The Truth about Bird Feeders 2

This article by Jerry Cates, first published on 21 February 2015, was last revised on 17 April 2019. © Bugsinthenews Vol. 16:02(01):


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Fig. 1. A Well-Stocked Bird Feeder. This feeder is filled with ordinary birdseed, which was most likely purchased in bulk from a local discount store. Note the large amount of seed in the tray under the perches, which has overflowed from the feeder. This seed will soon wind up on the ground underneath.

Bird feeders and other bird attractors make wonderful additions to the landscape. They summon birds to our yards, where we can enjoy their songs and bright colors, and be charmed by their antics.

Strategic placements of bird feeders in a yard guarantee a steady flow of colorful songsters. Few pleasures in life compare with watching our feathered friends as they cavort about, waiting for a chance to perch and share in the bounty.

What isn’t to love about that?

Properly designed, provisioned, and maintained bird feeders are a positive delight for every human concerned. But bird feeders don’t merely feed the birds that are attracted to them. Being provisioned with mixed nuts and seeds of various kinds, their contents appeal to a broad array of wild animals. Less than 25% of the birdseed contained within an ordinary feeder is consumed by birds perched on the feeder itself, while the remainder — 75% or more of the total — is swept from the feeder to the ground, by wind, rain, or feeding birds. As a result, most bird feeders soon become excellent attractors of all the other wild animals that eat what most birds eat.

Underneath the average, well-provisioned birdseed feeder, the landscape is heavily littered with birdseed. That litter is prized by rats, mice, raccoons, opossums, skunks and other wild animals. Rats that happen upon a birdseed littered area of landscape stop, eat their fill, and decide to hang around. These rats take root, build nests, and multiply. Our most common rat, the brown or Norway rat (Rattus norvegicus), burrows into the soil next to our buildings, and builds its nests out of sight, underground. Their burrow entrances are often hidden under shrubs, within a few feet of the bird feeders that sustain them.

Even in the presence of rodent bait stations containing fresh rat poison, rats will continue to multiply as long as they can get plenty of birdseed to eat. Why? They shun rodent bait in favor of fresh birdseed, which tastes even better. Though shunning the rodent bait, they often hide in rodent bait stations while waiting for ground birds to come near so they can capture, kill, and eat them (see fig. 4, below for more revelations about how rats sustained by a regular supply of birdseed make use of rodent bait stations to stash the birds they kill).

It should come as no surprise, then, that populations of rats and mice increase in the presence of well-stocked bird feeders. But the food chain that bird feeders create does not stop with rats and mice. Rats and mice are the favorite food of the vast majority of Texas snakes. As the population of rodents increases, so does the number of snakes that feed on them.

The truth about bird feeders, then, is that they also feed rats and mice, and those rodents, in turn, feed the snakes that prey on them. Wherever ordinary, well-stocked bird feeders are found, the population of rats, mice, and snakes also rises. Needless to say, fostering large numbers of rodents and snakes in areas where humans and their companion pets reside isn’t a good thing

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Fig. 2. The ground under the bird feeder in fig. 1. Birdseed litter beneath this feeder covered a circular area 8 feet in diameter. Click on the photo to enlarge it, and click again to see the highest magnification possible. A careful examination of the litter reveals the presence of fecal pellets from rats and mice that have visited the area, usually after dark at first, but even in the daytime when rodent populations soar in the presence of abundant food supplies. Some seed hulls are noticeable, but most seeds are intact. Note also that the grasses under the feeder have been overwhelmed by the birdseed litter, damaging the lawn and allowing the soil to erode.

This article covers the good, the bad, and the ugly truths about most bird feeders, and provides information on an alternative way to feed wild birds without risking a sharp increase in rodent and snake populations. In turn, it discusses other means of attracting birds to our yards and windows, and how best to install and maintain those alternate devices.

First, The Good…

OK, let’s discuss the good points about bird feeders: They bring birds to our yards, and joy to our hearts. It is impossible to overstate the importance of that.

