Jessie's RMBL Adventures

Saturday July 22, 2006

2006-07-19T19:06:00.000-07:00

Look really close!!! Who's looking back at you? It's the first chipmunk that's stayed still long enough for me to get a photo!

Hi everybody! This week we've been spending a lot of time on our rodent census- let me give you guys the low down...

Each evening, we bait 49 rodent traps with a mixture of peanut butter and oats. Here's what the traps look like:

Overnight, rodents are lured into the traps by tantalizing peanut butter/oat scents and step on a trigger that sets off the trap. Early the next morning , we check each trap. When we discover a sprung trap, we carefully empty it into a heavy plastic bag:

And here's what they look like in the bag- pretty cute:

Next, we identify, weigh, sex, and mark each individual. What do we catch? Lots of....

Jumping mice (Zapas princeps).

Deer mice (Paramyscus maniculatus).

And last, but not least... voles (Microtus montanus).

But the most exciting thing we caught this week...a weasel!!

Apparently, the weasel was pursuing a vole and the vole ran into the trap. As chance would have it, the weasel made it into the trap before the door closed, trapping both predator and prey. Needless to say, it was pretty gruesome. On the upside, it was probably a quick death for the vole; weasels kill their prey by separating the victim's vertebrate with their incisors. This method is so effective and efficient, weasels can dispatch of a den of small rodents within seconds.

And on to the beetles...

We've started a couple interesting behavioral experiments with the beetles. I'll give you a quick run through of one of the investigations- the orange dot experiment. So, as I've mentioned in previous posts, males fight over rights to the carcass. It's high stakes- the winner goes home with both the carcass and the female. Males have an orange dot on their forehead and we'd like to know if the size of this dot influences the outcome of the fight. Here's what the orange dot looks like- it's directly above the mandibles:

Anyways, we'd like to know if males are looking at other males and deciding if they have a reasonable chance of winning a fight. If the orange spot is used by males to judge one another prior to fighting and if the orange spot is advantageous to the fight, we'd predict males with larger orange dots would win more fights and thus, would secure more carcasses.

So, to examine this, we put males into equal sized pairs. We covered one male's orange dot with black paint and enlarged the the other male's dot with orange paint. Here's a male with an enlarged orange dot:

And here's one whose orange dot has been covered up:

Then, we placed the two males in a container with dirt, a female, and a dead mouse. Now we're letting them duke it out for a couple days.

However, we've run across one problem in our methodology. The paint used to alter the orange spots keeps rubbing off. We suspect it's because the beetles spend so much time digging through the soil- maybe the dirt is acting like a "make-up remover." Any suggestions on how to get the spots to stick???

Well that's it for now. Have a great week and I can't wait to hear how your own projects are going!

Well, one more thing...

This is the most recent plant to bloom, fireweed, or Chamerion angustifolium, of the evening primrose family. Note the lower flowers are blooming while the upper flowers have yet to open. This is known as potandry- it's a way to prevent the plant from pollinating itself.

Thursday July 13, 2006

2006-07-13T18:00:00.000-07:00

Hungry beetles getting a meal....

Hi guys,

I've got a special entry planned for today. First, I'll answer last week's intelligent (as always) questions and then... my roommate, Kim Ip, will explain some of her research on golden-mantled ground squirrels.

Hi Brittney,
So you're amazed tiny beetles can haul around a hefty mouse. I agree! Let's estimate the average burying beetle weighs in around .25 grams. And our burying beetles' ideal carcass weight is a 22 gram mouse. This means the male and female each haul 22 times their own weight! It's comparable to a 135lb woman carrying a small elephant, 1200 textbooks, or a med-sized truck! WOW!

I've got a couple movies of burying beetles performing this incredible feat, but I can't figure out how to upload them. I'll work on it, but in the meantime, be sure to check out the University of Nebraska's carrion beetle movie clips (super cool).

