Study

Survival and movements of greater sandhill cranes experimentally released in Florida

  • Published source details Nesbitt S.A. & Carpenter J.W. (1993) Survival and movements of greater sandhill cranes experimentally released in Florida. The Journal of Wildlife Management, 57, 673-679.

Actions

This study is summarised as evidence for the following.

Action Category

Foster eggs or chicks of cranes with wild non-conspecifics (cross-fostering)

Action Link
Bird Conservation

Release captive-bred individuals into the wild to restore or augment wild populations of cranes

Action Link
Bird Conservation
  1. Foster eggs or chicks of cranes with wild non-conspecifics (cross-fostering)

    As part of the planning for a whooping crane Grus americana reintroduction programme, a replicated study in Florida, USA, in 1982-7 (Nesbitt & Carpenter 1993) found that 22% of 23 wild Florida sandhill crane G. canadensis pratensis pairs successfully fledged chicks from captive-laid greater sandhill crane G. c. tabida eggs fostered in their nests. A further 35% hatched at least one egg but failed to fledge any chicks, 26% began incubation but then abandoned the substituted eggs and 17% immediately abandoned the eggs. Overall, survival of 34 cross-fostered eggs was 39% (from hatching to leaving the territory), lower than the 56% survival of captive-bred and released cranes, discussed in ‘Release captive-bred individuals’. The eggs came from a combination of wild birds in Idaho, USA, and captive birds from Florida. Greater sandhill cranes are migratory, whilst Florida sandhill cranes are not. Migratory movements of fostered birds were larger than a control group of Florida sandhill cranes, but not significantly so.

     

  2. Release captive-bred individuals into the wild to restore or augment wild populations of cranes

    A replicated study as part of the planning for a whooping crane Grus americana reintroduction programme, a study in Florida, USA, in 1986-7 (Nesbitt & Carpenter 1993) found that greater sandhill cranes Grus canadensis tabida released as sub-adults in a ‘soft release’ programme had higher survival than birds fostered to Florida sandhill cranes G. c. pratensis (56% of 27 birds surviving for one year vs. 39% survival for 34 fostered birds, discussed in ‘Foster eggs or chicks with wild non-conspecifics (cross-fostering)’). The nine to ten month-old cranes were prevented from flying and kept in an open-topped 1.5 ha enclosure for four to six weeks until they were released. Food was provided until the birds no longer returned to the enclosure. Greater sandhill cranes are migratory, whilst Florida sandhill cranes are not. Migratory movements of released birds were larger than a control group of Florida sandhill cranes, but not significantly so.

     

Output references
What Works 2021 cover

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, 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