Above is a presentation that CARRI's director, Scott Rashid gave in Aspen, Colorado.
Barn Owl Research
As many of you remember, we had placed live cameras on two pair of Barn Owls that had nested in our nest boxes. Many of you contacted us about how interesting you found that to be. This year, we will continue to bring you new and exciting video. This type of research is costly, the cost for each location runs about $1000.00 for materials, maintenance and the WiFi service. Donate for more projects like these!
**On May 5th, after checking several of our Barn Owl nest boxes we found 6 of our boxes were active with Barn Owls. The eggs should begin hatching later this month.
Between 2014 and 2016 the Barn Owls in our boxes raised over 70 baby Barn Owl. It has been said that a Barn Owl clutch is between 4 and 6 eggs. Some of our birds have read this and follow that protocal, yet others have not yet read that information, as they often lay up to 10 eggs. In 2017, we have one nest that has 8 eggs and another that has only 2.
The number of eggs that the female lays has a direct correlation to the amount of food the male brings her prior to egg laying. This year we have two male owls that are finding young rabbits and bringing them to their females. This is a first for us, as in the past the males only brought in voles and mice.
When we began this project, we built nest boxes that were 15 inches high, 15 inches deep and 30 inches long. Each box had a 6 inch, round entrance hole. This size box proved to be too small as some of the younger owlets perished because the box was too small. Now our boxes are 18 inches high, 15 inches deep and 40 inches long. With this larger box, the owls are more comfortable and so far we have not lost any young owls because the box was too small.
When placing our boxes we look for areas with specific habitat requirements.
In order for a pair of birds to use one of our boxes, the box are placed in areas that have large un-plowed grass covered fields, tall trees or juniper bushes where the male can roost during the day, and each box is placed far from busy roads and highways, so the birds don't get hit by cars. Our boxes are placed on buildings, as to lessen the chances of predators, such as Raccoons entering the nests to disturb the eggs and young. In many of our locations, the birds raise two broods per season and often raise over 10 baby owls each year.
Below are some photos of the Barn Owl research.
Barn Owl numbers have declined over the years due to man made causes such as loss of habitat and nesting sites. Many old buildings that Barn Owls would use have been torn down and replaced by new buildings with no openings for the owls. Therefore, volunteers for CARRI built and placed 10 Barn Owl nest boxes in what we thought would be good habitat for the owls.
Since the inception of this project in 2014, we have placed over 20 nest boxes for Barn Owls in Colorado. These boxes stretch from south Boulder, Colorado to North Fort Collins, Colorado, a distance of about 70 miles.
Through this research CARRI has answered several questions about Barn Owls including:
1) Barn Owls begin nesting in Colorado in March and occasionally in February, but can nest as late as August.
2) Barn Owls mate and raise a family when they are 1 year old.
3) Tall grass a plus for nesting Barn Owls as it is a great location for voles and mice that the owls catch with ease.
4) Barn Owls are an efficient and inexpensive method of rodent control.
5) Most Barn Owls find a new mate every year.
6) Barn Owlets (young owls) leave their nests at about 55-63 days after hatching.
7) Most often, male Barn Owls arrive at a nest location before the female. He both perches near it vocalizing and/or flies around, making dolphin-link clicks and screams, to entice a female to come close enough, so he can show her the nest site he has picked out.
Boreal Owl Research
The research that members of CARRI is doing with Boreal Owls has answered a number of questions:
- Boreal Owls do nest within RMNP
- Boreal and Northern Saw-whet Owls live in harmony with one another in Rocky Mountain National Park (RMNP).
- We are capturing different Boreal Owls within RMNP every year.
- We capture Boreal Owls within RMNP every fall, yet have never recaptured a banded bird.
Below are some questions about this species that have yet been answered
- Do Boreal Owls defend a territory or just their nest tree?
- What do Boreal Owls prey upon?
- Where do Boreal Owls move to in the fall?
- What is the lowest elevation that Boreal Owls can be found nesting in.
Northern Saw-whet Owl Research
Since 1998, we have been finding Northern Saw-whet Owls nesting in and around Rocky Mountain National Park and Estes Park. Many of these nesting birds move out of the area in the fall and hopefully return the following spring to nest.
Some of the questions we are trying to answer include:
- Northern Saw-whet Owls do not return to the same nest sites from one year to the next.
- Adult males seem to stay on their territories year round, as they often begin to vocalize in January and February.
- Where do the young owls move to?
- Placing nest boxes for Northern Saw-whet Owls does enable the owls to have larger families.
- Deer Mouse seem to be the preferred prey item of the Northern Saw-whet Owls in and around RMNP.
- Northern Saw-whet Owls seem to be nomadic, not migratory
- Water appears to be a deciding factor in whether or not Northern Saw-whet Owls nest in a certain area.
The members of CARRI began their Northern Saw-whet Banding Project in the fall of 2006.
