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Spotted Tinamou in Argentina
Habitat Use and Survival of the Spotted Tinamou (Nothura
maculosa) in Agroecosystems in the Province of Buenos
Aires, Argentina
Jeffrey J. Thompson1,2, John P. Carroll
Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602-2152 USA
Changes in the composition and configuration of agricultural landscapes stemming from grassland conver-
sion and agricultural intensification have contributed to the global declines of many grassland and shrubland
birds. In both North America and Europe there exists a large body of research on the effects of agriculture
on populations of terrestrial gamebirds. However, little research exists for these species in Argentina or Latin
America in general. In Argentina the most important gamebird species is the spotted tinamou (Nothura mac-
ulosa). This species has become increasingly scarce in a significant portion of its range, possibly due to
agricultural intensification over the last 15 years. Using radio telemetry, we examined habitat use, movements,
and survival of spotted tinamous in 2 landscapes in the province of Buenos Aires, Argentina; one dominated
by annual row crops and the other used for annual crops and grazing. During winter, individuals used in order
of preference: fallow fields and areas with short herbaceous vegetation, followed by wetlands. Areas in winter
wheat and field edges were used least in relation to their availabilty. Although birds generally maintained small
home ranges, in some cases changes in cattle density and the structure of row crops caused birds to move
considerable distances. Survival mid-winter to early spring was more than double in the mixed landscape (ˆs
= 0.73, SE = 0.19) compared with the landscape dedicated to row crops (ˆs= 0.33, SE = 0.19). Considering how
research in other parts of the world has demonstrated the effects of agricultural intensification on terrestrial
gamebirds, these results are not unexpected and suggest a precarious future for the conservation of grassland
and agroecosystem species in Argentina in light of present agricultural trends.
Citation: Thompson JJ, Carroll JP. 2009. Habitat use and survival of the spotted tinamou (Nothura maculosa) in agroecosystems in the province of
Buenos Aires, Argentina. Pages 111 - 119 in Cederbaum SB, Faircloth BC, Terhune TM, Thompson JJ, Carroll JP, eds. Gamebird 2006: Quail VI and
Perdix XII. 31 May - 4 June 2006. Warnell School of Forestry and Natural Resources, Athens, GA, USA.
Key words: agricultural intensification, conservation, Nothura maculosa, spotted tinamou, survival
Introduction
Globally, populations of grassland and shrub-
land birds have been declining due to habitat
conversion and agricultural intensification (Ask-
ins 2000, Goriup 1988, Murphy 2003, Pain and
Pienkowski 1997, Vickery and Herkert 1995). In
agroecosystems of austral South America habitat
loss and the intensification in management have
been extensive and rapid, particularly in the pam-
pas of Argentina starting in the early 1990’s, typified
by the increased use of external inputs, increased
yields, and a shift towards agricultural production
for export markets (Ferreyra 2001, Ghersa et al. 2002,
Hall et al. 2001, Solbrig and Vera 2001, Viglizzo et al.
2001).
The spotted tinamou (Nothura maculosa) is a com-
mon bird of grasslands and agroecosystems in east-
ern austral South America, one of the most impor-
tant terrestrial gamebirds in the region, and formerly
common in agricultural systems (Bucher and Nores
1988, Bump and Bump 1969, Cabot 1992, Davies
2002, Menegheti 1985). In recent years, within the
pampas of Argentina, the spotted tinamou has be-
come increasingly conspicuous by their absence ap-
parently stemming from the expansion and intensi-
fication of grazing and row crop practices.
All tinamous are relatively poorly studied; how-
ever, in austral South American grasslands the tina-
1Correspondence: jthompson@cnia.inta.gov.ar
2Present address: Instituto Nacional de Tecnolog´
ıa Agropecuaria (INTA), Instituto de Recursos Biol ´
ogicos, De los Reseros y las Caba˜
nas S/N, 1686
Hurlingham, Argentina
Gamebird 2006 |Athens, GA |USA 111 May 31 - June 4, 2006
Spotted Tinamou in Argentina
±
0 100 20050 km
Figure 1: Map showing the location of the district of San Miguel del Monte in the Province of Buenos Aires,
Argentina
mous replace the Galliformes and are their ecolog-
ical equivalent, which allows for inferences to be
drawn among the Galliformes and the Tinamiformes
in regard to tinamou ecology (Thompson 2004). We
used radio telemetry to investigate our theory of
ecological equivalence. Based upon the observed
effects of agricultural intensification on Galliformes
and existing knowledge of the spotted tinamou that
within pampean ecosystems we predicted that sur-
vival of spotted tinamous would be negatively cor-
related, and home range size positively correlated,
with increasing land use intensity while habitat se-
lection would favor areas most similar to natural
grassland in vegetative structure (Bump and Bump
1969, Thompson 2004).
