Kimball, R.T. 1997. Male morphology and nest-site quality in House Sparrows. Wilson Bulletin 109: 711-719.

Previous research on House Sparrows (Passer domesticus) in Europe indicated that males with larger bibs are more likely to obtain nest sites with multiple potential nests. To test this observation experimentally, I created nest sites containing either one or two nest boxes. I found no morphological differences, including bib size, between males at single-box nest sites (SBNS's) and those at double-box nest sites (DBNS's). Pairs in DBNS's were more likely to renest than pairs in SBNS's in 1992, leading to increased seasonal reproductive success for pairs at DBNS's. Although pairs at DBNS's fledged more young over the season, I could not detect a strong preference for DBNS's. Pairs in DENS's did not begin reproducing prior to those in SBNS's, as might be expected if birds preferentially occupied DBNS's prior to SBNS's. More DBNS's than SBNS's were occupied in 1991, but this was not true in 1992 when sample sizes were larger.