You also asked if carcasses lose mass as they decompose (thus making them lighter and easier to carry for the beetles). Carcasses definitely get lighter as they decompose- fluids evaporate and a whole slew of vertebrate scavengers and invertebrate (ants, flies, beetles, fungi, and bacteria) begin to feed upon the carcass. But get this, burying beetles are able to locate the carcass as soon as an hour after death (plus they can "smell" it from over a mile away). Quickly locating a carcass means less competion, but it also means a heavier carcass to haul and bury (burying = less competition). As are so many things in biology, it boils down to tradeoffs, in this case, more energy expenditure in exchange for less competition.

Hey Charlesatta,

Sure, I've encountered lots of cool Colorado critters, but most are animals you can see for yourself in St. Louis and the surronding areas. One of my favorite St. Louis places for viewing wildlife is Lone Elk Park. Lone Elk is full of bison, elk, waterfowl, deer, and more. To top it off, right across the street from Lone Elk, sits the World Bird Sanctuary and the Chubb Trail trailhead (great easy hiking). All within an half-hour of St. Louis City...

And regarding your question about wild animal encounters, most of the animals around here want nothing to do with humans, thus, they either ignore us or run away. We did receive pointers about how to handle a run-in with a bear (speak softly, back away slowly, stay away from cubs) or mountain lion (yell, make eye contact, don't run). Fortunately, I haven't had to put these pointers to the test.

Hi Tori,

Have you found any info on our fox scat/ trap phenomenon? It's happened a few more times, but I've decided to spare you guys the photos.

You asked what birds of prey are found here. Well, we have several members of Accepritridae (the eagle/hawk family), including sharp-skinned, red-tailed, and cooper's hawk, the northern goshawk, and bald and golden eagles. Do you know which are found in St. Louis? Also deserving of attention, we have the American kestrel, the smallest of North America's falcons.

Some cool facts about kestrels...after zeroing in on prey, they'll often dive to the ground and chase the prey down on foot...males and females form monogamous pairs that nest in cavities, especially woodpecker cavities...sometimes, they will even usurp occupied woodpecker cavities...

As for my favorite bird here...that's a tough one, but I'll have to go with the mountain chickadee, which looks to me like the eccentric crazy cousin of our black-capped chickadee:

I've received several questions about the black-billed magpies, so I'll try to address them in one fell swoop.
Black-billed magpies belong to the Corvidae family, and as a result, share many similarities with crows, ravens, and jays- including the susceptibility to West Nile Virus. While positive cases of West Nile have been documented in magpies, I'm unsure if the virus has decimated populations as was the case with crows in St. Louis. If you'd like to learn more about magpies, plus listen to a sound clip of their racous calls, click here.

(And Tori, I've yet to be harrassed by a magpie, but I'll keep you informed.)

And now I'll turn it over to Kim and her ground squirrels...

Hi! My name is Kim and I work with golden-mantled ground squirrels (Spermophilus lateralis) out here in Colorado.

My squirrels are probably the cutest mammals at the RMBL, with their big brown eyes, fluffy tails, and curious nature. They're also pretty chubby right now (around 200 grams for adults) because they're building their fat stores so that they can hibernate during the winter. They have until late September to eat everything they can before the snow sets in and forces them into their burrows for 7 months. Their burrows are underground and usually have 2 to 4 entrances. This is for protection in case a predator chases a squirrel into a burrow entrance. The predator will usually wait by that hole for a little bit and the squirrel can get away by sneaking out of a different entrance. Smart, aren't they?

So a little info about what I do....I spend half my time trapping squirrels and the other half watching and recording their behaviors. For trapping, I bait small wire cages with a combination of peanut butter and sunflower seeds rolled into a ball. The bait is put at the back of the trap so that a squirrel has to walk over a metal plate in order to get to it. When the squirrel steps on the plate it triggers the catch and the door to the trap quickly slams shut, trapping the squirrel. Once a squirrel gets caught in a trap I transfer it into a linen bag, put eartags in its ears (don't worry, the eartags don't hurt much; it's like getting your ears pierced), weigh it, determine gender, and put a unique black dye mark on it so that I can tell its identify from far away. The dye marks help with the second part of what I do, the behavioral observations.

