above) out of your body. A warmed piece of metal like tweezers will do the trick. After it starts to wiggle and appeared annoyed you can carefully pull it out without getting its head stuck inside your skin. Can you start to see where my general dislike for ticks is ... embedded? What happens if the head is not removed? Infection. Infection and the perpetual knowledge that you have a nasty little tick head stuck in your skin! Yuck!

The facts:

• you cannot really feel the tick biting, and wouldn't notice it unless you saw or felt a bump where the tick was attached.
• ticks CAN carry diseases like Rocky Mountain Spotted Fever or Lyme's Disease but more often or not they are innocent creatures looking for a meal.
• many mammals are hosts to ticks including deer, cows and bats. Even some lizards and birds are infected by ticks
• click (HERE) for a video about ticks

So this last trip I discovered that I had a tick but unfortunately everyone was sound asleep. So I was left with two options: 1. Buck up and deal by removing it or 2. desperately wait for help while shuddering in my sleep picturing it munching away at my blood while I try to sleep... I bet I could feel its minuscule jaw wiggling as it ate! I chose (1) to try to remove it with no help to prevent my thrashing while I myself performed the nearly-ritualized removal. The suffering was not as bad as I expected although the process took an excessive 30 minuets! So all was well when the next day after walking to and from the cave for work I found I had no less than 12 more new friends to remove! I can now say I am at least proficient at most tick self-removal (we will not talk about the nearly dime sized 'friend; i had in the center of my back that I had to ask for help with!

So what if we try to picture life through a tick's eyes? What would we see? Would we feel less repulsed? I mean just knowing that the Spanish name for these guys 'garrapata' (leg grabbers) makes I will admit feel a little sorry for them for their unfortunately condition of being born ticks.

"I am so hungry ... I could just cry. The girls left weeks ago when they sensed a warmth below and they jumped terrified entangled in each others legs (all 16 legs 8 each). I did not hear a peep from below and I cannot convince myself that they made it safely. I will never know. I know of only 2 to 3 times when we ticks have been re-united with our loved ones. And now I sit. I wonder and I remember. I told them it was safer to wait until they sensed not just heat but also the CO2 that would let us know that finally an end to our weeks of starvation were at an end. I explained that the CO2 could ONLY be released by a host but heat could be tricky that they should be prudent and wait. But they were desperate. And now I am here. alone. ALONE. And so hungry. It would be fine with the memories of loves lost (my husband died months ago and now I hope that I will find food in time to lay my eggs so he will at least be remembered one day by his 2000 children). I did not ask for this life but it is mine to live and for my children I choose to hold on tightly to this blade of grass waiting... and waiting."

what is a bat wing anyway?

The scientific name for bats CHIROPTERA provides an answer to this question of 'what is a bat wing'?

Bats have very long finger bones and webbing between each finger except the thumb! (Note a Jamaican fruit bat thumb compared to my own to the left). Other mammals that glide (bats are the only true fliers among mammals) have webbing but just attached to different body parts like from the elbow to knees of some 'flying' squirrels (flying is in quotes because they are technically just gliding i.e. falling gracefully!)

Together webbing and log fingers is what comprises a bat wing. I have tried to demonstrate this in the form of a drawing (below).

Off to Puebla and Artibeus jamaicensis galore

Tomorrow at 7:30 I am meeting one of two Mexican undergraduate students who are accompanying me to my field site in the Mexican state of Puebla. After renting a car, navigating Mexico City we will pick up the second student, load all our materials and drive for about 6 hours through various habitats. The drive starts in the polluted and traffic-heavy streets of Mexico City, transitions to the very densly populated area known as 'Mexico State' and interestingly will pass near to the famous mexican pyramids. Then we drive up in elevation to a coniferous forested area and drop down to a dry desert area that is also the birth-place of corn as we know it! Gradually we will increase in elevation again entering warmer tropical dry forests and eventually cloud forests. Finally we arrive in the area my bats are located that is also home to bannana and coffee farmers!

Because the drive is long we will first secure where we are staying, and ask to use the centrifuge housed at a ranch near (~ 45 mins. away) to the cave and walk to the cave (~half an hour walk across cow pastures) by this time in the dark to put cloths under the bat colonies to collect the food they drop while they eat in the roost!

More news pending our return!

Meanwhile- bats or bust!

Lovely Leptos

I just got back from helping a student at the Mexican university UNAM with his thesis research on these gorgeous bats: Leptonycteris or Mexican Long-tounged bats. Leptonycteris or 'Leptos' for short, eat nectar and as you can see they get pollen stuck to their fur (the fuzzy white stuff on his head) which they take from flower to flower pollenating the plants they visit similar to bees. To understand how much energy these little bats need to obtain from their food and how much energy they use nightly we used something called 'the doubly labeled water method' which I will explain in another post so stay tuned. Meanwhile- recall bats are nocturnal so after working all night with a small break and again at 4am-6am I am going to say 'good-night' for now!

