Breeding success in Blue Tits: good territories or good parents?

Abstract

J. 2001. Breeding success in Blue Tits: good territories of good parents? -J. Avian Biol. 32: 214 -218.Territorial quality and parental quality are usually assumed to be the main sources of variation in the reproductive success of passerine birds. To evaluate their relative importance for variation in breeding time (itself an important factor for breeding success), clutch size and offspring condition at fledging, we analysed six years of data from a Blue Tit Parus caeruleus population breeding on the island of Gotland, Sweden. Hatching dates and the condition of offspring were consistent for territories between years and accounted for 30% and 33% of the variation in these variables, respectively. After removing the effect of territory quality, none of the breeding parameters were significantly repeatable for individual females, but offspring condition was repeatable for males, accounting for 28% of variation. For females breeding on the same territory in subsequent seasons (combined effect of individual and territory quality) only hatching date was repeatable (45% of variation accounted for). In males, the combined effect of individual and territory quality was repeatable for offspring condition and accounted for 33% of variation, but this result was only marginally significant. Consistency of the peak frass-fall date for individual frass collectors over the study period suggests that repeatable hatching dates on territories may be related to the relationship between timing of breeding and timing of peak food availability on territories. Our results suggest that territory quality is more important than parental quality for breeding success in the Blue Tit, and that male (but not female) quality makes a considerable contribution to reproductive success.

Airborne Lidar for Woodland Habitat Quality Monitoring: Exploring the Significance of Lidar Data Characteristics when Modelling Organism-Habitat Relationships

“…Runts, defined as nestlings too small to ring at 11 days, do not survive to fledge and are rare; none were present in the broods in either 1997 or 2001. Mean nestling body mass is used as a measure of breeding success likely to reflect territory quality [40] because it combines the effects of food abundance with the adults' abilities to find it (foraging efficiency) and to deliver it to the nest (travel costs). In the absence of territory boundary data for each nest box, a 30 m radius area around each box is considered here to represent the core area of each territory (adapted from [27]).…”

Age-related improvement of reproductive success in BluethroatsLuscinia svecica

“…We also assess the influence of (1) territory quality, which can improve breeding performance (Högstedt 1980, McCleery & Perrins 1985, Przybylo et al 2001, (2) delay of re-nesting after brood failure or brood success, which can influence the number of broods per breeding season (Green 2001) and (3) chick body condition, because feeding rates are not always a reliable measure of parental investment (Saetre et al 1995) or quality (Sundberg & Larsson 1994).…”

An experimental test of whether pied flycatchers choose the best territory for rearing the young

“…Lundberg et al, 1981;Siikamäki, 1995;Eeva et al, 2000), the measured territory characters had only a relatively weak effect on breeding success. This may suggest that the importance of territory characters depend on environmental conditions and/or that the quality of parents is more important for breeding success than the territory quality (Siikamäki, 1995;Przybylo et al, 2001;Sergio et al, 2009). It is also possible that small quality differences between the territories were not recognized by birds (Canal et al, 2012), or that many of the territories were of equal quality (Goodenough et al, 2009).…”