If you are ever lucky enough to lay eyes on a ringtail, you first thought will probably be something like: “What was that?! It looked like a fox crossed with that wacky lemur character from the movie ‘Madagascar’!” Ringtails are hard to categorize. Edward Abbey, famed lover of our desert landscape described the ringtail in “Desert Solitaire” as “an animal that looked like a cross between a raccoon and a squirrel.”
Abbey came pretty close to getting it right. The ringtail (Bassariscus astutus), also know as a “ringtail cat” is not a cat at all, but a relative of the raccoon. But unlike its masked and cosmopolitan cousin, the ringtail is specialized for the desert. It is slender, with a long, black and white ringed tail and short legs. Ringtails are much smaller than raccoons, weighing less than three pounds and are about two feet long from nose to tail-tip.
This desert dweller has skills that would make the most avid rock climber, parkour enthusiast or “American Ninja Warrior” fan envious. Their ankle joints can rotate 180 degrees giving them tremendous grip and their long tail aids in balance. They have been observed using the climbing technique of “stemming” to move up vertical rock faces–wedging themselves in a crack with two paws on each side and walking up it. If the crack is too wide for this, they may ascend it by bounding back and forth between the walls of the crack like a pinball defying gravity.
The ringtail ranges throughout the southwestern U.S. and Central America. It favors rocky, desert habitats with sources of water. Like raccoons, ringtails are omnivores but their diet tends more towards meat. They eat insects, lizards, juniper berries, prickly pear, other fruits and especially rodents.
In the past, miners made pets of ringtails because they were such effective mousers and kept cabins, mines, and camps free of rodents. This earned them the nickname “miner’s cat.” Ringtails are supposedly relatively easy to tame. It is now illegal to keep ringtails as pets in Colorado– cute as they are, they belong in the wild.
Perhaps the most notable characteristic of ringtails, besides their tails, is that they are elusive. They are almost exclusively nocturnal, very shy and pretty solitary. Most people only see ringtails on the side of the road after the animal has been hit by a car. If you know what to look for, you might spot their tracks in the mud after a rain in a canyon bottom. Like raccoons, all five toes on a ringtail’s foot are visible in its tracks, however they are not “finger-like” as in a raccoon. Ringtails walk more on their toe pads like a cat.
Ringtails are currently considered a “species of least concern” by wildlife conservationists, but their elusive nature makes it hard to be certain how ringtail populations are faring. David Wyatt, a wildlife biologist who studies ringtails in California says they “appear to be locally abundant in some places, but rare to not present in other places that you should reasonably expect them to occur. So, range maps are merely guesses and their true status is just not known.”
Colorado is not monitoring ringtail populations at this time, but local Colorado Parks and Wildlife biologist Dan Neubaum said he’d be interested to hear if ringtails have been spotted in the area, especially if the sighting is confirmed with a photograph. You can contact Neubaum via email at Daniel.Neubaum@state.co.us.
The rocky canyon country surrounding the Grand Valley appears to be very suitable habitat for ringtails, but sightings are rare. Perhaps a keen-eyed and lucky member of our outdoor recreation community will catch a glimpse of this desert phantom. Maybe a hiker will snap a photo of a distinctive five-toed track near a pool in the Colorado National Monument. How enchanting would it be to know that after the sun sets, the ringtails are at play in our canyons?
Special Thanks to biologist David Wyatt for his excellent photos of ringtails. Please check out his bloghttp://bassariscus.me
At one time in my life, I was a (very minor) celebrity. I had only a handful of fans, but they were loud, devoted… and covered in black feathers. If they had spoken English, they would have cried out at my arrival: “She’s here! It’s really her! It’s the mouse lady!”
I was working at a facility that housed birds, including 3-4 Common Ravens in large outdoor aviaries. The aviaries were huge and enclosed on all sides with heavy wire mesh that kept the birds in and predators, like cats and hawks, out. Because predators were excluded and there was an abundance of bird seed and other goodies on the ground, the aviaries were a haven for mice.
Mice can carry Hanta virus, and will even eat disabled birds, so they were not welcome in the aviaries. I decided to put a dent in their population using snap traps. Every morning I collected a grisly pile of mouse corpses from my traps. It was disgusting. A few days into my mouse eradication campaign, I decided that instead of tossing my dead mice in the trash, I would give them to the ravens.
