Molecular analysis of nestling diet in a long-distance Neotropical migrant, the Louisiana Waterthrush (Parkesia motacilla)

Abstract

Elucidating the diet of Neotropical migratory birds is essential to our understanding of their ecology and to their longterm conservation. Reductions in prey availability negatively impact Neotropical migrants by affecting their survival as both nestlings and adults. Beyond broad taxonomic or morphological categories, however, the diet of Neotropical migrants is poorly documented. Using the molecular techniques of DNA barcoding and next-generation sequencing, we elucidated the diet of Louisiana Waterthrush (Parkesia motacilla) nestlings in Arkansas and Pennsylvania, USA. Waterthrush have been shown to respond negatively to the reduced availability of aquatic insects in the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT taxa). We hypothesized that Louisiana Waterthrush nestling diet would be primarily composed of these pollution-sensitive aquatic taxa, and that changes in the riparian insect community would be reflected in their diet. Unexpectedly, the orders Lepidoptera (92%) and Diptera (70%) occurred frequently in the diet of Louisiana Waterthrush nestlings. Among EPT taxa, only the order Ephemeroptera (61%) was frequently detected whereas Plecoptera (7%) and Trichoptera (1%) were poorly represented. The frequency at which aquatic Ephemeroptera and terrestrial Lepidoptera were detected in waterthrush nestling diet differed significantly over the nesting period in Pennsylvania but not in Arkansas, suggesting that phenological shifts in the availability of non-EPT prey taxa may be an important yet undescribed factor influencing the foraging ecology of waterthrush on the breeding grounds. Furthermore, these findings suggest that terrestrial insects may be more important to waterthrush nestlings than previously thought, which enhances our understanding of this biological indicator and Neotropical migrant.

Metabarcoding-based dietary analysis of hen harrier (Circus cyaneus) in Great Britain using buccal swabs from chicks

“…Success rates of recovering at least one prey species within a sample (97% with COI and 92% with Cytb) and those with > reads used for region/moor-type comparisons (84% with COI and 78% with Cytb) in this study are similar to previous studies using faecal samples e.g. 95% in Louisiana Waterthrush (Parkesia motacilla) (Trevelline et al 2016); 97% in Norway lemming (Lemmus lemmus) (Soininen et al 2013). Other studies have reported far lower success rates from faeces e.g.…”

Advancing the integration of multi‐marker metabarcoding data in dietary analysis of trophic generalists

“…This single marker approach has been widely used in many studies (Gordon et al, ; McClenaghan, Nol, & Kerr, ; Moran, Prosser, & Moran, ), but it may produce significant biases due to differential primer affinity for different taxa. For instance, although ZBJ is often used as a ‘universal’ marker for arthropods (Crisol‐Martínez, Moreno‐Moyano, Wormington, Brown, & Stanley, ; Jedlicka, Vo, & Almeida, ; Trevelline, Latta, Marshall, Nuttle, & Porter, ; Trevelline et al, ), it may have strong positive or negative bias depending on the taxa (Clarke, Soubrier, Weyrich, & Cooper, ; Piñol, Mir, Gomez‐Polo, & Agustí, ). The challenge is even worse in the case of omnivorous diets, because the variety of taxonomic clades consumed cannot be analysed using a single marker (De Barba et al, ; Taberlet et al, ).…”

Factors driving territory size and breeding success in a threatened migratory songbird, the Canada Warbler

“…Insect abundance may be important to territory size or breeding success, but our conclusions are relative to the scale at which each predictor was measured. Second, knowing which types of insects are provisioned to offspring would establish the most appropriate sampling protocol for robustly estimating food availability in a territory (e.g., Trevelline et al 2016). …”