Sunday, February 26, 2012

Living in the Sticks

Much like human homes, woodrat houses have a life to them - they're built anew, they age and decay, get damaged and renovated, handed down to kids, patched, abandoned, taken-over, redecorated and restored. Rooms are added, halls expanded, entries altered, and back stoops sometimes re-stooped. And, the roof is constantly getting tweaks - for drafts and leaks.

But at their core, all successful fuscipes houses have a strict architectural commonality: they're built like castles of yore - in-and-around a solid natural feature, that can't easily be dug out, torn apart, or burned through. E.g., a jumble of rocks, a tight cluster of trees or shrubs, a hollow log or stump, an abandoned car, an old fridge or outhouse...

woodrat stick house
Dusky-footed woodrat stick house in center of multi-trunk California buckeye tree

woodrat stick house
Stick house in cluster of rocks and bay laurel trees

woodrat stick house
Stick house in, over and around, a hollow and downed-but-live coast live oak

woodrat stick house
House in jumble of rocks and chaparral (chamise, toyon, ceanothus, coffeeberry...)

woodrat midden
Front end of car and bay laurel trees

creative woodrat
Old refrigerator/cooler and buried junk

neotoma power
Engine compartment and gap between rock, car and big bay tree

active woodrat nest in outhouse
Stick house in old outhouse in Sierra Nevada foothills. Folks also call woodrat houses "dens," "nests," "lodges" and "middens," the last working doubly well in this case

I.e., a fortress that coyotes, foxes, and badgers can't easily huff, puff and blow down. At least not until woodie safely scurries away. Seriously - can you imagine what a Cal grizz of days-gone-by could do to a free-standing stick house? One paw swipe and - poooom - brown bear would be sampling pantries & tenants before the twigs finished raining down.

woodrat stick house
Stick house in chaparral a coyote tried to dig out - until it ran into the hard, rocky center

Since they aren't burrowers, it's likely woodrats lived in and under things (as do their deer mice cousins), and then picked up the behavior of stick/rock/object collecting more recently in their evolution. Perhaps as a side-effect of their food caching that persisted for its benefits to safety and greater storage (to narrow cave and hollow-tree holes?).

Building materials... Be they branches, bark, leaves, twigs, or like, the "sticks" fuscipes use seem to be chosen first and foremost for availability, and then perhaps for climate needs and the woodie's sense of style. I say the last only 1/2 in jest - check out some of these hip homes...

woodrat stick house
House against base of a downed-but-live coast live oak, made out of eucalyptus bark

woodrat stick house
House made mostly of chunks of bark and rotted log

woodrat stick house
House in tangle made with some seriously large branches - a few are over 24" inches long. The typical adult Neotoma fuscipes is 8" long, with an 8" tail, so the equivalence is us dragging 8" diameter, 15-foot long, 100lb wooden beams around - with our mouths

In fact, there's an amazing story from the 1877 American Journal of Science of an "Iron-clad Nest" that highlights their building prowess and penchant for stick-shaped materials...

"This house (in Oregon) was left uninhabited for two years, and, being at some distance from the little settlement, it was frequently broken into by tramps who sought a shelter for the night. When I entered this house I was astonished to see an immense Rat's nest on the empty stove. On examining the nest, which was about five feet in height, and occupied the whole top of the stove (a large range), I found the outside to be composed entirely of spikes, all laid with symmetry, so as to present the points of the nails outward. In the center of this mass was the nest, composed of finely divided fibers of the hemp packaging. Interlaced with the spikes we found the following: About three dozen knives, forks, and spoons, all the butcher knives, three in number, a large carving knife, fork, and steel, several large plugs of tobacco; the outer casing of a silver watch was disposed in one part of the pile, the glass of the same watch in another, and the works in still another; an old purse containing some silver, matches and tobacco; nearly all the small tools from the closets, among them several large augers... all of which must have been transported some distance, as they were originally stored in different parts of the house. The articles of value, were, I think, stolen from the men who had broken in to the house for temporary lodging."

A perfect example of a generalist builder that specialized locally.