Common Ravens will eat just about anything, but they love carrion. I thought the captive ravens might enjoy a treat, so I pitched the day’s mice into the ravens’ bowl. The next morning they were gone, only some leftover dog kibble remained.
After a couple of days of receiving mice, I noticed that the ravens got excited whenever I arrived. They flew from perch to perch and croaked excitedly when I appeared. The other people that worked in the aviaries never got this greeting, not even the woman that fed the raven their daily ration of dog food. The ravens seemed to recognize me, regardless of what coat I was wearing, or if I had a hat or sunglasses on.
While I liked to joke about how the birds knew and loved me, scientists have recently shown that the Common Raven’s smaller cousin, the crow, does indeed recognize individual human faces, and it is likely that ravens can too. In fact these birds are capable of some impressive intellectual feats.
Bernd Heinrich, a biologist who studied raven behavior extensively and wrote the book Ravens in Winter, devised a clever test of raven intelligence. He tied a long piece of string to a branch and attached a piece of meat to the end of it. When a raven perched on the branch, the long string let the meat dangle of out reach below the bird.
But the raven solved the problem. The bird would reach down, pull up a length of string, lay it against the branch and step on it to hold it. Then it would pull up another length of string and hold it, effectively reeling in the sting until it could reach the meat. Heinrich tested multiple adult ravens and they not only solved the problem, they did it without using trial and error. The birds appeared to study the situation, think through possibilities and then quickly reel in the meat.
Ravens also have a good memory. They cache, or hide, food to eat later and because they have a lousy sense of smell, they need to remember where they put it rather than sniff it out. Young ravens will practice caching by hiding inedible items, they also practice another favorite raven trick– stealing each other’s caches.
Through a series of careful experiments, Heinrich and his colleagues were able to show that ravens can learn which individuals make a habit of stealing caches and they will wait until the thief cannot observe them before hiding their treat. Ravens can also attribute knowledge to other individuals and predict their actions. In other words, Rick the raven knows that Betty also saw where Cindy hid that tasty bit of rabbit. Some animal intelligence experts believe that the raven’s smarts are comparable to those of chimpanzees and dolphins.
So if you ever get the feeling you’re being watched by your neighborhood ravens, you’re probably right. They know your face and they probably know that Wednesday is trash day and that the Walkers have usually have roast chicken on Tuesday so there will be good leftovers in the bag at the top of the can.
This article was originally published in the Grand Junction Daily Sentinel on October 25, 2015
Let us give thanks that humans are much larger than praying mantids. If a praying mantis got any larger it would be downright terrifying. Their front legs, held in the “prayer position” that gives them their name, are actually lethal weapons. Lined with sharp spikes, they shoot out with lightning speed and snatch an unsuspecting insect, then hold its struggling body as the mantis devours it alive. The mantis relies on these “raptorial forelegs” and its camouflage to catch its prey. It is a “sit-and-wait” predator, perching motionless and blending into the foliage until an insect wanders within grabbing distance.
In our area, mantids don’t get very large, about four and a half inches of fierceness at most. But large mantids may eat hummingbirds when they get the opportunity. Mantids are also famous for cannibalism. Females are known to eat their mates, sometimes even during the mating act—but only if she is really hungry. Don’t feel too sad for the male mantis though, his life would have been short regardless of his mate’s appetite. Mantids live about a year at most and do not overwinter. After mating, female mantids lay a clutch of eggs and then die. The eggs are protected in a gob of what looks like brown Styrofoam. You can find these egg masses on twigs, weed stalks and even the sides of buildings or fences. In the spring, dozens of miniature mantids will emerge from the egg mass and head out to hunt.
Mantids are often green in color to blend in with summer leaves, but some species may be speckled grayish-brown later in the season when vegetation dries out. As the mantids grow larger, they molt their skin. With each molt they may adjust the color of their skin to match their habitat. Mantids are masters of disguise and can be hard to spot, especially when they are tiny. In our area they seem to be much more common in the late summer and fall, but really they have been around since spring. It is just that they have finally gotten large enough to spot easily. It is also easy to determine if an adult mantis is male or female. Females have a wide abdomen for producing their large egg masses, whereas males have a slender abdomen allowing them to fly more easily.
