American / Common Crow

American Crow

Latin Name: Corvus brachyrhynchos Order: Passeriformes Family: Corvidae

Photo courtesy of kopperheadpix, Akron Zoo

Corvus is Latin for “raven” and brachyrhynchos breaks down to “short beak”.  Corvids are a widespread family of passerines and include birds such as crows, ravens, jays, and magpies.

Overview 

Crows have the potential to be very impactful ambassador birds.  People see (and hear!) crows on a regular basis, but often don’t realize how special these birds are – ambassador crows help to deliver the message that amazing things can be found in your own backyard.  From their social structure, to language skills, to intelligence, to problem-solving ability, to tool-making talent, to long-term memory and the ability to pass that memory down, crows have an endless list of adaptations with which to wow an audience.  They are highly trainable for demonstrating behaviors which highlight those adaptations, too.  Ambassador crows tend to be most successful in their role if imprinted.  Zoos interested in acquiring a crow for their ambassador population should be aware that, while it is feasible for a crow to work for multiple handlers, the size of the handler group is often limited by skill and the ability to both establish and maintain a relationship with the bird.

Natural History Information 

Range and Habitat 

American crows are found year-round in the lower 48 states, outside of the deserts of the southwest.  They can also be found in Canada during breeding season.  They are highly adaptable to most any habitat, including open woodlands, grasslands, farmlands, coastal shores, and even human-populated suburbs and cities.

Longevity

Crows in the native habitat live on average 7-8 years, though the oldest known wild crow was nearly 15 years old.  In human care, crows have been known to live up to 30 years.

Ecosystem Role

Crows are often blamed for causing damage to crops, but the minimal damage they may cause the plants is outweighed by the benefit they provide in eating countless agricultural pests.  Crows are also seed dispersers and help to speed the process of decay and reduce disease transmission by feeding on carcasses.

Husbandry Information

Housing Requirements 

Life Cycle Natural History Relevant Information  

• American crows are social, diurnal birds.
• Ambassador crows are most often non-releasable rehab birds and are acquired and housed as single birds; it is important that their social needs be taken into consideration.

Habitat 

• Akron Zoo: Their crow is housed in an outdoor (approximately) 12’ x 6’ x 8’ space with brick and 1” aluminum mesh; mesh is covered with vertical pieces of 1” PVC to prevent crow from grasping the mesh and therefore damaging feathers.
• CuriOdyssey: Their crow has an indoor, double dog-run holding 90” x 70” x 70”, as well as access to an outside run holding.

Indoor holding

Outdoor access holding

Photos courtesy of RoseMarie Zar, CuriOdyssey

• San Francisco Zoo: Their crow has separate daytime/nighttime holdings; nighttime mew is a 4’ x 8’ KW Cages aviary, daytime mew is an outdoor 180 sq. ft. A thru Z aviary.

Daytime aviary

Photo courtesy of Kaela Schnitzler, San Francisco Zoo

• Boonshoft Museum of Discovery: Their crow is housed in an indoor 66” x 35” x 69” Corners Limited (1” x 1” mesh) holding.
• Tracy Aviary: Their crow is housed in an outdoor 4’ x 8’ x 8’ holding with wood supports and 1” x 1” plastic coated mesh.
• Texas State Aquarium: Their crow is housed in an outdoor 20’ x 10’ x 12’ exhibit space.

Temperature, Humidity, Light Cycles 

• Temperature: Crows are very adaptable to many temperature ranges, including extremes, with proper provisions i.e. wind break, shelter from rain/snow/sun, heat lamp, heated water bowl, water for bathing, misting station.
• Humidity: Crows are tolerant of a wide humidity range.
• Light: Those housing ambassador crows indoors may want to offer UV lighting. It would be recommended to first get baseline and adjusted data of behavior/use of space without UV lighting, and then introduce low level UV (Ferguson Zone 1) to start. Bulb UV output should be checked with a UV Index meter.

Substrate 

• Akron Zoo: Crow holding has concrete flooring.
• CuriOdyssey: Crow holdings (both indoor/outdoor) have concrete flooring.
• San Francisco Zoo: Indoor crow holding has concrete flooring, outdoor holding has wood chips.
• Boonshoft Museum of Discovery: Crow holding uses mulch substrate.
• Tracy Aviary: Crow holding uses a 50/50 utilite/soil substrate.
• Texas State Aquarium: Crow holding uses pea gravel substrate.

Other General Housing Requirements or Management information 

• Crows love to bathe and should have access to a water bowl large enough to do so.
• Crows should have a variety of perches (different diameters, textures) at multiple levels in the holding.
• Crows will also utilize platform perches; some crows seem to enjoy having a hide house of sorts.

Diet Requirements 

Diet in the Wild 

• Crows in the native habitat eat a huge array of food including grains, seeds, nuts, fruit, worms/insects/snails, eggs, nestling birds, frogs, crayfish, young turtles, clams/mussels, human food leftovers, available pet food, carrion. 

