Silent Spring: Warblers

In the chapter And No Birds Sing, Rachel Carson describes the consequences of DDT spraying (for elm bark beetles) for various bird populations in the Midwestern US. Two ornithologists at Michigan State University, George Wallace and John Mehner, documented the effects on American Robins on the East Lansing campus, where 370 adult robins were counted in 1954, before spraying began. By the end of June 1957, when approximately 300 young robins should have been foraging on the grounds of MSU, only one was reported.

Carson listed multiple studies and observations that documented the toxicity of DDT, accumulating in insects, earthworms, and freshwater crustaceans, for avian and mammalian species. Foliar spraying of elm trees devastated many insectivorous bird populations, including warblers, gnatcatchers, and kinglets. Below you’ll see altered book pages, in which I’ve painted over most of the text (it was a chapter about White-throated Sparrows, which apparently didn’t arouse the gun-crazy tendencies of the author). I added a quote from Silent Spring about warblers, and included a couple of little drawings of Yellow Warblers and Cape May Warblers.

More when I return from reviewing grant proposals ….


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West Nile Virus, Urban Vector Control, and the 50th Anniversary of Silent Spring

According to the September 18 update at the Centers for Disease Control website, over 3000 cases of West Nile virus (WNV) disease in humans have been reported in the US this year. Approximately half of these cases were classified as neuroinvasive disease (meningitis, encephalitis), and 134 infected individuals have died. West Nile virus (Flaviviridae) was introduced into the Western Hemisphere in 1999, and has spread throughout the Americas, usually transmitted between birds and Culex mosquitoes. American Robins (Turdus migratorius) are considered to be the primary avian vector for WNV, but many other bird species suffer from the infection. Crows and jays are particularly sensitive, and often die from WNV disease; I haven’t seen a Scrub Jay or Blue Jay – birds that usually dominate the squabble for seeds, suet, and nuts – at my backyard feeders for months. Nor are Culex the only mosquito species that carry WNV: the CDC website lists 64 mosquito species, across several different genera, which have tested positive for WNV since 1999. While dogs and cats (and, indeed, 80% of humans) that test positive for WNV typically show no signs of illness, the virus can cause encephalitis and death in horses. My two Thoroughbreds are vaccinated twice each year to protect against WNV viremia (which begs the question of why there is no vaccine for humans).

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Culex quinquefasciatus, a vector of West Nile virus ~ photograph by Jim Gathany (CDC), work in the public domain (US Copyright Code Title 17, Chapter 1, Section 105)

While the warmer temperatures across the US may contribute to the migration of vectors for Lyme disease and Hantavirus , the relationship between climate change and the spread of WNV is less clear. Although the virus originated in Uganda, the first US reports of the disease were not in subtropical Florida, but rather in New York, where the environment favors both mosquito and avian hosts for WNV. In 2008, Kilpatrick and colleagues examined the effects of temperature on WNV transmission in Culex pipiens, by performing plaque assays on salivary secretions from the mouthparts, as well as on the bodies and legs, of mosquitoes that had been maintained at different temperatures, following a virus-laced blood meal. Based on their results, the researchers predicted that the transmission of a particular virus genotype, WN02, would be accelerated with global warming. Kilpatrick doesn’t attribute the recent WNV disease outbreak in North Texas to climate change alone, however; other factors, such as droughts that kill predators of mosquito larvae, rainfall patterns, and human behavior, may influence WNV transmission.

In response to the 2012 WNV disease outbreak, the city of Dallas opted for aerial spraying of the mosquito-control product Duet at low volumes, from aircraft flying at heights of around 300 feet. The product fact sheet indicates that Duet is a mosquito adulticide composed of two pyrethroids (synthetic plant pyrethrins), sumithrin and prallethrin, combined with the synergistic compound piperonyl butoxide. When cautioned to stay indoors, and to bring pets, the rare child who actually plays outdoors these days, and line-dried clothing inside during aerial spraying, citizens are understandably concerned about possible toxicity of the pesticide treatment, and a petition to stop the spraying in Dallas has been posted at Opponents point out that the neighboring city of Fort Worth eschews pyrethroid spraying, and instead favors public education about eliminating standing water, using Bt (Bacillus thuringiensis) dunks, introducing fish that eat mosquito larvae, and reducing exposure to mosquitoes. Here in San Antonio, city workers are treating stagnant pools of water with larvicides, and citizens are advised to apply insect repellent and to wear clothing that covers legs and arms when working outdoors. I’m allergic to DEET (N,N-diethyl-meta-toluamide), and moderately sensitive to pyrethrins, so my choices for personal insect repellents are somewhat limited. I’ve been field-testing several alternatives, and I’m happy to share the results with anyone who’s interested.

