Eurasian or Common Kestrel:

Photo Credit – Wikipedia

American Kestrel

Photo Credit – Cornell Lab of Ornithology

Thank you, Sonoma Land Trust, for connecting me with the beautiful American Kestrel, the smallest raptor in North America, during a recent visit to the Sonoma Creek Baylands. Its larger and less attractive cousin, the Eurasian Kestrel, featured throughout my early days of birdwatching in England. I saw them pass through Spurn Point in 1961, and they were common around York in the late 1950s. My earliest sighting was a pair that nested in an abandoned farmhouse near my home, but unlike Billy, in the novel A Kestrel for a Knave by Barry Hines, I never climbed the chimney to inspect the nest. The American Kestrel and Eurasian Kestrel remain common today, although their populations have declined for unclear reasons.

If you wonder about the origins of the word kestrel, no one seems to know with certainty. Maybe it is an Old French or Middle English word used since the 15^th century and is most likely related to the bird’s cry.

Eurasian Kestrel Range Map

Photo Credit – CCNAB
Blue: year-round; Red: summer

American Kestrel Range Map

Photo Credit – Wikipedia
Purple: year-round; Orange – summer breeding; Blue – winter, non-breeding

The American Kestrel was known as a Sparrow Hawk until the 1960s, and its name officially changed in 1983. It is not a hawk; it does not particularly like sparrows, and looks like and is related to the Eurasian Kestrel. Its life span in the wild is short, frequently less than two years. Its preferred habitat is open grassland, desert, scrub, and enough isolated tall perches to hunt. They are also known for their hovering, preparing to catch their prey. American Kestrels are both residents and long-distance migrants. Those breeding in the north are more likely to migrate, sometimes as far as Central America, but most spend winter in the southern United States. There are records of the Eurasian kestrel in northeast North America, Alaska, and British Columbia, so distinguish the two species carefully if you are in those places.

Their calls are distinctive and often heard as an excited series (three to six) cry of klee or killy.

American Kestrel male and female

Photo Credit – inaturalist

The American Kestrel is about the size of an American Robin and smaller than another North American bird of prey called a Merlin. Their estimated global population is four million, with 2.5 million in the US and Canada. Its Eurasian cousin is larger, closer to the size of a Crow, and bigger than a Merlin. It is less colorful, with male plumage consisting of a chestnut-brown back with darkish spots, a grey head, and a grey tail with a black band near its tip. A population estimate is around five million worldwide and one million in Europe. The current British population is about 65,000.

As seen above, the male possesses slate-blue plumage near the top of its wings, a rufous orange back with black barring, and its tail is the same color with a large black band towards its end. Since you often only see this bird from a distance, be sure in its identification it has pointed wings and a long tail. It will be fast in flight, pumping its tail up and down while perched, and can be noisy. 

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Photo Credit – avianreport.com

The species’ diet is diverse and changes depending on the time of year. Small mammals comprise a more significant part of the kestrel’s diet in winter, with fewer insects. However, when insects are bountiful, the bird can consume 10 to 20 percent of its body weight daily. Its success in capturing its prey is estimated to be very high for invertebrates, less for rodents, and under 50 per cent for birds. It hunts only in daylight but deters potential attackers using the back of its head. It has two black spots called ocelli (false eyes). They deter would-be attackers and possibly attract a mobbing response from songbirds, allowing the kestrel to catch some of them. It also sees ultraviolet light, permitting it to find food hidden in grass and undergrowth. This includes spotting the bright blue-green glow of mouse urine. 

American Kestrels Nesting

Photo Credit – Cornell Lab of Ornithology

American Kestrels rely on natural or man-made cavities for successful nesting and will not breed if a suitable cavity is unavailable. This includes migrating kestrels returning to the same cavity each year. Bird boxes are welcome. However, it should be near the birds’ preferred habitat, away from outdoor pets, and a distance away from busy roads that cause a high rate of nest abandonment. Typically, the female will lay four to five eggs, and incubation becomes her full-time job, while the male brings her food.

Merlin

Photo Credit – Wikipedia

Sharp-shinned Hawk

Photo Credit – Cornell Lab of Ornithology

Above are two other species of raptor that you might confuse with kestrels. 

Merlin: the distinctions are its slate grey back (not rusty); short, dark tail (not long and narrow); it rarely hovers; it flies fast with sudden changes in direction (versus the shallow, deliberate wing beats of the kestrel); and chases its prey (rather than hovers or perches before diving on the victim).