Diet under human care 

• Akron Zoo: Crow is weight managed and weighed daily; diet varies between 30-60 g consisting of dog kibble, various produce, What’s Cookin’ (dried grains and produce reconstituted with water), Nebraska Bird of Prey diet, mealworms; pinkies/hoppers/mice/quail, waxworms/crickets/superworms/silkworms, sunflower seeds/peanuts, hard-boiled egg offered as training/enrichment items.
• CuriOdyssey: Diet consists of 15 g feline kibble, 30 g fruit/veggie mix, 10 g meat, 10 g hard-boiled egg, 5 g crickets OR 3 large superworms.
• San Francisco Zoo: Crow is weight managed and weighed daily; diet varies between 40-55 g consisting of some combination of the base diet of 15 g Science Diet feline maintenance light, 15 g fruit mix, 15 g veggie mix (no beets), 10 g meat, 10 g hard-boiled egg, 5 frozen crickets, 3 mealworms; bird is weight managed and weighed daily
• Boonshoft Museum of Discovery: Diet consists of 2T black oil sunflower seeds, 2T mixed bird seed, 15 g produce, 15 g chopped greens, ½ hard-boiled egg, 10 mealworms, 1T Iams mini-chunk dog chow (soaked), 1 mouse.
• Tracy Aviary: Diet amount varies daily, but consists of 40% Mazuri softbill pellets, 30% produce, 30% quail/mouse/rat/rabbit or egg; supplemental insects (crickets and mealworms) and nuts/seeds.
• Texas State Aquarium: Diet consists of 45 g frugivore mix (softbill pellets, small bird breeder pellets, fruit, veggies, mixed greens), 15 g mouse.

Veterinary Concerns 

• Crows are susceptible to West Nile virus.
• Crows can carry any number of common GI parasites, often without obvious symptoms; regular fecal screenings should be part of their care.

Enrichment & Training

Enrichment 

Behavioral Relevant Information

• Crows are social and engage in allopreening.
• Crows are curious, though cautious, of novel things.
• Crows cache food.
• Crows are good problem solvers.
• Crows will make and use tools.

Environmental Enrichment 

• Add new substrates
• Offer water bowls of varying size and depth for bathing
• Add new perching/stumps; approved browse
• Offer misting and/or fan stations
• Offer different heat sources (i.e. radiant heat panel vs. infrared lamp)
• If housed indoors, offer different lighting options (i.e. no UV, low UV, higher UV, UV with and without heat associated with it)

Behavioral Enrichment 

• Any number of foraging/puzzle toys (i.e. Kongs, Holee Rollers, Jolly Balls, various puzzle feeder sold for dogs, many dexterity toys for babies (stacking rings/cups), soft ball pit balls, Waffle blocks, Mega blocks, metal hay holders)
• Foraging/puzzle toys can also be made with various items (i.e. newspaper, craft paper, toilet paper/paper towel tubes, cardboard boxes, paper mache, Dixie cups)
• Provide opportunities for caching (i.e. leaf/straw/hay pile, boxes/boards with small holes)
• Nature videos and CDs; opportunities to see other ambassador animals
• Water enrichment (i.e. ice, floating dishes in kiddie pools)
• Socialization sessions with people (those with a strong relationship may be able to preen the crow, and let the crow preen them in return)
• San Francisco Zoo: Their crow paints (and only has 1 foot – you go, Russell!!)

Photo courtesy of Kaela Schnitzler, San Francisco Zoo

• Problem solving enrichment opportunities

Photos courtesy of James McKinney, Texas State Aquarium

Schedule

• Ambassador crows should be enriched at least once daily.

Other Enrichment Resources 

Training 

Behaviors Trained 

• Akron Zoo: Their crow is trained for voluntary scale and kennel, A → B flights between trainers, recycling (audience member can hand or toss him a paper ball and crow will place it in a recycling can), kibble catching (audience member can toss pieces of kibble to crow and he will catch it in his beak), dollar bill caching (audience members hand crow dollar bills after shows and crow caches bills in an acrylic “piggy bank”).
• CuriOdyssey: Their crow is in training to exit his kennel on a tabletop and go to a station on the table during presentations.
• San Francisco Zoo: Their crow is trained for voluntary kennel, A → B flights between trainers, vocalization on cue, color recognition, painting, voluntary nail trim.
• Boonshoft Museum of Discovery: Their crow is trained to be presented on hand/arm or rope-wrapped perch, walking on the ground, standing on a table.
• Tracy Aviary: Their crow is trained for free-flight, nut caching behavior, recycling behavior, and will walk with or fly between trainers during free walks in the park.
• Texas State Aquarium: Their crow is trained for A → B flights between trainers, will play Connect 4 with a guest, and will demonstrate solving food puzzles.