CARRI and their volunteers operate a banding station outside Estes Park. The research begins September 15 and runs through November 15. The banding station consist of a series of mist nets placed in a wooded area on a ridge top. Just after dark the birds call is broadcast. Throughout the evening the birds move through the area and come to the call fly into one of the nets and are captured. The nets are checked every 15 to 30 minutes. When a bird is caught, it is extracted, banded, weighed, measured, and released back into the darkness to continue its movement.
During the nesting season, members of CARRI monitor Northern Saw-whet Owl nests. Some are in natural cavities, others are in nest boxes. Owls nesting in nest boxes are banded, measured and weighed, with the hopes of gaining insight into their movements and longevity.
When a nest box has a family of owls in it, CARRI volunteers monitor it to determine the date the eggs are laid, the date the young hatch, the prey that the adults are feeding the nestlings and the fledging date of the owlets.
If you’re interested in seeing the Northern Saw-whet Owl Banding Project please contact Scott at: firstname.lastname@example.org
*Northern Saw-whet Owl 1014-28569 banded south of Estes Park, CO. on 10/4/2012 was recaptured live and released on 11/5/2016 in Pennsylvania
*Northern Saw-whet Owl 1014-43942 banded south of Estes Park, CO. 10/17/2015: Recovered 2/9/16 in Estes Park, CO.
*Northern Saw-whet Owl 0924-58637 banded in Pinewood Springs, Colorado 9/21/2009: Recovered 9/20/2011 in Estes Park, CO.
American Kestrel Research
American Kestrel numbers have declined across North America due to loss of habitat, loss of nesting sites and predation by larger raptors such as Cooper's Hawks. Members of CARRI are creating an American Kestrel nest box trail. When finished, the trail will stretch from Estes Park, Colorado to the Wyoming border.
We are interested in locations on private land where nesting boxes for the smallest North American falcon can be placed and monitored. American Kestrels prefer open country with a few trees. All we need is a post or tree in open country where a nest box can be placed. The middle photo below is a photo of one of our nesting boxes.
In 2016, we had a bumper crop of nesting American Kestrels with all but one of our nest boxes active with nesting kestrels. One nest (the second photo below) had 10, yes 10 eggs in it. A normal clutch is only 5 eggs.
Below are some photos of American Kestrels, including nests, eggs, young and adults.
Volunteers of CARRI are interested in answering these questions about American Kestrels
- American Kestrel's raise more young in nest boxes than in natural cavities.
- American Kestrel's raise, on average 5 young no matter how large their nest box is.
- The timing in egg laying and hatching of young at different elevations varies by a few weeks. they begin egg laying earlier at lowere elevations than higher ones.
- Pairs of American Kestrel will nest closer to one another if the prey is adequate.
Great Horned Owl Research
Members of CARRI have raised baby Great Horned Owls, and rehabilitated injured ones.
Throughout Northern Colorado, CARRI volunteers have monitored several Great Horned Owl nests. Volunteers have found Great Horned Owls nesting on cliffs, witches brooms, Common Raven nests and even heron nests (while the herons are nests right next to them).
In and around Estes Park, the Great Horned Owls feed upon rabbits and hares, ground squirrels, fish, game birds, and even domestic fowl. Throughout the Estes Valley, the owls usually raise one to two owlets.
Volunteers of CARRI are interested in answering these questions about Great Horned Owls
- Birds like Steller’s and Blue Jays harass Great Horned Owls on purpose to attract American Crows to the owls.
- Great Horned Owls prefer rabbits, however, they will prey upon a variety of species, including birds, animals, reptiles, fish etc.
- Some pairs nest nest in the same nest sites for years, yet others choose a different nest site from year to year.
- Some Great Horned Owls are bothered by photographers and birders during the nesting cycle, yet others seem not to care at all.
- Great Horned Owls seem to tolerate other birds of prey within their territory if the owls have enough food to raise their family.
Northern Goshawk Research
CARRI's director, Scott has been interested in Northern Goshawks ever since he was in high school. It has always been a dream of his to work with these magnificent raptors. On his first trip to Colorado, in 1989, he was told of an active Northern Goshawk nest on the property where he was staying. After being attacked by the adult female he was hooked on Northern Goshawks.
After moving to Colorado, Scott began researching Northern Goshawks. This research was soon over-shadowed by his Northern Pygmy-Owl research. His Northern Goshawk research was temporarily put on hold. However, in 2008, his research of the Northern Goshawk resumed. Recently, CARRI volunteers have assisted Scott with the Northern Goshawk research.
Please don’t ask CARRI volunteers where the nests are because they are very protective of the birds.
This year, 2017, a female Northern Goshawk (first photo below) was found incubating on 5.12.17.
Members of CARRI are interested in answering these questions about Northern Goshawks
- In some parts of the Northern Goshawk’s range the species preys heavily upon Ruffed Grouse, yet in area where Ruffed Grouse are absent, Northern Goshawks prey upon red squirrels, ground squirrels, chipmunks, woodpecker, jays, crows, nutcrackers and thrushes.