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DDT-infused cardboard parrot ~ photograph by Vmenkov, under GNU Free Documentation License and Creative Commons CC-BY-SA-3.0

This autumn marks the 50th anniversary of the publication of Rachel Carson’s seminal environmental book Silent Spring, and for all we fret about pyrethroids, DEET, and whatever the hell city workers here are spraying into puddles, direct exposures to some of the most toxic pesticides have decreased since the 1960s. I regret to recall running behind the “Foggy Man” truck as a young child, with the other neighborhood kids, all of us dancing around in a cloud of DDT. Bird-killing, eggshell-weakening, environmentally-persistent DDT, which was banned for agricultural use in the US in the early 1970s. The ban on DDT use in agriculture was extended worldwide by 2001 Stockholm Convention on Persistent Organic Pollutants. Contrary to the continuing smear campaign that blames Rachel Carson and other environmentalists for “millions of deaths in Africa”, public health applications of DDT for malaria vector control are allowed by the Convention, with support to aid the transition to less toxic and more effective insecticides.

To celebrate the anniversary and a reread of Silent Spring, I’ll post a series of my art journal pages on the topics of pesticides and the environment over the next few weeks.


Kilpatrick AM, Meola MA, Moudy RM, Kramer LD (2008) Temperature, viral genetics, and the transmission of West Nile virus by Culex pipiens mosquitoes. PLOS Pathogens 4(6):e1000092

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Urban Heat Islands and Climate Change

A recent story on NPR’s Morning Edition piqued my interest in the urban heat island (UHI) phenomenon, which has been recognized since the late 1980s. In the radio piece, the rather startling claim was made that cities are heating up at rates twice as fast as those measured for non-urbanized regions of the planet. The US city of Atlanta, GA is the focus of the NPR story, and Georgia Tech’s Urban Climate Lab director, Brian Stone Jr., is interviewed throughout, so I decided to take a look at the UCL website. The data on urban temperature trends are limited to fifty of the most populous US cities, but nevertheless support the need to develop mitigation strategies to counteract the impact of climate change on cities. For those who are interested in the comparison of warming trends in US cities vs. nearby rural areas, the climate trend map for the years 1961 through 2010 is here. Phoenix, Atlanta, Denver, and Greensboro are among the cities with the most alarming warming patterns.

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Atlanta skyline; photo by Chuck Koehler via Wikimedia Commons, under Creative Commons Attribution 2.0 Generic license

Many of us at OT live in large cities, whether in urban or suburban districts, and I was curious about how widespread the UHI phenomena of accelerated warming trends are worldwide. Turns out (not surprisingly) that there’s a huge amount of peer-reviewed literature available, and a variety of consequences for human health, as well as planned and implemented mitigation strategies, for cities across the globe. Wilby (2008) used data from studies by the London Climate Change Partnership to examine existing and projected changes in UHI intensity and ozone pollution in the city. UHI intensity is typically represented by a temperature gradient between an urban station (St. James’s Park in this case) and a rural reference station (Wisley, Surrey – 30 km from the city center), and the average nocturnal UHI for London is +2.2C in August. The factors that contribute to the UHI effect include building materials that retain more solar energy than do surfaces covered with vegetation, lower wind speeds, reduced evapotranspiration (due to a combination of fewer plants and relatively impermeable surfaces), and a concentration of anthropogenic heat flux (air conditioning, transportation, cooking). From long-term records, it’s clear that spring and summer nocturnal UHI intensities in London have increased since the 1960s. Using several different models, Wilby (2008) predicts that, by the 2050s, nightime UHI intensities for London will increase by another 0.5C for the months of May through October, and that there will be more frequent intense UHI episodes on a background of more persistent and extreme European heatwaves. This would mean, for example, that Londoners will experience an average of seven intense UHI episodes each August, compared with the current average of five.

