Are avian ectoparasites more numerous in nest boxes with old nest material?

Abstract

Researchers may reduce the numbers of haematophagous ectoparasites in nest boxes of cavity-nesting birds by removing old nests from boxes and, as a result, eliminate an important selective pressure that could influence the results from nest-box studies of birds. We recorded the numbers of parasites in tree swallow (Tachycineta bicolor) boxes in which we manipulated the presence, amount, and quality of old nests. Bird fleas (Ceratophyllus idius) were more numerous in boxes with old nests, and there was a positive correlation between nest volume and flea numbers. In one year, there was a positive association between fowl mite (Ornithonyssus sylviarum) numbers and nest volume; otherwise, fowl mites and blow flies (Protocalliphora sialia) were equally numerous in all nest types. We conclude that ectoparasites whose over-winter survival depends on old nests are more numerous in boxes with old nests, whereas parasites whose over-,winter survival is independent of old nests infect nest sites randomly. Also, reinfection and nest microclimate likely contributed to variance in parasite numbers between nest types and years, respectively. We recommend caution when speculating about the possible effects of cleaning boxes on parasites that occur in nests because different species of parasites are not influenced similarly by old nests.RCsumC : Les chercheurs peuvent diminuer le nombre d'ectoparasites hematophages dans les boites a nids de leurs oiseaux en captivite en enlevant les vieux nids des boites, Climinant ainsi une importante pression de selection susceptible d'influencer les resultats de leurs etudes ulterieures. Nous avons dCnombrC les parasites chez les Hirondelles bicolores (Tachycineta bicolor) nichant dans des boites oh la presence, la quantite et la qualit6 des vieux nids avait etC manipulee. Les puces Ceratophyllus idius se sont avCrCes plus nombreuses dans les boites contenant des vieux nids et il y avait une corrClation positive entre le volume des nids et le nombre de puces. Au cours d'une annee, nous avons observe une association positive entre le nombre d'acariens Ornithonyssus sylviarum et le volume des nids, mais, ce cas mis a part, les acariens et les calliphores Protocalliphora sialia etaient Cgalement nombreux dans tous les types de nids. Les ectoparasites dont la survie en hiver est reliee aux vieux nids sont plus nombreux dans les boites contenant des vieux nids, alors que les parasites dont la survie en hiver est independante de la presence de vieux nids sont repartis aux hasard a tous les sites de nidation. De plus, les cas de reinfection dans les nids ont probablement influence la variance dans le nombre de parasites d'un type de nid a l'autre et le microclimat, la variance du nombre de parasites d'une annee a l'autre. Les effets possibles du nettoyage des boites a nid sur les parasites peuvent donc varier puisque differentes espkces de parasites reagissent differemment a la presence de vieux nids. [Traduit par la Redaction]

Effect of Old Nest Material on Nest Site Selection and Breeding Parameters in Secondary Hole Nesters — a Review

“…It seems that determining the costs of using nest sites with old nests related to the potential increase of predation cannot be appropriately evaluated in nestbox studies, because the boxes themselves are primarily aimed at improving the safety of the birds nesting there. Besides this, potential predator pressure was often completely eliminated in studies conducted to date by the techniques used in hanging boxes (on smooth metal poles) and protecting them with predatory guards, making access very difficult (Rendell & Verbeek 1996a, Utsey & Hepp 1997, Blem et al 1999). This may be why no differences were found in the breeding success of birds using boxes with old nest material and those using cleaned nestboxes (cf Table 3).…”

“…Fleas overwinter most often as cocoons in old nest material, emerge in early spring, and very frequently wait for a bird host at the hole entrance (Humphries 1968, du Feu 1982. Mites may occur in old nest material also (Rendell & Verbeek 1996a), although clear data on their abundance in nest sites with/without old nest material are rare (Table 4). Flies and their larvae appear only after the nest sites are occupied, although Loye & Carrol (1998) suggested that fly imagines also remained in close proximity to sites used by birds, as well as the flies, in the previous season.…”

“…Therefore, their abundance in a new nest built on old material could be much higher than in the sites without such an old nest (e.g. Rendell & Verbeek 1996a). Ectoparasites may then attack new owners of a cavity and their nestlings, weakening them both, directly by blood sucking, as well as indirectly by transferring various pathogens (e.g.…”

Behavioural responses to ectoparasites in pied flycatchersFicedula hypoleuca: an experimental study

“…For the time that the original nests were treated (around 30 minutes), a fresh substitute nest was introduced into the nest-box (these nests had been collected in previous seasons after being abandoned prior to laying and kept frozen at -20 ºC until use). This treatment ensured that experimental nests did not contain live arthropods when placed in the nest-box (Rendell and Verbeek 1996), although some arthropods may colonize the nest material after the treatment. To avoid the loss of water during the heat-treatment, the nests were placed into a hermetic plastic container.…”

Yearly and Seasonal Variation of Breeding Parameters in a Declining Multi-Brooded Passerine, the Tree Sparrow

“…Thus, it is likely that time constraints (and, to a lesser extent, the lack of availability of empty nestboxes) deter the birds from moving in search of a new nest-site despite the accumulation of debris and the presence of ectoparasites (see more below), which can have detrimental effects on nestling condition (Richner et al 1993, Rendell & Verbeek 1996aMazgajski 2007). The costs of nest-site switching may offset costs associated with the reuse of soiled cavities as has been shown experimentally in other multi-brooded passerines (Stanback & Rockwell 2003).…”