Turkey vultures (Cathartes aura) are a common sight in many parts of North America. These large, mostly black-plumaged birds are often seen circling in the sky, using their excellent eyesight to search for carrion on which to feed. Turkey vultures do not kill live prey, but instead feast on the carcasses of dead animals. But where do turkey vultures go at night when they are not flying around looking for their next meal?
Roosting Habits of Turkey Vultures
Turkey vultures do indeed roost in trees at night. In fact, communally roosting in trees is a very common behavior for these birds after a long day of scavenging. Turkey vultures will gather together in large numbers just before dusk each night to settle down and rest in trees until the next morning.
There are several advantages to communally roosting in trees for turkey vultures:
- Roosting together provides safety in numbers from potential predators.
- With many sets of eyes, they can watch for potential threats.
- Being in a group helps conserve body heat on cool nights.
- Information can be shared among the flock about good food sources.
Turkey vultures most often choose to roost in large, mature trees that provide good cover and protection. Dead trees are frequently selected, as they have more cavities and spaces to grip onto with their feet. The vultures will gather by the dozens or even hundreds in very large roosts. They tend to choose the same roosting sites night after night over many years.
Turkey Vulture Roosting Behavior
When settling down to roost, turkey vultures assume characteristic poses in the trees. They often sit in a slumped position on a horizontal branch with their wings held half-open and drooping to the sides. The wings are held in this posture both to balance on the perch and to allow the sun to directly warm their bodies on colder days.
If it gets too cool at night, the vultures can fluff up their feathers for insulation and tuck in their heads to conserve heat. Their bare heads and necks do not have feathers that would otherwise get ruffled by the wind while in flight during the day. But being bareheaded is a disadvantage for retaining body heat at night, which is why they will tuck in close to their bodies.
In addition to relying on their grip strength to hang on to branches, the toes of turkey vultures have a special adaptation for clinging to limbs without exerting much effort. A tendon in their foot allows the toes to automatically lock into place around a branch when their leg muscles relax. This lets the birds sleep without fear of losing their grip and falling from the tree.
Advantages of Roosting in Trees
As mentioned earlier, there are several advantages to communal tree roosting for turkey vultures:
- Predator protection – Being in a large group in a tree makes it more difficult for predators like owls or eagles to successfully attack an individual vulture without being fended off by others.
- Social benefits – Information about food sources can be shared among the flock at a communal roost site. Vultures can also find mates here.
- Thermoregulation – Huddling together in a group helps the vultures retain body heat on cooler nights through shared body warmth.
- Preferential perches – Trees offer good perches elevated above ground with good views of the surroundings to spot potential threats.
- Convenient launch sites – Having multiple birds launch together gets them quickly up in the air currents to start the day’s scavenging.
Overall, the advantages of finding a large tree to commune with other vultures far outweigh any disadvantages for turkey vultures.
Where are Roosts Located?
Turkey vulture roosting sites are located in a variety of woodland areas, usually not too far from open habitats where the birds forage during the day. Ideal roosting locations include:
- Mature deciduous forests
- Evergreen forests
- Woodlots
- Windbreaks
- Tree-lined gullies
The specific trees selected are often tall, mature specimens that offer good views of the surrounding area. Dead and dying trees provide excellent roosting spots. Bare branches high up in the tree canopy are preferred perching locations.
Roost sites are often traditional and reused year after year, rather than randomly selected new locations each night. The birds appear to choose locations that have good local food availability nearby, moderate vegetation cover, and appropriate perching trees available.
Roosting Alone or in Groups
While turkey vultures do sometimes roost alone, they are much more likely to commune together in large groups. There are several advantages to communal roosting:
- Safety from predators in numbers
- Staying warm while huddling in a group
- Social opportunities to meet mates
- Share information about food resources
The size of turkey vulture roosting flocks varies greatly. Some key facts about their group roosting habits include:
- Roosts range from fewer than 10 birds up to 500 or more birds.
- In Florida, average roost size is about 100-150 birds.
- Juveniles and adults may roost separately.
- Congregating begins up to 2 hours before sunset.
- Communal roosts form due to limited suitable habitat.
Given the clear advantages of communal roosting, it makes sense that turkey vultures most often choose to gather together in large groups when settling down to rest at night in trees rather than roosting solitary and alone.
Other Turkey Vulture Roosting Behaviors
In addition to the typical tree roosting habits already described, there are some other interesting facts about where turkey vultures spend the night:
- May roost on the ground if very few trees are available.
- Radio towers with cross beams are also used as roost sites.
- Sometimes gather on rock ledges on cliffs.
- Have been known to roost on ship masts.
- Occasionally rest on fence posts if no trees available.
Roosting on man-made structures occurs more often in open areas without suitable tree perches. But turkeys vultures show a strong preference for tree roosting when available.
Timing of Roosting
Turkey vultures spend most of the day hours patrolling and soaring in search of food. But they become progressively less active late in the day as they start to gather for their nightly roost. The timing of roosting behavior includes:
- Activity starts decreasing about 2-3 hours before sunset.
- They start arriving at the roost around dusk.
- Peak numbers are reached about 1 hour after sunset.
- Most have settled down 30-40 minutes after sunset.
- They depart the roost around sunrise the next morning.
Light levels dictate the arrival and departure times, with communal roosting concentrated in the darkest hours between sunset and sunrise when diurnal foraging is not possible.
Do Young Turkey Vultures Roost Differently?
Young turkey vultures follow the same general tree roosting behaviors as adults, with a few differences:
- Form juvenile-only flocks separate from adults.
- Juvenile flocks are typically smaller in number.
- May not use traditional communal roost sites at first.
- Adults are dominant at shared roosting sites.
- Juveniles may practice communal roosting before migrating.
The segregation of young birds from adult flocks reduces competition. As the younger vultures gain experience and polish their roosting skills, they eventually integrate into the adult communal roosting groups.
Why Don’t Turkey Vultures Roost on the Ground?
Turkey vultures sometimes do rest on the ground if no suitable roost trees are available in an area. However, ground roosting comes with some distinct disadvantages compared to tree roosting:
- More vulnerable to predators on the ground.
- Lack an elevated vantage point to watch for threats.
- Nests and eggs can be easier for predators to access.
- Risk contamination from bacteria and parasites.
- No buffer from temperature extremes on the ground.
- Harder launch into flight without dropping from height.
Given the many protective benefits of trees for roosting sites, it makes sense that turkey vultures overwhelmingly choose to commune in trees at night whenever possible rather than settling down to rest on the ground.
Conclusion
In summary, turkey vultures most definitely do seek out trees to roost in at night. Communal roosting in large trees provides many advantages for these scavenging birds in terms of predator detection and avoidance, thermoregulation, social facilitation, and convenient launch sites to take off from at dawn. Mature trees in relatively open habitats make ideal roost locations. Ground roosting only occurs occasionally when trees are scarce. Roost site selection and habits are driven by the evolutionary advantages trees provide turkey vultures at night over less optimal ground resting spots. Their innate behaviors have adapted over time to enhance the survival and reproduction of the species.