Study Area
Our study sites were located in the district of San
Miguel del Monte in the province of Buenos Aires,
Argentina (Figure 1). San Miguel del Monte is lo-
cated in the flooding pampa, a regional subdivision
of the ∼760,000 km2R´
ıo de la Plata grassland system
that covers northeastern Argentina, Uruguay and
southeastern Brazil (Soriano et al. 1991). Tradition-
ally the flooding pampa has been used principally
for extensive livestock production (Hall et al. 1988),
however, since the early 1990’s row crop agriculture
has become an increasingly important land use.
We selected two study sites; one dedicated to
row crops and the other used for used for a mix
of row crops and grazing. The row crop site was
160 hectares, of which 85% was used for soybean,
corn, and winter wheat production, and the remain-
ing area comprised of wetlands or field borders. The
site with mixed row crop and grazing uses was 230
hectares, 50% of its area used for soybean, corn, and
winter wheat production, and the remainder, includ-
ing wetlands, used for cattle grazing.
May 31 - June 4, 2006 112 Gamebird 2006 |Athens, GA |USA
Spotted Tinamou in Argentina
Methods
During July 2003, we fitted 4 birds with pendant-
style transmitters (6.0 g, 2.2-2.3% of body mass)
equipped with an activity switch (Holohil Systems
Ltd., Ontario, Canada) at the row crop dominated
site and 14 birds in June 2004 at the mixed use site. In
2004, no birds were radio-tagged at the row crop site
because none were detected over a 2 month search
in the autumn of that year. All birds were captured
at night using spotlights and hand nets. Due to un-
certainties in sexing birds related to age (Bump and
Bump 1969), sexual differences were not included in
the study. In both years birds were located 3 times
per week from the date of capture until October 23
(mid-winter to early spring) dependent upon acces-
sibility to the sites.
Due to mortality, insufficient number of radio lo-
cations, radio failure, or radio loss we used 3 birds
from the row crop site and 8 from the mixed use site
in our analysis. Locations were entered into a geo-
graphic information system (GIS) for each site using
ArcGIS software (Environmental Systems Research
Institute, Inc.). Minimum convex polygons (MCP)
(Mohr 1947) were calculated for each individual us-
ing the Adehabitat Package Version 1.4 (Calenge
et al. 2006) in R 2.3.1 (R Development Core Team
2006) and the proportion of radio locations and MCP
in different habitat types determined using the GIS.
Within the row crop site we defined 6 habitat
types; winter wheat, fallow, wetlands, corn stub-
ble, tilled land, and field edges. For the mixed use
site we identified 5 habitat types; winter wheat, fal-
low, wetlands, mowed fallow, and grazed pasture.
We used compositional analysis (Aebischer et al.
1993), based upon radio locations and MCP, to eval-
uate habitat preferences. The compositional anal-
ysis was performed using BYCOMP.SAS (Ott and
Hoovey 1997) and, to obtain sufficient sample size,
we combined data from both sites and aggregated
habitat types into 5 categories; winter wheat, fallow,
wetlands, edge, and short herbaceous (corn stub-
ble, tilled land, mowed fallow, and grazed pasture).
Additionally, survival was estimated using Kaplan-
Meier staggered entry design (Kaplan and Meier
1958, Pollock et al. 1989). Standard errors were used
to determine statistically significance differences in
survival and mean home range size.
Results
The mean 100% MCP from the row crop site was
larger (19.0 ha, SE = 10.4 ha) than that from the
mixed use site (15.9 ha, SE = 7.3 ha), although dif-
ferences were not significant due to high variance.
Survival (ˆs= 0.73, SE = 0.19) was higher in the mixed
use site over 20 weeks compared to the row crop site
(ˆs= 0.33, SE = 0.19) over 15 weeks (Figure 2). Mor-
tality of the radio-tagged birds from both sites was
attributed mainly to predation (91%).