Many youngsters get their first up-close experiences with wild animals and the mysteries of nature by placing birdseed in small dishes outside and watching as birds and squirrels are attracted to their offerings. This encourages young minds to think about, and begin to love and appreciate, the wild animals with which they share their world. One of my earliest memories involves collecting suet from the kitchen, carrying it to the front porch, and being entertained by the wild birds that came near to snatch a morsel from my outstretched hand.

The elderly, too, often brighten their days by watching the action that takes place at most bird feeders. Watching from inside, as birds come and go, not only adds pleasure to their days, but brings back exciting memories from the past. When a family member is confined to bed, undergoes lengthy rehabilitation for an injury or a surgical procedure, or enters a long-term-care facility for the aged, a good way to help them through that difficult period is to install a bird feeder outside their loved one’s window. It’s always a hit, and the optimism and encouragement it engenders extends and adds flavor to their lives.

Yet, unless the bird feeders are properly designed and maintained, they often do more harm than good.

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Fig. 3. These two 7 gallon pails had been placed outside a Central Texas nursing home by the grown children of a resident there. They were being used to service two bird feeders nearby. The light colored patch in the grass on the left side of the pails is spilled birdseed. Note the lid of the pail in the foreground is ajar; rat feces was found in the birdseed of this pail, confirming rats were getting inside the pail to eat. Nurses on this wing of the facility began seeing large rats inside the home several months after the pails were placed outside. I checked the rodent bait stations along the outside wall and very little bait had been consumed. Birdseed is much more tasty than rodent bait, so the rats shunned the bait and grew big and fat on the birdseed. The facility’s administrator, on learning that the pails were associated with rats entering the building, had them removed immediately. In the absence of the birdseed, the rats quickly ate the rodent bait in the bait stations, and sightings of rats at this facility ceased within a matter of days.

Another Counter-Intuitive Idea?

If you’ve read other articles I’ve written for this website, you already know I don’t shrink from digging into and exposing the “gems” contained within counterintuitive topics. Mother Nature, a master of the ironic and unexpected, casts many of nature’s revelations in terms that often seem contrary to common sense. Thus, those like me who write about nature often have to grapple with, and get a firm grip on, the genuine, unadulterated facts that lie behind what appear to be vexing, even unexplainable conundrums. I almost always welcome such challenges with open arms. Yet, if you are one of the many nursing facility administrators I work with on a regular basis, you also know that although I’ve been talking about writing this specific article for years, I hesitated to compose and publish it for many years.

Why the delay? Simple. This is a highly controversial subject. Counterintuitive ideas always beg spirited debate, but this subject is unusually divisive. To many, the mere suggestion that the ordinary but universally hallowed bird feeder may negatively impact a residential home, a nursing facility, or a facility’s residents and staff is to many something akin to heresy.

When I converse with a nursing home administrator who doesn’t yet know me well — and try to explain why most of the bird feeders at their facility ought to be removed — my words are usually greeted with incredulity. For most, the very notion that some bird feeders might lead to negative results is total nonsense. It goes so firmly against the grain as to be utterly ridiculous.

After all, practically every Walmart, Lowe’s, Home Depot, and corner grocery store has at least part of one aisle devoted to bird feeders and bags of seeds with which to stock them. If they were bad, logic tells us, stores wouldn’t carry the stuff.

What we Want, vs. What we Need…

So, stores don’t sell us things that are bad for us? Please, let’s be serious… Stores sell what people want, not what people need. And no, I don’t write this in a critical way, but merely to state a plain truth. If it’s available in quantity, isn’t illegal, and people want it, stores will almost always sell it, no matter what “it” is. The same truth applies to the book market.

I recently searched the books online, at the world’s largest purveyor of the written word, and found 5,869 books on the subject of bird feeders. Those books covered every possible angle of the topic.

What does this mean? Well, to begin with, birders or birdwatchers constitute over 20% of the North American population. We (yes, I too am a bird watcher, and particularly enjoy studying them in wilderness areas) are also among the wealthiest members of society. North American bird watchers are estimated to have spent over $32 billion supporting their love of birds in the year 2001, and heaven only knows how much birders spent in 2014. Bird watchers enjoy reading books about how to bring birds to their yards, and bird feeders meet that demand. Some birders are also accomplished writers, and they naturally write books that address what the market seeks. It should be no surprise, then, that the market for books on bird feeders is overwhelming.