- Northern Goshawks often have more than a single nest within their territory.
- Northern Goshawks use a downed log or over hanging branch for their plucking post in RMNP.
- Northern Goshawks often build their nests in trees with a canopy above the nest.
A few unanswered questions we still have include:
- When do Northern Goshawks begin incubating?
- Why do some Northern Goshawks attack anyone that comes near their nests, yet other individuals seem not to be bothered by intrusions?
Our Director, Scott Rashid is one of a small handful of individuals in Colorado licensed to trap and band Hummingbirds. Scott has banded several thousand Hummingbirds over the years, mostly Broad-tailed Hummingbirds. His oldest Hummingbird lived 10 years!
In Colorado, there are two species of Hummingbirds that nest in Colorado; the Black-chinned Hummingbird and the Broad-tailed Hummingbird. There are two other species that arrive in the state every year beginning in July. Those two species are the Rufous Hummingbird and the Calliope Hummingbird.
Other vagrants that have been documented in Colorado include the Ruby-throated Hummingbird, Broad-billed Hummingbird, Costa’s Hummingbird, Magnificent Hummingbird, White-eared Hummingbird and Anna’s Hummingbird.
Members of CARRI have been working with these beautiful finches since 1999. Our research occurs in the winter, as all three species of rosy-finches come, often by the thousands, to the institute’s headquarters. The hungry birds are most often, seen in early morning, as the evenings are the longest time any diurnal species goes without eating.
Just after sunrise, the feeders are filled with sunflower seeds, and millet is spread across the deck under the feeders. As the birds arrive, they most often land on the feeders in ones and two’s. Shortly thereafter, the larger flocks land and devour the bird seed. Some days we can go though a coffee can full of bird seed every fifteen minutes.
There are three Species of Rosy-finches in North America: The Black Rosy-finch, the Brown-capped Rosy-finch and the Gray-crowned Rosy-finch (pictured below in that order). The Brown-capped Rosy-finch nests here in the Colorado high country. In most years, we see the Brown-capped Rosy-finch finches at our feeders from October though late November. From mid-November through early February, the rosy-finch flocks consist more of Gray-crowned Rosy-finches and Black Rosy-finches with a few Brown-capped Rosy-finches sprinkled within. In late February, the Brown-capped Rosy-finches return as the Gray-crowned's and Black's move to their nesting grounds. The Gray-crowned Rosy-finches nest from parts of California and Idaho and Montana, north through Alaska. The Black Rosy-finches nest in parts of Utah, Wyoming, Idaho, Nevada, and Oregon.
One day in 2004, we had over 10,000 rosy-finches in the area at once. We know this because we banded 200 finches by 8:00 a.m. and shortly after, that we counted 50 birds on the feeders, and only one was banded.
*****Members of CARRI have the longevity record for the oldest Brown-capped Rosy-finch ever recorded in North America. He was originally banded at the research station on 11/9/2002 and recaptured there and released alive on 5/10/2008. Since the inception of our banding project, we have banded over 4000 rosy finches.
Brown-capped Rosy-finch #1931-77742 was banded at the Institute on 1 May 2008 as an SY bird (meaning it hatched in 2007) and was recaptured at the institute on 4 April 2017, making this bird 10 years old!
This also makes it the oldest known wild Brown-capped Rosy Finch ever recorded!
Corvid…. What is that? A corvid is a crow, magpie, jay or raven. We at CARRI have been researching corvids since 1999. We capture the birds using a large crow trap that is on the grounds of the institute. To lure the birds we use large amounts of beef fat or suet. Each year we try to band every Black-billed Magpie in the neighborhood. In doing that we will gain the greatest amount of data.
Through our research,we have found that Black-billed Magpies have a territory of about a square mile and they use physical boundaries such as mountain ridges and large rivers as territories dividers.
Through our American Crow research we have found that some of the American Crows that winter in and around Estes Park, Colorado; nest in British Columbia and Alberta, Canada. Furthermore, our oldest American Crow lived 10 years. We also band more American Crows than anyone in Western North America. Below are some of our band recoveries.
American Crow # 975-48781 was banded at the institute on 12/13/2004 and recovered on 8/22/2014 in Alberta, Canada.
American Crow # 975-48972 was banded at the institute on 11/15/2006 and was recovered on 7/23/2007 in Alberta. Canada.
American Crow # 975-48975 was banded at the institute on 11/28/2006 and recovered on 2/2/2014 in Estes Park, Colorado.
American Crow # 975-48952 was banded at the institute on 3/21/2006 and was recovered on 3/9/2011 in Sheridan, Wyoming.
American Crow # 945-54602 was banded at the institute om 11/26/2014 and was recovered on 3/9/2014 in Nederland, Colorado.