|Timing, Nest Site Selection and Multiple Breeding in House Martins: Age-Related Variation and the Preference for Self-Built Mud Nests|
Piersma, T. (2013). Timing, Nest Site Selection and Multiple Breeding in House Martins: Age-Related Variation and the Preference for Self-Built Mud Nests. Ardea 101(1): 23-32
In: Ardea. Nederlandse Ornithologische Unie: Arnhem; Leiden. ISSN 0373-2266 , more
Delichon urbicum (Linnaeus, 1758) [WoRMS]; Hippoboscidae; Hirundinidae [WoRMS]
age effects; artificial nests; Delichon urbicum; Hirundinidae; louseflies; parasites; reproductive effort; timing of reproduction
Almost all accounts of the reproductive biology of House Martins Delichon urbicum are based on studies of birds breeding in artificial nests that are monitored every few days. Here, I provide a study on House Martins using self-built mud nests at a single colony in Gaast, The Netherlands (225 nest attempts in 2004-2011); the stages of breeding were inferred from 'remote' observations of parental and chick behaviour. Small chicks were noticed from 30 May onwards, with a first peak of nestling appearance in 5-9 June. A second, and larger, peak in small chicks occurred in late June. Large chicks from first broods were noticed from mid June to mid August, and the first large chicks from second broods from late July onward. The last fledglings left nests in late September. Among the 205 successful nest attempts, 62% had one brood, and 38% had two broods (three in one case). The first nest sites to be occupied in mid-April were always old nests that had survived the winter. Surprisingly, the use of old nests did not result in earlier incubation and chick-rearing activities. Nevertheless, re-used near-intact old nests hosted multiple broods in 72% of cases, a much higher percentage than in newly built nests (20%). The earlier occupation of old nests and the greater incidence of second broods was further associated with a relatively high percentage of older House Martins. Whereas only 8% of 126 nests hosting one brood were occupied by at least one known >2nd calendar year bird, no fewer than 30% of the 79 nests with two broods were. Despite a steady offering of clean wood-concrete nests at the colony, such artificial alternatives were occupied in only 23 out of 307 possible cases, rather than the near-100% occupancy of old mud nests and nest remains. Also, the start date of occupation was later than that of intact or partial old mud nests. This strong preference by old,er birds for (the remains of) existing mud nests and the rejection of clean, strong artificial nests, implies that any costs of being exposed to greater numbers of ectoparasites such as louse flies Crataerina hirundinis overwintering in old nests are outweighed by the signal of quality inherent in the occupation of parasite-infested old mud nests.