Effects of Bands & Radio Transmitters
The use of bands and radio transmitters and their methods of application to wild birds is not a casual activity. Our agency strives to conduct sound, responsible research and make the results of that research available to managers and policy makers. Our use of bands and radio transmitters is monitored and permitted by the U.S. Geological Survey’s Bird Banding Laboratory and all personnel receive training in the proper use radios and bands. Some radio transmitters require a short surgery conducted by a wildlife veterinarian. For more information about surgical implants and the data they generate, see these links.
Because we use information from marked birds to make inferences about populations, we are concerned about the impacts that bands and radios might have on wild birds. Therefore, we periodically conduct studies to ensure that the markers we use have no harmful effects and that the information we obtain from marked birds is similar to that from unmarked individuals. Publications from of such studies are listed below. Click on the publication title for more information.
Ely, C.R. 1990. Effects of neck bands on the behavior of wintering greater
white-fronted geese. Journal of Field Ornithology 61:249-253.
D., D. M. Mulcahy, and R. L. Jarvis. 2000. Testing assumptions for
unbiased estimation of survival of radio-marked harlequin ducks. Journal
of Wildlife Management 64:591-598.
J. W., G. A. Ruhl, J. M. Pearce, D. M. Mulcahy, and M. A. Tomeo. 2003.
Effects of abdominally-implanted radio transmitters with percutaneous
antennas on behaviors of Canada Geese. Journal of Field Ornithology,
P. M., S. A. Hatch, and D. M. Mulcahy. 1998. Effect of implanted satellite
transmitters on the nesting behavior of murres. Condor 100: 172-174.
D. M., and D. Esler. 1999. Surgical and immediate post-release mortality
of harlequin ducks (Histrionicus histrionicus) implanted with
abdominal radio transmitters with percutaneous antennas. Journal of
Zoo and Wildlife Medicine 30:397-409.
F. M., D. Esler, and M. K. Stoskopf. 1999. Loss from harlequin ducks
of abdominally implanted radio transmitters equipped with percutaneous
antennas. Journal of Field Ornithology 70:244-250.
J. A. and J. A. Morse. 2000. Effects of neck collars and radio transmitters
on survival and reproduction of emperor geese. Journal of Wildlife
D. and P. L. Flint. 1995. Effects of harness-attached transmitters
on premigration and reproduction of Brant. Journal of Wildlife Management
Effects of neck bands on the behavior of wintering greater white-fronted geese.
Activity budgets of adult greater white-fronted geese (Anser albifrons frontalis) with and
without neck bands during the non-breeding season revealed that geese with neck
bands spent more time preening than geese without neck bands while at foraging
sites, but not while at roosting sites. Neck-banded and control geese spent
equal time in other important activities (alert, feeding, sleeping, locomotor
activities, flying, or social interactions) while at both foraging and roosting
sites. Neck-banded geese apparently compensated for the increase in preening
activity by reducing the amount fo time spent in alert postures relative to
control geese (23.9 vs. 28.6%), although the decrease was not significant (P
= 0.106). There was a significant negative relationship (P = 0.038)
between the length of time a goose had worn a neck band and the amount of time
spent preening while at roost sites. After a short acclimation period, neck
bands probably have minimal effect on the activity of wintering greater
Testing assumptions for unbiased estimation of survival of radio-marked harlequin ducks.
Unbiased estimates of survival based on individuals outfitted with radio
transmitters require meeting the assumptions that radios do not affect survival,
and animals for which the radio signal is lost have the same survival
probability as those for which fate is known. In most survival studies,
researchers have made these assumptions without testing their validity. We
tested these assumptions by comparing interannual recapture rates (and, by
inference, survival) between radioed and unradioed adult female harlequin ducks
(Histrionicus histrionicus) and, for radioed females, between
right-censored birds (i.e., those for which the radio signal was lost during the
telemetry monitoring period) and birds with known fates. We found that recapture
rates of birds equipped with implanted radio transmitters (21.6 + 3.0%; ? + SE)
were similar to unradioed birds (21.7 + 8.6%), suggesting that radios did not
affect survival. Recapture rates also were similar between right-censored (20.6
+ 5.1%) and known-fate individuals (22.1 + 3.8%), suggesting that missing birds
were not subject to differential mortality. We also determined that capture and
handling resulted in short-term loss of body mass for both radioed and unradioed
females and that this effect was more pronounced for radioed birds (the
difference between groups was 15.4 + 7.1 g). However, no difference existed in
body mass after recapture 1 year later. Our study suggests that implanted radios
are an unbiased method for estimating survival of harlequin ducks and likely
other species under similar circumstances.
Effects of abdominally-implanted radio transmitters with percutaneous antennas on behaviors of Canada Geese.
We examined whether
surgically-implanted radio transmitters with percutaneous antennas affected
behavior of Lesser Canada Geese (Branta canadensis parvipes) in Anchorage, Alaska.
We implanted either a 26 g VHF radio transmitter or a larger VHF radio that
was the same mass (35g) and shape as a satellite transmitter in the coelom of
adult females captured during molt (n = 36 females/ treatment) in 2000. A control
group of females was marked with leg bands. We simultaneously observed behaviors
of radiomarked and control females from 4—62 d following capture. We observed
no differences in the proportion of time birds in different treatments allocated
among grazing, resting, comfort, walking, and alert behaviors during 173 pairs
of 10—30 min observations from 18 July—15 September. Females in different treatments
spent similar proportions of time in water. Implantation of radio transmitters
did not affect frequency of agonistic interactions. We conclude that coelomic
radio transmitters with percutaneous antennas had minimal effects on behavior
of Canada Geese.