Sharp-shinned Hawk, or Sharpies as they are nicknamed: are roughly the size of an American Kestrel but have rounded wings and longer tails; there are heavy markings on their front, and they lack the kestrel’s red-brown on the back; their hunting style is very different; they hunt fast and furious, flying stealthily at low altitudes and aggressively then accelerating to catch their prey. It is also the raptor you might see waiting at the side of your backyard bird feeder. It has occurred in my backyard, but its presence seems more likely to be as an observer than as an assailant. 

So, again, I thank Sonoma Land Trust for my most recent experience with kestrels. It was a successful day in the wetlands. As well as the American Kestrel, we had sightings of Red-tailed Hawks, Northern Harriers, White-tailed Kites, Sharp-shinned hawks, Peregrine Falcon, and a Merlin. 

Photo Credit – The Author

Eurasian Collared Doves

Photo Credit – Cornell Lab of Ornithology

Recently, I was walking alongside my local creek-side in Northern California when I heard the purring sound of goo-Goo-goo, and strove to find out what it was. I discovered a pair of Eurasian Collared Doves sitting in a tree. Later, they descended to the ground, presumably to consume their diet of seeds and invertebrates. Looking back at my bird-spotting in the early 1960s in the north of England, I registered sighting a Eurasian Collared Dove, but I don’t know where. At the time, I was much more interested in the smaller Turtle Doves that nested among the woodlands on the moor where I grew up. 

Turtle Dove

Photo Credit – The Guardian

The turtle dove is a beautiful bird, not seen in the United States, and migrates between Africa and parts of Europe. Unfortunately, since 1996, it has been on the British red list of birds most at risk of extinction, and today, only about 2,100 pair breed in the U.K., down an estimated 98 percent since the 1970s. This species is described in more detail in Chapter 17 of my novel She Wore a Yellow Dress. 

Eurasian Collared Dove Range Map

Photo Credit – Birdwatching HQ

But let us return to the Eurasian Collared Dove. The species occupies a territory that has dramatically increased over the centuries, giving it a reputation for being one of the great avian colonizers. The bird probably originated in the Bay of Bengal region, but by the 1600s it had expanded its range to include European Turkey and the Balkans. From there, it spread rapidly north and west throughout Europe during the 1930s and 40s. The species first nested in Britain in 1955, and by the mid1960s, about 3000 were nesting. Today, the British population of Eurasian Collared Doves is around 250,000 pairs. There is no clear explanation for this colonialism. Possibly it is genetic; it has dominantly been westwards, and climate – such as cold and the amount of rainfall – appears to affect it. 

Mourning Dove

Photo Credit – Cornell Lab of Ornithology

The Eurasian Collared Dove is medium-sized, a little larger than a Mourning Dove, pale, pinky-brown/gray, has a distinctive black half-neck collar edged in white, and its eyes are deep red. The two sexes are virtually indistinguishable. In the United States, a similar population explosion has occurred.

The species was first resident in the Americas during the mid1970s after about 50 birds escaped from a pet shop in the Bahamas, and presumably made its way to Florida. A burglary freed the first group, and the shop owner released the remainder. A few more may have found their freedom in 1976 when 72,000 inhabitants of Guadeloupe Island had to evacuate because of seismic activity. Today, in the United States, the Eurasian Collared Dove is broadly distributed across western, central, and southern states but not across the northeast. It is strongly dispersive, meaning it will move long distances from its birthplace but does not migrate. It is a chronic breeder and spreads prolifically. Studies in the United States indicate an annual population growth of 13 percent.

But despite arriving here by its own means, it is still considered invasive and a non-native species that possibly competes for food with native species. However, studies do not yet show a negative impact on populations of native birds. People hunt it for food and sport. I wonder about the fairness of this treatment, but then consider other introduced species, such as the House Sparrow, Starling, Rock Pigeon, and Mute Swan, and the damage they have caused.

Nine Invasive Birds of California

Photo Credit – A-Z Animals

Bald Eagle in Marin County

(Photo Credit – Elyse Omernick, Marin Living Magazine)

A friend of mine recently sighted a Bald Eagle near Fairfax, CA. an event that was inconceivable a few years ago. The Bald Eagle returned to Marin County, CA. in 2008 after 100 years absence, and its numbers have increased ever since. The trend is consistent with nationwide numbers that show there were only an estimated 450 breeding pairs of Bald Eagles in the continental United States during the 1960s, whereas today the number has increased to over 10,000. 

So what is going on? Global warming theoretically should push birds further north, beyond the lower 48 states. Clearly, this is not happening. The end of persecution and the banning of certain pesticides appear to explain the contrary trend.

