Black-Tailed Prairie Dogs

Cynomys ludovicianus

DESCRIPTION

Black-tailed prairie dogs are rodents within the squirrel family. They are ground squirrels roughly 14-17 inches long. They can weigh from 1 to 3 pounds and have typically brown coats, but the fur color can vary from brown, gray, black or white. As their name suggests, the tips of their tails are black.

They are diurnal burrowing animals that are found in short grass plains. Unlike other prairie dogs, black-tailed prairie dogs do not hibernate.

PREDATORS

There are many things that consider the prairie dog prey. These include the rare black-footed ferret, whose diet consists almost entirely of prairie dogs and whose numbers suffered tremendously with the decline of prairie dog numbers. So much so, that they were thought to go extinct twice, and are now being slowly reintroduced back into the wild. They are North America's most endangered mammal.

Other predators include the swift fox, ferruginous hawks, eagles, badgers, and coyotes.

If a predator tries to follow a prairie dog into its burrow, the prairie dog will try to plug up the hole behind it with dirt before the predator can get through. This often traps the predator, giving the prairie dog time to escape while the predator digs itself out.

BURROWS

Prairie dogs live in extensive underground burrows with entrances easily spotted from the surface by their raised mounds of earth. The raised mound of earth at each entrance has many functions. It prevents the tunnels from flooding, it facilitates ventilation so that they get fresh air in their burrows, and they also serve as lookout posts.

They have rooms for nurseries, sleeping areas, and even a designated place for a toilet. They constantly are making new rooms and tunnels, and closing off old tunnels that they no longer use to reduce the chances of a predator (like a black-footed ferret) sneaking in.

They live in family groups called coteries in each burrow, and several burrows in an area made up of different prairie dog families makes a town. Towns can sometimes have hundreds of prairie dogs living there.

Coteries are typically made up of an adult male, one or more adult females, and their offspring.

Family members will greet each other by “kissing” where they touch their front teeth and even swap a little saliva.

REPRODUCTION

The mating season for black-tailed prairie dogs is in March. They have a gestation time of 33-38 days, and pups are typically born in April of May. A litter size is 3-4 pups on average, but can be as little as 1 or as high as 8.

Pups are born altricial; this means they are blind, weak and hairless. It takes them several weeks to develop before they can leave the burrow.

Males will leave their coterie before the first breeding season of their lives and will either travel to another coterie or to a new site in order to establish his own territory and coterie. This trip is very dangerous, and many do not survive.

If the population density in a town is too great, cannibalism is preformed on the young new pups in the spring.

COMMUNICATION

Prairie dogs have a pretty intricate way of communicating with each other, and some studies show that they have different calls for dogs versus coyotes, a different call for a predator in the sky such as a hawk, and a different call for a predator on the ground. Some studies even suggest that prairie dogs can even describe the color of a persons clothing.

They do a “jump-yip” call, and this call is believed to be an “All is well” call, or "hurray it's a beautiful day!" There may be other reasons for this call as well.

Here are a few videos on prairie dog communication:

If you only have time for one video, watch this one!

  

DIET

Prairie dogs are mostly herbivores, eating grasses, sedges, flowering plants, roots, seeds and sometimes they will eat insects!

RANGE

Black-tailed prairie dogs once ranged all across the Great Plains, from Southern Canada to Northern Mexico. With numbers that used to be in the hundred millions, perhaps even billions, now there are only around 10 to 20 million, a 95% reduction in abundance. They were completely eradicated in Arizona, but have been reintroduced in a small area in the state again. They can be found now in 11 U.S. states, 1 Mexican state and 1 Canadian province.

FUN FACTS

• The Largest recorded black-tailed prairie dig town is in Texas, 25,000 square miles large, and might have around 400 Million prairie dogs!
• There are five species of prairie dog, the black-tailed, white-tailed, Gunnison’s, Mexican and Utah.
• Black-tailed prairie dogs are the most common
• Prairie dogs help to aerate and fertilize the soil
• Prairie dogs live in a very dry place, and get their water from the vegetation that they eat. A very important adaptation for living on the plains!
• The scientific name for Black-tailed prairie dog, Cynomys ludovicianus means dog-mouse of Louisiana

THREATS

The biggest threat to prairie dogs are humans. They are often exterminated by farmers who see them as pests, not only for eating grass that they would rather have for their cattle, but also for their burrows being dangerous places where the farmers horses or cattle might trip and break their legs. There are no known cases of this ever happening however.

Because of this dislike, prairie dogs are poisoned, or shot by farmers. In some places they are even killed for sport. Some cities will cull prairie dog colonies if they become too large or start to expand into unwelcome areas.

