At the Project:
During the next three months you'll have the opportunity to witness a great many
songbird behaviors, as performed by our representative songbird, the Tree Swallow.
Watching and trying to decipher the meaning of swallow nesting season behavior is
one of the most challenging yet fun things you can do at your project. You're going to
see Tree Swallows behaving in groups and as individuals, behaving as males and as
females, and behaving as parents, dependent young, and independent juveniles.
You're going to witness behaviors of self-maintenance and preservation, and you'll
also witness many of the complex behaviors the swallows perform in order to fulfill the
most vital function of their lives, the passing on of their genes to descendants. Since
you'll probably want to try to understand some of these behaviors it's worth taking a
few minutes now to consider some aspects of songbird behavior.
But first a word of advice: please be patient! You will become confused and perhaps
even bewildered by what you see and hear at times, but don't give up. If you persist
you'll start to notice regularities in your birds' behaviors. Gradually, coherent patterns
and themes will emerge and, although there will still be some gaps, you'll begin to
develop a real sense of the whats and whys of your swallows' actions.
Many of the behaviors you're going to see are reactions to things.
An event or situation in a bird's environment triggers a chain of reactions within it, and
specific cues cause the bird to react in specific ways.
- A bird's sense organs, usually its eyes or ears, perceive something of
significance to the bird.
- A signal is passed from the sense organs along nerves to the bird's brain.
- The brain initiates a responding signal that travels back out along nerves to
specific muscles, causing them to perform a particular action.
- These sequences are automatic. A bird doesn't have to stop and think about
what to do. It doesn't need to use foresight, to plan, or to reason because it has
a set of genetically-programmed responses that fire instinctively.
- These reactive behaviors will be performed mechanically whenever their
particular activating stimuli are strong enough when the bird notices them. The
male swallow in the picture above responded automatically to the sight of a
cavity hole, even though the cavity was lying on the ground.
- Every member of a songbird species possesses a set of that species' instinctive
behaviors, which allow it to follow the species' way of life. A bluebird has the
bluebird set, a cardinal has the cardinal set, etc.
- However, it's wrong to think of songbirds as completely rigid robots. Birds face
constantly changing circumstances and must make many choices each day.
They must have at least a small level of flexibility in their responses.
Aren't songbirds capable of learning?
- Learning is a process which an individual animal can use to change its
behavior. It's especially valuable when the animal must adapt to rapid changes
in its circumstances or in its environment.
- For instance, a bird must learn where food is located, or learn to distinguish its
mate from among many other individuals.
- Learning can also refine the details of instinctive behaviors, making the instincts
- But remember that songbird lives are short. There isn't much time for learning,
and most responses to things must be immediate, so their ability to survival and
reproduce relies primarily on instinctive behaviors.
- However, more than 40 years of watching Tree Swallows has shown us that they
most certainly are capable of learning from experiences.
As you watch your swallows try to determine the parts of their behaviors. Ask
yourself, what is the behavior's:
- Stimulus: The specific cue in the bird's environment that caused it to react.
- Response: The particular automatic behavioral reaction that was activated or
released after the bird perceived the stimulus.
- Result: How the situation was changed, if at all, for the bird or its surroundings
after the response was performed. Has the behavior helped the swallow
maintain itself in some way or helped it reproduce?
We can observe much of the "what" of a behavior, the physical motions or
actions. However, we can only make educated guesses about the "why," the
reason a behavior was performed.
- Some behaviors will appear clear-cut, with seemingly obvious chains of stimulus,
response, and result.
- Others will be more puzzling, but don't give up trying to figure what's going on.
Perhaps you simply need to see more repetitions of the behavior before you get
an "eureka moment."
- With some behaviors the "why" may stay shrouded in mystery. For instance, we
don't believe Tree Swallow "flutter flight" (you'll see it) has been satisfactorily
explained by the experts, yet.
- We have to accept that birds perceive the world differently than we do. Their
needs, abilities, and limitations are different from ours. We may not be able to
detect what stimuli they are reacting to, and some reactions are so subtle we
aren't even aware behavior is occurring.
- We also must avoid being "anthropomorphic," which means interpreting an
animal's behavior in terms of human emotions and motives. Tree Swallows
aren't being "playful," "angry," "loving," "mean," etc. Whatever they do is done
in the context of swallow survival and reproduction, not human.
It may help to distinguish between Maintenance Behaviors and Social
- Maintenance behaviors, such as foraging, preening, and reacting to potential
danger or inclement weather, are performed by individual birds to care for their
own bodies and avoid injury or death.
- Social behaviors, such as those involved in courtship, territoriality, raising
young, and flocking involve interactions among birds. Social behaviors use
sounds, postures and movements as signals to convey specific "messages" that
affect the behavior of others. Social signals of birds are not the same as human
spoken language. They are more like our "body language," which we produce
unconsciously all the time and which is probably a truer indicator of our feelings
and motives than our speech.
One can also distinguish between Immediate Causes and Ultimate Causes of
- Immediate Causes, (also called Proximate causes), are those stimuli in an
individual bird's present environment that release a given behavior.
- Ultimate Causes are the reasons found in a species' long-term history why
particular behaviors have become part of the genetically-fixed response
patterns possessed by every member of the species.
As the nesting season progresses through its series of stages you should
notice major shifts in behaviors.
- Nesting season behaviors are often due to changes in a bird's "internal state."
Shifts in hormone levels during the stages of breeding can affect which stimuli a
bird notices or seeks out, and what behavioral response will be triggered.
- Some behaviors will be seen throughout the nesting season, but become more
or less frequent over time.
- Others are linked to particular nesting stages, and are seldom or never seen at
Be aware that while each songbird species has a set of typical behaviors, the
performance of the behaviors can vary considerably among individuals within
- You're lucky. Your Tree Swallow project, with several pairs nesting relatively
near each other, allows you to compare individual behavior more easily than
you could with most other songbird species.
- Expect to see variation in when, how long, how often, and how vigorously
different birds execute particular behaviors.
- The more you watch the more you'll discover your swallows truly are unique
Also be aware that males and females may behave differently.
- The sexes' different roles in reproduction demand a somewhat different set of
- Males and females may have different "agendas" or "motivations," instinctive of
course, not involving conscious planning or forethought, that can even be in
conflict with those of their nesting partner at times.
- The sexes may respond in different ways or degrees to the same stimulus.
- You may learn to distinguish the sex of some adult songbirds by their behavior
- And, of course nestlings and juveniles like the ones below have their own sets of
All this may seen mind-boggling at first, but don't let that discourage you from getting
out there and watching your swallows. Remember, much of what you'll gain from the
"Nesting Guide" depends on the amount of time and effort you spend in the field
observing swallow behavior and all the other things that are going on.
Question for the next topic: Song and Calls.
- What is the purpose of the various sounds birds make?
Learn About Birds at Tree Swallow Nest Box Projects
|Nesting Guide, Spring Return, Songbird Behavior, Song and Calls, Nest Site Competition,
Pairing Up, Nest Building, Bird Flight, Mating, Eggs and Egg Laying, Incubation,
Takeovers, Feather Care, Hatching, Nestling Care, Sexing and Aging,
Nestling Growth, Mortality, Older Nestlings, Fledging, Ectoparasites, Juveniles,
Flocks, Migration, Molt, and Winter, Box Care and Project Assessment