What about the UHI effect in the large cities of Asia, Africa, and South America? Peng and colleagues (2012) analyzed seasonal and diurnal variations in UHI intensity for 419 global big cities, with populations over one million. Rather than relying on air temperature differences measured between urban and rural stations, the researchers used a land surface temperature (LST) data set from satellite remote sensing (MODerate-resolution Imaging Spectroradiometer = MODIS-Aqua) to compare urban and suburban areas, and thus calculate a Surface Urban Heat Island Intensity (SUHII). SUHIIs were computed for nighttime and daytime, and for winter and summer periods. Other parameters, including vegetation, climate, density, and albedo, were defined for urbann and suburban areas.

With the exception of a few cities surrounded by desert (e.g. Jeddah in Saudi Arabia and Mosul in Iraq), annual mean daytime SUHII is positive. Medellín, Colombia has the highest daytime SUHII (7.0C), followed by Tokyo and Nagoya in Japan, São Paulo in Brazil, and Bogatá in Colombia – all with daytime SUHIIs over 5C. Nighttime SUHIIs for most cities are between 0 and 2C, with Mexico City holding the record at 3.4C. Average daytime SUHII over cities in developed countries is higher than that over developing countries, whereas for nighttime SUHII there is no significant difference. The two major sources of energy that contribute to SUHII are downward net solar radiation and anthropogenic heat flux. During the day, evapotranspiration from urban vegetation has a cooling effect and reduces SUHII, whereas albedo and the thermal properties of urban surfaces influence nighttime SUHII. Interestingly, human metabolic heating accounts for only a very small fraction of anthropogenic heat flux – so don’t worry about going for a long run or playing tennis after work.

Obviously, the combination of global warming, an increase in extreme climate events, and accelerated urbanization requires that city planners consider measures to reduce SUHIIs. I hope to discuss a few of these strategies in subsequent posts.


Peng S, Piao S, Ciais P et al. (2012) Surface urban heat island across 419 global big cities. Environmental Science and Technology 46, 696-703.

Wilby RL (2008) Constructing climate change scenarios of urban heat island intensity and air quality. Environment and Planning B: Planning and Design 35, 902-919.

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Suburban Wildlife: Texas Spiny Lizard

In spite of (or perhaps because of) another very hot, dry summer here, my suburban backyard is a small refuge for a variety of insects, birds, and reptiles. Among the largest of the reptiles I’ve seen recently is the Texas Spiny Lizard (Sceloporus olivaceus), which is about seven or eight inches in length, including the tail. A handsome and spiky dragonesque creature, the Texas Spiny Lizard is nevertheless quite shy, and is usually heard, but not seen, skittering around after insects in the leaf litter under the Eastern Cottonwood (Populus deltoides). A very few times I’ve seen this native lizard sunning itself on a rock near the compost bin, or splashing through the birdbath; most of the time, its presence is known only by the noise it makes in the dry leaves, and by a fleeting glimpse of a long striped tail.

A few of you may remember that I’m fond of defacing altering books with paint, colored pencils, felt-tip pens, and my scribblings on wildlife. My primary art journal is currently locked up in a display cabinet at the university, as part of an exhibit on a neuroanatomy elective that a colleague and I “supervised” (two second-year medical students designed and implemented the course) this spring, so I returned to the altered book for the drawing below. The book is not valuable, and I bought it second-hand in London years ago; it’s filled with a lot of disagreeable “great white hunter” adventures, one of which I painted over completely, except for phrases including “owl” or “owls.” The altered page below is part of a chapter in which the author is trying to shoot a bear, which is warned off by the rattling call of a Belted Kingfisher. The author goes on to describe accidentally hooking a juvenile kingfisher, and then removing the hook from the unfortunate bird.


Texas Spiny Lizard and cottonwood leaves: colored pencil, Micron pen, watercolor pencil

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Deer OT ….