When I've caught all the squirrels in an area I walk around and observe their behavior. It's important to know which squirrel is doing which behavior so we put the dye marks on them as sort of a name tag. Everytime I see a squirrel I write down who they are, what they're doing (eating, grooming, watching, playing), what time it is, and their location. This allows me to figure out how much of their day they spend doing certain activities. It also tells me each individual's home range. That's important data for me because I'm studying spatial orientation and habitat selection.

The summer started off with 22 adult squirrels living at the RMBL. Now it's down to around 14 adults because of the red fox, who also lives here.

The fox has 2 kits she has to feed so she's been decimating the squirrel population. The squirrels are fairly large for rodents and easy to spot because they run around on the ground so the fox has been hunting them down. I have to keep track of the life history of every squirrel at the RMBL, which means knowing how they die. Everytime someone tells me that they've seen a dead squirrel I have to try to find the body and determine its identity. Doing this helps me figure out survival rates from year to year. Unfortunately, verifying the identities of dead squirrels is difficult if the red fox is involved. Once, she walked right past me with a dead ground squirrel in her mouth and I started chasing her, hoping that she'd get scared and drop the squirrel so that I could look at its eartags. After a good 5 minutes of flat-out sprinting I finally cornered her by a building. She must not have liked that because she dropped the squirrel and charged me, growling the entire time. Luckily, she stopped about 5 feet away from me, but I got the picture. That's one squirrel identity I'll never know.

Anyway, that's a quick overview of what I do here at the RMBL. Currently, 8 litters of baby squirrels have emerged so I have my hands full trapping and marking all the pups. Baby squirrels are so adorable and I'm really excited that I get to work with them. Thanks for reading about my study!

Thursday July 6, 2006

2006-07-06T15:42:00.000-07:00

Hello all! This week has been all about the rodent trapping. We catch deer mice, voles, and lots of jumping mice.

Also, in preparation for collecting beetle larvae, we've set out some mouse carcasses:

Note the bright yellow string tied to the mouse's leg. This is so when the beetles bury the carcass, we'll be able to relocate it, the beetle mating pair, as well as their larvae.

Soon after the beetles locate the carcass and a mate (which happened within 4 hours of setting out the carcasses!), they scout about, searching for a suitable place to bury their treasure. The beetle below has decided to use the hole (to the upper left of the beetle). Good choice, using a hole means less digging, less burying, less energy expenditure on the beetle's behalf...

Next, the beetle pair carries their carcass to the hole:

And bury it. Notice the string and the carcass's white ID tag are the only things sticking out of the ground. The carcass is buried just below where the ID tag is:

Now we wait about 10 days- during this time the beetles will process the carcass (see June 20 entry for more about that), mate, the female will lay eggs, the eggs will hatch into larvae, and finally, we'll collect the larvae...

Q & A time!

To Kate, who wanted to know why burying beetles are orange and black:

In nature, bright colors often indicate one of two things to potential predators, that the organism is poisonous or it's unpalatable. These fairly obvious markings serve as a warning to potential predators that these organisms are better left alone. This phenomenon is known as aposematism and there are many examples of it in the animal world, such as:

The paper wasp:

The poison dart frog:

And our friend, the burying beetle:

Besides aposematism, the burying beetle has other defense mechanisms up its sleeve. Beetles may play dead if threatened. Beetles may also "squeak" to scare away potential predators. Called stridulation, squeaking occurs when the beetles rub their legs against their abdomen, creating high-pitched sounds (similar to how crickets, grashoppers, and cicadas produce sounds). And last, but not least, the burying beetle has the ability to secrete extremely foul-smelling fluids from its mouth and anus (note our use of gloves in all the photos).

Hello Charlesatta,

To answer your question about acclimating to St. Louis, I've heard when people descend to lower elevations they feel super human for about a week and then readjust back to their usual selves. But... I've got the feeling it'll be pretty difficult to readjust to St. Louis weather in August!

You also asked if I've had any encounters with larger animals. Well, by strolling around at night without my flashlight, I've been trying to train my eyes to become better acustomed to darkness. This is perhaps a futile effort on my part, but it's how I nearly walked into a mule deer on the way back to my cabin. Mule deer are common throughout Colorado and are named for their particularly large ears.

