The white-tailed kite is a medium-sized raptor found in open grasslands, savannas, and wetlands in western North America. As an opportunistic predator, the white-tailed kite feeds on a variety of small mammals, birds, reptiles, and insects. Understanding the prey species that white-tailed kites target provides insight into their ecological role and hunting strategies.
Mammals
Small mammals make up the majority of the white-tailed kite’s diet. Some of their most common mammalian prey includes:
- Voles – Voles are small, mouse-like rodents that live in grassy areas. They make up over 50% of the white-tailed kite’s mammal prey. Species hunted include the California vole, long-tailed vole, and meadow vole.
- Mice – White-tailed kites prey on mice like the Western harvest mouse and deer mouse. Mice comprise around 15% of mammals taken.
- Rats – Rats like the California ground squirrel are opportunistically hunted, but make up less than 5% of the kite’s mammalian prey.
- Squirrels – Squirrels are occasionally captured, mainly young or injured individuals. This includes the California ground squirrel.
- Rabbits – Young rabbits are preyed on infrequently. Desert cottontails and brush rabbits are most often taken.
- Woodrats – Kites prey on woodrats like the dusky-footed woodrat on occasion, mainly juveniles.
- Shrews – Insectivorous shrews are captured opportunistically, but infrequently.
The percentage breakdown of mammalian prey is approximately:
- Voles – 52%
- Mice – 15%
- Rats – 4%
- Squirrels – 3%
- Rabbits – 2%
- Woodrats – 1%
- Shrews – 1%
Kites often locate small mammals by flying low over open grasslands or marshlands. They keep a lookout for any movement in the vegetation that may indicate a rodent or other small mammal. Once prey is spotted, they swiftly dive down to snatch it with their talons.
Birds
After mammals, birds make up the second largest portion of the white-tailed kite’s diet. Some avian prey species include:
- Small passerines – Sparrows, finches, larks and other small songbirds are frequently captured. This includes horned larks, house finches, and song sparrows.
- Doves/pigeons – Band-tailed pigeons and mourning doves are common bird prey.
- Quail – California quail and Gambel’s quail chicks and eggs are preyed upon.
- Starlings – Both juveniles and adults may be hunted.
- Blackbirds – Young red-winged blackbirds are taken often.
- Woodpeckers – White-tailed kites occasionally capture woodpeckers like northern flickers.
- Hummingbirds – These swift flyers are captured in midair infrequently.
The percentage breakdown of avian prey is approximately:
- Passerines – 32%
- Doves/Pigeons – 12%
- Quail – 5%
- Starlings – 2%
- Blackbirds – 1%
- Woodpeckers – 1%
- Hummingbirds – 1%
Kites often spot birds while soaring high above open areas. They will stealthily approach until within striking distance before diving rapidly to grab unsuspecting birds with their talons.
Reptiles
Reptiles are a small portion of the white-tailed kite’s diet. Some reptilian prey includes:
- Lizards – Fence lizards, western skinks, and side-blotched lizards are captured.
- Snakes – Gopher snakes are most often preyed upon.
- Turtles – Young western pond turtles may be eaten.
The percentage breakdown of reptilian prey is approximately:
- Lizards – 4%
- Snakes – 1%
- Turtles – 1%
Reptiles are snatched from the ground as the opportunity arises. Their bones and scales are usually indigestible and later regurgitated as pellets.
Insects
Insects are a very small part of the white-tailed kite’s diet. Some insects preyed upon include:
- Grasshoppers
- Crickets
- Cicadas
- Beetles
- Moths and caterpillars
Insects are opportunistically captured in flight or gleaned from vegetation. They likely compose less than 1% of the kite’s total food intake.
Other Prey
White-tailed kites occasionally prey on other food items like:
- Amphibians – Tree frogs and toads
- Fish – Small fish in wetlands
- Invertebrates – Earthworms, snails, spiders
- Carrion – Scavenges opportunistically
However, these food sources make up a very small percentage of the kite’s diet.
Hunting Strategy
White-tailed kites have several specialized hunting techniques to capture their prey:
- Hovering – Flutter in place above prey before plunging down.
- Low cruising – Fly close to the ground to spot prey.
- High soaring – Soar high to spot unsuspecting birds.
- Still-hunting – Perch on trees and poles searching for prey.
Their sharp eyesight and ability to remain motionless in the air make kites effective hunters. They often utilize lookout perches like shrubs, fence posts and small trees to get the best vantage point over hunting grounds.
Prey Selection
Kites are opportunistic foragers and will target the most abundant prey sources in a given habitat. However, they do exhibit prey preferences:
- Prefer voles over mice, rats, or squirrels.
- Target young, injured, or unwary prey.
- Shift between more mammals in winter, more insects/reptiles in summer.
- Scavenge less when preferred live prey is available.
Their diverse diet allows them to take advantage of many prey opportunities. Hunting success rates are estimated between 5-50% depending on prey type.
Consumption Rates
Studies on white-tailed kites provide estimates of their daily prey consumption:
- Require 120-150 g of prey per day.
- Capture 3-7 prey items per day.
- Increase intake before breeding season.
- Nestlings eat about 60 g per day.
Higher metabolic needs during breeding and nesting drive increased hunting. Kites without nests to provision require less daily food.
Geographic Variation
White-tailed kite prey selection differs across their geographic range:
| Region | Primary Prey |
|---|---|
| California | Voles, mice |
| Oregon | Voles, shrews |
| Texas | Insects, lizards |
| Florida | Snakes, lizards |
| South America | Insects, small reptiles |
Prey availability influences geographic differences in hunting. Kites are flexible in switching between locally abundant food sources.
Impact on Prey
Research shows white-tailed kites can impact prey populations and communities through:
- Regulation of prey numbers like voles and small mammals.
- Altering prey behavior to be more vigilant and take refuge.
- Influencing interspecific competition between prey species.
- Reducing reproductive success of vulnerable prey.
However, as generalist predators their regulatory impact is limited compared to specialists. Prey populations are also kept in check by other factors like food availability, predation, disease and competition.
Ecological Role
As predators, white-tailed kites play an important ecological role:
- Control prey populations like rodents.
- Prey on species damaging to agriculture like voles.
- Remove weak, old and diseased animals.
- Prevent overgrazing by keeping prey numbers in check.
- Influence prey behavior and community structure.
- Aid nutrient cycling from prey remains.
- Disperse seeds from prey ingestion.
Kites help maintain ecosystem stability through natural population regulation. Their opportunistic diet provides flexibility in dampening prey irruptions.
Conclusion
In summary, the white-tailed kite is a formidable predator of small mammals like voles and mice, as well as birds, reptiles and insects. Their diverse prey selection allows them to thrive across habitat types and switch between locally abundant food sources. Kites fill an important ecological role in regulating prey populations, scavenging, and cycling nutrients back into the environment. Understanding the hunting strategies and food choices of the white-tailed kite provides insights into the ecology of this unique raptor.