SYLVATIC PLAGUE

Prairie dogs have no known immunity to this plague, which entered North America in 1900. It can eliminate all or nearly all prairie dogs in an area within days.

If you live near a prairie dog colony and you notice a sudden decline in prairie dog numbers, it is best to inform someone immediately. Possible people to inform might be Animal Control or the city that you live in. Dusting of a prairie dog colony can kill the fleas and stop the spread of the plague.

A rabbit has taken over a prairie dog hole

BENEFITS OF PRAIRIE DOGS

As key stone species, this means that many species rely on prairie dogs for their own survival. Many kinds of insects, birds, reptiles and mammals will use their tunnels for nests or homes. This includes the burrowing owl, rattlesnakes, hares, and even the prairie dogs top predator, the black-footed ferret.

Along with the many species that benefit from prairie dogs as food, prairie dogs also support plant life and diversity by fertilizing the ground and aerating the soil.

While prairie dog numbers are in decline, there may be ways to help. By educating  people about the importance of prairie dogs and their important role in the prairie ecosystem, or by even working with the city and finding out more about its prairie dog management. In some places it has been found that simply having barriers of tall grass that prairie dogs do not like to go through can stop prairie dog colonies from spreading into places where they are unwanted.

Many ranchers do not realize that prairie dogs only consume 4 to 8 percent of the grass in an area, and they actually increase the productivity and diversity of grasses in a grazed area.

Black-tailed prairie dogs are not currently on the endangered species list, and this is something that should be changed. They were removed from the candidate list as an endangered species in 2004, possibly because of political pressure to poison prairie dogs for agricultural reasons.

SOURCES:

Conserve Nature

http://www.conservenature.org/learn_about_wildlife/prairie/prairie_dog.htm

Defenders of Wildlife

http://www.defenders.org/prairie-dog/basic-facts

National Geographic

http://animals.nationalgeographic.com/animals/mammals/prairie-dog/

Prairie Wildlife Research

http://www.prairiewildlife.org/btpd.html

U.S. Fish and Wildlife

http://www.fws.gov/mountain-prairie/species/mammals/btprairiedog/

Plains Cottonwood

The plains are almost a treeless place, and before the early pioneers worked the land and planted many of their own trees, the plains cottonwood tree was one of the few trees that doted the landscape.

Cottonwood trees have large shiny leaves and can be one of the largest trees in North America despite its harsh dry living conditions. They can grow as high as 100ft tall, with trunks as wide as 5ft in diameter.

Leaves are green and have serrated edges, and form a triangle shape. The bark is a smooth gray-brown that becomes grooved as it ages. 

Cottonwood trees can also be male or female. The female trees produce a fluffy white seed that gives the trees their name, which floats off the tree in a breeze like a summer snow. The male trees produce the pollen, which is the stuff that most people find that they are allergic to.

These trees have a great resilience, and not only do they survive in a place with little water (although you can always find them where there is some water, like a river or lake) they also have resistance against prairie fires. They have thick corky bark, that helps them survive these fires.

In the fall, the cottonwood tree turns a golden yellow.

The cottonwood tree has a remarkable star shaped pith. To see it, all you have to do is get a twig from the tree and break it. If you can get a clean break, you will see a star shaped inside! 

Because of this, the cottonwood tree was valued by the Arapahoe people, believing that the stars came from the earth, and climbed the cottonwood tree to the sky. The star shaped pith is what the stars left behind after their passing. 

SOURCES:

Colorado Tree Coalition

http://www.coloradotrees.org/feature_trees/cottonwood_plains.php

GNPC.Org

http://www.gpnc.org/cottonwood.htm

The Greenway Foundation

http://www.gnwy.org/web/index.php/chompers-chatter/speciesprofiles/beaver-21/

Bald Eagles

American Bald Eagle

Haliaeetus leucocephalus

January is National Bald Eagle viewing month, and so to celebrate I think it’s a good time to write a blog about these beautiful birds!

Remember when viewing Eagles to try to avoid disrupting them! It is best to give them space so that they do not waste precious energy avoiding you, when they could be hunting prey.

IDENTIFICATION:

The bald Eagle in its adult form is a highly recognizable bird. The only eagle unique to North America, its large brown body and white head and tail make it easy to identify. From a distance, you may see it soaring, rarely flapping its wings, and holding its wings flat. It has yellow feet, legs and a yellow hooked bill.

It takes about five years for a juvenile eagle to get its adult plumage. Until then, they have mostly dark heads and tails, with mottled white in varying amounts. 

