Rails, also known as the Virginia rail or Rallus limicola, are a small marsh bird found primarily in North America. They are omnivorous birds that feed on a variety of small prey, including insects, snails, spiders and even small fish. So the short answer is yes, rails do eat fish on occasion.
Quick Answers
Here are some quick answers to common questions about rails eating fish:
- Do rails actively hunt for fish? No, rails are opportunistic feeders and will eat small fish if they come across them, but they do not actively pursue fish.
- What kind of fish do rails eat? Rails will eat small fish that live in marshes and wetlands, like minnows, killifish and sticklebacks.
- How often do rails eat fish? Fish make up a very small part of a rail’s diet. They eat fish opportunistically, but insects and other invertebrates make up the bulk of their food.
- Are rails able to catch larger fish? No, rails only eat small fish that they can easily swallow whole. They do not have the size or hunting abilities to catch larger fish.
- Do rails hunt fish in groups? No, rails are solitary feeders and do not coordinate to hunt fish in groups or flocks.
Rail Diet and Feeding
Rails are omnivorous wetland birds that feed on a variety of small prey. Here is an overview of the rail diet:
- Insects: Crickets, grasshoppers, beetles, flies, caddisflies, dragonflies, moths
- Worms: Earthworms, insect larvae, leeches
- Crustaceans: Snails, shrimp, crayfish, crabs
- Spiders
- Small fish
- Frogs and tadpoles
- Reptiles and amphibians: Salamanders, newts, small snakes and lizards
- Seeds
- Aquatic vegetation
- Grains and berries
Insects and other invertebrates make up the majority of a rail’s diet. Fish are eaten opportunistically in small quantities. Rails forage for food while walking through densely vegetated wetland areas. They use their slender bills to probe into mud and vegetation to find prey.
How Rails Catch and Eat Fish
Rails are not designed for actively hunting fish. However, they have been observed catching and eating small fish using the following methods:
- Opportunistic feeding on stranded fish – After flooding or high water levels, small fish may become stranded in pools or puddles as the water recedes. Rails will walk along the edges looking for stranded fish.
- Disturbing hiding fish – As rails walk through vegetated wetland areas, they may startle or disturb small fish hidden in the plants, exposing them for the rail to grab.
- Feeding on juvenile fish – Young fish and fry are vulnerable prey for rails patrolling the shallows and vegetation edges.
- Scavenging on dead or dying fish – Rails are omnivorous scavengers and will not pass up an opportunity for an easy meal from a dead or dying fish.
Rails are able to swallow small fish whole. They do not have the size or predatory abilities to pursue and capture fast-moving fish. They rely on stealth and their slender bills to capture any fish they come across while foraging in wetland vegetation.
Fish Species Eaten by Rails
Rails have been documented feeding on a variety of small fish species, generally less than 5 inches long. Some fish known to be prey for rails include:
- Minnows – fathead minnow, creek chub, common shiner
- Killifish – plainfin midshipman, rainwater killifish, striped killifish
- Sticklebacks – brook stickleback, fatstickleback
- Livebearers – mosquitofish, least killifish, molly
- Sunfish – bluespotted sunfish, banded sunfish
- Perch – dusky perch
- Sculpins – prickly sculpin
- Topminnows – plains topminnow, blackstripe topminnow
Most of these fish species are small, averaging 2-4 inches in length. They tend to live in heavily vegetated wetland habitats favored by rails. These small fish make easy prey for rails that come across them while foraging.
Benefits of Fish in Rails’ Diet
While a small part of their overall diet, fish can provide some nutritional benefits for rails:
- Protein – Fish are a good source of protein for rails. This supports growth and muscle development.
- Fatty acids – The oils in fish provide beneficial fatty acids that support rail metabolism and feather maintenance.
- Micronutrients – Fish can provide important micronutrients like iodine, selenium and vitamin D.
- Water – The bodies of fish are high in moisture content, helping rails meet their water needs.
In times or locations where other prey may be scarce, fish can serve as a nutritious supplementary food source for rails. Even in small amounts, fish can provide hard-to-find nutrients that help support rail health.
Limitations on Rails Eating Fish
While rails opportunistically eat fish, there are some limitations and challenges they face in catching and feeding on fish:
- Bill size – Their slender bills limit the size of fish rails can swallow.
- Swimming ability – Rails cannot swim or dive effectively, limiting their access to fish.
- Vegetation – Dense marsh vegetation makes it hard to pursue fast-moving fish.
- Competition – Better adapted predators like herons compete for the same fish food sources.
- Weather – Cold weather and frozen waterways eliminate feeding opportunities.
- Habitat loss – Draining and development of wetlands removes rail habitat and access to fish.
Rails’ modest size and limited adaptations for piscivory prevent them from being major fish predators. They take advantage of any small fish they encounter during their normal insect-foraging activities in freshwater marshes and wetlands.
Differences From Herons and Other Avian Piscivores
While rails occasionally eat small fish, they differ significantly from other marsh birds more adapted for catching fish like herons:
- Morphology – Herons have long legs and necks and spear-like bills perfect for striking at fish. Rails have short necks and slender bills ill-suited for fish hunting.
- Diet – Fish make up 80-90% of heron diets, while they are a very small fraction of a rail’s insect-focused diet.
- Hunting – Herons actively hunt fish by standing motionless in shallow water or stalking prey. Rails opportunistically grab any fish they chance upon on land.
- Size – Large herons can swallow fish up to 18 inches long, while rails eat fish less than 5 inches.
- Technique – Herons have specialized hunting techniques like bill jabs, wing overcasts and cooperative group feeding. Rails lack complex fish hunting behaviors.
While herons are highly adapted piscivores, rails only occasionally supplement their insectivorous diet with small fish they opportunistically encounter. They lack most of the morphological tools and hunting techniques of dedicated fish-eating birds.
Conclusion
In summary, rails are omnivorous marsh birds that feed primarily on insects, worms, plant material and other small prey. On occasion, they will take advantage of opportunities to feed on small fish around 2-4 inches in length. Rails use their slender bills to probe into vegetation to grab any exposed fish. However, they lack many adaptations for actively hunting fish, setting them apart from wading bird piscivores like herons. While rails eat some fish, it makes up a very small proportion of their diet compared to invertebrate prey. Their opportunistic fish feeding provides some beneficial nutrition but is limited by their modest size and lack of swimming adaptations.