Study

Effects of herbicide treatment on vegetation structure and common tern Sterna hirundo nesting success at a breeding colony on Lime Island, Michigan, USA

  • Published source details Cook-Haley B.S. & Millenbah K.F. (2002) Impacts of vegetative manipulations on common tern nest success at Lime Island, Michigan. Journal of Field Ornithology, 73, 174-179

Summary

This study investigated the effects of herbicide treatment on vegetation structure plus nest-site selection and nesting success of common terns Sterna hirundo at a breeding colony on an old coal dock (colonised by grasses and forbs) on Lime Island (46°05'N, 84°01'W) in the Saint Mary's River, Michigan, northern USA.

 

In 1998, more than two weeks before the arrival of terns, vegetation manipulations were carried out in a 25 × 50 m area of the nesting colony. The experimental area was divided into 5 × 5 m plots, which were randomly allocated to one of three treatments: all vegetation sprayed with herbicide ('fully sprayed'; n = 16 plots); any vegetation over 1 m in height, or likely to exceed 1 m during the growing season, sprayed with herbicide ('partially sprayed'; n = 17); or left untreated (n = 17). The herbicide used was Round-Up® (120 ml/3.6 l water).

Nests were subsequently checked every 2–3 days from May to August to monitor clutch size, hatching success and the fate of eggs.

 

 

Not all plots were used by nesting terns, but 131 nests were initiated in nine fully sprayed plots (average: 14.6 nests/used plot), 47 nests in seven blocks partially sprayed plots (6.7 nests/plot), and 50 nests in 11 control plots (4.5 nests/plot). Average clutch size did not differ significantly among the three plot types. Fully sprayed plots had significantly lower standing vegetation cover (24% versus 41%) and higher litter cover (68% versus 52%) than partially sprayed plots.
Nest success was affected by treatment type, with the proportion of nests that were successful (i.e. hatched at least one egg) highest in partially sprayed plots (72%), intermediate in untreated plots (64%) and lowest in fully sprayed plots (37%).
Hence, despite their apparent preference for areas with low standing vegetation cover (i.e. fully sprayed plots) when selecting nest sites, terns had highest nesting success in areas with moderate amounts (40–50%) of standing vegetation cover.

Note: If using or referring to this published study, please read and quote the original paper, the abstract of which can be viewed at: http://www.jstor.org/stable/info/4131141

 

Output references

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.


Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust