Chimney Swifts are small, cigar-shaped birds that live predominantly in chimneys during the breeding season. They are aerial insectivores, meaning they catch and eat insects while in flight. Chimney Swifts migrate long distances, spending winters in South America after breeding in North America during the summer. Their diet consists almost exclusively of flying insects, which they scoop up into their large mouths while flying. Knowing what to feed Chimney Swifts requires understanding their natural diet and nutritional needs.
The Natural Diet of Chimney Swifts
In the wild, Chimney Swifts eat a variety of flying insects that they catch while flying. Their preferred foods include:
- Flies
- Moths
- Beetles
- Ants
- Wasps
- Bees
- Mayflies
- Caddisflies
- Dragonflies
- Damselflies
They occasionally also eat spiders that get caught in their webs aloft. Chimney Swifts have wide mouths that allow them to scoop up insects while flying rapidly through the air. Their saliva is sticky, helping them cling onto fast-moving prey.
While flying, Chimney Swifts will catch hundreds of insects each day, consuming up to 1/3 of their body weight daily. They need this high-protein diet to support their rapid metabolism and high activity levels. In terms of volume, it is estimated that an adult Chimney Swift eats around 14 grams of insects per day. This provides them with enough calories and key nutrients like protein, fat, vitamins and minerals.
Key Nutrients Needed in Chimney Swift Diets
To stay healthy, Chimney Swifts need a diet that provides:
- Protein – insects provide high quality, complete proteins needed for growth and repair of muscles and tissues
- Fat – insects provide fat and fatty acids for energy and vitamin absorption
- Calcium – needed for bone health and egg shell formation
- Sodium & potassium – electrolytes needed for nerve function, fluid balance and muscle contraction
- Vitamin A – supports vision, immune function, growth and epithelial tissue integrity
- B vitamins – essential for metabolism, red blood cell production and neurological function
When feeding Chimney Swifts in captivity, it is important to try and replicate their natural diet as closely as possible to provide complete and balanced nutrition.
Complete Insect-based Diets for Pet Chimney Swifts
For pet Chimney Swifts or those in rehabilitation, complete diets that contain a mix of insects can meet their nutritional requirements:
Mealworms
Mealworms are a suitable staple insect to use in Chimney Swift diets. They are high in protein and contain a balanced amino acid profile. Mealworms also contain beneficial fatty acids and are a good source of vitamin A and B vitamins like riboflavin, pantothenic acid and biotin.
However, mealworms are low in calcium so this needs to be supplemented in the diet through gutloading, dusting or adding a calcium supplement. Mealworms also have a hard exoskeleton, so they may need to be crushed for young swifts.
Crickets
Crickets are another excellent insect to use as a dietary staple for Chimney Swifts. They have a soft body so are easier for young birds to digest. Crickets contain 53% protein and are high in calcium, phosphorus and B vitamins.
For optimal nutrition, crickets should also be gutloaded before feeding by providing them a high calcium, nutritious diet for 24-48 hours. This further enhances their nutritional value for the birds consuming them. Dusting crickets with supplements is also recommended.
Fly Larvae
The larvae of various flies are soft-bodied and packed with nutrition. They have higher fat content than mealworms or crickets, providing more concentrated energy. Fly larvae such as maggots and gentles are readily accepted by most insect-eating birds. Calcium and vitamin D3 dusting is recommended when feeding fly larvae to balance out their phosphorus levels.
Mixed Insect Diets
The best approach is to provide a varied mix of insect prey items. Mealworms, crickets, fly larvae, small cockroaches, locusts, grasshoppers, silkworms and others can be mixed together. Variety ensures a more complete nutritional profile. Gutloading all the insects before feeding maximizes their nutritional value. Providing free access to a calcium supplement also helps balance the diet.
Meeting Full Nutritional Needs
In captivity, the diet of Chimney Swifts should be supplemented to more precisely meet all their nutritional requirements:
- Calcium – dust insects with calcium carbonate or feed cooked, crushed eggshells
- Vitamin D3 – needed to metabolize calcium, use D3 supplement
- Multivitamin – use avian multivitamin 2-3 times per week
- Grit – supports digestion, provide fine gravel grit
- Water – always provide clean drinking water
Following an insect-based diet supplemented with vitamins, minerals and grit will help ensure captive Chimney Swifts thrive and remain healthy. Consulting an avian veterinarian for diet recommendations is also advised.
How Much and How Often to Feed Chimney Swifts
In the wild, Chimney Swifts are constantly active during daylight hours hunting for food. For pet swifts, aim to mimic their natural feeding habits:
- Feed insects 2-3 times per day
- Provide 15-20 small insects per feeding for adults
- Young swifts may need to be fed more frequently with smaller portions
- Weigh bird weekly and adjust diet to maintain ideal body condition
- Remove uneaten insects within 1-2 hours
The amount of food needed will depend on the bird’s age, size and activity level. Weighing the birds and monitoring their body condition will allow adjusting amounts accordingly. Chimney Swifts maintained on an all insect diet tend to self-regulate well when provided frequent, smaller feedings.
Proper Insect Storage and Preparation
It’s important to take steps when storing and preparing insects to keep them nutritious and safe for Chimney Swifts:
- House insects in escape-proof containers at 60-80°F
- Provide insect feed and hydration to keep them nutritious
- Gutload insects on high calcium diet for 24-48 hours before feeding
- Avoid feeding insects that are too large for the swift to swallow
- Lightly dust insects with vitamin/mineral supplements as needed
- Discard any dead insects
- Wash hands after handling
Properly maintained live insects will stay nutritious food items for swifts when fed out within 1-2 weeks after receipt. Storing them appropriately prevents any safety issues.
Common Diet-Related Health Issues in Chimney Swifts
The main diet-related health problems seen in captive Chimney Swifts include:
- Metabolic bone disease – caused by calcium, vitamin D3 deficiency
- Nutritional secondary hyperparathyroidism – lack of calcium, vitamin D3
- Egg binding – can be caused by calcium deficiency
- Obesity – from feeding too many high-fat insects
- Malnutrition – due to imbalanced diet or feeding issues
- Gout – often from excess animal protein in the diet
Ensuring the diet contains adequate calcium, vitamins and is balanced in protein, fat, and carbohydrates is key to avoiding these issues. Consulting an avian vet about any diet-related concerns is recommended.
Transitioning Chimney Swifts to a New Diet
When switching a Chimney Swift to a new diet, go slowly over 2-3 weeks:
- Gradually mix in increasing amounts of the new food
- Avoid sudden 100% diet changes whenever possible
- Monitor the droppings – adjust if becomes too loose or changes color
- Watch the bird’s weight and behavior for signs of issues
- Consult a vet if the bird stops eating or shows signs of illness
Patience and incremental changes will help the swift’s digestive system adjust to new foods preventing upset. Be willing to pause or go back steps if the bird shows signs of not tolerating a change. The transition may take longer with more delicate birds.
Conclusion
Chimney Swifts are aerial insectivores requiring a species-appropriate high protein, insectivorous diet. In captivity, provide a varied mix of insects like mealworms, crickets and fly larvae. Gutload and supplement insects to meet the bird’s full nutritional needs. Feed smaller portions multiple times daily. Store and prepare insects properly to keep them safe and nutritious food items. Monitor the bird’s weight, behavior and droppings. Work slowly when transitioning diets. Consulting an avian vet helps ensure optimal nutrition to keep captive Chimney Swifts healthy and thriving.