Finding a praying mantis is your garden is definitely a good thing, they are harmless to humans and eat pests. But contrary to popular belief, mantids are not really suitable as biological control insect. They will not naturally rid your garden of all those pesky squash bugs and hornworms. That’s because mantids aren’t picky eaters—they’ll eat anything, beneficial insects, pests and other mantids. And because they can’t reproduce quickly, producing young just once a year, their populations can’t boom when the pest populations boom.
But a praying mantis is nice to have around simply because it is fascinating to watch. Their movements are oddly mesmerizing. With large eyes and an ability to rotate their heads 180 degrees, they seem, if not human-like, at least movie-alien-like. And it’s not just modern gardeners who are fascinated by the mantis. Many ancient cultures considered them gods and the word “mantis” derives from the Greek word for diviner or prophet. In China, two styles of martial arts were based on the movements of the mantis.
Next time you spot a praying mantis, take some time to watch this intriguing insect. And give thanks that it is not bigger, and you are not a fly or whatever careless insect it’s planning on having for dinner.
This post originally appeared in edited for in the August 22, 2015 issue of the Grand Junction Daily Sentinel http://www.gjsentinel.com
Do you know the difference between frogs and toads? No, kissing a frog doesn’t turn it into a prince and kissing a toad won’t give you warts. The truth is there is no difference. Biologically, toads are simply a kind of frog. The term “toad” is simply a common name for a frog that is brown and bumpy and spends more of its time out of the water. But plenty of frogs are brown and some species of toads are more closely related to frogs than they are to other “toads.”
Frogs are full of surprises. When hibernating, some species breathe underwater by absorbing oxygen through their skin. Most frogs lack ribs, which is part of the reason they slipped so easily through your fingers when you tried to catch them as a kid. Frogs are fascinating creatures and they can tell us a lot about the health of our environment if we spend a little time getting to know them.
The Children’s Nature Center in Fruita has partnered with FrogWatch, a nationwide citizen-science program created by the Association of Zoos and Aquariums, to get the public involved in collecting data on frog populations in local wetlands. Janet Gardner, Executive Director of the Center and local FrogWatch coordinator, says the Grand Valley is the only area on the Western Slope participating in the project. Because frogs spend at least part of their lives in wetlands and their permeable skin makes them sensitive to water pollution, they are considered “indicator species.” The health of our frog populations can tell us a great deal about the health of our wetlands.
Despite being semi-arid, the Grand Valley is home to plenty of frogs and toads. The American Bullfrog is the most familiar frog in our area, but surprisingly this big green frog is not native to Colorado. The Bullfrog belongs in the eastern U.S. and is considered an invasive species in our state. Though Bullfrogs feed primarily on insects, these large frogs are happy to eat virtually anything that will fit in their mouths—reportedly even rodents, birds and bats. Unfortunately they will also eat other frogs and it is believed that the invasive Bullfrog may be contributing to the decline of the native Northern Leopard Frog.
As its name suggests, the Leopard Frog is known for its spots. This attractive frog used to be quite common but has been declining since the 1970’s and is now listed as a species of special concern by Colorado Parks and Wildlife. The reason for the Leopard Frog’s population decline isn’t simple, but is probably a combination of factors including water pollution, habitat loss, disease and introduction of non-native predators. If you see one in our area, consider yourself lucky.
You are much more likely to come across a Woodhouse’s Toad. They can be found all over the valley, from suburban gardens to the dry desert scrub of the Monument. These classic brown, bumpy toads are most active at night. They make lovely tenants in your garden because they eat insects and slugs, but be prepared to wash your hands if you pick one up as the toad will likely “pee” on you. This tactic is used to startle the predator (you) into dropping it. Toads can also secrete a white toxic substance from glands on their skin that irritates the mouths of predators. So as with most animals, it is better to look and not touch.
The tiny Canyon Treefrog is a great example of a frog that looks like a toad. Its brown and blotchy appearance provides camouflage in the rocky canyon habitat where the Treefrog lives. These tiny frogs, which are about 2 inches in length, are relatively rare and more likely to be heard than seen. Their loud calls are described as a rapid stutter, similar to a woodpecker drumming or a bleating sheep.
