Interannual and interspecific variation in intensity of the parasitic fly, Philornis downsi, in Darwin’s finches

Dudaniec, Rachael Y.; Feßl, Birgit; Kleindorfer, Sonia

doi:10.1016/j.biocon.2007.07.006

Cited by 84 publications

(140 citation statements)

References 36 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…The number of parasites found per mangrove finch nest in CB and PTN was high and comparable with numbers observed in nests of several finch species on Santa Cruz Island (Dudaniec et al 2007). In the current study, partial and complete brood loss was linked to infestation by P. downsi resulting in an important proportion of mortality during the nestling phase in 2007/2008.…”

Section: Resultsmentioning

confidence: 72%

“…On the other hand, El Niñ o conditions result in prolonged breeding of finches (Grant & Grant 1987) and might thus be beneficial for the recovery of the mangrove finch given that rat control is intensified at the same time. However, the favourable conditions for finches might increase P. downsi infestation (Dudaniec et al 2007), outbalancing the positive effect.…”

Section: (D) Emerging Threatsmentioning

confidence: 99%

“…Fessl 2008, unpublished data). Flies lay their eggs in nests with bird chicks, and the blood-sucking larvae cause reduced fledgling weights, anaemia and tissue damage, often leading to death and bill deformations that persist into adulthood (Dudaniec et al , 2007Fessl et al 2006;Galligan & Kleindorfer 2010). Rats and flies have also been implicated in the local extinction of the Floreana warbler finch (Grant et al 2005).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

How to save the rarest Darwin's finch from extinction: the mangrove finch on Isabela Island

Feßl

Young

et al. 2010

Phil. Trans. R. Soc. B

Self Cite

View full text Add to dashboard Cite

Habitat destruction and predation by invasive alien species has led to the disappearance of several island populations of Darwin's finches but to date none of the 13 recognized species have gone extinct. However, driven by rapid economic growth in the Galápagos, the effects of introduced species have accelerated and severely threatened these iconic birds. The critically endangered mangrove finch (Camarhynchus heliobates) is now confined to three small mangroves on Isabela Island. During 2006-2009, we assessed its population status and monitored nesting success, both before and after rat poisoning. Population size was estimated at around only 100 birds for the two main breeding sites, with possibly 5 -10 birds surviving at a third mangrove. Before rat control, 54 per cent of nests during incubation phase were predated with only 18 per cent of nests producing fledglings. Post-rat control, nest predation during the incubation phase fell to 30 per cent with 37 per cent of nests producing fledglings. During the nestling phase, infestation by larvae of the introduced parasitic fly (Philornis downsi ) caused 14 per cent additional mortality. Using population viability analysis, we simulated the probability of population persistence under various scenarios of control and showed that with effective management of these invasive species, mangrove finch populations should start to recover.

show abstract

Section: Resultsmentioning

confidence: 72%

Section: (D) Emerging Threatsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

How to save the rarest Darwin's finch from extinction: the mangrove finch on Isabela Island

Feßl

Young

et al. 2010

Phil. Trans. R. Soc. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our finding of no young (Black 0) males in 2006 suggests unsuccessful breeding in the dry year of 2005 (see Dudaniec et al 2007 for rainfall data). Many two-year-old (Black 1) males were found in 2008 and may represent a cohort that fledged in 2006.…”

Section: Male Age Structure In Medium Tree Finchesmentioning

confidence: 75%

Avian population survey in the Floreana highlands: is Darwin’s Medium Tree Finch declining in remnant patches ofScalesiaforest?

O’Connor

Sulloway

Kleindorfer

2010

Bird Conservation International

Self Cite

View full text Add to dashboard Cite

SummaryIsland species typically exist in pathogen and predator sparse environments before human settlement, and are particularly vulnerable to the impacts of invasive species. In this study, we used the variable circular-plot method to estimate the density of birds in the highlands of Floreana Island, Galápagos Archipelago, where introduced parasites, predators, and habitat degradation are a known threat to endemic species. We recorded the number of birds seen and heard at 15 locations near Cerro Pajas Volcano in 2004 and 2008, an area that harbours the largest expanse of highland Scalesia forest on Floreana Island. We estimated the change in population density for nine bird species, including five species of Darwin’s finches. We specifically address changes in population density for the locally endemic Medium Tree Finch Camarhynchus pauper, which only occurs on Floreana Island and has a small population size. Comparing 2004 and 2008, our study found lower population density in the Medium Tree Finch, but stable population density in Small Tree Finch C. parvulus and Large Tree Finch C. psittacula. Based on data from three additional highland sites surveyed in 2008, we estimate that the maximum size of the Medium Tree Finch population is 1,620 individuals. In addition to the survey data, we observed breeding males in 2006 and 2008. We found: (1) low nesting success (six out of 63 nests produced fledglings) and high Philornis downsi parasite intensity, and (2) a biased age structure of the breeding population. No breeding males were one year old in 2006, and no males were five years old in either study year, indicating low reproductive success as well as limited lifespan. This research has contributed to the recent re-evaluation by IUCN, which has changed the Red List status of the Medium Tree Finch from ‘Vulnerable’ to ‘Critically Endangered’.

show abstract

“…In-nest chick mortality was caused by flesheating larvae of the introduced parasitic fly Philornis downsi (Kleindorfer et al, , 2014bO'Connor et al, 2010b;Dudaniec et al, 2010). Medium tree finch nests had more P. downsi larvae compared with most other Darwin's finch species (Dudaniec et al, 2007;Kleindorfer et al, 2014b). Although higher body condition is often linked with fewer parasites or higher survival under conditions of parasitism (Brown et al, 2000;Møller et al, 1998), this does not directly apply here because the parasite P. downsi consumes the blood of nestling birds and not adults Fessl et al, 2006;Huber, 2008;O'Connor et al, 2014).…”

Section: Discussionmentioning

confidence: 88%

Divergent foraging behavior in a hybrid zone: Darwin’s tree finches (Camarhynchus spp.) on Floreana Island

Peters

Kleindorfer

2015

Current Zoology

Self Cite

View full text Add to dashboard Cite

Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However, we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the foraging behavior and fitness of two species of Darwin's tree finches (Camarhynchus parvulus, C. pauper) and hybrid offspring on Floreana Island. Previous study showed that the percentage of hybrids in the tree finch population increased from 19% in 2005 to 41% in 2010, and their body and beak size increased by ~5% (parental phenotype did not change). In 2005-2006, all three tree finch groups (two parental species and hybrid birds) used the same foraging substrate, technique, and height. By 2010-2013, the small tree finch C. parvulus had changed its foraging technique and the medium tree finch C. pauper had changed its foraging height. Both parental species had higher body condition when foraging at (divergent) mean foraging heights per species but hybrid birds did not. We discuss the implications of conserving forest to facilitate vertical niche expansion and the role of hybridization for genetic persistence [Current Zoology 61 (1): [181][182][183][184][185][186][187][188][189][190] 2015].

show abstract

Interannual and interspecific variation in intensity of the parasitic fly, Philornis downsi, in Darwin’s finches

Cited by 84 publications

References 36 publications

How to save the rarest Darwin's finch from extinction: the mangrove finch on Isabela Island

How to save the rarest Darwin's finch from extinction: the mangrove finch on Isabela Island

Avian population survey in the Floreana highlands: is Darwin’s Medium Tree Finch declining in remnant patches ofScalesiaforest?

Divergent foraging behavior in a hybrid zone: Darwin’s tree finches (Camarhynchus spp.) on Floreana Island

Contact Info

Product

Resources

About