As mentioned, climate may also play a role in material choice. Here's a great example of a house in the Sierra Nevada foothills, where, in fall, some dusky-footers add a fresh layer of hand-sized black oak leaf "shingles" to help keep heat in, and rain & snow out:

woodrat midden
House in Sierra Nevada with black oak leaves and pine cones for weather protection

In some habitats, their choice of leaves for filling cracks and such has proven extra beneficial. For example, in the Santa Cruz Mountains, where Neotoma fuscipes annectens collect bay laurel and eucalyptus leaves for both food and roof repair, the oils in the leaves rub off on them, and help reduce the number of ectoparasites they carry (e.g., ticks and fleas).

And yes, those leaves and twigs in their walls are often back up food sources.

Occasionally, woodrats - both males and females - build in trees. Always fighting gravity and wind, these houses don't usually last long though. The added safety isn't worth the extra work.

woodrat stick house
Tree house 10 feet up a coast live oak that's made of nipped off branches from the tree

Not all dusky-footed woodrat houses have stick piles, btw. If they find a safe space that doesn't need clogging up, such as in a hollow tree, tight rock crevice, wood pile, or attic - the woodie may not add any sticks, and go stealth. But, being a clever critter, it's also possible they do this just to purposefully annoy the scientists trying to determine their population densities.

Now let's talk woodrat interior design...

The main room of the house - the nesting chamber - is what the lodge was actually built around, and is usually tucked away in the toughest, safest location of the house. I.e., the center of the hollow log, the deepest crack between the rocks, or a remote recess of the tree trunk cavity.

perfect woodrat nest
True woodrat "nesting chamber" - where the home owner sleeps, has pups, etc. This one is made of oat straw and cedar shreddings, and is hidden in a stack of firewood. Note the bedside snack of hollyleaf redberry and buckbrush ceanothus - yum!

That core nesting chamber is connected to multiple pantries, entries and back doors by a series of small "tunnels" that the woodrats chew through the sticks, as needed. And, as a house gets larger and older, the number of corridors, pantries, nooks and exits often increases to the point where some aren't actively used. Which may be where a few of the housemates live.

Pantries are here-and-there in the house, and often item specific - oak and toyon leaves in one, fungi in another, and acorns in a 3rd... However, this separate stashing may have to do with the temperature and drying needs of the food source, and not woodrat OCD. The sensitive woodies are well-known for their climate control - so much so, that Native Americans were rumored to hide items in their houses on occasion, knowing they'd never rot.

sectioned midden
Accidentally sectioned house showing central tunnel from one side to other that's under the protection of the core structural log, and quite dry

Because woodies haven't developed inside plumbing yet, they poop on the back stoop. I.e., not inside their house. Unless weather or safety doesn't allow, of course - then they poop in the doorway and clean it out later. Thus, if you find a latrine, there's a rear door near by.

woodrat poop
Woodrat latrine - also in a pile of old firewood, but on periphery of the core living area where nesting chamber and food pantries are

Building codes, intelligent interior design, outside toilets, and ecologically-conscious community construction. And we call ourselves the first truly civilized species.  :)

Hope you've enjoyed this week's episode of This Old Woodrat House.

Editor's Post-Note: here are 6 woodrat stories that included this post, in order:
====
References: 
  • A. W. Chase, American Journal of Science, 1877 - An Iron-clad Nest
  • H.E. Anthony, J. Walker McSpadden, The University Society, 1917 - Mammals of America
  • Linsdale and Tevis, UCPress - The Dusky-footed Wood Rat
  • The American Society of Mammalogists, Nov 1991, No. 386 - Neotoma fuscipes
  • Dr. C. Hart Merriam - Abstract of a study of the American wood rats, with descriptions of fourteen new species and subspecies of the genus Neotoma, Proceedings of the Biological Society of Washington
  • E. W. Jameson, Jr., and Hans J. Peeters, UCPress - Mammals of California
  • Smithsonian National Museum of Natural History - Neotoma fuscipes
  • Wikipedia - Neotoma fuscipes
  • Nature of a Man (this blog) - Life on Berry Lane
  • Nature of a Man (this blog) - The Ecotones
  • Nature of a Man (this blog) - Battles Under the Bay Laurel
  • Nature of a Man (this blog) - The Coast Packrats
==========

Sunday, February 12, 2012

Life on Berry Lane

If the Ecotones' stick house is situated in a hip, connected, edge-of-the-city neighborhood, then the house of Lady Prunus is on one of those classic, quiet, colonial, tree-lined lanes - in an old neighborhood, where droppin' by for a cuppa coffee is commonplace.