Gardner says that FrogWatch volunteers have documented six species in the Grand Valley: American Bullfrog, Northern Leopard Frog, Woodhouse’s Toad, Canyon Treefrog, Red-spotted Toad and the Great Basin Spadefoot. Because frogs are generally masters of camouflage, the best way to find them is by listening. Most species only call during the breeding season, which can begin as early as February for some. Though frog surveys have concluded for this year, Gardner hopes to expand the program next year. If you are interested in participating, please email her at email@example.com. In the meantime, you can do some informal frog watching at your local pond, or check out some more exotic species, like the tiny colorful poison dart frogs, at the Children’s Nature Center.
This post originally appeared in edited form in the Grand Junction Daily Sentinel on July 25, 2015.
If your first glance at this photo caused an involuntary shudder, you are not alone. Fear of snakes may be the most common phobia according to psychologists. Even people who are not actually terrified of snakes generally do not get a “warm fuzzy feeling” upon spying one.
Snakes have long been cast as the villain in mythology and folklore, but it is time to change our attitude towards snakes because the vast majority that you may encounter in our area are not only harmless, but likely very beneficial to you.
In the Grand Valley the three snakes that you are most likely to see are the Terrestrial Gartersnake, the Bullsnake and the Great Plains Ratsnake. None of these snakes is venomous or dangerous to humans and all three of them can benefit your backyard by reducing pests at no cost or inconvenience to you.
The Terrestrial Gartersnake, which many people call by its nickname “garden snake,” is one of many species of gartersnakes in North America. This is the snake most commonly seen in the suburbs, but they live in a variety of habitats and have even been found in the alpine tundra at 13,000 ft.
Why do you want a gartersnake in your garden? Because they eat insects, including grasshoppers, as well as slugs. Really large gartersnakes will also eat mice. If you like your lettuce without holes and your cherry tomatoes un-nibbled, a gartersnake is nice to have around. Gartersnakes rarely bite, and then only if you try to pick them up. Their teeth are tiny and razor sharp and I know from first hand experience that their bite is no worse than a paper cut. A gartersnake’s first line of defense when snatched up by a predator or curious human is to release a foul smelling musk substance all over the offender’s hands. It stinks, but it washes off easily.
Our other common snake, the Great Plains Ratsnake is also known as a corn snake because it often hangs around places where grains like corn are stored. It doesn’t eat corn– it eats the mice and rats that eat corn. Ratsnakes are frequently found in barns and sheds where rodents hang out. If you find one in your shed, count yourself lucky and let the snake go on its merry way. With a ratsnake around, you’ll have fewer rodents raiding your birdseed stores, making nests in your stored camping gear or potentially exposing you to Hanta virus.
Like the ratsnake, the Bullsnake (also known as a Gophersnake) is an effective rodent killer. Bullsnakes are often mistaken for rattlesnakes and killed because when threatened they mimic the posture of a rattlesnake to scare off predators. Frightened Bullsnakes may even vibrate their tails against the ground to make a rattle-like sound.
There are only two venomous snakes in our area, the Prairie Rattlesnake and the Midget Faded Rattlesnake, and “sightings of these snakes are rare” according to Dan Neubaum, wildlife biologist with Colorado Parks and Wildlife. They are usually seen on rocky outcrops, mesa tops and the scree slopes of canyon country—not in backyards. These snakes are generally shy and just want to be left alone- that’s why they have a rattle to warn people and other threats to “please go away.”
There is a saying that your risk of snakebite increases with the “T” factors: tequila, testosterone, teasing, etc. That’s because a significant proportion of rattlesnake bites are suffered by young men who get drunk and decide it’s a good idea to tease or pick up a snake. Rattlesnakes do not want to bite you. They typically only bite when stepped on or grabbed. If you can avoid getting drunk and teasing snakes, you have already substantially reduced your risk of snakebite, beyond that, the best advice it to be aware of your surroundings. If you are in rattlesnake country, watch where you are putting your hands and feet. Rattlesnakes like to hide from their predators and are well camouflaged. Don’t step anyplace you can’t see clearly or reach into rock crevices. Keep your ears open and listen for a warning rattle- don’t wear headphones. Wear study boots or shoes that protect your feet so that if you do step in the wrong place, a bite won’t break the skin.