HOW TO TELL THE DIFFERENCE BETWEEN A IMMATURE BALD AND GOLDEN EAGLE:

This is often difficult to distinguish. Golden eagles have smaller heads and are more streamlined, and will have a blonde or golden nape.

The immature Golden Eagles also have a mottled white color, and they have large white patches under the wings and a solid broad white band at the base of their tails that immature Bald Eagles do not have.

While Bald Eagles soar with their wings flat, Golden Eagles soar with their wings slightly raised.

Golden Eagles tend to live in more mountainous regions, and are not common in the Eastern part of North America.

FUN FACTS:

• The Bald Eagle has been the national emblem of the United States since 1782
• Because Bald Eagles often steal their prey from other birds, Ben Franklin disagreed with using the Bald Eagle as the National bird, suggesting the ‘noble’ turkey instead.
• Bald Eagles are believed to mate for life.
• Bald Eagles in the Northern parts of North America get to be much larger than Bald Eagles in Southern North America.
• Bald Eagle nests are some of the world’s largest nests, the largest on record was 9.5ft wide and 20ft high. It weighed more than two tons!
• Bald Eagles sometimes play, and one spectator has even seen these eagles passing sticks to each other in flight!
• Bald Eagles can fly hundreds of miles a day searching for a place to call their own.
• While typically solitary, Bald Eagles can congregate by the hundreds at communal roosts and feeding sites, especially during the winter when prey is scarce.
• The female is larger than the male

MIGRATION:

In some places the Bald Eagles are residents and stay year round. In Colorado there are only a few places where there are year-round residents, and many migrate here during the winter to breed and then away again when spring arrives.

DIET:

Bald Eagles are mostly fish eaters, but they also eat mammals, waterfowl, and even carrion or garbage. They often will harass other birds and take their prey.

LIFE HISTORY:

Bald Eagles are thought to mate for life, and can live as long as 28 years in the wild and 36 years in captivity.

Mating season may be anywhere from late September to early April, depending on the region. They lay about 1-3 eggs, and the eggs incubate for 35 days.

Bald Eagles build some of the largest nests, and both male and female will bring materials to build the nest. The female, however, does most of the placement. Weaving together sticks and filling in the cracks with soft materials like grass, these nests are usually five to six feet in diameter and two to four feet tall.

The shape of the nest can also vary. Depending on the supporting tree, the nests can be round, flat or even conical.

The inside of the nest is lined with woody material like lichen, and then covered with soft material like downy feathers.

These nests can take up to three months to build, and are often reused and added to year after year.

Bald Eagles typically nest in trees, but in some areas they will make due when only cliff faces and ground sites are available. They tend to prefer tall sturdy pines that rise above the canopy, giving them easier flight access and visibility. It is unknown whether the male or the female choose the nest site.

Bald Eagles have some of the most amazing courtship dances, where they fly high into the sky and lock talons, where they then cartwheel downward together, breaking off at the last minute before crashing into the earth below.

BALD EAGLES AND DDT:

While Bald Eagles are now up to 5,000 nesting pairs in the lower 48 states, with roughly 70,000 estimated to be in North America, this number was as low as 500 nesting pairs in the lower 48 states.

DDT was a harmful pesticide that was being used on crops. The chemicals were washed off of crops, usually by rain, and made it into rivers and lakes where the chemicals built up in fish. When the eagles ate the fish, their main diet, and the chemicals weakened the eggshells and the young often did not hatch.

DDT was not restricted until 1972, and in 1978 Bald Eagles were protected under the Endangered Species Act. Since DDT’s restriction, Bald Eagles, along with many other birds of prey who were affected by DDT have made a tremendous comeback. By the late 1990s, breeding pairs of Bald Eagles can be found throughout most of North America again.

While Bald Eagle numbers have made a significant comeback, they are still most abundant in Alaska and Canada, where people compare them to nuisance birds like gulls because they are so common.

In June of 2007, Bald Eagles were removed from the Endangered Species list, and are now listed as least concern. This is a huge improvement for the Bald Eagles and a fantastic success story for a National Symbol that was almost driven extinct.

Bald Eagles are still facing human threats, such as car collisions, habitat loss, lead poisoning from hunter shot prey, and are still vulnerable to environmental pollution.

SOURCES:

Cornell Lab of Ornithology

http://www.allaboutbirds.org/guide/bald_eagle/id

Daily Camera

http://www.dailycamera.com/ci_13073419

Defenders of Wildlife

http://www.defenders.org/bald-eagle/basic-facts

National Geographic

http://animals.nationalgeographic.com/animals/birds/bald-eagle/

National Wildlife Federation

http://www.nwf.org/news-and-magazines/national-wildlife/birds/archives/2010/seeing-bald-eagles.aspx