This area has several other larger species including elk, black bear, mountain lion, bighorn sheep, lynx, and mountain goat, but I haven't been fortunate enough to encounter them yet. I'll keep you posted.

Hi Tori,

You had a great question, inquiring why I'm able to get so many photos of wild animals. Well, first off, I'm in a pretty remote location. There are many more animals here than in more urban locations such as St. Louis and the surronding areas. As a result, I'm more likely to run into animals while I have my camera handy. Furthermore, many of the animals I've gotten close to are babies and most of these I've unintentionaly stumbled across. The best protection for these young animals (aka potential food for predators) is to hide and remain hidden. I'm much less likely to notice the fawn hidden in tall grass versus the fawn bounding across the meadow.

As for our resident fox, I think she's simply taking advantage of Gothic's large rodent population. She probably has never been threatened by a human and therefore isn't shy around us. As a side note, we've finally fox-proofed our beetle traps by placing heavy stones on top of them. Oftentimes, when we go to check them, this is what we encounter:

Fox scat on our traps!! This has happened at least 6 times so far. Does anyone have an hypothesis as to why this may be occuring? If so, let us know...

Tori, you also asked about Gothic's birds. Several Missouri species are also found in this area of the Rockies, such as the downy and hairy woodpeckers, northern flickers, crows, robins, black-capped chickadees, nuthatches, and wrens, to name a few.

Here's a photo of the black-billed magpie, a member of the crow family (Corvidae) I'd never seen before, but that's quite common in these parts:

Magpies are notorious camp robbers, taking advantage of food left unattended at campsites, sometimes even entering tents! Male and female magpies form long-term pair bonds and together construct large messy domed nests that are later used by other birds and mammals.

Hi Lizanne, Mark, and Thomas!

I must admit, you guys have got me stumped on your bluebird observations. While mountain and eastern bluebird ranges do overlap, the overlap doesn't occur near the St. Louis/Dupo regions. I believe there's been documented rare occurences of mountain and eastern bluebirds mating, but I think these matings produced infertile eggs. I did come across this site that may prove helpful: North American Bluebird Society.

We have a healthy population of mountain bluebirds around Gothic, this one's a male:

One cool thing about bluebirds is that while they're brillant blue, there's no blue pigment in their feathers. The blue color is created when incoming light is scattered about by inner feather structures. In fact, if a blue feather is crushed, it's brillant blue hue will turn to brown.

One more thing... here's my latest whistle-pig photo...

Thursday June 29, 2006

2006-06-29T17:01:00.000-07:00

Fun picture first this time...can you spot the three chillin' marmots?

Hi guys... the week is nearly done and I must admit, I'm ready for some R&R. Maybe now is a good time to answer Aleks' question, what does my average day look like? Why don't I use today as an example...

6:00am: The alarm sounds and I stumble downstairs, gaining speed as I go- it's COLD here in the morning. I make my way to the outhouse (also cold), do my duties, and gratefully rush back inside. If I haven't hit the snooze button one too many times, I eat some toast, but more likely then not, I race out the door to meet with Dr. Smith and Bill, my fellow RA.

7:00am: We hop on our trusty field vechicles and pedal to Kettle Ponds, our low elevation site:

7:20am: Made it! Now we really get down to buisness... checking 49 rodent traps and 10 beetle traps (remember, our field data will be used for population censuses).

Rodent traps first; we don't want any trapped mice overheating in the quickly warming morning. When we discover a sprung trap, we empty the contents (rodent, food, bedding) into a plastic bag.

Then we weigh the bag plus its contents (later we weigh the bag without the mouse; by subtracting this from the previous weight, we can determine the rodent's weight). Next we carefully retrieve the rodent from the bag, by firmly grasping it behind its neck.

