Fledging Success is a Poor Indicator of the Effects of Bird Blow Flies on Ovenbird Survival

Abstract

Resumen. Las infestaciones con las moscas parásitas Protocalliphora spp. y Trypocalliphora braueri tienen varios efectos negativos sobre la condición de los pichones de las aves. Sin embargo, la infestación por sí sola rara vez reduce el éxito de emplumamiento en ausencia de otros agentes de estrés, como el clima inclemente. Estudios previos han documentado los efectos de estas moscas sobre la condición de los pichones y el éxito de emplumamiento, pero sin información acerca de la supervivencia de los volantones, por lo que el efecto completo de la infestación no resulta claro aún. Para investigar de forma completa el efecto fLEDGING SUCCESS IS A POOR INDICATOR Of THE EffECTS Of bIRD bLOw fLIES ON OVENbIRD SURVIVAL El Éxito de Emplumamiento es un Mal Indicador de los Efectos de las Moscas Parásitas de Aves sobre la Supervivencia en Seiurus aurocapillaAbstract. Infestations of bird blow flies (Protocalliphora spp. and Trypocalliphora braueri) have various negative effects on the condition of nestling birds. In the absence of other stressors such as inclement weather, however, infestation alone rarely reduces fledging success. Previous studies have documented effects of blow flies on nestling condition and fledging success. without information regarding fledgling survival, the full effect of blow-fly infestation remains unclear. To fully investigate the effect of blow-fly infestation on reproductive success of the Ovenbird (Seiurus aurocapilla), we monitored infested and noninfested nests and monitored fledglings from each by using radio telemetry. blow flies did not affect birds during the nestling period, as brood size, mean nestling mass, fledging success, and time to fledging in infested and non-infested nests were no different. fledgling survival and minimum distance traveled the first day after fledging, however, were significantly lower for infected fledglings than for those that were not infected. we conclude that the stress of the early fledgling period combined with recent or concurrent blow-fly infection increases mortality in young Ovenbirds. Our results demonstrate the importance of including the post-fledging period in investigations of the effects of ectoparasitic infestations on birds.

Direct and indirect effects of landscape structure on a tri‐trophic system within agricultural lands

“…Feeding larvae are typically anchored to the most accessible part of nestlings (feet, legs and belly), although some species can be found in the auditory and nasal cavities (Whitworth and Bennett 1992). In most v www.esajournals.org cases, parasitized nestlings have lower hematocrit and haemoglobin levels (Whitworth and Bennett 1992), decreased body temperature and metabolic rates (Simon et al 2005), reduced growth rates (Whitworth and Bennett 1992), lower fledging survival and reduced dispersal in the first days following fledging (Streby et al 2009). …”

Lethal and Sublethal Effects of Botfly (Philornis seguyi) Parasitism on House Wren Nestlings

“…Because we did not follow the young after they left the nest, we cannot rule out the possibility that infested nestlings that fledged had higher mortality immediately after leaving the nest, as shown by Streby et al (2009). Those authors found that blowflies (Protocalliphora spp.…”

Trade-offs in the early development of tree swallows (Tachycineta bicolor): offspring characteristics, offspring quality, and parental care

“…offspring have observed what appear to be negative consequences of parasitism (Chapman 1973;Richner et al 1993;Hannam 2006;O'Brien & Dawson 2008;Dawson et al 2011;Pigeon et al 2013;Harriman et al 2014); others have reported no effect of ectoparasites on nestlings (Roby et al 1992;Johnson & Albrecht 1993;Thomas & Shutler 2001;Gentes et al 2007;Streby et al 2009). Meanwhile, studies of parental effort in relation to nest ectoparasites have also been equivocal, with some finding that one or both parents increase their energy expenditure when their nestlings are parasitized (Christe et al 1996a;Christe et al 1996b;Thomas & Shutler 2001;Tripet et al 2002), some finding a decrease in parental energy expenditure (M0ller 1994; M0ller et al 1994), and others finding no change (Rogers et al 1991;M0ller 1994;Saino et al 1998;O'Brien & Dawson 2008).…”

“…Simply fledging, however, does not guarantee survival. A study on ovenbirds (Seiurus aurocapilla) that had been infested with T. braueri larvae determined that although infestation had not affected physical condition or survival to fledging, it did significantly decrease how much fledglings moved around in a day and increased mortality during their first few days out of the nest (Streby et al 2009). This suggests that although young tree swallows that were parasitized in the nest are surviving to fledge, they may be suffering from higher mortality rates within their first few days postfledging.…”

“…Nestling house wrens (Troglodytes aedon) showed little direct effects from parasitism by blow flies, other than a slight loss of mass (Johnson & Albrecht 1993), and no negative effects of Trypocalliphora braueri infestation were found on the mass or probability of fledging of nestling ovenbirds (Seiurus aurocapilla; Streby et al 2009). A number of studies have also found no effect of parasitism by blow flies on nestling tree swallows (Roby et al 1992; Thomas & Shutler 2001;Gentes et al 2007).…”