On the Evolution of Flightless Birds

A new analysis does not
help evolutionists explain
permanently grounded birds

 

Flightless Bird Evolution
Theorists Forced to Accept an Unlikely Tale

by Jerry Bergman, PhD

Many claimed examples exist of evolution, not by the gain of a function or a structure, but by a postulated evolution due to the loss of a structure or function. One of the best examples of this is the theory that flightless birds evolved from flying birds. By flightless birds, we are referring to those that are completely unable to fly, not those that still retain the ability to achieve some flight.

The most common examples of this “evolution by loss” of flight are ostriches, emus, rheas, cassowaries, and the small kiwis of New Zealand. Evoutionists claim that each of these birds, called ratites, evolved from flying birds with well-developed wings. One reason for the notion that they used to fly is that other potential evolutionary possibilities are even less probable. The main reason for claiming that flightless birds evolved from flying birds is the observation that they are “found on many different continents – South America, Africa, Australia, and New Zealand” and that this finding “has been difficult for scientists to explain.”[1] Since flightlessness followed the breakup of the supercontinent Pangaea, the non-flyers must have lost their ability to fly independently on each continent where they are found today.

One assumption embedded in the evolutionary story is that the flightless birds in South America, Africa, Australia, and New Zealand today originated from flying ancestors. They must have devolved into flightless birds on each continent after arriving there. This implies that flightlessness must have devolved many times, obviously a major problem for evolution. Nonetheless, it is the accepted explanation, according to Clara Widrig, who wrote in The Conversation (29 Sept 2025) that this explanation is “a remarkable case of parallel evolution.” She writes:

Ostriches, rheas, emus, cassowaries, and kiwis did not share a flightless common ancestor. Instead, in a remarkable case of parallel evolution, they all became flightless separately from each other.”[2]

Evolutionary Pressures to Devolve

Speculations used to support the story are many. Here’s one: if a bird can obtain all of its food on the ground, and also does not need to fly to escape predators because none exist in this area, “it will probably evolve towards being flightless,” Widrig says.[3] Adaptation to small environmental niches is well known. When some birds colonize islands, their body shape or other traits may change. For example, small-island bird populations tend to have smaller flight muscles and longer legs compared to birds living on the mainland.[4] But does this idea explain the many radical changes required to turn a flyer into a well-adapted running bird like the ostrich?

A minor example of this change is explained, using evolutionary terms, as follows: “Island bird species have evolved smaller flight muscles than their continental relatives.”[5] Actually, the amount of change is similar to that which occurred with the peppered moth: a change in the ratio of two varieties of the same species.[6] In this bird case, only the ratio of larger muscles to smaller muscles has changed. One would expect, in a different environment with predators and less food on the ground, the ratio could change back to what originally existed before the birds colonized the island. Nothing evolved; only the population of larger to smaller muscles has changed. Selection would favor shorter wings and longer legs to facilitate traveling on the ground. Such small changes are termed microevolution, which is not controversial. Creationists would explain this as a change in the population density of a Genesis kind.

Flight Offers Many Advantages; Why Would a Bird Devolve It?

Flying birds can adapt to a wide variety of environments. Taking to the air is an excellent way for birds to escape many ground-based and climbing predators. Flight allows birds to travel rapidly over large areas to find and exploit food sources and locate prey. Many bird species migrate thousands of miles to take advantage of seasonal food availability and optimal breeding grounds. This strategy increases their ability to survive harsh winters and provides abundant resources for raising young.

Flight also gives birds access to secluded elevated nesting locations, such as high cliffs or tree branches that are inaccessible to many other animals including their predators. Flight provides the most intense and effective aerobic exercise for a bird, leading to strong muscles and greater stamina. The mental stimulation of processing visual information at high speeds also helps improve vision and spatial awareness.

Evolutionists should expect these many advantages to support their story that “selection pressure” led to the emergence of flight from flightlessness, not the other way around. Flightlessness, which would result in losing all of these advantages, should be unexpected. Why would permanent flightlessness ever evolve? And why would it happen multiple times independently? Whatever they claim, Darwinians cannot use the loss of traits to build a picture of progress from molecules to man.