Once out of the bag, we sex the individual and mark it by brushing a thin line of black dye along its belly. Marking the rodents is crucial to our population census because it allows us to know if we've caught the same individual more than once. The method we use to estimate the population size is called the mark-recapture method and here's an abbreviated version of how it works:

1. A sample of the poplulation is caught and marked with an identifier (in our case, black dye).
2. The marked individuals are released back into their environment and enough time is given to allow them to mix with the rest of the population (aka- the unmarked individuals).
3. Then, another sample of the population is caught. This time, some of the trapped individuals will already be marked (recaptures) and others will be caught for the first time.
4. Finally, by plugging the number of captures and recaptures into an algebraic formula, the population size of a certain area can be estimated.

Anyways, after the rodent is marked, we place it on the ground exactly where the trap was set. Exact placement is important since some rodents have quite small ranges- we don't want to place them in a new or foreign location.

8:30am: On to the slightly smellier, but no less exciting, beetle traps. And one very important announcement here...

THE BURYING BEETLES HAVE EMERGED!!!

And here's how we check the beetle traps... first, we remove the mesh covering and look to see if any of our guys are crawling on the surface of the carcass/chicken/soil. We also poke around in the soil; if it's warm, the beetles will often burrow underground.

When we capture a beetle, first we decide if it's male or female. Usually, males have a large orange dot on their face and hairy front legs, whereas females are dotless and hairless. However, there's always exceptions to the rule and when in doubt, we squeeze the beetle's belly. This causes the beetle's genitals to pop out (they're hidden otherwise) and then a positive identification can be made.

After sexing, we measure the length of the beetle's wing coverings or elytra. Elytra length is correlated to size, thus it's a quick and easy way to measure how large a beetle is out in the field. Finally, we mark the beetle by snipping a small shape into its elytra. Don't worry- this doesn't harm the beetle or inhibit its flying ability. Once again, this mark will allow us to recognize recaptures for our population census.

9:30am: We bike back to Gothic for a coffee/breakfast/nap break. I trudge up the hill to my cabin and jot a letter to Mom, assuring her I'm still alive and well.

10:30am: Soon enough, we're off to Belleview Mountain (high altitude field site) to check the rodent and beetle traps there...speaking of Belleview, this is what we found on our hike up the mountain:
(She's a baby snowshoe hare...)

1:00pm: Lunch!!! I scarf down leftover macaroni and cheese (the fancy kind!) and treat myself to a couple of my roommate's homemade cookies...

2:00pm: We enter today's data onto Excel spreadsheets, sex, weigh, and tag mouse carcasses (see my June 20th entry for more on that) and finally... the rest of the day's mine...

4:00pm: A much needed shower!!!

Well, I'm running out of time so I'll have to depart. Hope all is well in St. Louis and with your own projects!

Tuesday June 27, 2006

2006-06-27T17:47:00.000-07:00

First off, let me say how impressed I am with all the intelligent and thought-provoking questions and observations I've received. I'll spend the rest of this entry addressing these very insightful comments.

Charlesatta,
Hello! I'm having a blast up here and there's wildlife everywhere. Since I know you guys are into sparrows, here's a little natural history about one of the sparrows around here, the white-crowned sparrow (Zonotrichia leucophrys):

The white-crowned sparrow's song is made up of long whistles followed by shorter trills. Females select which males to mate with based on their songs. Males learn their song at a young age by listening to the songs sung around them. Because males learn to sing from their environment and migrate to the same location each spring, lots of regional "dialects" exist in the white-crowned sparrow song. In fact, some people can tell which valley of the Rockies they're in just by listening to the white-crowned sparrow's song! Another cool tidbit, both males and females of this species get pretty territorial during the breeding season and will readily challenge invaders to of all things, singing contests!

Hi Tori,
Opportunities abound for you to do biology fieldwork. And lots of them don't involve insects (well, at least not as the study organism). For example, here at RMBL, scientists are studying marmots, ground squirrels, woodpeckers, plant communities, climate change, and the list goes on. And as a side note, RMBL offers on-site summer college courses in subjects like ornithology, animal behavior, field ecology, etc. They also have a NSF program called Research Experience for Undergraduates (aka REU), where undergrads spend 10 weeks working with a scientist mentor on their own field research project here at Gothic. If you'd like to learn more about these programs, here's the link to RMBL's homepage: rmbl.org. These are opportunities you guys should keep in mind as you begin your college careers.