At the row crop site winter wheat, wetlands, and
field edges were used less, and corn stubble more,
than their availability based upon both the mean
proportions of MCP and radio locations within those
habitat types (Figure 3). In tilled land the mean pro-
portion of MCP and radio locations indicate approx-
imately equal use in relation to availability, while in
fallow, based on the mean MCP use was equal to
availability, but considerably higher than its avail-
ability based upon the mean proportion of radio lo-
cations (Figure 3). As at the row crop site about half
of the area of the mixed use site was in winter wheat,
which was utilized less than its availability (Figure
3). Fallow, mowed fallow, and wetlands were all
used more than their availability, while based upon
the mean proportion of MCP, grazed pasture was
used equal to its availability, and less than its avail-
ability based upon the mean proportion of radio lo-
cations (Figure 3).
The compositional analysis using the aggregated
data from both sites, and based upon MCP, ranked
short herbaceous habitat as the most utilized habitat
in relation to availability, with fallow, winter wheat,
and edge ranked equally as second, followed by
wetlands (Table 1a). No habitats were used signif-
icantly more than others (P= 0.05) but fallow and
short herbaceous habitat were preferred over wheat,
fallow over wetlands, short herbaceous over fallow,
and wetlands over short herbaceous (Table 1a).
Gamebird 2006 |Athens, GA |USA 113 May 31 - June 4, 2006
Spotted Tinamou in Argentina
Row crop
Proportion
0.0
0.2
0.4
0.6
0.8
1.0
Grazing/Row crop
Proportion
0.0
0.2
0.4
0.6
0.8
1.0
June
July August September October July August September October
AB
Figure 2: Estimated survival and standard error for spotted tinamous in the A) site dominated by row crops (n= 3) and B) the mixed grazing
and row crop site (n= 8)
May 31 - June 4, 2006 114 Gamebird 2006 |Athens, GA |USA
Spotted Tinamou in Argentina
Row Crop
Wheat
Wetland
Fallow
Edge
Corn Stubble
Tilled
Proportion
0.0
0.2
0.4
0.6
0.8
Habitat
MCP mean
Points mean
Grazing/row crop
Wheat
Wetland
Fallow
Mowed
Grazed
Propotion
0.0
0.2
0.4
0.6
0.8
AB
Figure 3: Proportional habitat use by spotted tinamous based on mean area of minimum convex polygon (MCP) and mean number of ra-
dio locations (Points) in relation to proportional availability of habitat types for A) the row crop site and B) the mixed use site. Error bars
represent standard error.
Gamebird 2006 |Athens, GA |USA 115 May 31 - June 4, 2006
Spotted Tinamou in Argentina
Table 1: Results of compositional analysis based on a) minimum convex polygon (MCP) home ranges and
b) radio locations. Higher ranking indicates greater use compared to availability. Within the matrix, (+)
signifies that the row habitat is preferred over the column habitat, whereas a (-) signifies the opposite.
Significant difference between habitats (P<0.05) is indicated by (+++) or (– – –).
a
Habitat wheat wetlands edge fallow short herbaceous rank
wheat . . . – – 2
wetlands . . . – + 1
edge . . . . . 2
fallow + + . . – 2
short herbaceous + - . + - 3
b
Habitat wheat wetlands edge fallow short herbaceous rank
wheat . – . – – – – 0
wetlands + . . – – 1
edge . . . . . 0
fallow +++ + . . + 3
short herbaceous + + . – . 2
Note: Because of low or no use a P-value for edge habitat could not be computed.
The same analysis using radio locations ranked
fallow and short herbaceous habitats as the first and
second most utilized habitats, respectively, in re-
lation to availability, followed by wetlands (Table
1b). Winter wheat and edge were equally the least
used in relation to availability (Table 1b). Fallow
was utilized significantly more than wheat (P= 0.05)
while fallow, short herbaceous, and wetlands were
preferred over wheat, fallow and short herbaceous
were preferred over wetlands, and fallow over short
herbaceous (Table 1b).
Discussion
The mean range size of spotted tinamous at both
sites was affected by movements related to chang-
ing habitat amounts and characteristics and cattle
disturbance. At the row crop site as winter wheat
reached ∼10cm in height birds began to utilize those
areas, often exclusively and as the wheat matured to
∼25cm in height those areas were abandoned for ar-
eas with shorter vegetation. Within the mixed use
site the largest movements by birds were related to
disturbance by cattle.
The lower surival in the row crop dominated
site is consistent with observations of Pinheiro and
L´
opez (1999) who found lower abundances of spot-
ted tinamous in agricultural land in southern Brazil
compared to natural grasslands. Additionally, for
the Galliformes there are multiple cases where in-
creased intensification in land use has led to lower
survival and declining populations (e.g. Berner
1988, Hill and Robertson 1988, Jansen et al. 2000,
Malan and Benn 1999, Potts 1986). Based upon this,
the observed differences in survival between the two
sites are expected if the spotted tinamou is viewed as
an ecological equivalent to the Galliformes. Admit-
tedly, sample sizes are small, particularly for the row
crop site; however, the rarity of spotted tinamous at
the row crop site in 2003 and their absence from the
site in 2004 suggest a real process rather than a sta-
tistical artefact.
