DOI: 10.5061/dryad.gtht76hvt
title: Wood duck nest survival and duckling recruitment is minimally affected by interspecific brood parasitism from hooded mergansers and black-bellied whistling-ducks

description: In the southeastern United States, wood ducks (Aix sponsa) have
 historically experienced interspecific brood parasitism (IBP) primarily
 from hooded mergansers (Lophodytes cucullatus), but the recent northward
 expansion of black-bellied whistling-ducks (Dendrocygna autumnalis) has
 added a new complexity to these interactions. We monitored nest boxes in
 Louisiana to evaluate the influence IBP had on wood duck daily nest
 survival rate (after, DSR) and duckling recruitment. We monitored 1,295
 wood duck nests from 2020−2023 and found 112 (8.7%) were parasitized by
 hooded mergansers and 148 (11.5%) by whistling-ducks. Parasitic egg-laying
 by hooded mergansers lowered wood duck DSR, while DSR for nests
 parasitized by whistling-ducks was comparable to clutches containing only
 wood duck eggs. We considered the wood duck capture histories of 2,465
 marked female ducklings and 540 banded adult females to estimate a
 duckling recruitment probability for the entire study period. We
 recaptured 50 ducklings as adults; 6 (12.0%) hatched from clutches
 parasitized by hooded mergansers, 1 (2.0%) from a clutch parasitized by a
 whistling-duck, and 43 (86.0%) from clutches containing only wood duck
 eggs. The duckling recruitment probability was 0.039 (95% credible
 interval = 0.028, 0.051). Nest initiation date had a negative effect on
 recruitment, wherein most recruits hatched from nests initiated earlier in
 the season. Given only ~9% of wood duck nests contained hooded merganser
 eggs, we conclude IBP writ large had no detrimental effect on DSR at a
 population level. The lower DSR of clutches parasitized by hooded
 mergansers is potentially linked to a high abundance of early-season
 parasites that produce “dump nests” and these clutches are often abandoned
 without being incubated. Despite ongoing parasitism by hooded mergansers
 and the range expansion of whistling-ducks, wood duck productivity in
 Louisiana appears to be minimally affected by interspecific brood
 parasitism.
description: # Wood duck nest survival and duckling recruitment is minimally affected
 by interspecific brood parasitism from hooded mergansers and black-bellied
 whistling-ducks
 [https://doi.org/10.5061/dryad.gtht76hvt](https://doi.org/10.5061/dryad.gtht76hvt) Metadata for manuscript on interspecific brood parasitism in wood ducks, hooded mergansers, and black-bellied whistling ducks by Dylan L. Bakner, Kevin M. Ringelman, and Larry A. Reynolds. This metadata file describes the data for a manuscript that evaluates wood duck nest survival and duckling recruitment, and how these vital rates are affected by interspecific brood parasitism from hooded mergansers and black-bellied whistling-ducks. Data and R code to reproduce the analyses described in manuscript are described in detail below. This manuscript will published in PLOS ONE in 2024. ### **DATA** **adultEncHist.csv** This file is an encounter history for 540 adult female wood ducks that were captured and banded from nest boxes. Each column in this file represents a year, with the first representing 2020 and the last representing 2024. This file was used to report adult female sample sizes in manuscript. *Numeric codes* 2 = individual was captured from a nest box and observed as an adult 3 = individual was not observed **ducklingEncHist.csv** This file is an encounter history for 2465 female wood duck ducklings that were captured and marked from nest boxes. Each column in this file represents a year, with the first representing 2020 and the last representing 2024. This file was used to report duckling sample sizes in manuscript. *Numeric codes* 1 = individual was captured from a nest box and observed as a duckling 2 = individual was captured from a nest box and observed as an adult 3 = individual was not observed **jointEncHist.csv** This file binds the adultEncHist.csv and ducklingEncHist.csv by rows and was used to complete an analysis to estimate duckling recruitment probability. *Numeric codes* 1 = individual was captured from a nest box and observed as a duckling 2 = individual was captured from a nest box and observed as an adult 3 = individual was not observed **zeroInflateData.csv** This file contains information on the wood duck broods in which ducklings were marked from. This information was then used to determine which brood characteristics affected duckling recruitment probability. *Columns* 1\. id: brood identity 2\. year: year brood was observed 3\. marked: number of female ducklings in brood that were marked 4\. recap: number of female ducklings recapture as breeding adults 5\. broodSize: total number of ducklings in the brood (i.e., both male and female) 6\. bbwds: number of black-bellied whistling-ducks in brood 7\. homes: number of hooded mergansers in brood 8\. freq: always "1" and used to report summary statistics in manuscript **nestData.csv** This file contains information on the wood duck nests that were monitored. This information was then used to determine which nest characteristics affected wood duck nest survival. *Columns* 1\. id: brood identity 2\. Year: year brood was observed 3\. Site: study site identitiy 4\. NestInit: julian date for when a nest was initated 5\. AgeFound: the age of the nest when it was first observed 6\. FirstFound1: julian date for when the nest was first observed 7\. LastPresent1: julian date for the last known day in which the nest was alive 8\. LastChecked1: julian date for the last day the nest was visited 9\. Fate: 0 = nest hatched at least one egg, 1 = nest failed to hatch any eggs 10\. ActFate: specific cause of nest failure 11\. IncDate: julian date for the first day the nest was incubated 12: MaxClutch: maximum observed clutch size for the nest 13: ParaHOME: number of parasitic hooded merganser eggs in nest 14: ParaBBWD: number of parasitic black-bellied whistling-duck eggs in nest 15: MemH: number of hatched hooded merganser eggs 16: MemW: number of hatched wood duck eggs 17: MemB: number of hatched black-bellied whistling-duck eggs 18: incFate: NA 19: type: early = wood duck nest with only wood duck eggs (initiated prior to April 1); late = wood duck nest with only wood duck eggs (initiated after to March 31); mixedHOME = wood duck nest containing at least one hooded merganser egg; mixedBBWD = wood duck nest containing at least one black-belled whistling-duck egg 20: censor: NA 21: freq: always "1" and used to report summary statistics in manuscript ### CODE FILES **fullCode.R** *This file contains all the code reproduce the analyses outlined in the manuscript* The general flow of R code: 1\. load in the data files 2\. load the required packages 3\. obtain summary statistics for first paragraph of results 4\. run Poisson models to describe clutch characteristics in second paragraph of results 5\. execute jags nest survival model for third paragraph of results 6\. report female and duckling summary statistics for the fourth paragraph of results 7\. execute jags duckling recruitment model for fifth paragraph of results 8\. execute brms duckling recruitment model for fifth paragraph of results