Brittney,
Hi! While I'm slowly adjusting to the altitude, I'm also coming to terms with the fact that I'm not as fit as I previously thought! Oh well...I'm sure the mountains will whip me into shape soon enough. Here's a photo of our high altitude field site, Belleview Mountain. We work about halfway up it:

And here's a photo of me, exhausted and collecting data, after hiking up Belleview:

Hello Anna,
One of the many things that interests me about our burying beetles is their complex reproductive behaviors (see June 20th post). We tend to associate parental care with vertebrates or the social hymenoptera (ants, bees, wasps). Burying beetles are a fascinating exception to this generalization. And last, but not least, the burying beetle research being conducted at RMBL has wider implications. For example, Dr. Smith has discovered if the larval sizes (small, medium, or large) of a brood is known, then by applying probabilities one can reasonably predict how many larvae will emerge as adults (vs. how many will die during winter). The ability to predict how many adults will emerge from a given brood may be useful for programs aimed at the conservation of another species of burying beetle, the critically endangered American burying beetle (Nicrophorus americanus). In fact, the St. Louis Zoo's Insectarium runs both a breeding and reintroduction program for the American burying beetle (which, by the way, is native to, but has been extirpated from, Missouri). If you'd like to learn more about the Zoo's program and see some cool burying beetle pictures, click here.

Oh and one more cool thing about our burying beetles....they share a symbiotic relationship with a species of mite (the mites are the little brown things on the burying beetle's head- I know, ewww!!):

Symbiosis is a close relationship between individuals of two different species. In this case, the relationship is termed mutualistic symbiosis because both the beetle and the mites benefit from associating with each other. The mites live on the beetle till the beetle locates and buries a carcass. Then the mites leap off and eat any fly eggs that have been deposited on the carcass. No fly eggs translates into no maggots which means more food for the burying beetle larvae. The mites also help to keep the beetles clean while they do their dirty work.

Hi Lyndell,
We thought for sure we had outwitted the fox, but this is what we encountered when we went to check the beetle traps this afternoon:

So we've tried reinforcing the traps with heavier stones. If she can get to the meat now, she's either got super fox powers or a backhoe. I can't be too upset with her though, she's scavenging in part for her litter of pups. They're living in a drain pipe in the middle of town:

We do check the beetle traps everyday. We haven't gotten beetles yet, but in the past they've emerged around June 29th (only a couple of days away!). However, we still check and record the absence of beetles in our log books. This is important negative data for us because when the beetles do emerge, we'll be able to give a specific date. Conversely, if we were only checking the traps every once in awhile, we wouldn't be able to say with certainty when the beetles emerge.

The beetles we trap at our high and low elevation field sites are weighed, sexed, marked, and released. This data will be used in a population census. We also have 5 traps set up around Gothic; these beetles will be kept and used in behavioral and reproduction experiments. I'm not sure what the details of these experiments are yet, but when I find out I'll let you know!

Hi Nathan,
Thanks for the great comments! There are some pretty marked differences between the beetle populations at high and low elevations. Here's a run-through:

- Population Density: While beetle populations fluctuate yearly at both sites, there are always significantly more beetles at lower elevations.

- Morphology: Beetles at higher elevations tend to be larger than the beetles found at lower elevations. This may be in part due to:

- Differences in Reproductive Behavior: At the high elevation site, females lay about the same number of eggs, regardless of the size of the carcass. This means that if the eggs are on a large carcass, the hatched larvae will have more to eat, and eventually emerge as larger adult beetles. On the other hand, at the low elevation site, the number of eggs increases with increasing carcass size. This means, there will be more larvae on a larger carcass. As a result, larvae at lower elevations tend to be of a more uniform size.

