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Posts Tagged ‘raptor’

In 1982, the year I was born, there were only 22 California Condors alive in the world. Those 22 birds were all that remained of a population that once spanned the western US, and bits of Canada and Mexico. The Condor population plummeted as a result of lead poisoning, hunting, habitat loss and pollution.

California Condor 01

Geographic range of the California Condor in the 1880s

By 1987, the world population of California Condors was 27 birds. Since the causes of the California Condor decline were distinctly human activities, it only seemed appropriate for humans to step up and attempt to fix what they had broken. To that end, the 27 birds were captured and taken into a captive breeding program run by the U.S. Fish and Wildlife Service. The goal of that captive breeding program was to first raise Condors and establish multiple captive breeding populations, and then to establish multiple wild populations. It was an ambitious plan.

Over the last 37 years, the program has overcome countless challenges from figuring out how to hatch condor eggs, to how to raise babies that will grow into wild adults, to teaching those young adults to find food. California Condors are not fast breeders. A pair will only lay one egg each year, and they sometimes skip years. The young birds take several years to grow and gain full independence, and will begin to breed after about five years. It has taken extensive amounts of money and time, but success after success have become realities.

California Condor 03

An adult California Condor

A small number of captive breeding populations were established in zoos raptor breeding facilities. In 1992, Condors began to be released into the wild. Additional releases established small populations in California, Arizona, Utah, and Mexico.

Now a new milestone has been reached. In March of this year, the 1000th California Condor chick has hatched since 1987 when the captive breeding population was initiated. This brings the living population to around 500 individuals, since numerous chicks, juveniles, and adults have died in the last 37 years. The 1000th chick hatched in the wild to a pair of Condors living in Zion National Park in Utah.

A population of 500 individuals is still not big enough to be out of danger of extinction, and as such are still protected by the U.S. Endangered Species Act. But it is certainly a wonderful accomplishment, and the 1000th chick born is also a occasion to be celebrated. Hopefully, the California Condor population will continue to grow, and the amazing birds, the largest in North America, with their 9 foot wingspans will be circling 15,000 feet over our heads in greater numbers and across greater areas as the next 37 years unfold.

California Condor 02

 

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If you are in the Davis or West Sacramento area in the late summer or early fall, and have an evening to spare, go and find a spot where you can sit beside the Yolo Bypass Causeway. This is where highway I-80 crosses over the Yolo Bypass.

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Streams of Mexican Free-tailed Bats over the Yolo Bypass

Just as the sun begins to set, you will see an amazing sight. Columns of bat will flood out from under the bypass and stream across the sky in sinuous ribbons. About a quarter of a million Mexican Free-tailed Bats (Tadarida brasiliensis) live under the bypass this time of year, and every night they pour out and spread across the surrounding area to find small flying insects to eat.

These bats are incredible! They can fly about about 100 miles per hour, making them among the fastest mammals in the world! Remember that Cheetahs are the fastest land-mammal, but bats have them beat by a healthy margin. These bats can fly as high as a mile above the ground, and can forage out distances of several miles from their night roost before returning around dawn to sleep. Using their sonar they can detect and pinpoint the exact position of little insects flying through the air and then capture those insects on the wing, at speed!

My wife, daughter, and I joined some friends and went out for an evening visit to see the bats about a month ago. I was a spectacular evening in the Yolo Bypass Wildlife Area. We saw lots of Swainson’s Hawks; herons, egrets, and ibis galore; some of the biggest Western Saddlebags (which is a species of dragonfly) I have ever seen; and then we got to the causeway.

When we arrived, the sun was still a touch above the horizon, so we had some time to stand around the dirt road that runs parallel to I-80 and chat and watch the sunset. We got a very nice surprise when an adult Peregrine Falcon flew past and landed in the top of a tree a little ways to the west of us. I was so excited to see this bird that, in turning around for a better look, I clumsily stepped on my wife toes (sorry sweetheart)!

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Mexican Free-tailed Bats as they leave from under the Yolo Causeway.

As the light began to fade, we started seeing little movements under the causeway. The first bats were starting to move. Interestingly, the bats do not wake up, take flight, and simply fly out from under the causeway wherever they happen to be. Instead, they wake up, take flight, and then fly directly under the causeway for a few hundred yards before turning a sharp left, and lifting up into the open sky. I have no idea why they decide to do this, but volunteers at the Wildlife Area know it is gong to happen so consistently, that they can tell you exactly which tree the bats will fly out near.