…. I wish you a belated Happy Birthday! I’m preparing for a meeting, so I got nothing at the moment, except some photos of wacky white-tailed deer, hanging out on campus.


By the parking garage


The shrubbery … is it crunchable, preciousss?

Also, latecomer blogger is late.

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Plain arrows are langweilig, nicht wahr?




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City Reads

Do you know what it means to miss New Orleans?
And miss it each day and night?
I know I’m not wrong – this feeling’s gettin’ stronger
The longer I stay away.

Miss them moss-covered vines, the tall sugar pines
Where mockingbirds used to sing
And I’d like to see that lazy Mississippi
Hurryin’ into spring.

~ Louis Alter and Eddie DeLange

That first line, of a ballad performed by Louis Armstrong and sung by Billie Holiday in the movie New Orleans, serves as the title for the introduction to Andrei Codrescu’s essay collection, New Orleans, Mon Amour. The introduction was penned post-Katrina, and in spite of the author’s descriptions of the resilience and humor of New Orleans residents, one can certainly sense his broken heart over the devastation of the city and diaspora of its natives. It was indeed a heart-breaking and shameful tragedy for all Americans, whether or not one had spent any time in the Big Easy. I kept thinking of this strange faded sticker on a light pole in my New Orleans neighborhood: Pray the Rosary to Save New Orleans. I passed it on my daily walks or runs to Lake Pontchartrain, and it usually brought a brief godless smirk to my face. My old neighborhood was completely inundated in the aftermath of Katrina, and neither praying the rosary, nor the finger bones of some poor wee saint at a nearby church, could save it.

I’m currently savoring Codrescu’s essays, and the first dozen or so I’ve read are delightful, full of the weirdness, “mythifying”, and magical realism characteristic of life in New Orleans. He describes the 19th-century serial novel by Baron Ludwig von Reizenstein, entitled The Mysteries of New Orleans: “Readers complained about the graphic details (especially the sex) but couldn’t put it down.” Musicians, artists, writers, and chefs sheltered at Codrescu’s Baton Rouge home following Katrina, and one of them (justifying the preparation of elaborate gourmet meals) stated ” … it may be the end of the world, but that’s no reason to become uncivilized.” A chapter entitled Cookin’ includes recipe names from local cookbooks: Microwave-baked Juicy Swamp Rabbit, Smothered Doves (O Picasso, O Paloma!), Garfish en croute, Gator Meatballs, Stuffed Teals, Sally’s Armadillo. There are a couple of topics, namely ghosts and dreams, which, as a rational scientist, I should dismiss snappily, but I couldn’t dispel a sense of familiarity while reading Codrescu’s essays. Wrong Number, a hilarious account of how the city is famous for wrong numbers and has a “telephonic voodoo cult”, posits that telling the caller that the person they’re seeking has died is no solution, because “… often the calls are for dead people.”

In Se Habla Dreams, Codrescu writes that New Orleans is a “city that dreams stories.” He claims that ghosts and pirates inhabit the city, and the dead saunter by casually; such supernatural events cannot help but influence the work of a writer. The varied scents and odors of New Orleans evoke a sense of “rotting and generating”; I am in complete agreement with this olfactory assessment of the city. While living in New Orleans, I once sent a handmade book, wrapped in a plastic newspaper sleeve, to an old friend who lived, as I do now, in a semi-arid city that enforces a sort of comparative hyposmia. He remarked that he smelled a humid New Orleans spring day – river mud, musk, roasting coffee, jasmine, magnolia – when he took the book out of the wrapper. I’ve also had dream experiences similar to the ones that Codrescu relates, particularly about Lake Pontchartrain (though mine were typically more unsettling and sinister).

I’m starting a list of non-fiction books about cities, and of fictional works in which a particular city or cities figure prominently; maybe I’ll keep track of this project on my About page. In any case, please please PLEASE leave your suggestions for city reads in the comments. Below are books I’ve read recently or that are queued on my Kindle.