Still, our understanding of bird feeders needs to extend beyond learning what attracts birds most easily. The birdseed that brings the most birds may also bring the most rats and mice. This article seeks to express the truths that apply to bird feeders in a way that lifts the veil and makes what appears counterintuitive to be what it really is, genuine commonsense. Every counterintuitive but true idea makes total sense once the reasons behind it are made clear. That’s what we shall do here. We’ll list all the reasons why some — actually most — bird feeders should never be used around a home of any kind. And we’ll explain, by examples taken from actual experience, why those reasons make sense.

Note that some of the most important explanations will be in the captions under the photographs embedded in this article. The reader is encouraged to read the captions for each photograph carefully. Each photograph can be enlarged by clicking on it, then enlarged even further by clicking on it again.

But first, Let’s Talk More Good…

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Fig. 4. Recently killed bird inside a rodent bait station located near an array of bird feeders, photographed on 12-31-2013. The bait blocks have been nibbled, but are mostly intact. A ground feeding bird, attracted to the feeders, ventured close to the bait station and was attacked and killed by a rat hiding there. The rat dragged the bird into the bait station and made a meal of it. Note that the toes on the bird’s legs are arranged with three pointing forward, one pointing backward, characteristic of passerines. When I approached this same bait station in January 2015, a finch was observed foraging on the ground nearby, and when the station was opened the partly eaten carcasses of two passerine birds were found inside. The birdseed feeders remain in place, nearby.

Not every bird feeder or bird attractor on the market is bad. Some — specifically those within three broad classes of bird attractors, discussed below — are quite good.

FIRST,  though they don’t feed birds, bird baths provide birds of all kinds with a refreshing drink and a means for bathing. For this reason, bird baths probably provide the best possible choice for attracting birds to a window or a special place in the landscaping.

SECOND, nyjer-seed tube feeders are excellent attractors of passerine birds in the Fringillidae family. Besides being some of the most colorful birds found in nature, passerine fringillids — known mostly as finches — sport gentle natures, exhibit an unusual, bouncing flight style, and sing enchanting songs. Nyjer-seed feeders usually do not attract rats or mice to the areas where they are placed. To begin with, the tiny nyjer seeds are packed in the feeders in a way that allows the birds that feed there to pull out one seed at a time, without wasting seeds in the process. Thus birds that feed in nyjer-seed feeders generally do not scatter the feeder’s seeds on the ground as do birds feeding in ordinary birdseed feeders. Furthermore, because the seeds stored in nyjer-seed feeders are so small, each seed provides only a small amount of dense nutrient to the animals that feed on them, and rodents do not find them as attractive as ordinary birdseed.

THIRD, hummingbird feeders — filled with specially formulated water — are excellent attractors of some of the most beautiful, exciting birds on earth.

Birdbathology 101…

Bird baths attract all kinds of birds, and do so more effectively than bird feeders. Not all birds eat seeds, but all need water to drink and to bathe in. Still, to work well, a bird bath should be properly placed, constructed, and maintained. Placing and maintaining a well-designed bird bath is not a trivial procedure. But don’t let that discourage you, because properly placing and maintaining an ordinary bird feeder is just as complicated.

BIRD BATH DESIGN: Concrete bird baths sold in most stores today are designed as good lawn ornaments, but function poorly as bird baths. The water should be  no more than 1/2 inch deep at the edges of the bath, and no more than 2 inches deep in the middle. A fairly flat surface is better than a bowl-shaped one, as the birds can stand in the shallow water without getting all their feathers wet; this allows them to sink their heads and necks into the water, then shake the water over their bodies without having to be fully immersed. The rim of the bath should be flat and textured, allowing the birds to maintain a good footing while drinking. Coarse sand or gravel in the bottom of a bird bath give the birds an underwater surface to walk on that mimics what they encounter in nature, along a slow-moving stream.