And those trees on the lane? Hollyleaf Cherry, Prunus ilicifolia, California Coffeeberry, Frangula californica, and Christmasberry, Heteromeles arbutifolia, also called Toyon.

prunus house  prunus
The house of Lady Prunus is in a cluster of toyon (that's the cam trap in the foreground), and right next to 2 big hollyleaf cherry, and several California coffeeberry

lady prunus
"May I help you?" Lady Prunus, sitting on her front porch, giving the camera a look-see. She seems a bit plump - I wonder if woodrats "show" when they're pregnant?

lady prunus
Heading out on some errands. She has a branch highway too (or root sidewalk?)

cuppa coffeeberry?
Coming back with a cuppa California coffeeberry

Now we know why she lives on Berry Lane. In fact, Neotoma fuscipes annectens is a herbie that will happily eat the leaves, buds and fruit of all 3 species, with toyon and coffeeberry being top foods. They also forage the foliage/fruits/seeds/acorns of live oak, bay laurel, willow, poison oak, blackberry, rose, elderberry, snowberry, soap plant, gold-back fern, and even the non-native European olive. Plus, they go after fungi, such as boletes, puffballs and brackets. In biologist speak, they're "generalist herbivores that specialize locally."

Notice that the core of their diet is some pretty tough and toxic stuff. But also note that many of those leaves come from evergreen perennial shrubs & trees - i.e., plants that are around all year, including in winter (woodies don't  hibernate), and during harsh California droughts, when many annuals might not come up or survive. Smart.

And what about those toxins? Well, they have that well handled too. Not only are their complex guts rich in mutualistic protozoa that help detoxify many of the tannins and polyphenolics, but, they also "age" some leaves in their larders, to allow the toxins to reduce naturally, and make them more digestible. You know - like Tequila.

bay laurel snips    toyon snips
Woodrat forage sign. They climb up into the shrubs and trees, nip off branch tips, and then climb down and collect them (often over several nights) to stock their pantries back home (bay laurel, toyon, coast live oak and European olive)

live oak snip    olive snip

And when they forage, they prune. Which seems to have a beneficial effect on the shrubs - they branch more, and thus produce more flowers and fruit. Which is also good for pollinators, and birds, and, and, and...

pruned coffeeberry
Coffeeberry pruned by a dusky-footed woodrat

If the shrub or tree is tall, the woodies will also clear out small internal branches to make it easier and faster for them to climb up and forage.

coffeeberry
Coffeeberry next to Lady Prunus' stick house with nice, open interior for easy climbing

Master-class forest gardeners, the dusky-footed woodrats.

Lady Prunus also has several friends and suitors that visit her on Berry Lane...

male suitor
A male suitor or mate dropping by

female neighbor?
A female or young male popping in for a visit. She (I think) has the black eye ring of Mr. Most-Interesting. Perhaps they're related - they live less than 500 feet apart, and young woodrats will disperse that far when venturing out to find/build their first home

And, she's quite the popular landlady. Her house appears to be home to 3 species of Peromyscus mice: californicus, maniculatus and truei. I.e., California, Deer & Pinyon.

With the lucky ensatina, that makes 4 Neotomaphilic species we've caught to-date. A far cry from the numbers that researchers have found. There are literally hundreds of documented species of mammals, herps and inverts that co-habitate in woodrat stick houses. Here's a taste of the laundry list of live-ins: shrews, rabbits, mice, lizards, frogs, salamanders, snakes, spiders, scorpions, centipedes, millipedes, and every kind of insect, from beetles to butterflies. 