London: The Biography, by Peter Ackroyd

The City of Falling Angels (Venice), by John Berendt

New Orleans, Mon Amour, by Andrei Codrescu

Green Metropolis: Why Living Smaller, Living Closer, and Driving Less are the Keys to Sustainability, by David Owen

The Neighborhood Project: Using Evolution to Improve My City, One Block at a Time, by David Sloan Wilson

Emerald Cities: Urban Sustainability and Economic Development, by Joan Fitzgerald

Soft City, by Jonathan Raban (via cromercrox)


Kraken, by China Miéville. London figures prominently in this urban fantasy novel.

Un Lun Dun, by China Miéville. London and its nonsensical mirror version, UnLondon.

Perdido Street Station, by China Miéville. Set in the fantastical city of New Crobouzon (suggested by cromercrox)

The City and the City, by China Miéville. Mystery set in two cities in the same place that ignore each other (suggested by cromercrox)

The Alexandria Quartet, by Lawrence Durrell. Not set in Virginia (via cromercrox)

The New York Trilogy, by Paul Auster. Described by Wikipedia as “meta-detective fiction” (via cromercrox)

Ulysses, by James Joyce. Dublin is an integral component of this novel.

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National Public Lands Day in a Drought City

2011 has been a year of exceptional heat and drought throughout most of the state of Texas, and 2012 isn’t looking much better. Although the city of San Antonio obtains water from the artesian Edwards Aquifer, this is a limited natural resource for a rapidly expanding population, all of whom live and work in a semi-arid climate at the edge of the Chihuahuan Desert. Not surprisingly, the city parks department and the water management system encourage and reward xeriscaping efforts in residential and public spaces.

Today is National Public Lands Day in the US, during which volunteers work to improve and restore parks, beaches, forests, and other public spaces. NPLD is partnered with the Obama intiatives America’s Great Outdoors and Let’s Move Outside, which address the issues of protecting our natural heritage, environmental education, and childhood obesity and inactivity. As a longtime tree-hugging hippie pinko liberal, I haven’t been happy with many of the Obama administration’s decisions, but when you combine environmental protection, outdoor activities, and social justice initiatives, I’m all over that like a nine-banded armadillo on a fire ant mound.


NPLD T-shirt for volunteers

I’ve been been somewhat depressed lately because my teaching and research schedules, combined with recently acquired responsibilities for developing the neuroscience module in our new medical school curriculum (“Extreme Makeover” – ugh!), severely limit my opportunities to travel. Not that they were ever that great, and I guess I should be happy that no air travel = greatly reduced carbon footprint. But I decided that rather than mope around about my reduced carbon footprint, I should get involved in a few local activities. National Public Lands Day seemed like a good fit, and the local public radio station was sponsoring a xeriscaping project at a new public library in South San Antonio.


Rainwater cachement system at Mission Library

At this point, I should explain something about large cities in the US; this something is not anything to be proud of, and it could certainly be the subject of several blog posts. Many large US cities – and San Antonio is no exception – have fairly steep gradients of socioeconomic privilege that sweep from one limit to the other. I don’t know why this is, but it is. San Antonio’s gradient sweeps roughly northwest to southeast, with the very wealthy and privileged concentrated in the northwest, and the poor and marginalized in the south and southeast. The Mission Branch Library opened in May 2011, in an economically depressed Southside community that had lacked such resources for far too many years. The library is next to Mission Park and the 18th century Mission San José y San Miguel de Aguayo, restored in the 1930’s by the Works Progress Administration.


Mission San José, as seen from the library. Trees are dying due to the drought, rather than turning fall colors.

Behind the Mission Library are four metal cisterns that collect rainwater (when it rains) from the roof, and condensate from the air conditioning. The plan for the volunteers on NPLD was to hardscape the area around the cachement system with permeable gravel beds, and to prepare beds for drought-tolerant plants in a rain garden. The plants will be placed in the beds at a later date, perhaps when the drought subsides. We started at 7:30 AM, fueled by that staple of the San Antonionian diet, the breakfast taco – not too bad for your health, if you stick to the ones with beans, potatoes, and/or eggs, and avoid the ones with bacon and sausage. For 2.5 hours, I shoveled topsoil and mulch, raked mulch and gravel, and hauled/dumped mulch in a wheelbarrow. The mulch was rather annoying for a variety of reasons, not the least of which was the dust that mixed with sunscreen to create a gritty brown paste on one’s skin, but it allowed us to make silly jokes such as “Thank you very mulch” and “Mulchas gracias.” After working steadily with shovel, rake, and wheelbarrow for a couple of hours, I decided that teaching in gross anatomy labs for 4-5 hours per day, four days a week, really isn’t such a bad job. I’m sure that my muscles, unaccustomed to real physical labor, will be complaining tomorrow. Below is a photo of the work we accomplished today, and I can’t wait to visit the library once the plants are in place.