BIRD BATH PLACEMENT: First ensure that a hose bib is close by, so water is available as needed. It is also best to place bird baths under shade, so direct sunlight doesn’t cause the water to get too hot to bathe in and evaporate too quickly under a hot summer sun. Shade trees also give birds limbs to roost and preen on before and after a refreshing drink or bath. Don’t place the bath too close to shrubbery, as cats and other animals, hiding in the shrubs, may prey on the birds attracted to the bath. If a shade tree is not available at the site, it may be possible to install a pergola or similar sunscreen over the bird bath to break up the sunlight.

BIRD BATH MAINTENANCE: As mentioned above, without a good source of water, and a hose to deliver the water when it is needed — on a daily basis — bird baths quickly become dirty and non-functional. The bird bath should be easy to clean, and the easiest way to do that is to run a stream of clean water from a hose directly into the center of the bath until it overflows, washing away the contaminants that have collected in the water with it. Gravel or coarse sand in the bottom of the bath helps facilitate cleansing in this manner, by distributing the water stream through the gravel or sand particles, forcing contaminants out, into the water flow, and out of the birdbath.

Done right, a well-designed, properly placed and carefully maintained bird bath ought to attract more birds, and produce more fun and joy than any kind of bird feeder imaginable, including hummingbird feeders. But hummingbird feeders — discussed later in this article — have a special allure and should not be overlooked.

Finchology 101…

Compared to ordinary birdseed feeders, bird baths, and hummingbird feeders, taking steps to attract finches to a yard or window is relatively simple. This is especially true if the better-designed nyjer-seed feeders are purchased and installed according to the manufacturer’s instructions.

The better nyjer-seed feeders on the market provide a rigid exterior superstructure that defeats efforts by squirrels to access the seeds, and a ventilation system that allows airflow from the bottom up, keeping the seed store fresh longer. Even with the best nyjer-seed feeders, however, the seed content can become moldy over time. It is important to check the seed content regularly and replace it when the slightest evidence of mold or mildew is observed. Better yet, replace all nyjer seed at least once a month during normal months, and once every two weeks during unusually wet periods.

NEVER use ordinary birdseed feeders for nyjer-seed, as the design of most birdseed feeders is such that much of the nyjer-seed will end up on the ground. When that happens, the clumps of nyjer seed will attract rodents much as do ordinary birdseed feeders. Specialized nyjer feeders must be used. Though sock feeders can be a good choice where squirrels and other animals are not problematic, they are poor choices in most locales. Rigid tubes of plastic, with a surrounding superstructure that prevents squirrels from accessing the seed, is almost always the best choice.

More than 24 species of birds are commonly attracted to nyjer-seed feeders, and they include some of the most beautiful, and colorful birds found in North America:

  • Red-breasted Nuthatch
  • Rose-breasted Grosbeak
  • Chickadee
  • Yellow-bellied Sapsucker
  • American Goldfinch
  • Red-winged Blackbird
  • Common Redpoll
  • Evening Grosbeak
  • Pine Siskin
  • Northern Cardinal
  • Dark-eyed Junco
  • Hairy Woodpecker
  • Tufted Titmouse
  • European Starling
  • White-breasted Nuthatch
  • Jay
  • House Finch
  • Common Grackle
  • Purple Finch
  • Mourning Dove
  • Sparrow
  • Northern Flicker
  • Downy Woodpecker
  • Domestic Pigeon

Hummerology 101…

Hummingbird feeders are available from most discount stores, grocery stores, and home improvement stores. Although subtle distinctions in design abound, most are distinguished by having significant amounts of red in their housings. This is because hummingbirds are attracted to the color red more than by any other color, though they have no trouble lapping nectar from yellow, blue, white, and pink blossoms as well.

Select a hummingbird feeder that is conspicuously red in color, that is provided with ant guards, and that is “bee-proof.” All of those features should be described clearly on the advertising for the feeder you buy.