If you are interested in learning more about our local reptiles, check out Colorado Partners in Amphibian and Reptile Conservation (https://www.facebook.com/groups/163973464573/) which shares information and runs “herping” field trips. “Herping” is the reptile and amphibian equivalent of “birding.” The website http://www.coloradoherping.com documents Kevin Urbanek’s adventures herping in Colorado with his young son and is the source of the wonderful photos that accompany this article.
Maybe learning about the benefits of backyard snakes hasn’t turned you into a snake-lover. But at the very least, I hope it has convinced you to live and let snakes live, even when you find them in your yard. They are good additions to the garden.
Does spring fever give you the urge to frolic in fields and chase butterflies? If so, grab a net and go for it. If anyone gives you a funny look, tell them you are doing important scientific research.
Scientists with the Pieris Project are asking people all over the world to collect cabbage white butterflies. This small, delicate-looking butterfly is one of the world’s most successful invaders. The cabbage white originated in Europe, but has spread to most continents and adapted to a wide variety of environments. Scientists want learn how this world traveler and agricultural pest pulled it off. To figure it out, they are enlisting the help of citizen scientists armed with butterfly nets.
The cabbage white butterfly (Pieris rapae) is small, only 1 to 2 inches in wingspan. It is mostly white, with a dark gray tip and one or two spots on its front wings. The rear wings can be white, grayish-white or pale yellow. The cabbage white is one of the most common butterflies in North America. In fact, in the course of writing this I have seen at least 3 of them flutter through my backyard.
As a caterpillar, this butterfly feeds on plants in the mustard family, which includes many popular vegetables such as cabbage, broccoli, kale and Brussels sprouts. Scientists believe this insect was accidentally introduced to the East Coast around 1860 when it stowed away in some cabbages brought from home by European immigrants. Then it hitched a ride on the railroad, hiding in vegetable cargo, and in about 40 years it had spread all over North America.
Scientists with the Pieris Project are asking citizen scientists to catch these butterflies and send them to their lab at the University of Notre Dame. There, researchers will analyze the butterflies’ DNA to learn more about the genes that allow it to invade new environments. They will also study how the butterfly has changed as it spread across the globe.
So far, citizen scientists have sent in butterflies from 25 states and ten different countries. Even Mesa County has contributed a sample! Josh Jahner, a Colorado Mesa University alumnus who is now studying entomology at the University of Nevada, Reno, collected a few cabbage whites in Orchard Mesa last summer when he drove through the Grand Valley.
But Sean Ryan, founder of the Pieris Project, says that they are hoping to increase participation this year and that more samples from Mesa County and Colorado are welcome. Ryan is Ph.D. student at the University of Notre Dame and very enthusiastic about getting citizens, young and old, involved in science. He and his team are even developing teaching modules so that teachers can incorporate the Pieris Project into their science curriculum.
Sadly, participating in this science project does involve killing some butterflies. Because they are agricultural pests, cabbage whites need to be dead before you ship them across state lines. You can kill them humanely by placing them in a container in your freezer overnight. But don’t be too sad- these butterflies are abundant and have short life spans even if they don’t participate in this project. And a cabbage white in the net may mean healthier broccoli plants in your garden this summer.
To get all the details on the Pieris Project, as well as everything you need to know about identifying, catching and shipping cabbage white butterflies, please visit their website: http://www.pierisproject.org. Then grab your net and get ready to chase some cabbage whites!
If your favorite summer treat is a warm, ripe tomato straight from the garden, or even if the closest you get to a tomato is the ketchup on your burger, you should thank a bee, specifically a bumblebee or mud bee.
When we think of bees, we picture usually honeybees. But honeybees are not native to the Americas- they were brought here by European settlers. Some honeybees escaped, forming wild colonies and some remained domesticated. But how were flowers pollinated before the arrival of the settlers and their bees? By native bees and other pollinators of course.
Native bees are less familiar to most people because their habits differ from honeybees. Many are not social, do not form colonies or hive, and prefer to live alone and inconspicuously. Some bees nest in the ground, or in holes in wood. Many native bees have mild stings or cannot sting at all. There are over 4,000 species of native bees in the United States and these natives, along with honey bees, pollinate 75% of the fruit, vegetables and nuts grown in this country- about $16 billion dollars worth of crops.