The numbers of bats moving under the causeway built and built until there were bats streaming along between the support pillars. Then they made that left, and out in to open they came! A snaking stream of bats began raising and twisting into the sky! Thousands and thousands of bats following one another out from where they had been sleeping to look for food. As we watched the seemingly endless flow of bats, we got a very cool surprise. That Peregrine Falcon that we had seen earlier came back. It started strafing through the flow of bats. It was hunting bats!

I have seen this behavior of raptors hunting bats as they leave their night roost on video before, and it is pretty spectacular to see on a screen. Seeing it in real life was thrilling! After a couple of passes, the Peregrine made a quick move to one side, and suddenly it had a bat in one talon! It flew off and out of sight carrying it’s dinnertime snack.

The rest of the bats were generally nonplussed by the Peregrine attack, and keep streaming and streaming into the coming night.

Finally, the last bat that was going to leave had departed, and the darkness was getting deep enough that we would not have been able to see the bats fl by even if they were there, so we piled back into our cars and headed for home.

All in all, a terrific way to spend and evening!

 

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A friend of mine has been volunteering with the National Park Service to track the nesting activities of raptors in the Presidio in San Francisco, CA for the past twenty years. There are four species of bird of prey that nest in the park. They are Red-tailed Hawk, Red-shouldered Hawk, Cooper’s Hawk, and Great Horned Owl.

Information that has been collected include where these birds nest, how many nest in the park, when stages of nesting (breeding, egg laying, incubation, etc.) occur, how many chick fledge from each nest, etc.

This project has taken a wonderful turn this year with the installation of nest cams! My friend, and others, have been working with the Park Service to get funding to purchase and install nest live-cams on some of the active nests. One of the first such cams has now been installed on a Red-tailed Hawk nest that has been built between the branches of a Blue Gum Eucalyptus Tree. The live-stream of this nest cam can be found on YouTube HERE.

RTHA Nest Cam Capture

Male Red-tailed Hawk in the Presidio, San Francisco, CA incubating the one egg that had been laid at this point. Note thin, black barring that are restricted to near the base of the tail.

The pair of Red-tailed Hawks have laid one white, and lightly speckled egg in the nest as of 3/7/2018. The male and female can be distinguished by a few characteristics. The best is by tail pattern. The male has a few, very thin black bars on its red tail. These bars are limited to the base of the tail. The female, on the other hand, has those thin black bars on the tail that extend just about all the way down to the black subterminal band near the tail tip. Beyond these tail pattern differences, the male and female have different molt patterns on the secondary flight feathers, the male is slightly smaller than the female, and the male is banded!

RTHA Nest Cam Capture F

Female Red-tailed Hawk in the Presidio, San Francisco, CA incubating the one egg that had been laid at this point. Note the thin, black barring that extend all the way to the subterminal tail band.

I have already noticed a few interesting things after only checking in on the nest for a couple of days. One is that when the the male comes to the nest to give the female a break, he sometimes brings nesting materials to add to the nest. He does this even though the nest is complete and an egg has been laid.

So far, about 60 people have been watching the nest at any given time. I am sure that this number will go up, and it will be great to push it as high as possible, since I am also sure that the Park Service will be more inclined to install more live-cams if the public response is positive and strong. So watch the Red-tailed Hawks and see what is going on at  the nest!

 

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The Sacramento-San Joaquin Delta Conservancy (where I know work) was allotted $50,000,000 from the voter approved Proposition 1 for projects that will enhance habitat, improve water quality, and/or increase sustainable agriculture in the Delta. These funds are to be given out over the course of five years, starting with the first solicitation in fall of 2015. The Delta Conservancy created a competitive grant program where applicants can send in proposals and Delta Conservancy staff, with the input from other experts, determine which proposals have the best chance of success and will enact the most valuable projects. This first round of projects could be planing projects of up to $100,000 or implementation projects of up to $2,000,000. A major component of my work has been to help administer this grant process and evaluate the proposals that have applied for the Delta Conservancy’s Prop 1 money in this first year. We, the staff, shepherded projects through the process and made recommendations to our governing board, who voted to approve or reject the various projects that were submitted. Going forward, I will continue to be highly involved in the next 4 years of funding cycles.