Make your own hummingbird nectar to use in the feeder. Recipes for hummingbird nectar are available at hundreds of Internet websites. Most are similar to the following:

  1. Add one part (by volume, e.g., cup for cup, or teaspoon for teaspoon) sugar to
  2. 4 parts water, then
  3. bring the resulting mixture to a boil, and allow it to boil for 1-2 minutes, then
  4. cool the boiled mixture to room temperature and
  5. fill your hummingbird feeder to no more than 1/2 full and
  6. store the remainder of your boiled mixture in a closed container in the refrigerator.

NEVER use honey, artificial sweeteners, or food dyes in your hummingbird nectar! Why? Honey ferments readily, and is known to cause mouth lesions in hummingbirds. Dyes do not improve the palatability of the mixture and may be harmful to the hummingbirds that drink it. Artificial sweeteners have no food value.

Every 3-4 days or less (2-3 days during the hottest months) the hummingbird feeder should be emptied of any unused nectar, rinsed with purified water (use no detergents), and brushed with a bottle brush. All mold or mildew should be thoroughly removed with the bottle brush before the feeder is re-filled. Again, only fill the feeder 1/2 full.

Consider buying several hummingbird feeders to use in rotation. Take a fresh feeder to the station, properly filled with nectar, and change it out with the one in use. Then take the used feeder back into your home, rinse it out thoroughly and set it aside to dry, awaiting its next rotation into service. This procedure reduces the likelihood that mold will develop and be retained in the feeder between service periods.

The Bad and the Ugly of Birdseed Feeders…

Birdseed feeders attract rodents to the yards where they are installed and maintained. Fig. 4 shows what happens when rats become too numerous around birdseed feeders. The bird carcass inside the rodent bait station in Fig. 4 was alive shortly before this picture was taken, but had been killed and dragged into the station by the rat, where it could feed on the bird’s carcass at its leisure. Although the rodent bait station was provisioned with fresh bait, little of the bait had been eaten. There are two reasons for that: first, the birdseed under the nearby feeders was so abundant that the rodents got their fill by eating the birdseed. It is impossible to make rodent bait that is as attractive to the rodent palate as fresh birdseed. Second, though, the presence of ground-feeding birds provides rats with an even more tasty food source, fresh meat. By hiding in the shrubbery near the bird feeder the rats lie in wait until a bird ventures too close, where they can seize and subdue it. It is doubtful that any of those who install birdseed feeders around their homes realize that, by doing so, they risk having some of the birds being captured, killed, and eaten by rats the birdseed feeders also attract to their yards.

But there’s more. We’ve discussed earlier the attraction of snakes to yards with bird feeders and the populations of rats and mice those feeders tend to produce. As rodent populations increase so does the risk that some of those rodents will eventually enter the buildings around which the birdseed feeders are placed. Rats get into crawlspaces, attics, wall voids, and the living spaces of homes near bird feeders, and when they do so those who live in those  homes are exposed to much more than the rats and mice themselves.

Rodents and their parasites help spread disease, including murine typhus, tularemia, salmonellosis, rat-bite fever (Streptobacillus moniliformis), leptospirosis, lymphocytic Chorio-meningitis, plague, and hantavirus. Often the victims of these diseases have no idea how they became infected, so no efforts are taken to prevent future infections.

The number of wild animal forays — raccoons, opossums, skunks, foxes, and feral cats — into residential yards and landscapes diminishes markedly when there are no rodents there to prey upon. Subsequently, the presence of harmful mites, ticks, fleas, and the multitude of annoying and potentially dangerous ecto-and-endoparasites that fall from, are brushed from, or that jump from the bodies of wild animals during foraging visits, as well as those that are deposited on the ground in wild animal scat, will decline as well…


Appendix A: Arboreal, Terrestrial, and Burrowing Rodents of Central Texas.

The nearly 2,000 species of rodents that are presently recognized worldwide comprise about 40% of all living mammals. 68 rodent species are known to be found in Texas, and 24 of these are found in Central Texas, all fully capable of invading yards, landscapes, and man-made structures.