Bald Eagle in flight

(Photo Credit – AP)

In the past, Bald Eagles were hunted for sport, slain because they were believed to be a menace to livestock and fisheries, and destroyed for money by bounty hunters. During the period 1917-52, bounty hunters in Alaska killed more than 100,000 Bald Eagles. The United States Bald Eagle Protection Act, enacted in 1940, made the killing of Bald Eagles illegal, but Alaska was exempt until it accepted statehood in 1959.

The population decline continued after this legal intervention because of the arrival of the pesticide DDT that made the shells of the eagles’ eggs thin and easily broken. It was banned by the United States in 1972, but still the population declined. In 1978 the species was declared endangered by the US government, and as a result of interventions, by the mid1990s, the population in the lower 48 states had increased to 4,500 pairs, and to 6,300 pairs by 2000. Today, lead poising still poses a threat to Bald Eagles. Hunters and anglers leave tons of lead behind each year, and an amount the size of a grain of rice can kill a Bald Eagle within 72 hours. Habitat loss also remains an issue, as do lethal collisions with powerlines and wind turbines.

Bald Eagle Range Map

(Photo Credit – Cornell Lab of Ornithology)

Bald Eagles mostly eat fish, up to 90 percent of their diet. They will also take the occasional waterfowl, seabirds, live animals, such as rabbits and squirrels, and eat carrion. Consequently, their preference is to live close to bodies of water containing fish, and also to have access to stands of tall, old-growth trees for perching, roosting, and nesting. Primary locations are coastal regions and inland where there are large lakes, rivers, or reservoirs. The species is native to North America, and ranges from Alaska through Canada, and as far south as northern Mexico. Southern and west coast birds often remain in their breeding territory all year, whereas northern birds migrate for winter. The best time to see Bald Eagles in California is during winter, mainly from December to March, when hundreds of migrating birds arrive from the north. 

I have been fortunate enough to observe Bald Eagles in Alaska and Wyoming, but never during my childhood days in England, as evidenced in my novel She Wore a Yellow Dress. The species fails to appear in Europe except for very rare reports of vagrants in Ireland.  

Bald Eagle chasing an Osprey

(Photo Credit – Phil Lanoue Photograhy)

The arrival of the Bald Eagle brings with it its own risks and consequences. Rather than carrying out their own fishing, Bald Eagles will choose to chase after birds that have already caught fish, and especially Ospreys. They harass the Osprey until it drops its prey in mid-air, and the eagle swoops down to collect it. Bald Eagles have excellent eyesight and can hunt from as high as 10,000 feet (3km). They see three times as far as humans, and have a 340 degree field of vision. Marin County has already experienced declines in its Osprey population. In the area of Kent Lake (reservoir created in 1958), there once were 50 or so Osprey nests; that number is now down to about 10. 

Great Seal of America

(Photo Credit – American Heritage Education Foundation)

In spite of these behaviors, the Bald Eagle was chosen as the national bird of the United States around 1789, attracting disparagement from the then President Benjamin Franklin who wrote that “the Bald Eagle is a bird of bad moral Character. He does not get his Living honestly…. (he) is too lazy to fish for himself. Besides, he is a rank Coward”. 

In 1782, when the design of the Great Seal was approved, the Bald Eagle was adopted because of its fierce beauty, proud independence, and powerful strength. 

Adult Bald Eagles are readily recognizable. They are the largest birds of prey in the United States. Their white head and tail with an evenly brown body are distinctive, they soar high in the sky on their long, broad, slightly-rounded wings, their tail is wedge-shaped, and their bill is a bright yellow. The name “Bald” has nothing to do with the absence of feathers on their head. The name derives from the Old English word “piebald”, meaning “white patch”, and is reference to their bright white heads. Males and females look the same, although the female may be up to 25 percent larger than the male.

Bald Eagle Juvenile

(Photo Credit – Cornell Lab of Ornithology)

Recognizing juvenile Bald Eagles is not so easy. They do not exhibit the characteristic white head and tail until they are about five years old, and instead display dark heads and tails, with brown wings and bodies mottled white. For the first four years of their life they live a nomadic exploration existence. 

Bald Eagle Nest

(Photo Credit – American Eagle Foundation)

Once Bald Eagles mate, it is for a lifetime relationship, and the typical life span is around 25 years. Their nest is a large platform of sticks, typically built high in a tree, and used repeatedly over many years. The clutch size is one to three eggs, and they are laid relatively early during February.

The question for the future is whether communities will continue to welcome the return of the Bald Eagle, without reservations, or will decide to impose limitations because of the species’ behavior, or to safeguard human interests. For example, 30 year kill permits are now being issued to wind turbine energy developers to allow them to take or incidentally kill Bald Eagles, even though camera systems can be used to spot eagles and trigger shutdown of nearby turbines. 

