Although corvids are generally known as scavengers and omnivores, the diet of different corvid species varies considerably, both between species and throughout the seasons. For example, only about 40% of the rooks’ diet consists of animal protein, primarily worms, insects, and larvae. They usually don’t eat carrion because their beak is not designed to tear animal carcasses into manageable pieces. The remaining 60% of the rooks’ diet consists of plant-based products such as fruits, seeds, and vegetables. During winter, carrion crows prefer seeds, berries, and carrion, while during summer, they primarily rely on animal protein like snails, worms, insects, small mammals, and eggs.
Hatchlings (Up to 3 Weeks)
When raising hatchling corvids, it’s important to feed them a diet consisting solely of insects for the first two weeks of their lives. Ideally, these birds should be fed an insect mash containing the following ingredients:
- Frozen fresh insects such as crickets and wax worms
- Mineral and vitamin mixture like Korvimin ZVT+Reptile (WDT)
- Boiled egg yolk
- Soaked NutriBird Bird Complete pellets (Versele-Laga)
- Minced beef
- Small amounts of feathers and fur can be occasionally added to the mash, but only when the bird is older than 2 weeks, as it helps with pellet production
- Alternatively, one can create a baby food mixture (modified recipe, original recipe by Samantha Bedford of Bedfordshire Wildlife Rescue) based on the following ingredients:
- 2 parts ground chicken biscuits (80%) (Applaws Kitten Food Chicken)
- 1 part Hagen Tropicana Breeding Mash
- 1 part Heath’s Prosecto Insectivorous Soft Food
- Dried ants, flies, and daphnia
- Korvimin ZVT+Reptile by WDT (Nutrobal for Birds by Vetark)
- Bene-Bac Powder for Birds and Reptiles by PetAg (AviPro Plus by Vetark)
Nestlings (Older Than 3 Weeks)
When the bird reaches 3 weeks, the amount of mash should be reduced, and soaked cat biscuits should be introduced in addition to the mash. GoCat Chicken and Duck Complete pet food for adult cats (Purina) is suitable for corvids as it provides the necessary high protein content. It contains 20% rehydrated meat and animal derivatives, with a minimum of 4% chicken and 4% duck (30.0% protein, 10.0% fat content). Canned dog or cat foods are not suitable for corvids and are likely to cause diarrhea.
Fledglings
Once the birds have fledged, a wider variety of food items will be added to their daily menu, along with hand feeding in a dish to encourage self-feeding. The diet will be supplemented with Korvimin ZVT+Reptile by WDT (Nutrobal for Birds by Vetark) to prevent calcium deficiency. Alternatively, thoroughly cleaned empty snail shells can be ground and used as a cheap, natural, and easily digestible calcium supplement. The basic diet plan for all corvid species consists of:
- Soaked cat biscuits (GoCat Chicken and Duck Complete pet food for adult cats (Purina))
- Minced beef
- Vegetables (fresh corn or maize, corn on the cob, or peas)
- Fruits (berries, grapes, apple, or pear)
- Scottish Rough Oatcakes
- High-quality bird seed mix enriched with peanuts, suet pellets, and dried mealworms
- Live mealworms (larval form of the mealworm beetle – tenebrio molitor) and wax worms (larval form of the wax moth – galleria mellonella)
- Dead or frozen fresh insects such as crickets, calci-worms (larval form of the black soldier fly – hermetia illucens), or natural pinkies (larval forms of bottle flies)
- Hazelnuts or walnuts for jays
- Occasional food items, particularly for crows, include dead mice, day-old chicks, raw pigeon eggs, and cuttlefish bone
Worms and snails should not be fed to corvids, despite being part of their natural diet, as they can carry coccidia and worms. While birds are encouraged to feed themselves, assisted hand feeding needs to continue until they are completely weaned. Fledglings should also be moved to a suitable and spacious aviary where they can learn to forage and store food.