Reinforcers used & schedule of reinforcement 

Other

Social Housing/Colony Management 

• Sexual maturity is reached at 2-4 years of age, with females generally maturing faster.  
• Though crows are monogamous, it is not too uncommon for outside males to mate with a “spoken for” female, which helps to increase genetic diversity.
• Crows typically begin nesting in March, and incubation is ~20 days.
• Females are the primary incubators; young fledge at about 1-2 months of age, but stay with the family group for another 2 months generally.
• Crows are sometimes cooperative breeders, with older offspring (typically males) “helping” to raise the current season’s young.

Colony or Breeding Management

Individual Identification

• Male and female crows are not sexually dimorphic; if housing more than one ambassador crow in the same holding, colored leg bands are probably the easiest visual identification, though most likely they will have different behavioral traits that will enable identification, too. 

Programmatic Information

Messaging Themes

• Native animals can have amazing traits.
• Crows can help to increase empathy with audiences by teaching about their family structure
• Animals are intelligent and can learn, they are not just instinctual.
• There are responsible ways to safely share space and resources with native animals near your home.
• Though crows are often perceived as agricultural pests, they eat many insects that are much more damaging to crops. They are also effective seed dispersers. 
• There are many negative myths that surround crows – dispel them!
• There are regulations in place against keeping most native animal species as pets.

Threats and Conservation Status

• The American crow is listed as a species of least concern – this is despite past efforts to exterminate them through hunting and use of dynamite on their winter communal roosts.

Interesting Natural History Information 

• Crows can learn to mimic sounds just like parrots.

Did you know…

• Crows have an encephalization quotient (brain to body size ratio) on par with chimpanzees.
• Some crows have been observed to use bread crumbs to lure fish to the water surface and then catch the fish.
• Crows will drop nuts to the ground from high distances to crack the shell; crows in Japan have also been observed to place nuts in crosswalks so cars will run over them – they will even wait for the traffic light to change so they can safely collect the opened nut
• The famous University of Washington facial recognition study proved that not only did crows have superb facial recognition capabilities, they also were able to communicate that information to others, even spanning several generations of birds.
• Crows have a strong response to seeing dead crows. They often gather in large groups around a dead crow, and will often not again visit an area where they witnessed a dead crow.
• Crows have regional differences/dialects in the way they make their calls.

Handling & Presentation Tips

• Though ambassador crows can be presented in various manners (on hand, on table, walking on ground, in free flight, etc.), a consistent theme amongst institutions housing these birds is that limited staff work with the bird.  Others may be able to provide husbandry/enrichment and basic behaviors, but training of complex behaviors is often limited to a few skilled trainers.
• Texas State Aquarium: Their crow has worn telemetry for free flight training outdoors.
• Akron Zoo: Their crow wears jesses, though jesses are rarely held. Holding of the jesses is a cue to the bird to stay on hand.

Use Guidelines 

• Crows without equipment of any kind are often presented indoors only.
• Texas State Aquarium: They have wind restrictions for flying their crow outdoors.
• San Francisco : They have a 1 program usage daily restriction (for usage that occurs outside of bird’s exhibit holding).

Public Contact and Interaction Guidelines 

• Public interaction is typically indirect (i.e. handing items to crow, feeding, crow flighted over audience)

Transportation Tips 

• If using a crate with a built-in perch, the crate should be placed so that the perch is perpendicular to the vehicle wheel axle; this gives the bird the ability to brace itself during acceleration/braking
• Covering the crate during travel is dependent on preference of individual crow.
• Keep in mind animal relationships when placing crates in vehicles, especially if they can see one another.

Crating Techniques 

• Akron Zoo: Crate is a small Varikennel with built-in natural wood perch and lined with astroturf; covered for travel.
• CuriOdyssey: Crate is a medium size plastic pet carrier with perch attached and lined with newspaper or astroturf.
• San Francisco Zoo: Crate is a Petnation Port-a-crate lined with astroturf.

Photo courtesy of Kaela Schnitzler, San Francisco Zoo

• Boonshoft Museum of Discovery: Crate is medium or intermediate Sky Kennel, no perch, lined with a dri-dek mat, covered for travel.
• Tracy Aviary: Crate is a small Varikennel, no perch, lined with Monsanto mat.
• Texas State Aquarium: Crate is a small dog/cat carrier with built-in natural wood perch.

Temperature Guidelines

• Akron Zoo: Maximum temperature for outdoor presentation is 90 degrees, full shade.

Acquisition Information

• Ambassador crows are most often acquired from local wildlife rehabilitation centers.

 Look for specialty/exotic rescues such as:

Resources

• For IC contact info email Maureen O’Keefe

Contributors and Citations 

• Akron Zoo
• CuriOdyssey
• San Francisco Zoo
• Boonshoft Museum of Discovery
• Tracy Aviary
• Texas State Aquarium 

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Photo Credits: 

All photos are credited within text

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