Somecolor-banding
techniques
for flockingbirds
Martha Hatch Balph
In studiesof avian behavior or ecology,it is
sometimesnecessaryto identifyindividualbirdsin
thefieldwithoutrecapturing
them.Coloredplastic
leg bandsoftenare usedfor thispurposeandcan
be highly effective.However, certain problems
may arise. For example,if large numbersof individualsmustbe color-banded,
it maybe difficult
to identify particularcolor combinations
quickly
andaccuratelyand to maintainrecordsefficiently.
Further difficultiesmay ensueif one mustobserve
qolor-banded
birds underpoorlightingconditions
or if the birds are able to remove their bands. All
of theseare problemsI have encounteredwhile
studyingthe socialbehaviorof severalspeciesof
winter-flockingfinches.This paper describessome
techniques
by whichI haveattemptedto reduceor
eliminatesuchproblems.Thesemethodsmay be
ßfamiliar to banders who have conducted studies
similar to mine. For any who plan to initiate such
studies,I hopethatmy comments
maybe of help.
sothatbirdsfluff theirfeathersandpartiallyconcealtheirbands,or if one'sviewof a birdishasty.
A secondadvantage
appliesparticularlyto studies
of speciesthatare capableof removingtheirown
bands.As Buckleyand Hancock(1968)have
pointedout,usingonlyonetypeof bandarrangement facilitates the detection of band loss. It also
preventspossibleconfusionof identities,e.g.
betweenthe birds in Figures1-A and 1-B if the
formershouldlosetheupperbandfromitsleftleg.
Finally, bandingboth legs permits rapid discrimination between unbanded and banded birds
in the field, even when only one leg is visible.
Alternatively,
if oneusessingle-leg
bandarrangements,andif onlyoneof a bird'slegsisvisibleand
thatleg hasno bands,muchtimemaybe wasted
waitingfor the bird to shift its positionto learn
whetherornotit isbandedat all.Theabilitytodistinguishquickly between unbandedand banded
birdsis particularlyusefulif one mustdetermine
manyindividualidentitiesin the spaceof a few
minutes or if one wishes to collect field data on
ratios of unmarked to marked birds to estimate
Band arrangements
The arrangementof bandson a bird's legscan
havean importantinfluenceuponthe speedand
accuracyof field identification.
I find it helpful,
first,t3useonlyonetypeof bandarrangement
consistently
for all individualsof a givenspecies.
For
example, if I have decided to use the four-band
arrangementshown in Figure l-A, I do not mark
anybirdswith a patternof twobandson theright
leg and oneon the left (Figurel-B) or viceversa.
Secondly,
I findit besttoplacebandsonbothlegs,
ratherthanon a singleleg (Figure1-C).
Thereare at leastthreeadvantages
in usingthese
techniques.
Thefirst,andperhapsthemostimportant,is that onecantherebydetermineimmediately whether or not all of a bird's bandshave been
noted.For example,if I invariablyuse two bands
on each leg but believe I have seenthe combina-
populationsize.
The band arrangementI have found mostsuccessful is a four-band combination with two bands on
eachleg -- theU.S.F.W.S.aluminumbandand one
coloredbandon oneleg and twocoloredbandson
the other leg (Figure l-A). This arrangement
permitsa relativelylargenumberof uniquecolor
combinations
(to be discussed);
yet at the same
time there are sufficientlyfew bandsper leg that
even specieswith short tarsi, such as Pine Siskins
(Carduelis pinus), generally can accommodate
them.To recordthe identityof a bird bandedin
this manner, I note the initials of the colors on the
bird'srightleg(upperfollowedby lower)andthen
do thesamefor thebird'sleft leg.! abbreviatethe
U.S.F.W.S. band as "X". Thus, the combination
shownin Figure1-A (aluminumupperright,blue
tion in Figure l-B, I know that this observation is
incorrect and that I must continue to search for an
recorded as "XBRY". I often find such com-
additionalband on the bird's left leg. Usinga
singletypeof bandarrangement
canbe especially
binationseasierto rememberif I mentallypronouncethe initialsas an acronymwhile making
valuable for avoidingerror if the weather is cold,
Page158
lowerright,red upperleft, yellowlowerleft) is
field observations.
North AmericanBird Bander
Vol. 4, No. 4
C
B
A
Figure1. Three different arrangementsof bands.
Band colors and color combinations
Table 1. Numberof uniquefour-bandcolorcombinations
in
rolation to number of availablo colors.
