reliable means of damage assessment. The purpose of this study was to
develop a damage assessment method for accurately determining the loss
of corn as a result of rat damage.

Two procedures were required to assess rat damage to corn. First, a
sampling method was needed to determine the proportion of rat damaged
ears in the field. Secondly, a means of relating corn weight and some
parameter of damage to define the extent of loss on individual ears
was needed. In situations where partial damage to an ear means a com-
plete loss (as in sweet corn grown for commercial markets), only the
first sampling procedure would be required to estimate economic loss.
Where partially damaged ears are measured, both procedures are
required to obtain estimates of yield loss.

Rat damage in corn occurred mostly at the periphery of the fields,
probably as a result of proximity to adjacent uncultivated areas which
provide good cover for rats. Damaged plants were generally restricted
to certain areas of the field rather than being widely distributed. A
more uniform distribution of damage noted in one field was associated
with a relatively higher rat population.

Areas of intact kernels on an ear of corn can be determined by the use
of a compensating polar planimeter or by the "cut-and-weigh" method
using cardboard materials that simulate the damaged area. The rela-
tionship between corn loss (g) and surface area (cm2) on intact ears
and those with simulated rat damage can be best described by a simple
linear regression. These factors were highly.correlated for both the
planimeter and "cut-and-weigh" methods on damaged and undamaged areas.
The relationship between corn loss (g) and area (cm2) occupied on
ears of corn could be used for predicting the extent of damage to ears
of corn. (dela Paz, M.S. thesis, in progress.)

Glue stakes reduce bird damage in ricefields

The use of "glues" on tree branches or artificial perches as a means
to capture or repel depredating birds is a traditional practice in
many countries. This study was conducted to evaluate the effective-
ness and potential of this technique for reducing bird damage in
Philippine ricefields.

Four contiguous 0.25-ha plots were selected within a 6-ha ricefield
near Namanparan, Diodi, Nueva Vizcaya. Rice plants within the plots
were nearly mature while surrounding fields contained plants from
booting to mature stages. The numbers of birds visiting each plot
were recorded at 10-min intervals from sunrise (0600) to early evening
(1700) during four consecutive days. Bird (Lonchura spp.) damage in
each plot was estimated by counting total tillers and bird-damaged