Clearly we need bees for more than just honey, but our bees are in trouble. In the mid-2000s beekeepers began noticing a dramatic increase in the number of honeybee colonies dying off- they named this phenomenon “Colony Collapse Disorder” or CCD. Scientists have been trying to figure out what causes CCD. Possibilities include parasites, pesticides (especially neonicotinoids), fungicides, loss of wildflower diversity, and disease. A recent study concluded that the cause is probably a complex combination of all these factors. Poor nutrition due to loss of flower diversity or exposure to pesticides can make bees more susceptible to parasites and disease.
It is not just honeybees that are suffering from CCD. Native bee species are declining too although less is known about their populations. Our native bees may not produce honey for humans, but they are crucial for pollination of our crops.
Many of our favorite plants are pollinated by natives. For instance, tomatoes can be pollinated by the wind, but to produce large and numerous fruits they need “buzz pollination.” Honeybees, though they buzz, do not “buzz pollinate.” Buzz pollination is a special behavior in which the bee holds onto the flower, vibrates its flight muscles, and makes the flower vibrate as well. This loosens the pollen and maximizes pollination of the plant. Native bumblebees and mud bees buzz pollinate, so if you want productive tomatoes in your garden, you need these species.
Plants in the squash family, such as zucchini, melons and cucumbers, are also best pollinated by natives. While honeybees do visit these plants, if you see a bee at your zucchini plant very early in the morning, it’s probably a squash bee. Squash bees look similar to honeybees, but behave differently. They get up earlier because squash flowers open early in the morning and they nest in the ground, often right under the squash plant.
We can help keep our native bees around by doing a few simple things in our own backyards. Plant a few bee-friendly plants in your garden, especially native plants which require less care and are favorites of many native bees. Avoid using pesticides when possible and when you do use them, apply carefully to avoid spraying bees. Bees need to drink and many native species use mud in their nests. Providing a source of pesticide free mud and water can be a huge benefit. You can also put up a “bee block,” simply a chunk of wood with some small holes drilled into it. This provides critical nesting sites for mason bees and other species that nest in cavities. And don’t fear, these cavity-nesting bees are not aggressive, and rarely sting, so you are not inviting trouble into your backyard.
So if you enjoy fruits and vegetables or want a lovely, productive garden, do the bees a favor- make your backyard “bee friendly” and look out for our amazing native bees. They have been doing us the favor of pollinating our farms and gardens for thousands of years. Support the bees, both honeybees and native bees- we won’t have much to eat without them!
This article first appeared in the Grand Junction Daily Sentinel on March 25, 2015.
Last week, I watched as a sharp-shinned hawk made his daily foray through my yard, trying to nab one of the birds visiting my feeders. The birds dashed for cover and the hawk missed his target and alighted on the fence to plot his next move. Meanwhile, 3 black-capped chickadees that had reached safety in the branchy crown of the willow began a furious chorus of their characteristic “chicka-dee” call. But why were these tiny birds drawing attention to themselves while a deadly predator sat less than ten feet away? If you learn to speak a few words of “Chickadese,” you might be surprised at how much they were saying.
When we think about bird sounds we usually think about their songs. But birds make different sounds for different reasons, and in some cases, ornithologists have figured what these sounds mean. Songs are a vocalization that birds make when trying to attract a mate, or tell neighbors that this is their territory and “get off my lawn!” When chickadees sing it sounds like a clear whistled “fee-bee” or “fee- bee- bee.”
Chickadees also make what is described as a “gargle” call, but to me sounds like a super-speeded up recording of someone talking. This call is used in aggressive encounters between chickadees and seems to mean something like “get out of my space bozo!” The gargle call is apparently also used frequently between members of a mated pair—I am not sure what this says about the state of chickadee marital relationships.
When danger is near, say a predator is on the attack, chickadees will make a high pitched “seee” alarm call. High pitched, “thin” sounds like the “seee” call are harder to localize- many species of birds use similar sounds as alarm calls. Ornithologists believe these types of calls allow birds to warn others without giving away their location to the predator.
The “chicka-dee” call is used in multiple situations, but it is frequently used as a “mobbing call.” Birds use mobbing calls when they want to attract attention to a predator. Most predators need the element of surprise. If the prey spots the predator before the attack, the predator usually gives up and moves on. When chickadees are mobbing a predator, their chickadee call is essentially saying “Hey guys! There’s a hawk over here! Let’s go yell at him so he knows we see him!”