Rodents are distinguished from other mammals by the kinds and arrangements of their teeth: all rodents have a single pair of upper, and a single pair of lower incisors that are separated, from several pairs of chewing teeth, by a large gap (diastema). The chewing teeth of typical mice consist only of molars, while squirrels and their allies, jumping mice, and cavylike rodents have both molars and premolars. Rodent incisors grow continuously from birth to death, and have chisel-like cutting edges:

Pocket gophers (Geomyidae)

Llano pocket gopher (Geomys texensis): subterranean; common in west-central part of Central Texas; small, dark brown or sandy brown on back, paler sides, white underparts; prefers deep sandy loam, gravel, or sand in Texas Hill Country; breeds in spring and early summer.

Pocket mice & kangaroo rats (Heteromyidae)

Hispid pocket mouse (Chaetodipus hispidus): terrestrial, throughout Central Texas; head and body 3.75 inches; large and colorful, with brown back, grizzled with orange and black; a broad orange lateral line on sides; white belly, broad orange ring around eye, bicolor tail is short and not tufted; breeds year-round; prefers grassy areas in plains and deserts, usually on sandy soils.

Merriam’s pocket mouse (Perognathus merriami): terrestrial, throughout Central Texas; head and body 2.25 in, tail 1.75 in.; breeds Mar-Dec; found on sand, gravel, and hard-packed soils.

Silky pocket mouse (Perognathus flavus): terrestrial, throughout Central Texas; head and body 2.25 in.; tail 1.75 in., shorter than other pocket mice; very small; grizzled orange-brown back, with pale orange lateral line, and white belly; sifts through sand for seeds, climbs stalks to harvest green seeds; breeds Mar-Oct; prefers sandy soils, rocky areas, and clays.

Mice & rats (Muridae)

Black Rat (Rattus rattus): arboreal, terrestrial, and opportunistically subterranean throughout Central Texas; head and body 5-7 in., tail 3-4 in.; scraggly black to light brown fur with lighter undersides; nocturnal, congregating around warehouses, residential buildings, and similar human settlements; prefer in urban settings to live in palm and pines; nests are ball-shaped and are made of shredded sticks, leaves, vegetation, and cloth; will build nests in abundant leaf litter and thick ground cover and under some circumstances will burrow into the ground; generalist omnivores, adapt to food supplies available locally; excellent vectors for disease transmission due to an ability to carry bacteria and viruses in their blood streams; particularly known to carry Streptococcus pneumoniae, Corynebecterium kutsheri, Bacillus piliformis, Pasteurella pneumotropica, and Streptobacillus moniliformis; preyed on by owls, cats, foxes, and coyotes.

Brown Rat (Rattus norvegicus): subterranean, terrestrial, and arboreal throughout Central Texas: head and body 8-10 in., tail 7-10 in.; brown or dark gray back with light gray underparts; nocturnal, excellent swimmer and burrower, often excavating extensive burrow systems; true omnivores, though cereals form substantial part of diet; breed throughout the year, females able to produce 5 litters annually; gestation period is 21 days, pups become sexually mature in five weeks, permitting populations to grow by a factor of 10 in 15 weeks; live in large, hierarchical groups in burrows or subsurface places such as sewers and cellars; generally begin new burrows adjacent to an object or structure, as this provides a roof for the set ion of the burrow nearest to the ground’s surface; burrows develop to include multiple levels of tunnels as well as a secondary entrance; burrows are used to escape perceived threats; carry a number of pathogens and parasites.

Deer Mouse (Peromyscus maniculatus): terrestrial, arboreal, and subterranean, throughout Central Texas; head and body 3.5 in., tail 2.25 in.; so closely related to the white-footed mouse (Peromyscus leucopus) that the two are best distinguished via RBC agglutination tests or karyotype techniques, though, physically, the deer mouse is distinguishable by its long, multicolored tail; 66 subspecies are recognized, all are tiny and plentiful throughout their range; nocturnal, foraging by night, spending day in trees or burrows, the latter having nests of plant matter; reproduce throughout the year, esp. Mar-Oct, var. based on food availability; preyed on by snakes, owls, skunks, foxes, and domestic cats.

