The Mighty Kestrel

by Claudia Kirscher

Liberty Wildlife Volunteer

The American Kestrel is North America’s smallest and most colorful falcon. Like other birds of prey, the female kestrel is larger and heavier than the male. They are about the size of a mourning dove or jay. Unlike other falcons in North America, males and females have different plumage coloration (see photos above).

They are found from Alaska to the southern tip of South America. Kestrels in colder climates will migrate to warmer areas for winter months. They are highly adaptable to climate and elevation. They prefer open country, grasslands, deserts, farmland, and shrublands rather than tree cover. They are even found in our urban environment. Kestrels prefer to be able to see their entire territory easily from any one perch.

They do not build their own nests, preferring to take over a nest cavity in a tree, saguaro, buildings, or nest boxes. 1-7 eggs are laid, typically one every other day. Incubation begins in full after the clutch is complete. The female does the majority of incubation, with occasional help from the male, while the male usually hunts and brings her food. Hatching takes 27-31 days. The chicks are full adult size in about 20 days of age and fledge or first flight happens at 27-32 days of age.

Kestrels will eat just about anything they can catch. Prey includes insects, small birds, mammals, amphibians, and reptiles.

They will readily defend their territory against just about any size raptor.

As a small bird of prey, they are hunted by larger birds such as Northern Goshawks, Red-tailed Hawks, Barn Owls, Crows, Ravens, and Sharp-shinned and Cooper’s Hawks as well as snakes, and fire ants.

Unfortunately, scientific data shows a long term decline in American kestrel populations. In fact, 2019 represents another year of unusually low kestrel reproductive success (Hawk Mountain). In North America there has been a 47%-66% decline in breeding population with some northeastern states experiencing higher rates. There is a further projected loss of 50% by 2075. Once considered quite common, kestrels are now listed as endangered or threatened in four northeastern states, and 21 states list them as a species of concern. They are not considered a species of Greatest Conservation Need in Arizona (Azgfd.com). Many factors are considered responsible for this decline. West Nile Virus hit them hard in the early years, Cooper’s Hawk population increases and predation, habitat loss, fewer available nesting spots, widespread use of toxic pesticides plus climate changes. Studies are also ongoing to identify problems on wintering grounds or along migration routes.

How can you help? Reduce or eliminate use of pesticides!! Where possible, leave standing snags and saguaros with nest holes. Kestrels will take readily to nest boxes. Consider putting up a nest box to attract a breeding pair (instructions can be found online on many sites including the Peregrine Fund, Cornell Lab of Ornithology and Azgfd.com). Put it up well before breeding season and in the recommended location. Be sure to attach a guard to keep predators from the eggs and young. Research shows that kestrels will also spend the night in nest boxes on winter nights. These boxes are actually important for more than just nesting!

And finally …….While monitoring a bald eagle nest for several years, we have come to know and admire a little male kestrel we dubbed Conan (The Barbarian). This small falcon has no idea of his size relative to other raptors. We have often watched him harass and drive an adult bald eagle off its perch and then to add insult chase the eagle a hundred yards across the field to ensure that Conan’s territory and tree were reserved only for him and Mrs. Conan. He has taken a variety of large and small prey in his area including birds, lizards, insects, and a round-tailed ground squirrel that looked to weigh as much as Conan. Indeed, a Mighty Kestrel!

Conan with a lizard – photo by Melanie Herring

Conan with a squirrel – photo by Melanie Herring

Resources: allaboutbirds.org; Audubon.org; peregrinefund.org; hawkmountain.org; azgfd.com/wildlife/speciesofgreatestconservneed/raptor-management/kestrel-management

That’s Not My Name

by Nathan Thrash

Liberty Wildlife Staff

Do you know the difference between a fish hawk and an Osprey? Osprey are excellent anglers, with between a 25 and 70 percent success rate on dives. Fish hawks are also excellent anglers, making a catch about once every 12 minutes. Fish hawks have a reversible outer toe, so they can grasp with two toes in front and two toes behind. Osprey have barbed pads on the soles of their feet to help them catch slippery fish. They occupy the same range and eat the same food. So, what’s the difference between a fish hawk and an Osprey? Nothing. They’re the same thing, with Ospreys being referred to colloquially as ‘fish hawks’.