Swainson's Hawk - Jabari Bellamy

Adult Swainson’s Hawk hunting over a California grassland (Photo compliments of Jabari Bellamy)

One of the projects that applied for the Delta Conservancy money was submitted by the Environmental Defense Fund to convert approximately 300 acres of private agricultural working land currently used for growing various row crops into pastureland bordered by hedgerows of native vegetation. This crop conversion will encourage Swainson’s Hawk prey species and so make this land high quality foraging habitat for Swainson’s Hawks. This project scored in our competitive process and was approved by our board (pending a some final administrative paperwork). To read more about the project, and find out more about the work that the Environmental Defense Fund is doing, check out this link to their write up of the project.

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A post from AbirdingNaturalist has been accepted to the website NatureWriting! With the acceptance of my piece titled “A Vomiting Vulture,” I am now a contributor. This is the first time one of my posts has been featured on another website, so I am pretty excited!

NatureWriting can be found here.

My post can be found here.

Check them out!

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I was walking along the edge of a plowed field along the Clarksberg Branchline Trail in West Sacramento a couple of days ago when I saw a hatch year Northern Harrier quartering back and forth, low over the ploughed earth. The raptor was not very far from the edge where I stood, so I was able to get a really great view as I watched it coursing along and staring at the ground intently as it hunted for its breakfast. Suddenly, it made a sharp turn, almost flipping over itself, and dove for the ground. It landed on something and after a moment standing on the ground, it took off. As it did so, I saw a small, brown object in its talons. I assumed at first that it was a small mammal, and that the Harrier had made a successful hunt, but when the bird was about 20 feet off the ground, it dropped the brown object. As the thing dropped back to the earth, I was able to see that it was not an animal at all, but was actually a clod of dirt.

What had happened here? Did the Harrier make a mistake and attack a mouse-shaped bit of dirt thinking that it was, in fact, the makings of a meal? Given how amazingly keen the eyesight that raptors possess this seems unlikely. And it seems especially unlikely given that the bird was only about 20 or 30 feet off the ground when it started the dive. Making that big a mistake at that close a range is hard to believe. So what was the hawk doing? Was it practicing? This was a young Harrier. Perhaps, not seeing any actual voles or mice at that moment, it decided to do a little target practice. I don’t think of raptors needing practice, but of course that is probably kind of silly. Young songbirds need to practice their song, and often sound amusingly bad at first. However, of the course of a few weeks, they practice and hone their vocal abilities and end up producing songs that sound like the other adults of the species. So, raptors practicing their hunting skills seems pretty understandable. The amount of skill required to be a predator is rather impressive, and even when you consider that many of these skills are hard-wired instinct, that still leaves a lot of room for learning and improvement: practice. Here was a raptor that, perhaps, just picked a particular earth clod on the ground and wanted to see if it could hit it at high speed, just to see if it could. It did, so that practice run was successful! Practice does make perfect!

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HMANA Press release – October 14, 2014

Over One Million Migrating Hawks Counted during International Hawk Migration Week

Hancock, NH – The Hawk Migration Association of North America (HMANA) celebrated its first annual International Hawk Migration Week (IHMW) September 20-28, 2014 by tallying over 1.2 million migrating hawks, eagles and vultures at 100 sites throughout Canada, the United States, and Mexico.

Each year hundreds of thousands of hawks, eagles and vultures make their journey from Canada and the United States through Mexico to wintering areas as far as South America. Dedicated counters at hawk watch sites document this movement starting as early as 1 August and continuing daily into December. Their daily numbers are reported to HMANA’s online database, HawkCount.org. This particular week in late September was chosen due to the sheer number of hawks that are counted across North America.

One hundred watch sites from 33 states and provinces across the continent counted an astounding 1,203,067 raptors during September 20-28. Twenty-nine species were tallied, the vast majority being broad-winged hawks (1,125,597) – since IHMW took place during their peak migration. Other high counts included 24,899 Sharp-shinned Hawks, 8,909 Mississippi Kites, 8,724 Turkey Vultures and 7,192 American Kestrels.

Raptors tend to follow topographic features during fall migration such as north to south running ridgelines, coastlines, and river valleys. As they move further south, there’s a funneling effect as they approach the southern US. The majority of hawks choose to avoid long water crossings so are then squeezed along the coast of the Gulf of Mexico and on through Mexico. This is why the Veracruz, Mexico watch sites counted more than any other at 812,949 during IHMW. Corpus Christi, Texas located on the US Gulf coast tallied 226,224 raptors. Other counts across the continent included 15,862 at Hawk Ridge Bird Observatory, MN; 4,151 Holiday Beach Conservation Area, ON; 4,811 at the Goshute Mountains, NM and 2,777 at the Florida Keys Hawk Watch, FL.

