Songbird Behavior

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 witness many of
the complex behaviors the swallows perform in order to fulfill that most vital
function of their lives, passing on 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 features of songbird behavior.

Concepts:
Many of the behaviors you're going to see are reactions to things.  
Some event or thing in a bird's environment triggers a chain of reactions
within a bird, and specific cues cause the bird to react in specific ways.
  • A bird's sense organs, usually its eyes or ears, perceive something in
    the environment.
  • A signal is passed from the sense organs along nerves to its brain.
  • The brain initiates a responding signal that travels back out along
    nerves to specific muscles, causing them to perform a particular
    movement.
  • These chains of events are automatic.  The bird doesn't have to stop
    and think about what to do because it has a set of innate, genetically-
    fixed movements and sounds it uses instinctively.  These reactive
    behaviors will be performed mechanically whenever their particular
    activating stimuli are present in sufficient strength and are noticed by
    the bird.
  • The behavioral signal system of birds should not be considered the
    same as human spoken language.  It is 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.  












As you watch swallows behaving try to determine the:
  • 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 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
    linking stimulus to response to 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 the swallows' "flutter flight" (you'll see it)
    has been satisfactorily explained, even by the experts.
  • 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 need to avoid being "anthropomorphic", that is interpreting
    bird 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
Behaviors.  
  • Maintenance behaviors, such as foraging, preening, and reacting to
    potential danger or inclement weather, are performed by individual
    swallows 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 particular sounds, postures and movements that act as
    signals conveying specific messages meant to affect the behavior of
    others.   














One can also distinguish between Immediate Causes and Ultimate Causes of
behavior.
  • 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 of every member of the species.

You should note changes in how often certain behaviors are performed as
nesting progresses.
  • Some will be seen throughout the nesting season, but become more or
    less frequent over time.
  • Others are linked to particular nesting stages, and are seen rarely if at
    all at other times.

Be aware that while each songbird species has a set of typical behaviors, the
performance of the behaviors can vary considerably among individual within
the species.
  • You're lucky.  Your Tree Swallow project, with several pairs nesting
    relatively near each other, let's you compare individual behavior more
    easily than with most 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
    individuals.

Also be aware that males and females may behave differently.  
  • The sexes' different roles in reproduction demand a somewhat
    different set of reproductive behaviors.
  • Males and females may have different "agendas" or "motivations",
    instinctive of course, not conscious, that can even be in conflict with
    their nest mate 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 alone.
  • And, of course nestlings and juveniles have their own sets of age-
    specific behaviors.

All this may seen mind-boggling right now, but don't let that discourage you
from getting out there and watching your swallows.  And 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 sounds birds make?

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Learn About Birds at Tree Swallow Nest Box Projects