Effect of implanted satellite transmitters on the nesting behavior of murres.
We implanted 6 Common Murres (Uria aalge) and 10 Thick-billed Murres (Uria
lomvia) with satellite transmitters and compared subsequent presence at the
colony, nesting status, and provisioning to a control group that underwent a
simple surgical procedure. In the 10 days following implantation, we resighted
10 of 11 control birds at the colony and 6 of 16 implanted birds. Of the birds
that returned, 7 of 10 control birds retained breeding status, whereas zero of
six implanted birds retained breeding status. We conclude that abdominal
implantations alter murre nesting behavior.
Surgical and immediate post-release mortality of harlequin ducks (Histrionicus histrionicus) implanted with
abdominal radio transmitters with percutaneous antennas.
Radiotelemetry is an essential tool in the study of free-ranging bird
populations and a variety of transmitter attachment methods have been developed.
A promising new method is abdominal implantation of a transmitter with a
percutaneous antenna. Researchers using this technique should be concerned about
and aware of mortality during surgery and the immediate post-release period (the
14 d period following surgery). Of 307 radio implant surgeries done in 1995
through 1997 in Harlequin Ducks (Histrionicus histrionicus), we
documented 7 (2.3%) deaths during surgery and anesthetic recovery and 10 (3.3%)
deaths in the immediate post-release period. Modifications to anesthetic
procedures in the 204 surgeries done in 1996 and 1997 corresponded to reduced
mortality rates of 1.5% during surgery and 1.5% during the immediate
post-release period. Anesthetic modifications included: intubation of all birds,
placing birds on an elevated platform that allowed the bird’s head to rest at
a level lower than that of its body during surgery, use of a heated water
blanket under the birds during surgery, monitoring of body temperature, and use
of a heart monitor in addition to Doppler ultrasound to monitor heart rates and
arrhythmia. Low levels of mortality associated with abdominal implantation of
radio transmitters may be unavoidable, but can be minimized with adaptive
adjustments to anesthetic technique.
Loss from harlequin ducks of abdominally implanted radio transmitters equipped with percutaneous antennas.
We documented extrusion and loss of abdominally implanted radio transmitters
with percutaneous antennas from adult female Harlequin Ducks (Histrionicus
histrionicus). Birds were captured during wing molt (late August to
mid-September) in 1995-1997. Of 44 Harlequin Ducks implanted with radios and
recaptured, 7 (16%) had lost their transmitters and 5 (11%) had radios in the
process of extruding. Most (11 of 12) extrusions and losses occurred in birds
implanted with radios in 1996 and recaptured in 1997. We suggest that
transmitter extrusions and losses were due largely to changes in transmitter
design made between 1995 and 1996. Transmitters implanted in 1996 were
cylindrical rather than spherical, had a flat end with an abrupt edge, and the
lower portion of the antenna was reinforced. Radio losses occurred after the
7-mo monitoring period and caused no apparent harm to the birds. Investigators
using implanted radios with percutaneous antennas for long-term projects should
be aware of the potential for radio extrusion and should design minimize the
problem by using transmitters that have no sharp edges and that are wide, rather
Effects of neck collars and radio transmitters on survival and reproduction of emperor geese.
Neck collars have been used widely for studies of goose population biology.
Despite concerns about their negative impacts, few studies have employed designs
capable of clearly demonstrating these effects. During a 1993--98 study of
emperor geese (Chen canagica), we contrasted survival and reproduction of
geese marked with tarsal bands to those marked with either small neck collars,
large neck collars, or small neck collars with attached radio transmitters.
Annual survival of adult females marked with tarsal bands varied among years and
averaged 0.807 ± 0.140 (0 ± SE). Survival of geese with other types of markers
also varied among years but was lower (0.640 ± 0.198). Collars with radio
transmitters lowered breeding propensity, as indexed by resighting rates.
Although clutch sizes of tarsal banded birds were similar to those for unmarked
birds, other markers reduced clutch sizes by about 1 egg. Egg mass and hatch
date were not affected by marker type. Future studies of goose demographics
should seriously consider use of alternative markers.
Effects of harness-attached transmitters on premigration and reproduction of Brant.
Radio transmitters are
an important tool in waterfowl ecology studies, but little is known about their
effects on free-ranging geese. We attached transmitters to female brant (Branta
bernicla nigricans) to investigate migration schedules at a major fall
staging area, return rates to nesting grounds, and nesting rates of returning
females in subsequent breeding seasons. Radio-tagged females (n = 62)
carried either 35-g back-mounted transmitters attached with ribbon harnesses, or
26- or 32-g back-mounted transmitters affixed with plastic-coated wire harnesses
(Dwyer 1972). Arrival and departure schedules at Izembek Lagoon, Alaska, did not
differ (P > 0.05) between radio-tagged females and the entire
population in 1987-89. Color-banded females with transmitters returned to the
breeding colony in subsequent nesting seasons (1988-92) at a lower (P <
0.003) rate (<4%) than color-banded females without transmitters
(57-83%). The 1 returning color-banded female with a transmitter did not breed,
while an average 90% of the returning color-banded females without transmitters
nested in subsequent breeding seasons (P = 0.005). Four radio-tagged
females returned to the breeding colony without their transmitters and 3 of
these bred in subsequent breeding seasons. Back-mounted, harness-attached
transmitters may bias data in studies of waterfowl behavior, productivity, and