In addition to submitting their daily migration counts to HMANA’s HawkCount.org database, sites celebrated across the map with hawk watching festivals, identification workshops and live bird of prey events. Dr. Laurie Goodrich of Hawk Mountain Sanctuary, Kempton, PA (the oldest hawk watch site in the western hemisphere) said: “IHMW is a fantastic demonstration of the popularity of hawk watching and the value of raptors in the environment.”

About HMANA

HMANA (www.hmana.org) is a non-profit organization with a mission to advance scientific knowledge and promote conservation of raptor populations through the study, enjoyment, and appreciation of raptor migration. It oversees the online database, Hawkcount.org, an archive of count data with a wealth of information for birdwatchers and general public alike, including maps and directions to sites, average counts, population status and migration timing by species.
HMANA partners with Hawk Mountain Sanctuary PA (www.hawkmountain.org), Hawk Watch International (based in Utah: http://www.hawkwatch.org), and Bird Studies Canada (in Ontario: http://www.bsc-eoc.org) in the Raptor Population Index program, which aims to track changes in hawk populations for conservation purposes.
For directions and contact information for hawk watch sites near you, visit http://www.hawkcount.org.

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I was out along the shores of Bucks Lake near Quincy, CA, last week, in the hope of getting some more of my field work done. Unfortunately, I did not think to check the weather report before I left. It has been so dry this summer that it did not even cross my mind that it might rain! Well, this was the day that rain it did. A lot! It started as I was driving up into the mountains, and did not stop all morning! When I got to Bucks Lake I parked near Haskins Creek and sat in my car for a while. I soon decided, however, that if I was going to up there, I might as well get out and do some birding. Maybe I would find some Evening Grosbeaks and see what they were up to in the rain.

Well, I did not find any Evening Grosbeaks, but I did get a good bit of birding in. I spent most of my time watching a big flock of White-crowned Sparrows, Golden-crowned Sparrows and Dark-eyed Juncos. Watching the birds forage in the rain was pretty cool. The lighter showers were not enough to bother most of the birds most of the time, and so they stayed along the roadside. It was only when a heavier downpour began that the birds would retreat into the cover of some dense willow thickets and wait until the rain lightened up again. I was struck, as I often am, by how dramatic an event migration is. Just last week, I was up in the mountains and saw my very first White-crowned, and Golden-crowned, Sparrows of the fall. Now, here is a flock of about 60 White-crowns and 20 Golden-crowns! Just like that, this synchronized wave of millions of birds has descended upon California!

As I continued to watch this flock, I started to pick out the odd birds that were mixed in. There was one Song Sparrow. A few Yellow-rumped Warblers flew in and out. Of these, two were of the Myrtle subspecies, which is generally the more eastern subspecies, so they were cool to find. I continued to watch through my binoculars, but suddenly the birds that I could see scattered. I took my binoculars down and saw that the whole flock was racing for cover! I looked up and found out the reason for the sudden panic. An adult Red-shouldered Hawk was flying right up the middle of the meadow and directly over the foraging passerines. The hawk did not actually make any directed move towards the small birds, but instead flew off into the trees. A little later, an adult Bald Eagle also flew, rather dramatically through the rain and mists, over the flock. This bird did not cause any reaction from the sparrows at all, and neither did a Common Raven a few minutes after the eagle. The sparrows can apparently tell the difference between various predators, and know which they should worry about. I thought this demonstrated some pretty fine ID skills on the part of the sparrows!

In spite of being cold and wet and not finding any Evening Grosbeaks and not getting any field work done, I really enjoyed that morning in the storm. It made me realize how much I have missed being out in the rain!

Here is my full species list:

Bald Eagle (1)

Red-shouldered Hawk (1)

Northern Flicker (2)

Steller’s Jay (11)

Common Raven (1)

Mountain Chickadee (3)

Red-breasted Nuthatch (3)

Golden-crowned Kinglet (5)

American Robin (8)

Yellow-rumped Warbler (3 Audubon’s, 2 Myrtle)

Song Sparrow (1)

White-crowned Sparrow (60)

Golden-crowned Sparrow (20)

Dark-eyed Junco (20)

Brewer’s Blackbird (1)

 

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On the morning of the 19th, I was out birding in the early morning along the Clarksberg Branchline Trail in West Sacramento. I was poking around the section of trail just north of Lake Washington Blvd. from about 6:20am to 7:30am. It was one of those morning where I decided to not worry about covering a lot of ground. Instead, I wanted to take my time, relax, and covered the ground thoroughly really investigating each bird I heard or saw and taking my time to enjoy it. I was rewarded by some lovely views and fun finds. My species list is at the end.