In addition to the type of band arrangement,the
particular colorsone usescan affect observational
speed and accuracy.It is important to use colors
that are both easyto detectand easyto distinguish
from
Number ef
colers'
one another in the field. This factor can
becomecritical if bands are small or if lighting
conditionsare poor,ason overcastdaysor early in
the morning.The colors! generallyprefer to use
are red, yellow, dark blue, light green, and (if
necessary]orange and/or purple (A.C. Hughes
Regd. bands]. Conversely,I sometimesfind it
difficult
to discriminate
between
The number of colors in use has a substantial effect
upon the number of unique color combinations
possible.If one U.S.F.W.S. aluminum band and
three coloredplasticbands are includedin each
combination,this relationshipis describedby the
equation:
p = 4n •,
whereP = totalnumberof uniquefour-bandcomn = number
of available
colorsexclusiveof aluminum (see Buckley and
Oct.-Dec.1979
2
32
3
108
4
256
5
500
6
7
1372
8
2048
864
'Not includingU.S.F.W.S.
aluminum
2Assuming
that oneU.S.F.W.S.
bandis includedin eachcombination.
such colors as
yellow and white, dark blue and dark green, or
lightblue and lightgreen.I havenot experienced
difficultyin identifyingadjacentbandsof the same
color,althoughthis elementis a problemin some
studies(seeDuncan1971).
binations and where
Numbor ef
combinatiens'
Hancock1968for a generalizedequationof the
relationshipand Duncan 1971for further refinements].As one adds to the set of permissible
colors,the numberof permutations
risessharply
(Table 1]. At the sametime, however,it becomes
increasinglydifficult to distinguishthe various
colorsquicklyandaccurately.
Thus,I findit helpful to estimatein advancetheprobablenumberof
birdstobe bandedandtouseonlyenoughcolorsto
guaranteethat number of unique combinations.
For example,I haveusedfour colorsfor Dark-eyed
Juncos(Juncohyemalis),which winter in relatively small, sedentary flocks, as compared to six
colorsfor EveningGrosbeaks(Hesperiphonavespertina), Cassins'sFinches(Carpodacuscassinii),
NorthAmericanBird Bander
Page159
and Pine Siskins,which occurin larger and less
stable flocks.
Record maintenance
In studiessuch as mine, where large numbersof
individual
birds must be color-banded and subse-
quently observedin the field, record-keepingcan
presenta challenge.For example,if one wishesto
locate a particular bird's color combinationin a
large file to documenta sightingor behavioral
observation,how is one to avoid searchingthrough
the entire file, particularlyif many bandedbirds
are observedeach day?
To increasethe efficiencyof recordmaintenance,I
mentallyencodeeachavailablecolorasa number
(U.S.F.W.S.aluminum= 0, red = 1, yellow = 2,
blue = 3, etc.1. I then use the variousuniquefourband color combinationsin numerical order. Thus,
the firstindividual that I band of a givenspeciesis
XRRR (= 0111),the secondis XRRY (=0112), and
so forth. Using color combinationsin a predetermined,systematicorder allowsone to locateparticular combinations
readily in a file or list. Moreover, this proceduremay reduce the likelihoodof
accidentallyusingthe samecolorcombinationfor
two different birds.
Band retention
As many banders are aware, birds of certain
speciesmay remove their own bands. Further
lossesmay occur from other causes.The colorbanding system I have described does prevent
error by allowing one to detect band loss as it
occurs. Nevertheless, if a bird loses a band, one is
obliged to spend time attemptingto recapture the
bird so as to determineits individualidentityand
replace the missingband.
Of the speciesI have studied,EveningGrosbeaks
and Cassin'sFinches sometimesmay partially
open or remove their bands {typicallya colored
Page160
plasticband),whereasPineSiskinsandDark-eyed
Juncosapparentlydo not. I have been able to
lessenthisproblemin the larger-billedspeciesby
closingthe endsof the U.S.F.W.S.band to meet as
exactlyaspossibleand by sealingthe split in splitring coloredbandswith acetone.Band lossin my
color-bandedbirds now averagesa few percent at
mosteach year.
Summary
This paperdescribessomeproceduresto facilitate
field observationsof individually color-banded
birds. Consistentlyusing a single type of band
arrangement {e.g. two bands per leg) reduces
observationalerror and simplifiesthe detectionof
band loss.Banding both of a bird's legs permits
rapid discrimination between unbanded and
banded
individuals.
Colors should be as con-
spicuousas possibleand readily distinguishable
from one another. The number of colors in use
shouldbe justlargeenoughtogeneratethedesired
numberof uniquecolorcombinations.
Usingcolor
combinations
in a systematicorder allowsone to
locateparticularcombinations
rapidlyin a file and
may decreasethe likelihoodof accidentallyusing
the same combinationtwice. Applying acetoneto
plasticcoloredbandsmayreducethe incidenceof
band lossin certainstrong-billedpasserines.
Literature
cited
Buckley,P.A., andJ.T.Hancock,Jr.1968.Equations
for estimatingand a simplecomputerprogram
for generatingunique color- and aluminum
band sequences.Bird-Banding39:123-129.
Duncan, K.W. 1971. A generalized computer
programin Fortran IV for listingall possible
colorband permutations.
Bird-Banding
42:279287.
Departmentof Wildlife Science,UMC 52, Utah
State University, Logan, UT 84322.
NorthAmericanBirdBander
Vol. 4, No. 4