Colloquial terms are fairly common among birds of prey. Until 1983, the most common name for the American Kestrel was ‘sparrow hawk’. This was due to a mistaken familial connection of the American Kestrel to the Eurasian sparrowhawk.

American Kestrel

Eurasian Sparrowhawk

But the American Kestrel isn’t a hawk at all, it’s a falcon. The Peregrine Falcon is another case of a falcon being colloquially referred to as a hawk, known unofficially in North America as a ‘duck hawk’. This is due to the Peregrine Falcon’s diet consisting of mostly medium-sized birds, including ducks. The Pergrine Falcon’s scientific name, Falco peregrinus, means ‘wandering falcon’. I don’t know about you, but if I were a Peregrine Falcon I would much rather my nickname be ‘wandering falcon’ over ‘duck hawk’.

Last, but not least, let’s talk about chicken hawks. When you hear the term ‘chicken hawk’, what kind of hawk do you think about?

For me, I think about Red-tailed Hawks. The only people I know with a chicken coop are my grandparents, who live in Kansas, where the top of every other utility pole is occupied by a Red-tailed Hawk. But, here’s where things get a bit more complicated. Unlike any of the other names I’ve mentioned before, chicken hawk is the unofficial designation for three hawks: Cooper’s Hawk, Sharp-shinned Hawks, and Red-tailed Hawks. The term came about as a way to signify which birds would kill chickens, and therefore be considered ‘pests’. This justified their killing in the past, where they were perceived to be a threat to small pets and livestock. The term ‘chicken hawk’ is probably the most-widely used colloquial term out of the bunch.

So there it is. Whether you’re a seasoned birder, or someone who is new to birding like me, now you know what someone is talking about when they say “Look at that fish/chicken/duck/sparrow hawk!”.

Breeding Season Bird Watching

by Gail Cochrane

Liberty Wildlife volunteer

Spring is a busy time for birds and bird watchers. The earliest clues to spring’s arrival are the vivid colors of plumages. Many birds molt before breeding season and their bright new feathers are a siren call for mates. Nest building is a sure sign of things to come. Gila woodpeckers can be seen drilling in saguaros as early as January, as the cavities must cure before nesting starts. Hummingbirds are early nesters and you might see a hummer carrying a wad of spider web. Curved-billed thrashers, mockingbirds, and cactus wrens clutch twigs in their beaks, destined for new nests.

A cactus wren nest in a staghorn cactus.

Once eggs begin to hatch, the activity notches up even further. By April many birds you see are likely feeding families. Insects provide much-needed protein for growing nestlings and in a perfect world, insects are hatching in great numbers just as birds are in need of them.

Many desert birds produce several clutches of eggs every year. So, nesting continues past April into May and June. Northern mockingbirds produce up to four broods in a season, curved-billed thrashers produce up to three, and cactus wrens will raise two to three broods. Heck, mourning doves have been known to lay six clutches of eggs, and are still making babies into August.

A mourning dove in its palm tree nest.

Among the raptor species, the Harris’s hawk is one of the few to produce more than one brood per year. This works for the Harris’s because youngsters from the previous generation usually hang around for another year to help raise new babies.

Next comes the fledglings. Baby birds may spend some time on the ground while the parents care for them. Others manage to stay in trees or shrubs as they learn to fly. Mom and Dad continue to feed the youngsters until they learn to make do on their own. Or not. This period of time is the most perilous of a bird’s life, and many don’t make it. Some get a second chance at Liberty Wildlife!

It’s a busy time of year for bird enthusiasts. Keep your eyes and ears peeled. You may hear the insistent call of a baby mockingbird as its parents hunt tirelessly for insects to keep it fed. You may see a Gila woodpecker reaching into a saguaro cavity nest, feeding bits of juicy cactus fruits to the three or four hungry nestlings inside.

A house finch in colorful plumage.

If you see a baby bird on the ground have a careful look at the situation. Does the baby have feathers? That’s a good sign its nearly ready to fly. Mom and Dad are probably nearby. Is the situation safe? As long as there is not a busy road, a pool or other hazard in the near vicinity, the parents probably have the situation under control.

Reading up on the nesting and breeding habits of birds that frequent your area is a sure way to gain greater enjoyment from your bird watching. Bird Nests and Eggs by Pinau Merlin is a comprehensive field guide, providing more in-depth information than you might find on the Internet birding sites.