Right as I started my walk, I saw a long, slim animal run out from the edge of the blackberry tangle along the trail ahead of me. It stopped out in the open for a short moment and then continued on towards the large pond just east of the trail. To my surprise, I realized that it was a Mink! I have seen River Otters at this location before, but never a Mink. What was it doing here? As I scanned the pond, there were no birds swimming in the water except three domestic ducks that were probably dumped here to become feral. As I stood by the water’s edge, I head several birds in one of the willows that grow right on the bank. I walked that way, and found a Marsh Wren singing in the cattails and my first White-crowned Sparrow of the fall for West Sacramento! It was a really good looking  adult bird that was sitting in, and calling from, that willow. Soon the Central Valley will be covered in millions of White-crowned Sparrows back from their breeding grounds in Canada and Alaska to spend a comparatively warm winter in lovely California.

As the sun rose, beautifully tinged blood red by the smoke from the King Fire that is burning just east of Sacramento, I stumbled my way into a mixed insectivore flock. At this time of year, with migrants and vagrants wandering all over the country, mixed insectivore flocks are always worth spending some time with. Often, many birds will come together to forage, and this can attract individuals of species that you might not get to see otherwise. In this case, the bulk of the birds were Bushtits, maybe 25 of them, which were streaming from oak tree to oak tree giving their high pitched contact calls as they told each other where they were. As I watched these tinny birds, I started to notice the other species in the flock. A Western Scrub-Jay, a coupe of Northern Mockingbirds, and a lovely pair of Black-throated Gray Warblers which came low in some small trees and afforded me some great looks! The day ended with a total of 5 of these warblers which is a lot compared to what I am used to seeing in winter, which is just one or two.

After I left the mixed flock, I walked out into an open field that had been mowed and tilled. As I walked along the line of tree that marks the edge of this field I was treated to a fast triple-raptor encounter. First, a Swainson’s Hawk took off from one of the tree tops and doove down into the field. It pulled up before landing, apparently the prey animal it had seen got under cover in time to avoid becoming breakfast for the hawk, and returned to its perch. right after that a Red-tailed Hawk came barreling of the line of trees and cruised over the field and away. As I was watching the Red-tail, a Red-shouldered Hawk started calling behind me. It was circling at about tree top level and proclaiming dominion over this patch of ground. The Red-shouldered Hawk is a resident bird that I see almost every time I bird this area. The Swainson’s Hawk breeds nearby somewhere, but then leaves, with the rest of it’s species members, to head south in winter which is something that will be happening soon. The Red-tail could go either way in that it could be a resident or a migrant just here for the summer. How these different hawks interact and adjust to one another is a question that has long interested me. Take the Red-shoulder, for instance. It has a territory that it defends year-round. Suddenly, in mid-March this Swainson’s Hawk shows up trying to find a place to settle and nest. How does the Red-shoulder respond? Does it simply move out of the larger hawks way? Do the birds compete and adjust their territory boundaries to one another? Do these birds eat different enough foods that they don’t really care about each other? And then, how does the Red-tailed Hawk fit into all this? How resident birds adjust to the comings and goings of migrants is not something that has gotten a lot of attention and I think could make for a really cool research project.

Looking at the open field with the naked eye, I did not see anything out there, but just on a whim I decided to give it a scan with my binoculars. As I looked slowly across the field I saw no less than 15 Killdeer scattered about foraging. So much an empty field! It reminded me that a lot can be hiding and go unnoticed when only a cursory inspection is done.

This was a really nice morning birding. I saw some beautiful birds that got me thinking about interesting ideas and taught me a thing or two all at the same time.