Eastern woodrat (Neotoma floridana): terrestrial, semi-arboreal, and subterranean pack rat, on eastern edge of Central Texas; head and body 9 in., tail 6.25 in., moderately haired; back gray brown, dark brown, or sandy brown; sides washed with buff; belly grayish white or cream white; ears large; eats leaves, fruit, berries, fungi, nuts, and seeds; in east Texas uses underground burrows; breeds year round; common, widespread, and able to thrive in a wide variety of habitats.

— Fulvous harvest mouse (Reithrodontomys fulvescens): arboreal and terrestrial, on northern, eastern, and southern edges of Central Texas; head and body 2.75 in., with long tail; back rusty brown peppered with black, sides orange, belly white or buff; breeds in spring and fall; constructs baseball sized nests of shredded plant material in vegetation.

Hispid cotton rat (Sigmodon hispidus): terrestrial and subterranean throughout Texas; head and body 6 in., tail 4 in.; upper parts grizzled dark brown and buff, belly grayish white; mainly crepuscular but active day or night; eats grass and other plants, insects, and fungi; makes nests in thick grass clumps or short underground burrows.

— House mouse (Mus musculus): terrestrial, throughout Central Texas; head and body 3-3.9 in., tail 2-3.9 in.; fur light to dark brown; adults are good jumpers, climbers, and swimmers, are crepuscular or nocturnal, sleep 12 or more hours a day, and nest in cryptic places near food sources; naturally omnivorous, but preferentially feeds on plant matter; known to be capable of transmitting a few human diseases, including Lymphocytic choriomeningitis, but such infections are not commonly reported and, when diagnosed, are generally mild; mice often contaminate food and damage food packaging; mice tend not to be as infested with fleas as rats, and thus are not effective vectors of plague.

Northern pygmy mouse (Baiomys taylori): terrestrial and subterranean, throughout Central Texas; head and body 2.5 in., tail 1.75 in.; dark gray-brown back, gray sides, grayish white belly; small eyes, medium ears, tail short and nearly naked; mainly nocturnal but sometimes diurnal; eats seeds, fruit, green vegetation; nest is ball-shaped with one or two openings, and is situated under logs, in vegetation, and in small burrows.

Plains harvest mouse (Reithrodontomys montanus): terrestrial, throughout Central Texas; head and body 2.7 in., tail 2.25 in.; feeds on weed flowers and seeds, and on grasshoppers and other invertebrates; nest is ball shaped constructed on or just above the ground; breeds year round; prefers open countryside with short grasses.

Southern plains woodrat (Neotoma micropus): terrestrial, in western half of Central Texas; head and body 8.5 in., tail 6 in.; large, with back and sides steely gray or blue-gray, white belly; eats cactus leaves and fruit, mesquite beans, acorns, and plant matter; makes a house under prickly pear cactus, with 2-5 entrances, and likely uses the house for life.

Texas mouse (Peromyscus attwateri): terrestrial and semi-arboreal throughout Central Texas; 3.75 in. head and body, 4 in. tail; eats seeds, other plant materials, and insects.

White-ankled mouse (Peromyscus pectoralis): terrestrial, throughout Central Texas; head and body 3.75 in., tail 3.75 in.; gray-brown upper parts, brown sides with narrow orange lateral line, white belly; often found on rock ledges and in leaf litter; eats juniper berries, acorns, hackberries, seeds, and invertebrates; breeds year round.

White-footed mouse (Peromyscus leucopus): terrestrial, semi-subterranean, and semi-arboreal, throughout central Texas; head and body 3.5 in., tail 3 in.; dark brown upper back, sides orange-brown, white belly; eats seeds, nuts, fruit, invertebrates, and vegetable matter; makes ball-shaped nests in logs, standing trees, abandoned burrows, bird nests, and inside man-made structures; breeds mainly in spring.