You might ask why these differences between high and low populations exist? Well, that's one of the things we'd like to know too! Perhaps it's caused by environmental cues or maybe it's genetic. One of Dr. Smith's graduate students, Kira Pontius, is delving into this question. She plans to breed high elevation beetles at low elevation sites and low elevation beetles at high elevation sites. If the high elevation beetles bred at low elevation sites still produce offspring with characteristics of high elevation beetles, we can infer that environmental cues do not play a large part in the differences seen between the two populations. Instead, there may be a genetic component. However, it the high altitude beetles bred at low altitudes suddenly produce smaller babies whose larval numbers are dependent upon carcass size, we can infer that there must be some environmental cue that is dictating these differences.

As for abiotic differences between the two sites, let's see...there is less air pressure at the high elevation site. It is definitely a harsher environment- it is consistently colder, with higher winds, later snowmelt, etc. The soil types also differ, with the high elevation site being more rocky. As for biotic factors, past yearly censuses have shown there are less rodents at the high elevation site (by the way, great observation on the rodent-beetle population correlation). There may also be differences in the amount and type of competition at the two sites. Burying beetles experience two types of competition over their food resource, interspecific, which is competition with other species (think carrion flies, ants, and fungi) and intraspecific competition, which is competition between members of the same species. Intraspecific competition occurs when the burying beetles fight over who gets the deed to the rodent carcass.

And switching gears, on to the ground-nesting birds...yes, raccoons could definitely threaten populations of ground-nesting birds. Furthermore, raccoons are one of the highly adaptable species that have thrived in the midst of human encroachment and development. Surprisingly, we don't have raccoons in this area of the Rockies. Another species that's greatly contributed to the decline in numbers of ground-nesting and flightless bird species is none other that the domesticated house cat. While cats make sweet and affectionate pets, we must remeber they are skilled and effective predators. Case in point:

These are specimens of the Stephens Island Wren, a small flightless bird that was once endemic to St. Stephens Island in New Zealand. In the late 1800s, a lighthouse keeper brought his cat, Tibbles, to the island. Killing and bringing home several individuals each day, Tibbles hunted the Stephens Island Wren into extinction within the span of just one year.

Click here for an interesting article about cat predation in Missouri.

Once again, I want to say thanks for all your questions and comments. Keep them coming!

Thursday June 22, 2006

2006-06-22T19:42:00.000-07:00

Hi guys. Today was my first day of real field work and I'm exhausted! We were out bright and early this morning to set up beetle traps and transects for rodent traps at two field sites (photos coming soon!). These traps are going to be used for population census studies. Dr. Smith, the scientist I'm working for, has been recording populations of both burying beetles and small rodents since 1995. She has found when there's a large rodent population one summer, there's a large burying beetle population the following summer. (Why do you think that is?) Because Dr. Smith has noticed differences in beetle populations at varying elevations, we have field sites at both high and low altitiudes. These differences are pretty extensive, ranging from population density to morphology to reproductive behaviors. These are some of the variables we'll investigate this summer.

Let me describe the burying beetle traps. They are large tin cans with holes punched in the bottom (for water drainage). We fill the cans with a little bit of soil and place a chicken leg on top of the soil: Then we rubberband a piece of wire mesh over the can:

The wire mesh has a hole in the middle and we push this area inward, creating a funnel shape. Then the can is buried, leaving only the top exposed. Because we have a very wily red fox running about, we cover the trap with a sturdier piece of wire mesh, held down with large stones:
Here's how the trap works: burying beetles smell the rotting meat and are attracted to the trap. They locate the hole in the wire mesh and enter the can to feast upon the chicken leg. Once they're full, the beetles attempt to crawl up and out of the can, however the wire mesh's funnel shape means the hole is not at the top, it's slightly lower. The beetles' tendency is to continue crawling upward, therefore they don't locate the exit hole and are trapped. Ingenious...now all we do is wait...

What else have I been up to?

While I'm still adjusting to the altitude, I've been doing some hiking about. This is a photo of the big blue grouse (Dendragapus obscurus) that scared the living daylights out of me when it burst out of the brush into my path. Grouse are well adapted to life on the ground; they rarely fly. In fact, females even make their nests on the ground. (Can you think of any invasive species/domesticated animals that have the potential to threaten populations of ground-dwelling birds?) Grouse feed on insects and vegetation they forage from forest floors and meadows. They don't eat right away, instead they store food in a crop at the base of their neck. Later on, when the bird is resting, the food is emptied into their stomachs and digested. Turkeys and guinea perform this same gastronomic feat.