Double-crested Cormorant (1)

Turkey Vulture (1)

Canada Goose (12)

Red-shouldered Hawk (1)

Red-tailed Hawk (1)

Swainson’s Hawk (1)

Killdeer (15)

Western Gull (3)

Rock Pigeon (70)

Mourning Dove (20)

Anna’s Hummingbird (3)

Belted Kingfisher (1)

Nuttall’s Woodpecker (4)

Black Phoebe (3)

Western Scrub-Jay (11)

American Crow (12)

Oak Titmouse (4)

Bushtit (25)

Bewick’s Wren (3)

Marsh Wren (1)

Blue-gray Gnatcatcher (1)

American Robin (5)

Northern Mockingbird (2)

European Starling (30)

Cedar Waxwing (8)

Orange-crowned Warbler (5)

Black-throated Gray Warbler (5)

Spotted Towhee (2)

California Towhee (1)

White-crowned Sparrow (1)

Red-winged Blackbird (30)

Mink (1)

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You are walking down a trail in a city park right here in the city of Berkeley. As it winds its way between huge boulders and beneath overhanging bushes, your attention is drawn up into a nearby tree by the sound of scratching. There, a squirrel is scrabbling up the trunk of a tree. As it ascends you notice a thick mat of sticks higher in the tree, way up near the tree’s crown. Is it the squirrel’s nest? The squirrel climbs higher, and then moves beneath the lower edge of the stick platform and then up around the side. As the squirrel begins to get on top of the mass of sticks, it is met with the oncoming rush of the beak and talons of a female Cooper’s Hawk. The mass of sticks is not squirrel’s home, it is the Hawk’s. The squirrel is in full retreat now, and the Cooper’s Hawk in full pursuit. The squirrel begins racing in the direction in which it can go the fastest, strait down the tree trunk. The Cooper’s Hawk immediately drops after it, skimming strait down along the bark of the tree. As the hawk gains, the squirrel jumps, letting go of the tree completely and free-falling into the bushes below. It is only then that the hawk gives up the chase and returns to her nest.

What you just witnessed was the defense of one of about a dozen Cooper’s Hawk nests in Berkeley and Albany. Cooper’s Hawks in Berkeley? That’s right. These roughly crow-sized predatory birds get along quite well with humans and the cities humans live in. They eat birds and small mammals which they often capture by ambushing their prey in dense vegetation and then chasing it down in a burst of speed. They are superbly adapted to this style of hunting with short rounded wings which give the speed while not getting hung up on foliage and a long tail which acts and a rudder allowing them to turn and twist through thick undergrowth and not lose their prey.

The ability to live well with humans is unusual for a predator. Most birds of prey are too sensitive to disturbance to live in such close contact with humans or need larger areas of open spaces in which to hunt than are available within such a human-dominated landscape as downtown Berkeley, but Cooper’s Hawks find a way. They are so tolerant in fact, that in Berkeley and Albany, more Cooper’s Hawk nests can be found per square mile than in any other recorded area in North America. They nest in mature trees in almost any kind of habitat from quiet city parks to busy city intersections. And Berkeley in not alone in being an urban area that has nesting Cooper’s Hawks. In California, most urban areas have populations. Outside of the state, populations that have been studied in some detail include urban areas of Arizona, Illinois, and Vancouver, Canada.

Beginning about 15 years ago, a group of dedicated volunteers have been keeping tabs each year on the levels of Cooper’s Hawk activity in Berkeley. The group, the Cooper’s Hawk Intensive Nest Survey (CHINS), has divided the 10.4 square miles of Berkeley into smaller units. Each volunteer takes responsibility for one of these units, and searches it to locate and track the presents of Cooper’s Hawks. Searching begins in late January when the hawks first arrive in the area back from their wintering grounds, and continue all through the breeding season until the adults and a new generation of young Cooper’s Hawks depart to return south in August. In between, many observations are made and recorded such as when the hawks arrive, when nest building begins and ends, how many young hatch and when, how many young fledge and when, what they are eating and how much, and finally when the adults and young disperse.

Some the information that CHINS has found is that while Cooper’s Hawks nest in greater density in Berkeley than elsewhere.Also, they are eating a lower number of species then in more rural areas, and of these fewer species a large portion (~33%) are Rock Pigeon, European Starling, and other species that are not native to California. On this limited diet, the hawks are able to breed just fine with most nests fledging 3-4 young each year.

The CHINS project is a branch of the Golden Gate Raptor Observatory, and both are examples of scientific studies made possible by volunteers from the community working to monitor and record raptor populations. Cooper’s Hawks, and birds of prey as a whole, can function as indicators of ecosystem health and stability. This makes them especially important and useful to study, and the fact that individuals from the community are able and willing act as citizen scientists and devote their time and energies to such an endeavor show both that such work can be done and that there is interest and support that such work be done.

To find out more about the CHINS Contact Allen Fish at (415) 331-0730 and find out how you can help protect your raptorial neighbors.

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