Native Owls of Hillsborough County

Did you know Hillsborough County is home to five native species of owls? 

The Eastern Screech Owl (Megascops asio), Burrowing Owl (Athene cunicularia), Barn Owl (Tyto alba), Barred Owl (Strix varia), and Great Horned Owl (Bubo virginianus).

Size comparison of native owls. https://arc4raptors.org/

You might ask "What is so special about these birds?". Well, let's dive in for a closer look. 

Owls are known as birds of prey, or "raptors" (like eagles, hawks, falcons, and vultures) and are protected under the federal Migratory Bird Treaty Act. However, owls do not migrate, but travel seasonally for food. Most owls are nocturnal, except the burrowing owl which is more diurnal (active during daylight). Many owl species make familiar hoot sounds while others make harsh screeches, hisses, clicks, and trills. 

Owls have several natural adaptations to help them hunt. They have fringed flight feathers which allow them to fly almost silently. They also have excellent hearing with asymmetrical ears that allow for precise sound triangulation to locate prey under dense brush. Some species have ear tufts which are not actually ears, but elongated tufts of feathers called plumicorns, which are used for camouflage. When an owl wants to hide from predators or blend into a tree trunk, it will pull its feathers tight, stretch its body, and raise its plumicorns. This breaks up the round, recognizable outline of the owl's head, making it look like a broken, jagged tree branch. They also possess tube-shaped large eyes to see in darkness and can rotate their head 270 degrees. 

Owls benefit humans in numerous ways. They act as natural pest control agents and eat thousands of mice, rats, and insects each year. This reduces disease and health risks in humans since these pests carry harmful pathogens. They also provide crop protection by removing rodent populations and lower pesticide use. Lastly, they provide ecotourism revenue to a region as birdwatchers travel and spend money to view owls in the wild. 

Now, let’s look at the native owls of Hillsborough County! 

The first species we will discuss is the Eastern Screech Owl (Megascops asio). They come in several color variations such as slate grey, rusty red, or a brownish morph. Screech owls are the smallest of the five native species at about 6 -10” tall and weigh between 4.3-8.6 oz. They have very prominent ear tufts with bright yellow/green eyes. They can be found in deciduous/coniferous forests, woodlands, parks and suburban/urban neighborhoods. They are a very common species and you can find them at several Hillsborough County Conservation Parks such as Lettuce Lake, Eureka Springs, Upper Tampa Bay, and Flatwoods Conservation Park. These owls make their nests within tree cavities or artificial nest boxes. Their diet includes rodents, insects, reptiles, and amphibians. An interesting fun fact about them is that they will often carry blind snakes to the nest, a species that feeds on insects within the nests but leaves the bird eggs alone. That’s a smart bird! 

Eastern screech owl (red morph) by Bill Waller, CC-by-3.0

Eastern screech owl (gray morph) by Wolfgang Wander, CC-by-3.0

 

Burrowing Owls (Athene cunicularia) are a unique species in that they nest underground in burrows by digging up sandy soils using their feet and beaks or occupying existing burrows. Unfortunately, these species are considered threatened due to habitat loss for development. They require open grasslands and prairies, but will also use golf courses or airports. Fortunately, there is an existing resident colony at MacDill Air Force Base in Hillsborough County which also serves as a relocation site. Additionally, conservation efforts like Audubon’s Project Bur-O exist to help increase populations of this species. This project involves installing artificial, non-collapsible burrows in sandy soils to provide critical shelter. They have brown feathers with patches of white spots and a white underside with brown bars. Their very long legs help them run along the ground and catch prey such as insects, snakes, frogs, lizards, birds, and rodents. They are a little larger than screech owls at about 7.5-10” tall and weigh between 4.5-8.5 oz. Burrowing owl chicks are known to mimic the hissing sound of a rattlesnake to deter predators. Pretty cool! 

Burrowing owl on the lookout by Dori, CC-by-3.0

Burrowing owl near burrow by birdphotos.com, CC-by-3.0

Next up is the Barn Owl (Tyto alba). They have a distinct white, heart-shaped face which acts like a satellite dish collecting sound waves that funnel sounds towards their ears. Their bodies are a golden-brown color with a grayish back and a white/buff chest which often has fine spots or barring. They are about 12-14” tall, and weigh between 11-20 oz. They often inhabit prairies, pastures, agricultural fields, and rural/urban farm buildings. They are one of the least common species of native owls, but you may be able to spot them at several nature preserves within Hillsborough County such as Fred & Ida Schultz Nature Preserve, Lower Green Swamp Nature Preserve, or Lower Hillsborough Wilderness Preserve. They prefer to nest in old tree cavities, cliffs, barns, or nest boxes. Their diet is similar to other owls and includes mice, rats, voles, and shrews. An interesting fun fact about barn owls is that can hunt in complete darkness with an astounding degree of accuracy! 

Barn owl on perch by https://www.goodfreephotos.com

Barn owl in flight by DannyMoore1973, CC-by-1.0

One of the most widespread and common native owl species is the Barred Owl (Strix varia). They have a mottled brown/white feather pattern with brown “bars” across their chest, a yellow beak, and large dark eyes. They are one of the larger species of native owls weighing about 1-2.5 lbs and standing 16-24” tall. Barred owls can be found within mature dense forests, oak hammocks, and cypress swamps. They are commonly found within Hillsborough County at Lettuce Lake Park, Edward Medard Conservation Park, and Hillsborough River State Park. Like the barn owl, they also nest within existing tree cavities or nest boxes and have a similar diet. One of the mnemonic tricks used to identify this species is by their primary call which sounds like "Who cooks for you? Who cooks for you all?" 

Barred owl by Judy Gallagher, CC-by-2.0 

Barred owl by Mwanner, CC-by-3.0

The last native owl species in Hillsborough County is the Great Horned Owl (Bubo virginianus). They are the largest, weighing 2-5.5 lbs and standing 18-25" tall with an impressive wingspan of 40-60". Their coloration is often a mottled gray brown to dark brown with a white throat patch and barring on the chest. They have prominent ear tufts like the screech owl. Great horned owl populations are considered stable and secure. They frequently inhabit woodlands, swamps, prairies, uplands, pastures, and agricultural fields. You might spot them at Cockroach Bay Nature Preserve. They prefer to use stick nests built by other birds like hawks or crows and have a similar diet to the other native owl species. This species has one of the strongest grips of any bird. To open their clenched talons, an estimated 300 to 500 pounds per square inch (psi) of pressure is required. This immense strength helps them to instantly snap the spine of their prey.

Great horned owl by Greg Hume, CC-by-3.0

Great horned owl by islandDebra, CC-by-2.0

Now you know all about the wonderful native species of owls in Hillsborough County! Get outside and look for these beautiful birds!