Some of the hardscaping accomplished for the rain garden today.

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First, a few lines about Texas weather from On the Road:

Great clouds of gritty wind blew at us from shimmering spaces.

Nightfall seemed like a million miles away as we resumed for Coleman and Brady — the heart of Texas, only, wildernesses of brush with an occasional house near a thirsty creek and a fifty-mile dirt road detour and endless heat.

We were all red-eyed from the continual mistral-winds of old Tex-ass.

That crazy cat Jack Kerouac! Tried every mind-altering substance known to humankind, fried all the neural circuits in his frontal cortex, reddened and embloatened his facial features with alcohol, and could still write deadly accurate smack about Tex-ass.

Blistering heat continues indefinitely, no end to the drought, and no jet-setting escapes to cooler climes for some of us who are already locked into multiple lectures and four- to five-hour anatomy lab sessions. Never mind … let’s talk about something more pleasant, like those in the tribe of academe who, through their long years of intellectual and physical toil, have earned some relaxing retirement. Two such individuals of my acquaintance have reached this milestone: one a few years early, and the other several more years late (usual retirement age in the US is 65, though that will soon change to 67, and eventually to 70 or 72 years). Recently, I and a couple of my colleagues lightheartedly contrasted the characters of the two retirees.

Retiree #1 is an eminent researcher in her field, trained numerous successful, productive postdocs and grad students, maintained continuous NIH funding, and has been a delightful, generous research collaborator and mentor for many of her colleagues, including myself. That reminds me, I have another manuscript to write this year. She and her (also retired) scientist husband have a beautiful, spacious house not far from mine; theirs is perched on a high hill, and includes several acres of natural semiarid Texas wood pasture. They also have a spacious newly-built home in a foreign country, which I have not ever visited. But the house here in town is filled with collections of artwork, exotic plants, and lovely souvenirs of their many travels. Retiree #1 is gregarious, effusive, and hosts parties, for graduating students and nest-leaving postdocs, which are replete with good wine, expensive cheeses, and other luxurious foods and drinks. For her retirement party, Retiree #1 was very forthcoming and very specific about the gift(s) she wanted, down to species and source. From me, she requested a specific handmade item, and I was happy to oblige.

Retiree #2 has had a very different career path in which professional school (medical and dental) teaching predominates. He is laconic and precise in his speech and writing, and is what would be best be described as ascetic of mien. Retiree #2 is the sort for whom it is difficult to plan a party, because his diet is limited and ascetic (by choice), and even those who have worked with him for decades know very little about him outside of the university. Fortunately, his wife has been helpful in party planning, but the only material item that Retiree #1 desires as a gift costs less than the usual individual faculty donation to such a fund. His house, which is also close to mine (none of us is the long commute type), is much more modest (I’m told) than the one on the high hill, and he and his wife also own wilderness property near a local state natural area. I’ve been out there for a picnic lunch, and there’s a small cabin, very spartan, on the property. In many ways it’s easier for me to talk with Retiree #2 and his wife, as I certainly haven’t had a high-flying research career, and I have more in common with them in terms of inexpensive, local interests in gardening, crafts, and wildlife. But Retiree #1 has been a supportive collaborator and a much-treasured mentor for me, and her absence is keenly felt. Retiree #2 plans to continue teaching at the university without pay, and I’m also grateful to him for sharing his contributions to a course I now direct. He has also been a mentor, but more by example, than by active engagement. It takes all types in academia, and I will miss them both.

No photos of the retirees, of course, so I offer instead two gratuitous puppy photos. They are 7.5 months old now, and clearly not pure Pomeranian. Part dachshund, mebbe?





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