Kestrels and Aplomado falcons are both small falcons found in North America. However, there are some key differences between these two species of raptors. In this article, we will explore the similarities and differences between kestrels and Aplomado falcons in terms of their physical characteristics, habitat, diet, hunting strategies, and conservation status. Understanding the distinctions between these birds can help birders properly identify them in the wild.
Physical Characteristics
Kestrels and Aplomado falcons share some physical similarities since they belong to the same taxonomic family, Falconidae. However, there are some noticeable differences in their size, coloring, and markings.
Size
Kestrels are very small falcons, with the American kestrel being the smallest falcon in North America. They measure around 9-12 inches long with wingspans of 20-24 inches. Their bodies are slim and lightweight.
Aplomado falcons are slightly larger than kestrels. They measure 14-18 inches long with wingspans of 34-43 inches. While still compact, Aplomado falcons have stockier bodies compared to the delicate kestrels.
Coloring
While both species exhibit sexual dimorphism, the males and females differ more dramatically in Aplomado falcons than in kestrels.
Male kestrels tend to have blue-gray wings, rusty spotted patterns on their backs, and banded tails. Females have brown wings and streaked bellies. Their tails may be less prominently banded than the males.
Male Aplomado falcons have striking black and white banded patterns on their wings and long, blue-gray tails. Females are larger and browner overall, with less pronounced tail banding.
Markings
The most distinctive marking of the kestrel is the two vertical black stripes on either side of its white face. These stripes extend down from the top of the head past the eyes.
Aplomado falcons lack any bold facial markings. Instead, the white eyebrow line above their eyes helps identify them.
Habitat
Kestrels and Aplomado falcons inhabit different ecosystems based on their environmental adaptations.
Kestrel Habitats
Kestrels thrive in open country habitats throughout most of North and South America. They nest in cavities in trees, cliffs, buildings, and other structures. Their habitats include:
– Grasslands
– Meadows
– Pastures
– Parklands
– Agricultural areas
– Mountain valleys
– Urban/suburban areas
They are absent from densely forested regions. Kestrels can adapt to human-altered environments as long as there are open hunting grounds and some trees or structures for nesting.
Aplomado Falcon Habitats
Aplomado falcons inhabit savanna and grassland environments. They are found in:
– Coastal prairies
– Inland plains
– Desert grasslands
They avoid forested areas. Aplomado falcons need scattered trees, shrubs, utility poles, or other lookout perches for hunting. They nest in old stick nests built by other birds.
Historically, they were widespread across the southwestern U.S. and Mexico. Habitat loss has now restricted them to isolated pockets of their preferred grasslands in these regions.
Diet
The kestrel and Aplomado falcon are both carnivorous raptors that feed on small animals. But their diets differ somewhat based on habitat and hunting styles.
Kestrel Diet
Kestrels are opportunistic hunters that eat a wide variety of prey, including:
– Large insects (grasshoppers, dragonflies)
– Small mammals (voles, mice, shrews, bats)
– Small birds
– Reptiles (lizards, snakes)
– Amphibians (frogs, salamanders)
They typically hunt from perches, swooping down to grab prey on the ground. Kestrels sometimes hover in mid-air while hunting. Their diverse diet reflects the variety of potential foods found in the open environments they inhabit.
Aplomado Falcon Diet
Aplomado falcons feed more selectively, preying predominantly on:
– Birds (doves, quail, meadowlarks, grackles)
– Large insects (grasshoppers, dragonflies)
– Small mammals (mice, reptiles)
They strongly favor avian prey, with 75-90% of their diet consisting of birds when available. Aplomado falcons tend to actively pursue birds in flight during hunts. Their more specialized diet matches the bird diversity found on the grasslands where they live.
Hunting Strategies
Kestrels and Aplomado falcons employ different hunting techniques tailored to their environments and prey.
Kestrel Hunting
Kestrels are perch-hunters and also sometimes hover while hunting:
– Perch hunting – Kestrels sit on an elevated perch like a tree branch or utility wire. They scan for prey movement below, then stoop down to grab the prey.
– Hover hunting – Unique among falcons, kestrels have the ability to beat their wings rapidly and hover suspended in mid-air. They can hover 20-60 feet above an area while scanning for prey.
Both perch hunting and hover hunting allow kestrels to effectively spot and capture prey across open country.
Aplomado Falcon Hunting
Aplomado falcons employ an active aerial hunting technique:
– Aerial pursuit – Aplomado falcons search for prey while flying over grasslands and savannas. When they spot a bird, they engage in a swift aerial chase, pursuing the prey in flight until they can overtake it.
This style of fast hunting on the wing allows Aplomado falcons to catch birds, their preferred prey. They will also perch hunt at times.
Conservation Status
Kestrels and Aplomado falcons have very different conservation needs currently.
Kestrel Conservation Status
The American kestrel is one of the most widespread and abundant falcons in North America. Its total population is estimated at around 1.2 million pairs. Other kestrel species also have large global populations. The kestrel is classified as:
– IUCN Red List: Least Concern
– ESA Status: Not listed
Though still common, there is evidence of declining kestrel numbers in some regions due to habitat loss. Kestrels readily adapt to human environments which helps maintain their numbers.
Aplomado Falcon Conservation Status
The Aplomado falcon has a much smaller population estimated between 1,000 to 2,499 individuals. Habitat destruction reduced its range dramatically in the 1900s. Due to these declines, it is classified as:
– IUCN Red List: Vulnerable
– ESA Status: Endangered
Conservation efforts to protect grasslands and restore nesting habitats are underway to help the Aplomado falcon population recover. But the species remains vulnerable to extinction currently.
Comparison Chart
Here is a chart summarizing some of the key differences between kestrels and Aplomado falcons:
Trait | Kestrel | Aplomado Falcon |
---|---|---|
Size | Small, 9-12 in. long | Medium, 14-18 in. long |
Habitat | Open country, grasslands, parks, urban areas | Coastal and inland grasslands, savannas, deserts |
Diet | Diverse – insects, small mammals, birds, reptiles | Specialized – mainly birds |
Hunting | Perch hunting, hover hunting | Aerial pursuit |
Conservation | Least Concern | Vulnerable |
Conclusion
In conclusion, while kestrels and Aplomado falcons share similarities as small North American falcons, they differ significantly in their preferred habitats, diets, hunting styles, and conservation needs. Kestrels are diverse generalist hunters adapted to open habitats including those modified by humans. The Aplomado falcon is a specialist bird predator dependent on its fragile native grassland environments. Maintaining habitat protections will be key to preserving Aplomado falcon populations into the future. Being able to distinguish these species helps bird enthusiasts appreciate their unique attributes.