Proposing an Extinct Bird as Ancestor

Widrig and colleagues looked at the bones of an ancient extinct bird for clues. Using scanning and geometric morphometric analysis of the sternum of this fossil, they speculated that the “ancestors of ostriches and emus were long-distance fliers.” Since all the descendants are distant from each other, they proposed that the putative evolutionary distant ancestors of ostriches and other large flightless birds once flew great distances.

The report stated that the claimed ancestor of most flightless birds, the “Lithornithids,” are

an assemblage of Palaeogene fossil birds thought to represent stem-group [i.e., ancestral, less-evolved] members of Palaeognathae…. the phylogenetic interrelationships and geographic distributions of palaeognaths imply that their early relatives were capable of long-distance dispersal… palaeognaths, the sister group to all other extant birds, have been the subject of much debate.[7]

Note the qualifying terms “thought,” “imply,” and “have been the subject of much debate.” What Widrig et al., actually found was that this extinct bird family, the Lithornithids (judging by details of its sternum), were excellent flyers. This would seem to argue against loss of flight, not favor it.

The uncertainty in the paper contrasts with the bravado in the article in The Conversation that boasts: “In our new study of a 56-million-year-old fossil bird, my colleagues and I show that the distant ancestors of ostriches and other large flightless birds once flew great distances.”[8] All they found was evidence that an ancient extinct bird family were excellent flyers, not that they spread to different continents. Furthermore, this determination only speaks to the loss of flight; it does not begin to explain the unique adaptations of flightless birds like ostriches, emus, cassowaries and kiwis.

In the chapter about kiwi birds in my book Wonderful and Bizarre Life Forms in Creation, I show that this “peculiar creature” has baffled evolutionists. The smallest member of the Ratites (Paleognathae), the kiwi lays the largest egg of any bird relative to its body size. Its wings are not vestigial, but aid the kiwi in running rapidly through the brush. Its shaggy feathers provide excellent insulation. At the tip of its long, thin beak are its nostrils, giving the kiwi an excellent sense of smell. These adaptive traits, and the fact that no fossils show a connection to other ratites, argue against the notion that the kiwi evolved from a Lithornithid long-distance flyer. Similar arguments could be given about ostriches, emus, cassowaries, moas, and other ratites, each exhibiting unique and successful traits.

Summary

This look at evolutionary stories about the origin of flightless birds illustrates that claims in popular venues are often misleading. What Widrig et al., found was, compared to the scholarly, peer-reviewed journal from which the articles were taken, evidence that an extinct bird, which was postulated to be the basal animal to some kinds of flightless birds, was an excellent flyer. Aside from disuse effects, evolutionists have failed to present fossil evidence or Darwinian explanations for the successful adaptations of flightless birds. Nor have they been able to explain the process, and the evolutionary advantages of, the devolution of flying birds into well-adapted birds that are permanently flightless, other than to speculate about “selective pressures” leading to what we see today.

See also:

• Bird Evolution Wrong for 155 Years (1 Dec 2022)
• Birds Surprise Evolutionists (17 Sept 2014)
• How Big Bird Evolved into Little Kiwi (24 May 2014)

References

[1] Widrig, Klara, “The ancestors of ostriches and emus were long-distance fliers – here’s how we worked this out,” The Conversation, https://theconversation.com/the-ancestors-of-ostriches-and-emus-were-long-distance-fliers-heres-how-we-worked-this-out-266081, 29 September 2025.

[2] Widrig, 2025. Italics added.

[3] Widrig, 2025.

[4] Wright, Natalie, et al., “Predictable evolution toward flightlessness in volant island birds,” PNAS 113(17):4765-4770, 11 April 2016.

[5] Wright, et al., 2016.

[6] Hooper, Judith, Of Moths and Men: An Evolutionary Tale: The Untold Story of Science and the Peppered Moth, W.W. Norton & Co., New York, NY, 17 January 2004.

[7] Widrig, 2025. Emphasis added.

[8] Widrig, 2025.

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Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,900 publications in 14 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.