The species is no longer classified as endangered but the requirements of the Bald Eagle and Golden Eagle Protection Act still apply. The 1940 original Act was amended in 1962 to include the Golden Eagle. Criminal penalties may be imposed on any person who “takes, possesses, sells, barters, or offers to sell a Bald Eagle, alive or dead”, and penalties for violations were increased in 1972.

Global warming also threatens the birds’ future by impacting bodies of water and river systems that the Bald Eagle uses as its source of food.

Male Black-throated Gray Warbler

(Photo Credit eBird)

During May this year, the Black-throated Gray Warbler made its way onto my birding “life list” as a result of a visit to Yosemite Valley. Not that these birds are rare in California ,but I had never seen one since resuming birding to escape the lock-ups imposed by the COVID pandemic. The species usually occupies coniferous and mixed forests, especially stands of pinyon pine, juniper, and oak. These warblers are short to medium-distance migrants. They breed west of the Rockies, from British Columbia to New Mexico, and winter in lowland dry forests, dense scrubland, and pine oak woods in Mexico, and the southwestern United States. Nesting occurs from late May to July, and the fall migration begins in mid-August. A few sightings of Black-throated Gray Warblers have been recorded in eastern North America but these are very rare. Migrants follow the western mountain ranges and the Pacific coastline, and a few occasionally pass through the Bay Area, close to my home. The ones in Yosemite seemed to be foraging for insects, and were seen close to Mirror Lake. 

A “not-so-good” image from Yosemite

(Photo credit: the Author)

Black-throated Gray Warblers have a bold and distinctive pattern of black-and-white on their crowns, around their eyes and on their throat, and a gray back that gives them their name. Also, there is a splash of yellow between the eyes and the bill. The female has a more dingy facial plumage, and adults are about five inches (13 cm) in length. The species is not considered threatened by human activities, and seems to have extended its breeding range due to a warming climate. It is classed as “Least Concern” from a conservation perspective.

Orange: breeding; yellow: migration; Blue: nonbreeding

Black-throated Gray Warbler Range Map

(Photo Credit: Cornell Lab. of Ornithology)

It was satisfying for me to be able to distinguish these birds from the more ubiquitous avian species that occupy Yosemite Valley, such as Steller’s Jays, American Robins, and Dark-eyed Juncos.

Steller’s Jay

(Photo Credit: Author)

American Robin

(Photo Credit: Wikipedia)

Dark-eyed Junco

(Photo Credit: Unknown)

I should mention that the family of warblers is one of the more difficult groups from which to distinguish individual species. There are so many varieties, they are small birds, they often are obscured by trees and scrub, you usually need to look upwards to spot them, their coloring can act as camouflage in their surroundings, they forage silently, and many display similarly colored plumage. 53 species of warbler are found in North America, and a total of 111 species are identified in the New World. Some do not look “warbler-like” such as the Water Thrush and Yellow-breasted Chat. Virtually all are in the family of Parulidae, and are found only in the New World. Curiously, warbler species in the eastern half of the United States were generally named after places, whereas in the West, they are named in recognition of their plumage or using the name of a person, typically an ornithologist. Identification methods include considering plumage, voice, habitat preference, and behavior when foraging.

Birds known as warblers elsewhere in the world are unrelated to New World warblers, and have been given the “warbler” name because of their “warbling” sound. Thus, birds such as the Willow Warbler, Garden Warbler, Whitethroat, Wood Warbler, and Reed Warbler that I recorded during my youth in England, have no relationship to the Black-throated Gray Warblers that I saw in the Yosemite Valley. Even the Olivaceous Warbler that I recently encountered in Israel has no relationship with the Yellow-rumped, Townsend’s, and Wilson’s Warblers that occasionally visit my California backyard.

Yellow-rumped Warbler

(Photo Credit: Cornell Lab. of Ornithology)

Orange-crowned Warbler

(Photo Credit: eBird)

Wilson’s Warbler

(Photo Credit: eBird)

Mute Swan
Photo Credit: Wikipedia

I was surprised recently to see two pairs of Mute Swans feeding on grass and submerged vegetation at Schollenberger Park, Petaluma, CA. They appeared to be partners and presumably were preparing to breed in March or April. As we passed them with two small dogs one of them, I assume the male, hissed loudly, straightened its neck, and moved in the direction of our pets. The next step, if we had not moved our dogs to one side, was that the bird would flap its wings and physically attack. These birds maybe graceful and beautiful, but their aggressive behavior is out of line with their appearance. As well as chasing pets and children, they physically injure and will sometimes kill other birds, such as waterfowl, and when nesting they are known to attack canoeists, kayakers, and boaters on jet skis.