— Woodland vole (Microtus pinetorum); subterranean, throughout Central Texas; head and body 4 in., tail 0.75 in.; reddish brown back, orange-brown sides, gray belly; eyes and ears small; eats roots throughout the year, grass stems in summer, fruit and seeds in the fall, bark in winter; breeds year round; favors sandy soil.

Squirrels (Sciuridae)

— Black-tailed prairie dog (Cynomys ludovicianus): subterranean; along the western edge of Central Texas; though capable of invading yards and landscapes, it is unlikely to do so.

— Eastern gray squirrel (Sciurus carolinensis): arboreal and terrestrial; eastern half of Central Texas; uppermost parts gray with yellow-brown cast on upper back and head; white or pale orange eye-ring; ears gray to rusty brown, sometimes white with slight tuft in winter; white belly; mainly arboreal but spends much time on ground; nest made of twigs, leaves, and plant material, in hollow trees or inside hollow trees; each squirrel uses more than one nest; breeds twice a year in Jan-Feb and June-July; favors hardwood forests.

— Fox squirrel (Sciurus niger): arboreal and terrestrial; throughout Central Texas; variable in color but most commonly grizzled yellow-brown above, with pale orange to rusty brown belly, cheeks, eye-ring and feet, and tail edged in orange-brown; larger than eastern gray squirrel where range overlaps; travels and rests in trees, but feeds extensively on ground; eats nuts, acorns, seeds, fungi, and fruit; makes leaf nests on branches, in hollow trees, or in voids of man-made structures; mates Jan-Feb and May-June; prefers open stands of deciduous and evergreen woodlands, shunning woods with dense undergrowth or closed canopies.

— Mexican ground squirrel (Spermophilus mexicanus): subterranean and terrestrial; throughout Central Texas; feeds on mesquite leaves and beans, grass and herb seeds, insects, carrion, and small vertebrates. It makes burrows that have multiple entrances, and willingly uses the burrows of pocket gophers. It prefers areas with sandy soils.

Rock squirrel (Spermophilus variegates): arboreal, terrestrial; throughout Central Texas; in Texas most commonly found with blackish head and shoulders, dark brown or cream forelegs, but can be entirely black with a pale eye-ring and yellowish belly; mostly seen on the ground but capable of climbing well and sometimes nests in trees; eats fruit, seeds, plant matter, roots, cacti, and invertebrates; prefers rocky canyons, cliffs, and hillsides in arid areas.

Thirteen-lined ground squirrel (Spermophilus tridecemlineatus): subterranean and terrestrial; along the eastern edge of Central Texas; is the “gopher” most people notice along roadsides, on lawns, and on golf courses. It eats seeds of grasses and herbs, but will also consume small insects and vertebrates. Though they will form colonies when conditions permit, adults are not social and defend only the areas around their nest burrows. Deeper nest burrows are built near shallow escape burrows. They prefer short grass meadows and prairies, and avoid wet, low-lying areas.


Appendix B: References to Scientific Literature

  • Reid, Fiona A. 2006. Mammals of North America. Peterson Field Guides.


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2 thoughts on “The Truth about Bird Feeders

  1. Sam Mar 12,2015 4:43 pm

    Enjoy this article! Thanks for writing this up.

    I wonder, would you be willing to change the verbiage in Appendix A? You title it “Invasive Arboreal, Terrestrial, and Burrowing Rodents of Central Texas…” In reality, only the Brown Rat, Norway Rat, and House mouse are invasive — the other rodents are native to the area, if I’m not mistaken. They can increase in numbers due to birdfeeder waste, but I don’t think they’re invasive. It’s hard to invade your home territory! 🙂 They were definitely here first!

    Anyways, it’s a great article nonetheless! Keep up the great work!

  2. admin May 4,2015 10:51 pm

    Editor: Sam, you make an interesting and provocative point. My focus, when using the word “invasive” was that of the typical homeowner who doesn’t feel rodents have a natural “right” to occupy their yard or home. You point out that the meaning is more broad than that, and after mulling it over I’ve come to the conclusion that some editorial changes should be made to the text to reflect your inputs. Thanks.

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