Renowned ornithologist Richard Prum delves into the fascinating world of avian biology, exploring topics from the evolution of flight to the aesthetics of birds.
His unique insights, drawn from a lifetime of studying birds, offer a fresh perspective on these creatures and their behavior.
Controversy in Flight Evolution
The intermediate steps towards the evolution of flight in birds are a subject of controversy.
One plausible explanation suggests that flight evolved from gliding, like a flying squirrel, and then controlling gliding movements to create flight.
Evolution of Flight
The evolution of flight in birds is explained by two main theories: the ground-up cursorial theory and the arboreal theory.
The former suggests that birds evolved from running to flying, while the latter proposes that birds evolved from gliding to powered flight.
The current consensus leans towards the arboreal theory.
Beauty in Nature
Beauty in nature is not arbitrary, but rather a result of evolutionary processes and the need for species to reproduce.
This perspective challenges common beliefs about sexual attraction and aesthetics in nature.
Unique Evolutionary Developments in Birds
The lack of a penis in most birds has led to unique evolutionary developments.
This biological difference means that female birds have more freedom of choice in selecting mates, which has led to the evolution of more beautiful birds as males must appeal to female choice to reproduce.
Delayed Maturation in Birds
Birds, particularly albatrosses, don’t breed until they’re around 10 to 20 years old.
This delay could be due to the need for these birds to become efficient at foraging before they can raise offspring.
Cooperative Breeding in Birds
Cooperative breeding, where multiple birds of reproductive age live together and raise offspring, is a common phenomenon in Australian birds.
This social system is likely a response to the unpredictable rainfall and habitat variability in Australia, which makes resource availability uncertain.
Bird Duetting
Duetting, where bird pairs sing together, occurs in about 16% of bird species.
Often associated with social complexity, duetting is prevalent in tropical birds where pairs endure for the whole year and remain resident on a territory.
However, the distribution of duetting is largely historical and concentrated in a few groups, such as songbirds.
Role of Historical Explanation in Biology
Historical explanation plays a crucial role in understanding biological phenomena.
For instance, a significant proportion of the universe of duetting in birds can be explained by historical persistence and path dependence.
Songbirds originated in Australia and persisted there for a long time, leading to a lot of lineages with female song and duetting.
Multiple Equilibria in Ornithology
Multiple equilibria exist in ornithology, similar to economics.
This isn’t a problem, but rather a reflection of the diversity in nature.
Communication isn’t always about the efficient exchange of information, but can also be about persuasion.
Cooperative breeding, this special variation in the avian family life where you get a cooperative behavior among reproductive age individuals with unpredictable rainfall… rainfall is unpredictable… and also the other combination is the habitat is saturated right so there aren’t a lot of places to go. – Richard Prum
The most fundamental factor is that most birds don’t have a penis… that’s where we start. Most birds don’t have a penis which means that one of the things that happens in avian evolution… is that the kids require a lot of care but they also have to… they’re growing up in the nest. – Richard Prum
Aesthetics of Birds
Humans find birds beautiful due to our intelligence, curiosity, and excess cognition.
The mystery of why humans find certain natural phenomena, such as the smell of flowers, beautiful, is a topic that requires further research.
Avian Evolutionary Theory and Flower Pollination
Avian evolutionary theory can learn from how flowers attract pollinators.
Flowers need to be ‘memorably rewarding’ to attract pollinators, which is similar to how male birds need to be attractive to female birds to reproduce.
This comparison highlights the role of advertising in nature.
Sexual Dimorphism in Birds
The most fundamental factor in sexual dimorphism in birds compared to mammals is that most birds don’t have a penis.
This biological difference leads to distinct evolutionary paths for birds and mammals.
In avian evolution, offspring require a lot of care and are very vulnerable until they can fly, necessitating the involvement of both parents in most cases.