Many, such as the California mouse, are so dependent on the active houses, that their populations rise and fall with the woodrat's booms and busts.

cal mouse
California Mouse, Peromyscus californicus. Key characters: large size; round brown body with buffy side and white chest; long tail that's not particularly bi-colored

cal mouse
Same California mouse - note the long tail and big body

juvenile cal mouse
Juvenile California mouse with almost all gray body

One nice thing about a fixed position camera - if the critters are roughly in the same spot in the shots, you can compare their relative size.

deer mouse
Deer mouse, Peromyscus maniculatus. Key characters: small size; rust-brown body with stark transition to white chest and throat; smaller ears; wide eye set; tail that's the same length as body and is sharply top-bottom bi-colored

deer mouse
Same deer mouse - you can really see the rustiness and body-length bi-colored tail

You might think that the mice would be competing for the same foods, and thus - why doesn't the woodrat chase them off? It seems that between their size differences, and the mouse preference for insects, they're limited competition (dusky-footers don't eat crawlies).

brush mouse
Pinyon mouse, Peromyscus truei. Key characters: medium size; gray-brown body with buffy stripe on side and cheek; larger ears; larger eyes; long bi-colored tail

brush mouse
Same pinyon mouse showing off the bi-colored tail and sizable ears and eyes

Bush bonsai and home building that helps hundreds.

Due to these amazing ecosystem engineering skills and willingness to take on tenants - and like beavers, prairie dogs and woodpeckers - dusky-footed woodrats are a keystone species. I.e., a species so relied upon by numerous other species, that loss and fluctuations can have drastic effects on those commensal species. Like pulling the keystone from an arch.

And, it appears, that the classy Lady Prunus is quite a keystone to life on Berry Lane.

Editor's Post-Note: here are 6 woodrat stories that included this post, in order:
====
References:
  • Camera Trap Codger - mucho verbal and blog post brilliance on woodrats
  • Linsdale and Tevis, UCPress - The Dusky-footed Wood Rat
  • Wikipedia - Keystone Species
  • Numerous amazing papers by Marjorie D. Matocq, Museum of Vertebrate Zoology and Dept. of Interpretive Biology, UC Berkeley, and Dept. Biological Sciences, Idaho State University (and now University Nevada, Reno) - including the following:
    • Reproductive success and effective population size in woodrats, Molecular Ecology
    • Morphological and molecular analysis of a contact zone in the Neotoma fuscipes species complex, Journal of Mammalogy
    • w/ Eileen A. Lacy - Philopatry, kin clusters, and genetic relatedness in a population of woodrats, Behavioral Ecology
  • Roberta Fargo, William F. Laudenslayer, Jr., USDA Forest Service - Are house counts reliable estimators of dusky-footed woodrat population size?, Transactions of the Wildlife Society
  • Howard F. Sakai, Barry R. Noon, US Forest Service - Between habitat movement of dusky-footed woodrats and vulnerability to predation, Journal of Wildlife Management
  • The American Society of Mammalogists, Nov 1991, No. 386 - Neotoma fuscipes
  • Dr. C. Hart Merriam - Abstract of a study of the American wood rats, with descriptions of fourteen new species and subspecies of the genus Neotoma, Proceedings of the Biological Society of Washington
  • E. W. Jameson, Jr., and Hans J. Peeters, UCPress - Mammals of California
  • Smithsonian National Museum of Natural History - Neotoma fuscipes
  • Wikipedia - Neotoma fuscipes
  • Nature of a Man (this blog) - The Ecotones
  • Nature of a Man (this blog) - Battles Under the Bay Laurel
  • Nature of a Man (this blog) - The Coast Packrats
==========

Saturday, February 4, 2012

The Ecotones

In this episode of Woodrat Theater, we look in on The Ecotones.

La Casa de los Ecotones is a stately manor, deeply embedded in old-growth chamise, and situated on the border of a dense live-oak woodland. I.e., prime real estate for a pair of Neotoma up-and-comers, like Mrs. Ecotone and her mate.

Not only does the location allow the duskies to forage both ecosystems, but building in the middle of a big chamise shrub, with its sturdy trunk and thick tangle of stout, outwardly arching branches, also protects the house from being dug out by coyotes, foxes and badgers.

the ecotones house
Dusky-footed woodrat house in chamise, on ecotone between chaparral & oak woodland

And, the well-selected spot also creates - around, through and over the house - a very useful tool that fuscipes are happy to refine and exploit: the woodrat branch super highway system.