Habitat preferences by the spotted tinamou, and
the closely related Darwin’s Tinamou (Nothura dar-
winii), within both natural and agricultural habi-
May 31 - June 4, 2006 116 Gamebird 2006 |Athens, GA |USA
Spotted Tinamou in Argentina
tats, favour areas with relatively low (10-30 cm) and
sparse vegetation (J.J.Thompson pers. obs., Bump
and Bump 1969, Isacch and Martinez 2001, Leveau
and Leveau 2004, Mosa 2004) and explains the pat-
tern of habitat use at both sites. For example, use
of winter wheat was most frequent when plants
were 10-25 cm tall. Although wheat was generally
avoided once it reached >25cm in height, birds then
used it as escape cover.
The most preferred habitats; fallow, mowed fal-
low, and corn stubble all shared in common a well
developed ground cover of herbaceous vegetation,
both living and dead, that was not in excess of 50
cm and with little or no emergent vegetation above
that level. Tilled land was used more as it was colo-
nized by herbaceous vegetation, particularly clover
(Trifolium spp.), and vegetative cover increased.
Spotted tinamous are often common in pasture-
land (J.J.Thompson pers. obs., Bump and Bump
1969, Menegheti 1985, Pinheiro and L´
opez 1999),
as are Darwin’s tinamou (J.J.Thompson pers. obs.,
Bump and Bump 1969, Mosa 2004), due to the
low vegetative structure that is maintained through
moderate grazing. At the mixed use site, however,
pastureland was overgrazed so that ground vegeta-
tion was cropped near to ground level, which ex-
plains a lower than expected preference for grazed
areas. The preference for relatively short vegetation
also explains the avoidance of field edges in the row
crop site. Field edges consisted of tall (>1m) and
dense grass and also contained woody vegetation,
which were avoided by the birds.
The difference in the use of wetlands among the
sites appeared to be a function of the water levels
within wetlands at each site. At the row crop site
wetlands contained water and were avoided, where
as at the mixed use site, wetlands were dry and con-
tained suitable herbaceous cover along their perime-
ter that was utilized by the birds. It should be noted
that although wetlands were not used by individ-
uals at the row crop site, much of the fallow areas
were not put into production due to their proximity
to wetlands, subsequently wetlands were indirectly
responsible for the availability of preferred habitats.
The preferences and differences in habitat use
within and between sites are consistent with the re-
sults of the compositional analysis since fallow areas
and the habitats comprising the short herbaceous
category, while more variable, are the habitats most
similar in structure to natural grasslands. Similarly,
the quality of wetlands varies annually dependent
upon precipitation, reducing interannual use, while
row crop fields and edge were avoided or used con-
siderably less in relation to their availability.
The preferences in habitat, size of home ranges,
and survival that we observed were consistent with
our expectations based upon existing knowledge of
tinamou ecology, and the response of Galliformes
and other bird species to the intensification of agri-
cultural land use (Thompson 2004). From this study
and others (Canavelli et al. 2003, Bellis et al. 2004,
Demar´
ıa et al. 2002, Fernandez et al. 2003) it is ap-
parent that the intensification of agriculture that has
occurred in Argentina has resulted in similar nega-
tive ecological effects as observed in other regions.
The continued expansion and intensification of
agriculture in Argentina suggests that pampean
agroecosystems will continue to be degraded, with
the most ecologically valuable systems being main-
tained in areas only suitable for extensive livestock
production. Moreover, within intensively managed
systems, fallow and areas unsuitable for production
(i.e. wetlands) will increasingly become critical for
biodiversity conservation.
Acknowledgments
This work was facilitated by a Fulbright Student
Grant to Argentina, research scholarships from the
American Pheasant and Waterfowl Society and the
Leslie E. Tassell Avicultural Foundation, and sup-
port from the University of Georgia (Latin Amer-
ica and Caribbean Studies Institute, The Gradate
School, Warnell School of Forestry and Natural Re-
sources) to JJT. C. Villalba, A. Iturralde, J. Tangerini,
M. Dominguez, H. Mega, and M. Conroy provided
assistance in the field.
Gamebird 2006 |Athens, GA |USA 117 May 31 - June 4, 2006
Spotted Tinamou in Argentina
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