responsible for a reduction in earthworm abundances.
There was a severe drought from Oct.
2001 to early May 2002 (Fig. 2). In drought conditions,
earthworms may enter a resting stage deep
underground where they become motionless, and
probably do not feed, grow, or breed (Lee 1985).
This situation made it difficult for the adults to collect
enough earthworms for the nestlings.
Earthworm scarcity during the breeding season not
only forced the adults to search for alternative
foods, but also caused the breeding season to be
postponed for at least 2 wk in 2002. Between the
breeding seasons of 2000 and 2003, 40 nests
within the study area were located (RS Lin, unpubl.
data). In normal years, the breeding season usually
begins on about 10 May, but in 2002 it did not
begin until 23 May. Food abundance constrains
the breeding performance of adults, and affects
annual fecundity (Holmes et al. 1992, Siikamaki
1998, Rodriguez-Estrella 2000). Zimmermann and
Noske (2003) found that the breeding period of the
Rainbow Pitta coincided with the wet season, and
the start of the breeding season varied annually
with rainfall.