Being a busy lady, Mrs. Ecotone often uses the highways for her errands:

mrs. ecotone
Mrs. Ecotone on the woodrat super highway - note how she uses her tail for balance

Not only do the branch highways allow fast travel, they make it easier for the woodies to orient and navigate. They're also very quiet - unlike walking on dry oak leaves, which can be pretty risky in areas where silent-death-from-above owls are always listening.

mrs. ecotone
Mrs. Ecotone carefully tip-toeing through the noisy oak leaves

mrs. ecotone
Ah - a perch - much better

Her mate, Mr. Ecotone, also uses the branch highways as he comes and goes...

branch walking
Mr. Ecotone on the super highway

A modern and well-positioned couple, the Ecotones.

I say "couple" in humor, of course. Woodrats aren't specifically monogamous. But, some females have been known to choose the same male each go round, and not mate with any others. I guess those guys must be woodrat Mr. Rights.

In the case of Mrs. Ecotone, she doesn't seem to have any males other than Mr. Ecotone visiting her house. And he appears to be there often - hanging out in front, coming and going, sitting on the door step... (did someone say clingy?)

But, I'm happy for it. Because, his wonderful warm-bloodedness triggered the cam trap and allowed us to catch this treat - a Yellow-eyed Ensatina salamander, Ensatina eschscholtzii xanthoptica, trotting into the stick house entry, right by Mr. Ecotone's feet:

ensatina going into woodrat house
"Come right in Mr. Ensatina. Sorry about the flash. Damn paparazzi." Ensatinas are one of many species of herps that are well known to live in woodrat houses

And, Mr. Ensatina wasn't the only Neotomaphilic tenant seen. Pinyon mice, Peromyscus truei, also live in Mrs. Ecotone's stick house on the edge. And they use the super highways, too:

brush mouse
Pinyon mouse, Peromyscus truei, also living in the woodrat's house. The mice and other tenants don't inhabit the same rooms as the woodie, but instead live in the walls, attic and basement - much like when critters move into our homes

The Ecotone's neighborhood is also popular with a few local foragers. Likely they're poking around for inverts or lost seeds...

cal thrasher
California Thrasher

juve golden-crowned sparrow
Juvenile Golden-crowned Sparrow

Ah, yes. Location, location, location. Even in woodrat houses.

Editor's Post-Note: here are 6 woodrat stories that included this post, in order:
====
References: 
  • Numerous amazing papers by Marjorie D. Matocq, Museum of Vertebrate Zoology and Dept. of Interpretive Biology, UC Berkeley, and Dept. Biological Sciences, Idaho State University (and now University Nevada, Reno) - including the following:
    • Reproductive success and effective population size in woodrats, Molecular Ecology
    • Morphological and molecular analysis of a contact zone in the Neotoma fuscipes species complex, Journal of Mammalogy
    • w/ Eileen A. Lacy - Philopatry, kin clusters, and genetic relatedness in a population of woodrats, Behavioral Ecology
  • Roberta Fargo, William F. Laudenslayer, Jr., USDA Forest Service - Are house counts reliable estimators of dusky-footed woodrat population size?, Transactions of the Wildlife Society
  • Howard F. Sakai, Barry R. Noon, US Forest Service - Between habitat movement of dusky-footed woodrats and vulnerability to predation, Journal of Wildlife Management
  • The American Society of Mammalogists, Nov 1991, No. 386 - Neotoma fuscipes
  • Dr. C. Hart Merriam - Abstract of a study of the American wood rats, with descriptions of fourteen new species and subspecies of the genus Neotoma, Proceedings of the Biological Society of Washington
  • E. W. Jameson, Jr., and Hans J. Peeters, UCPress - Mammals of California
  • Smithsonian National Museum of Natural History - Neotoma fuscipes
  • Wikipedia - Neotoma fuscipes
  • Nature of a Man (this blog) - Battles Under the Bay Laurel
  • Nature of a Man (this blog) - The Coast Packrats
==========