Above average adult bobwhite survival sets stage for good late season hatch
The atypical ENSO weather patterns that we have experienced this summer has provided a respite from the drought conditions, but has resulted in some subtle oscillations related to the quail hatch. During March and April the dry weather had many in the region concerned that burning would not get completed due to difficulty of obtaining permits. By June, however, ample rainfall washed away any concern of a dry summer and therein potential negative impacts of drought on nesting activity—the cover has responded in spades. As a result of these good cover conditions, adult survival has been excellent in both the Red Hills and Albany area during the spring and summer. This survival bonus bodes well for late breeding season production, which can be a boon for fall recruitment and population growth.
Productivity, in terms of nests and broods produced, is about average for the Red Hills region and moderately above average in the Albany region. We are not setting any records but the birds are holding their own. Some delightful news lies in two common indicators of a good production—male incubation and brood amalgamation. This year, male incubation of nests has been very high, nearly 30% on some sites already, compared to long-term averages of ~15-20%. Similarly, brood amalgamation is high at nearly 55% of all broods captured so far this year being comprised of chicks with multiple age groups suggesting brood mixing—this is way up compared to our long-term amalgamation rate of ~24% (see Figure). Notably, when brood amalgamation is high (e.g., 2002, 2003 and 2014), fall abundance is usually excellent as well; time will tell as to how the remainder of the season unfolds.
Chick survival is also definitely improved this year compared to previous years. However, some localized heavy rainfall events has negatively impacted chick survival, especially in the Red Hills. In particular, the latter part of the first hatch in mid-June coincided with several days of extended rainfall, impacting chick survival which created a gap in brood ages. But, a strong second hatch in July was evident and contributed to a plethora of brood mixing and some very large broods observed as a result. This is good news in that we believe that chick survival increases with brood amalgamation, especially for younger chicks mixing with older broods. Taken collectively, the stage is set for a good late hatch given adult survival has been above average, cover conditions are excellent and a decent number of chicks are already on the ground favoring good late season chick survival for those late hatching chicks.