Skip to main content
Dryad

Wood duck nest survival and duckling recruitment is minimally affected by interspecific brood parasitism from hooded mergansers and black-bellied whistling-ducks

Cite this dataset

Bakner, Dylan; Ringelman, Kevin; Reynolds, Larry (2024). Wood duck nest survival and duckling recruitment is minimally affected by interspecific brood parasitism from hooded mergansers and black-bellied whistling-ducks [Dataset]. Dryad. https://doi.org/10.5061/dryad.gtht76hvt

Abstract

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.

README: 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

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

Funding

Louisiana Department of Wildlife and Fisheries

United States Department of Agriculture

Nemours Wildlife Foundation

National Institute of Food and Agriculture, Award: LAB94294, McIntire-Stennis Grant

Louisiana State University Agricultural Center, United Waterfowlers of Florida

Louisiana Ornithological Society