Why Study Birds?

I have always been entertained listening to family and friends try to explain what I do. I commonly hear, "She studies birds."

It's not untrue, I do study birds. I'm also kind of a huge bird nerd. But there are actually many reasons why so many researchers use birds as model systems. Birds really aren't so different from people. Many species are awake during the day (though of course there are also the night owls!), they're abundant, social, and we can study them in their natural habitat. Around 92% of species form social pair bonds (think of it as a relationship - in some species it's short term while others mate for life) and in 85% of species both parents provide care for young (a relatively rare phenomenon in the animal kingdom). We even see that offspring are not always a genetic match to the social father (i.e., some birds cheat on their social partner). Below, I've mentioned just a few of the many ways we can study birds to learn more about ourselves.

Personality

There are TONS of online personality tests where you fill out a survey about yourself and the internet tells you your 'personality type' (I'm an ISTJ on the Meyers-Briggs scale, in case you were wondering). There are fascinating studies in human psychology that research how personality types relate to other things. For example, researchers have found relationships between personality (being introverted or extroverted) and number of lifetime sexual partners, marital satisfaction, and likelihood of hospitalization. However, when you do a survey like this, you're often being asked to describe yourself. There can be differences in self-perception of behavior (how you see yourself) and how others see you. You would also be described differently by close friends, people who dislike you, and new acquaintances. If we want to remove any influence of self-perception or biased perception by others, we can study birds. Birds have measurable personalities, just like people. For example, some individuals are shy and others are bold. Individuals of the same species can be very aggressive, while others are not. We can use birds to study how personality will influence responses in different situations, without the influence of self-perception.

Maternal and Parental Effects

When we want to understand the argument for nature (genetics) versus nurture (experiences during development), or how much nature and nurture contribute to traits of interest, birds are an incredible study system! Females lay eggs, so it's easy to do what's called a cross-fostering experiment. Once a female lays her eggs, they can be swapped with another female's eggs. Each female and her social mate continue to care for the eggs and young as if they were their own. It allows researchers to separate the influence of genetics and the environment experienced during development on varying characteristics. As one example, we can study how the number of siblings effects adult physiology (hormone levels and response to stress), morphology (size, growth, and development), and behavior. Additionally, studying birds is a great way to understand how maternal hormones experienced by offspring provide cues about the environment (for example, food availability) during development. We can measure and even change hormone exposure in the egg without the added influence of maternal hormones that would be experienced in utero by mammals. Using birds, we can learn how receiving these cues influence rate of development and behavior.

Urbanization

We inhabit an increasingly urbanized world. Urbanization has exposed us to things like light pollution, which can have detrimental impacts on human health. For example, light at night in city-dwelling humans has led to an increase in asthma, cancer, and other health issues. Birds have also adapted to this city-dwelling lifestyle. Different populations live and breed along a gradient of urbanization, from right in the heart of large cities, to small towns, to completely rural, uninhabited areas. This provides an excellent way to study the impacts of urbanization by directly comparing populations of the same species living in urban areas to those living in rural areas. For example, city-dwelling birds have an attenuated stress response compared to rural-dwelling counterparts, which means that they produce a lower quantity of stress-related hormones during a stressful encounter. They also behave differently in stressful situations. Birds are a great model system to study the effects of urbanization.