About a decade ago, ornithologists at the University of Montana noticed that sometimes the “chicka-dee” call has just a couple “dee” notes at the end: “chicka-dee-dee,” and sometimes it has more: “chicka-dee-dee-dee-dee-dee.” They presented chickadees with a variety of different predators and discovered that the number of “dee” notes in the call corresponded to the level of threat the predator posed. So if chickadees were mobbing a great horned owl, the calls would have fewer “dee” notes, i.e. “chicka-dee-dee” because great horned owls hunt small to medium sized mammals, rarely chickadees. Whereas if the chickadees were presented with a perched merlin, a falcon that specializes on small birds, they would add lots of “dee” notes: “chicka-dee-dee-dee-dee-dee.” Chickadees that heard mobbing calls with more “dee” notes responded with more intensity.
When the chickadees in my yard started calling in response to the sharp-shinned hawk, I started counting. Sure enough, their calls had 4-5 “dee” notes, very similar to what the ornithologists recorded in response to high threat predators. A sharp-shinned hawk is definitely a big threat to a chickadee, if he can catch the bird unaware. But these bold little chickadees were having none of that. They agitatedly hopped about in the willow tree, “chicka-dee-dee-dee-deeing” with all their might. “We see you! We see you, you dangerous hawk! Now scram! You can’t surprise us!” I swear if chickadees could hold flaming torches, they would have been waving them at the hawk, they were such an angry mob. And after a few minutes of this, the hawk seemed to shrug his shoulders and then flew off to hunt somewhere else.
Feeding the birds is typically associated with peaceful domesticity and little old ladies singing “tuppence a bag.” But when you feed the birds, you invite nature into your backyard and as Tennyson put it, nature can be “red in tooth and claw.”
In the wintertime, one of the regulars at my backyard feeder is not there for the birdseed, but rather for the seed-eaters. A Sharp-shinned Hawk, North America’s smallest hawk, visits almost everyday and occasionally makes a meal out of one of the sparrows, finches or doves that come to dine. A visit from a bird-eating hawk is not unusual during the winter. Nic Korte recently wrote about hawks visiting his backyard feeders in the “Birds and More” blog. Typically, you only see Sharp-shinned Hawks in town during the winter, because they spend the breeding season in dense forests, such as those on the Grand Mesa. They move to forest edges or suburban areas in the non-breeding season.
The idea of a hawk in your suburban backyard may seem odd because we usually think of hawks as large, soaring birds like the Red-tailed Hawk. These birds are usually seen perched on a telephone pole or soaring high above grassland. But the Sharp-shinned Hawk is a different kind of hawk all together.
Hawks are divided by biologists into two groups: the large, soaring hawks with long wings and relatively short tails are buteos; while the smaller, shorter-winged hawks with longer tails are accipiters. Accipiters are build for speed and maneuverability in order to catch their main prey- other birds. While a buteo will typically dive down on an unsuspecting rodent from high in the sky, an accipiter engages in high-speed ambush and pursuit to catch a bird.
There are only three species of accipiter in North America and the Sharp-shinned hawk is the smallest- less than a foot high. It is easily confused with its cousin, the Cooper’s Hawk, which has virtually identical markings, but is larger and in flight, you can see that the end of its tail is curved rather than straight. (Here’s a trick to remember “Straight = Sharp-shinned, Curved = Cooper’s.”) Sharp-shinned Hawks are also sometimes confused with Merlins, another very small bird of prey with similar markings. However the Merlin is a falcon, built for high speed with very pointy wing tips. If the Sharp-shinned Hawk is fast and agile like a Porsche, then the merlin is a fighter jet.
Maybe you will think me ghoulish if I admit that I enjoy having the Sharp-shinned hunt in my yard. It’s always easy to tell when the hawk is around: in a flash, the birds disappear into the nearest dense cover and start giving a high-pitched, soft “chip” call- a warning to their fellows. My kids and I immediately start looking for the “Sharpie” as we call him. Usually he misses and perches in the tree right across from our kitchen window to plot his next move. Occasionally, he will succeed and fly off with a hearty breakfast clutched in his talons. And if we are lucky, he will enjoy his meal in our yard while we watch and talk about how we feel bad for the little bird, but the hawk has to eat too. After all, nature is not gentle, and bird feeding is not always for the timid.