Rodriguez el al. • VENEZUELAN BIRD SURVEYS 
241 
would provide a higher chance to detect rare 
species (Fig. 4). which are well known to 
represent a large proportion of species in a bird 
community (Preston 1962, Gaston 1994). A larger 
number of species detected would, in turn, allow 
us to generate more accurate estimates of total 
species richness. Sixty-seven (11%) of the 593 
species detected during the surveys were recorded 
only by S2. and 20 only during the third count 
period. Second. S2 can be used to estimate 
detection (Alldredge el al. 2007), although this 
topic will be addressed elsewhere. We cannot 
conclusively say yet that conducting two inde¬ 
pendent surveys at each location (SI -t- S2) is cost 
effective, and presently would recommend per¬ 
forming only one (SI) if time, funds or personnel 
were constrained; but encourage exploring alter¬ 
native schemes (S2) whenever possible. Our 
second survey (S2) was able to increase the total 
species detected by 11%, plus it allows us to later 
examine biases during the surveys (such as those 
generated by time of day) and estimate species 
detection. Further research should be conducted to 
identify the most efficient strategy for a second 
day of surveys. 
Our main survey (SI) lasted an average of 
5.5 hrs. which is I to 1.5 Ins longer than an 
average BBS route (Bystrak 1981) with the same 
sample effort (50 3-min point counts). This was 
mostly due to poor road conditions for most 
transects, even after selecting the 'best' available 
secondary road in each cell. Other minor delays 
due to logistic problems, roadside obstacles, 
w'eather conditions, etc., could probably be 
avoided in an optimized survey scheme. However, 
we believe the average survey time could hardly 
be <5 hrs in Venezuela or other neotropical 
developing countries. We kept registering new 
species (up to 20% of the total) in the last 2 hrs of 
the survey on about one-third of the transects, 
which indicates these last hours were actually 
necessary and that bird activity did not decease as 
drastically as is normal in BBS counts, at least for 
a moderate proportion of the transects. 
One main difference between NeoMaps and the 
BBS is that NeoMaps is conducted during the dry 
season (typically Nov to Mar), when most 
Venezuelan birds are not breeding (Hilry 2003). 
The main reason for choosing the dry season is 
logistical, minimizing potential field days lost to 
rain It is also when up to 135 species of boreal 
migrants are present as wintering birds (Hilly 
2003); this allows us to quantify this important 
component of our avifauna. Synchronizing Neo¬ 
Maps surveys to a breeding season would not be 
possible, as avian breeding in the Neotropics is 
not synchronized (Karr 1981), and species dis¬ 
tribute themselves along the 7-month long rainy 
season (Hilty 2003). 
Our methodology has both strengths and 
weaknesses: once a team of people has been 
trained, it is useful to perform quick inventories 
with rather low costs, yielding reliable results for 
a large number of common diurnal species. It is 
not useful to accurately assess nocturnal, colonial 
or rare species. Poor road conditions or total lack 
of roads may be an important hindrance in 
producing reliable census results in some pails 
of many neotropical countries by either making 
die surveys too long (>5 hrs) or leaving important 
areas completely undersampled. Further experi¬ 
mentation with the survey methodology is desir¬ 
able. 
AC KNOW LEDGM ENTS 
This research work was supported by the lnstituto 
Venezolano de Investigaciones Cientfficas and TOTAL 
Venezuela S.A. We are grateful to our field team leaders: 
Jose Clavijo, Anthony Crease, Marieta Hernandez, Jose G. 
Leon, Curtis Marantz, and Alejandro Nagy; our field 
assistants: Rudy Badiu. Lorenzo Calcano. Diana Esclasans. 
.lose L. Garzon, Paul Granado. Karen Lopez, Gonzalo 
Medina, Vili.su Moron, Jessica Ortega, Juan Papadakis, 
Alfonso Frisco, Haydee Sturhahn. Judit Szabo, Ivan 
Tepedilio; and Pio Colnienares. Helios Martinez, Monica 
Nunez, Ana M. Perez, and Chris .1. Sharpe for their support 
ami collaboration throughout the project. The manuscript 
was greatly improved by comments from C. John Ralph, W. 
Douglas Robinson, and Clait E. Braun. 
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