True metabolizable energy of submersed aquatic vegetation in semi-permanent marshes for dabbling ducks in the Upper Midwest

Lancaster, Joseph D.; Yetter, Aaron P.; Hagy, Heath M.; Gross, Margaret C.; McClain, Sarah E.; Simpson, John W.; Jacques, Christopher N.

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https://hdl.handle.net/2142/102227 Copy

Description

Title

True metabolizable energy of submersed aquatic vegetation in semi-permanent marshes for dabbling ducks in the Upper Midwest

Author(s)

• Lancaster, Joseph D.
• Yetter, Aaron P.
• Hagy, Heath M.
• Gross, Margaret C.
• McClain, Sarah E.
• Simpson, John W.
• Jacques, Christopher N.

Issue Date

2018-12-21

Keyword(s)

• energetic carrying capacity
• duck energy day
• daily ration model
• duck food
• energetic use day
• aerial survey
• wetland community, aquatic bed

Geographic Coverage

Illinois River Valley, Illinois

Abstract

We completed 186 TME assays with mallards (n = 72) and gadwall (n = 114) between 2015 and 2018. Bioavailable energy (i.e., TME) of submersed aquatic vegetation was highly variable among duck and vegetation species as supported by their interaction in the most parsimonious model (wi = 0.42; R2m = 0.33, R2c = 0.47). For gadwall, mean TME (± SE; kcal/g[dry]) was greatest for Eurasian watermilfoil (0.77 ± 0.32, n = 19), followed by Canadian waterweed (0.70 ± 0.31, n = 20), coontail (0.55 ± 0.28, n = 18), southern naiad (–0.61 ± 0.34, n = 17), wild celery (–0.98 ± 0.39, n = 20), sago pondweed (–1.07 ± 0.33, n = 20). Mallards assimilated greatest energy from Canadian waterweed (1.66 ± 0.26, n = 13), followed by coontail (1.51 ± 0.28, n = 8), southern naiad (1.37 ± 0.39, n = 14), sago pondweed (0.50 ± 0.22, n = 14), wild celery (0.05 ± 0.42, n = 11), and Eurasian watermilfoil (–0.13 ± 0.26, n = 12). There was evidence from a competing model (wi = 0.11; R2m = 0.34, R2c = 0.47) that females acquired 0.52 kcal/g (± 0.34) more energy from vegetation than males and that TME declined 0.20 kcal/g (± 0.16) for every 100 g increase in initial mass. We estimated energetic carrying capacity at 318 random points within 20 wetlands across three years (2015–2017) in the Midwest, USA (Simpson et al. 2017). Across all points, Ceratophyllum spp. was the most commonly encountered genera (n = 188) of submersed aquatic vegetation, followed by Myriophyllum spp. (n = 64), Najas spp. (n = 47), Elodea spp. (n = 41), and Stuckenia spp. (n = 36). These five genera comprised 91.5% of the total energy density across all points and years. Extrapolated energy density estimated at sample points ranged from 0 to 5,624 EUD/ha (𝑥𝑥̅ = 426 ± 52) and biomass estimates ranged from 0 to 2,340 kg/ha (dry) (𝑥𝑥̅ = 204 ± 22). Evidenced from the best supported model (wi = 0.68; R2m = 0.19, R2c = 0.27), energy density was 195 EUD/ha (85% CI = 39 – 964) greater at managed points than unmanaged points, decreased 2 EUD/ha (85% CI = 1 – 3) for every 100 cm increase in water depth, increased 9 EUD/ha (85% CI = 6 – 12) for every 100 cm increase in Secchi depth, and increased 3 EUD/ha (85% CI = 0 – 11) if emergent vegetation was present.

Publisher

Illinois Natural History Survey

Series/Report Name or Number

Technical Report INHS 2018 (42)

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/102227

Sponsor(s)/Grant Number(s)

Upper Mississippi River and Great Lakes Joint Venture U.S. Fish and Wildlife Service, Region 3, Contract Number F15AP00687

Copyright and License Information

This document is a product of the Illinois Natural History Survey, and has been selected and made available by the Illinois Natural History Survey and the University Library, University of Illinois at Urbana-Champaign. It is intended solely for noncommercial research and educational use, and proper attribution is requested.

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