More to come soon....

Tuesday June 20, 2006

2006-06-20T18:23:00.000-07:00

Hey guys. Well I made it out here/up here safe and sound. I'm in the southwestern Rockies in an old mining town called Gothic. During the goldrush, Gothic was a big and bustling town, but it was eventually bypassed in search of more promising areas. It survived as a ghost town until the earlier 1900s, when Gothic was converted into a biology field station, the Rocky Mountain Biological Lab. This summer, there are about 40 different projects going on and I'll introduce you to some of them as the season gets under way. But first things first...

It's beautiful out here. Here's my view when I step outside my cabin:

Isn't that crazy!?! All I want to do is get out and explore the mountains, but I'm still adjusting to the altitude difference. While St. Louis is 465 feet above sea level, Gothic is 9500 feet. A 9000 foot difference in elevation can really do one in. There's less oxygen in the air here than there is in St. Louis, plus the lower atmospheric pressure means it's harder to absorb the oxygen that is present. This translates into me huffing and puffing all the time. Especially, climbing the hill to my cabin. But with the view, I shouldn't complain...

I'm sharing my cabin with 3 other people (soon to be 5). It has two stories (well one is an attic); the bottom floor is a kitchen/living room:

And the topfloor is divided into 6 sleeping areas remniscent of horse stalls. Here's mine:

Pretty cozy...

Unfortunately, I can't explain my project in detail yet. The scientist I'll be working under, Dr. Rosemary Smith, isn't arriving till later this week. I can however, relate some cool life history tidbits about the organism I'm studying, the burying beetle, genus Nicrophorus. These little guys are carrion beetles; their diet consists of small dead rodents. Male and female pairs locate recently deceased rodents by smell. Once located, they excavate the ground beneath the carcass, in effect slowly burying it (hence their name). Burying the carcass means the beetles don't have to deal with competition from other scavengers, such as maggots. Once buried, the beetles remove all the fur from the dead rodent, chew the flesh into a ball shape, and secrete an antibacterial substance the slows the carcass' decomposition. Then the female lays 10-30 eggs in a chamber she has created above the body. Soon the eggs hatch into grub-like larvae (see photo to right) and both parents feed their babies by regurgitating portions of the carcass. It's really rare to see this type of parental care in beetles, because it's a behavior that's usually restricted to social insects like ants, bees, and wasps. As the larvae develop, the parents continue to tend to the carcass, removing mold/fungii and secreting more antibacterial substances. After about a week, the larvae have consumed all but the bones of the carcass. At this point, the parents fly away and the larvae enter pupation.

Yesterday, we processed about 30 mice carcasses that had been caught in cabins over the winter. These are going to be used as food for burying beetle mating pairs. First, we determined the sex of each individual. After sexing, we weighed each carcass, gave it an unique number, and returned it to the freezer. We need to know carcass' weights because carcass mass influences how many eggs the female decides to lay... and this is one of the things we plan to investigate. Note in the photo, I'm wearing a hepa-filter mask. This is a precaution against the Hantavirus, a nasty virus carried by rodents that's 50% lethal if contracted. There haven't been any cases of Hantavirus at Gothic, but better safe than sorry.

One more thing...

This is a photo I got on my way to the computer lab to type up this entry. This fat critter is a Yellow-Bellied Marmot (Marmota flaviventris), a rodent we sure don't have in St. Louis. They're also known as whistle-pigs; they whistle to one another to warn their colony of danger. Anyways, marmots are all over Gothic. In fact, we have to keep the outhouse toliet lids closed so they don't fall in (they're quite curious) and suffer horrendous deaths. Last summer, a marmot did fall in- thankfully, someone pulled him out in the nick of time. He had to be decontaminated and the cleaning stripped his fur of its natural oils. As a result, he looked like he was sporting a marmot 'fro for the next couple days...