Swans are a non-native species to the United States and were introduced in the mid-1800s and early 1900s to adorn ornamental lakes, ponds, and city parks. Some went native and escaped to the wild, such as the ancestors of the four we discovered in Petaluma. Their preferred habitat is shallow coastal and fresh water such as estuaries, bays, waterways, streams, ponds, and lakes. Mute Swans are now distributed across North America, and their most significant populations are on the North Atlantic coast, across the Midwestern states, and into parts of the Northwest. There are smaller, localized populations in Canada and throughout the United States. These birds will migrate small distances, but generally do not wander far.

Mute Swan Range Map
Red – breeding habitat/resident; Blue – migration/winter area
Photo Credit: Wildfowl Photography

They are large birds, weighing up to 30 pounds (14 km), and are around five feet (150 cm) in length. The body of the adult is solid white. The distinguishing feature from other swan species is their orange bill, with its fleshy, black knob at the base of the upper bill. As described in my novel She Wore a Yellow Dress, my first experience with these birds was in England in the 1950s, when a pair would breed annually in a pond near my farm, and I would frequently visit their nest. I would dare myself to get as close as possible to the birds before the flapping and hissing of the male swan frightened me away. Today there are an estimated 7,000 to 16,000 breeding pairs in the UK. The species is native to much of Euro-Siberia where there are an approximate 500,000 birds, of which 350,000 are in Russia. They winter as far south as North Africa, the Near East, and northwest India and Korea. Mute Swans are not endangered and efforts to control their numbers are underway in some parts of their non-native territories.

They are not the only swan species I can see here in California.

The most common species in North America is the Tundra Swan that usually makes its appearance in California from November to mid-March. They are North America’s most numerous swans, with a global population of around 280,000. They breed in the Canadian Arctic and coastal Alaska, on lakes, ponds, and pools that are near river deltas, and migrate to the Pacific Northwest, inland across to the Great Lakes, and as far as the coastal mid-Atlantic. The species is identified by its yellow patch at the base of its black bill. Sometimes it is referred to as the “Whistling Swan” because of the sound it makes with its wings in flight.

Tundra Swan
Photo Credit: Wikipedia

Tundra swans are also found in the UK and across northern Siberia to Japan. The British call it the Bewick’s Swan, the name that it was given in 1830 to recognize the work of the engraver Thomas Bewick, who specialized in illustrations of birds and animals. My sightings of this species have all been in California.

Tundra Swan Range Map
Orange – breeding; Yellow – migration; Blue – nonbreeding
Photo Credit: Wikipedia

Next there is the Trumpeter Swan, the one species that is native to North America, but rarely seen in California. Trumpeter Swans breed in northwestern Canada and Alaska and migrate to the Pacific Northwest. They can also be seen around the Great Lakes, and some migrate to the central interior of the United States. They are the only swans you are likely to see foraging in open fields. The bird is entirely white except for its black bill, legs, and feet. It has been spotted a couple of times in the UK, but I am still waiting to see my first one on either continent.

Trumpeter Swan
Photo Credit: All about Birds, The Cornell Lab

Trumpeter Swan Range Map
Purple- all seasons; pink – breeding; blue – winter (all regarded as uncommon)
Photo Credit: National Audubon Society

Finally there is the Whooper Swan, a species that is native to Eurasia, and a very rare vagrant to North America. A few birds from Siberia winter in small numbers in the Aleutian Islands, Alaska, but otherwise it is extremely rare. It can be identified by its fairly long, straight neck, black bill with a large triangular yellow patch, and a short tail. It is a species I have seen in the past. Back in the 1960s I saw the occasional Whooper Swan pass through Spurn Point in Yorkshire. It remains a winter migrant from Iceland to Britain, and about 16,000 birds appear annually. 

Whooper Swan
Photo Credit: e-Bird

Whooper Swan Range Map
Orange – breeding; Blue – non-breeding
Photo Credit: Birds of the World

And as a postscript, who could prepare an article on swans and overlook the Australian Black Swan? This species is native to the south-east and south-west regions of Australia and is the official emblem of Western Australia. For Europeans, it is a bird that in history could never exist. It fell into the same category as “flying pigs”. Now, most fortunately, Black Swans have become a highly popular ornamental water bird in countries such as Japan, China, the UK, the United States, and New Zealand. The last time I saw this species was on an ornamental pond outside a hotel on the island of Kauai. Enjoy your swan watching.

Photo Credit: e-Bird