World War II's Other Secret Weapon- BAT BOMB

Believe it or not but during World War II plans were made and nearly successfully executed to attach tiny bombs onto bats. These bats would do what bats do- find nice areas to roost inside homes, with a catch, they had a bomb with them wherever they decided to call home. Because homes in Japan were made of wood and paper the idea was that bombs would destroy houses that were common throughout Japan.

Plans for what became called Project X-Ray was hatched by Donald Griffin, a Harvard scientist and famous bat researcher and a very young Jack Couffer among others.

An excellent and often funny book on the topic titled Bat Bomb by Jack Couffer tells the whole story. A famous bat named 'Flamethrower' is also discussed in the book. Flamethrower was a Mastiff bat (Eumops perotis) which is the largest bat that occurs in the US, weighing around 60 grams (~2 oz). Because the bombs that were designed for bats to carry needed to be small and light-weight Flamethrower who was tame was used as a model for various prototypes. The problem however was that Flamethrower as a Mastiff bat was much larger than the bats that were going to be used for Project X-Ray! Needless to say the project had so many problems (including unplanned bat-initiated explosions!) that it never went into action.

White nose syndrome- what is it?

White nose syndrome is a disease that infects bats and was first discovered in 2006. This disease kills bats while they are hibernating and was named for the unusual fuzzy white fungus that is evident on the nose of the some infected bats (click here to see photos).

This disease has killed bats in numerous states in the eastern US:

• Connecticut
• Delaware
• Maryland
• Massachusetts
• New Jersey
• New York
• New Hampshire
• Pennsylvania
• Tennessee
• Vermont
• Virginia
• West Virginia

And in Canada

• Ontario
• Quebec

It is estimated that over 1 million bats have died from this disease. The causes of white nose syndrome are still somewhat unclear however what is known is that a fungus previously undescribed (Geomyces destructans) infects the skin of bats infected by white nose syndrome. Bats that usually hibernate during the winter are having difficulties maintaining the fat deposits that they metabolize (break down) for energy during the winter. Without the fat stores required for hibernation, bats are staying active during cold winter temperatures which is energetically expensive particularly because food (insects) is limited during winter months.

Researchers are very concerned that the disease is moving west. Unfortunately the fungus associated with White Nose Syndrome has already been found in Oklahoma and Missouri.

Learn more about this disease by clicking HERE.

Getting ready for the field! Spring trip 2011

I am happily getting prepared for my next field trip. I plan on leaving for Mexico March 7th and visiting at least the 2 caves I work at in Puebla, Mexico and Morelos, Mexico. Additionally I hope to join a student who is working with one of my favorite bats: Leptonycteris (Mexican long-nosed bats). I hope to have lots of nice photos and stories to share during my trip!

Bat websites

Just in case you are intersted in learning more about bats here are a few suggested websites:

Bats in general:

Bats everywhere for kids!

More bat fun

Bats and plants

Bat sites by location:

Alaska bats

Arizona bats

California: bats of Orange County

Canada

Colorado: USGS bat research Costa Rica Louisiana Nevada New Mexico: Carlsbad Caverns New York Panama's Adaptable Bats (from National Geographic- with GREAT photos!) Texas: the famous CONGRESS BRIDGE (below) Utah

Desert bats

This may or may not come as a surprise but deserts are home to many species of bats. This is in part because of the ability of bats to fly long distances to access water, as well as the ease with which many species are able to extract water from their food (normally insects). Additionally, by being nocturnal (active at night while sleeping during the day) they limit their exposure to high temperatures i.e. the extreme daytime temperatures of desert days, by roosting in nice cool habitats like caves, abandoned mines and even rock piles.




So what are some of the desert bats in the US and Mexico?
To the left is one of the most unique species called the Pallid bat (Antrozous pallidus). These bats lovingly referred to as 'Werebats' by my co-workers in the field primarily eat large insects like scorpions, and centipedes in the American Southwest and Northern Mexico. They are known by biologists by their amazing ability to get almost all the water they need from the food they eat by having highly specialized kidneys (the organ responsible for concentrating and regulating the water in our bodies via a process termed osmoregulation). This little guy I captured in Arizona in at the KOFA National Wildlife Refuge.



Another interesting bat is the California leaf-nosed bat (Macrotus californicus) shown here on the left. Perhaps on first glance this bat looks quite similar to the first but look closely at its nose. You can see what researchers refer to as a 'leaf' on its nose. These bats are much more rare than Pallid bats and normally are only found in Mexico and in the US near the border in Arizona and California. These bats are not good at thermoregulation (keeping their bodies warm by producing heat) and shiver while you hold them to generate heat.

Here is another bat called the California myotis (Myotis californicus). These bats are smaller than the above species but much more common. While this bat was captured in Arizona the species ranges from Canada to Guatamala.

Photos (Saguaro cactus: T. Orr, bats: C. Gilman)

**Please come back as I update the species listed.