Collected Evidence: Collected Evidence: Foster eggs or chicks of gannets and boobies with wild conspecificsA small controlled study in Australia found that Australasian gannet chicks Morus serrator were lighter, and hatching and fledging success lower in nests which had an additional egg or chick added. However, overall productivity was (non-significantly) higher in experimental nests.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F507https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F507Thu, 06 Sep 2012 14:17:32 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of waders with wild conspecifics Two small trials in North America found that piping plovers Charadrius melodus accepted chicks introduced into their broods, although in one case the chick died later the same day. A replicated study from New Zealand found that survival of fostered black stilts Himantopus novasezelandiae was higher for birds fostered to conspecifics rather than a closely related species.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F508https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F508Thu, 06 Sep 2012 14:30:39 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of vultures with wild conspecificsTwo small studies, one a New World vulture and one of an Old World species found that single chicks were successfully adopted by foster conspecifics, although in one case this led to the death of one of the foster parents’ chicks.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F509https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F509Thu, 06 Sep 2012 14:34:30 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of raptors with wild conspecifics Ten out of 11 studies from across the world found that fostering raptor chicks to wild conspecifics had high success rates. A single study from the USA found that only one of six eggs fostered to wild bald eagle Haliaeetus leucocephalus nests were hatched and raised. The authors suggest that the other eggs may have been infertile. A replicated study from Spain found that Spanish imperial eagle Aquila adalberti chicks were no more likely to survive to fledging if they were transferred to foster nests from three chick broods (at high risk from siblicide), compared to chicks left in three-chick broods. A replicated study from Spain found that young (15–20 years old) Montagu's harrier Circus pygargus chicks were successfully adopted, but three older (27–29 day old) chicks were rejected.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F510https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F510Thu, 06 Sep 2012 14:42:31 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of owls with wild conspecifics A replicated study in the USA found high fledging rates for barn owl Tyto alba chicks fostered to wild pairs. A replicated controlled study from Canada found that captive-reared burrowing owl Athene cunicularia chicks fostered to wild nests did not have significantly lower survival or growth rates than wild chicks.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F511https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F511Thu, 06 Sep 2012 15:57:35 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of cranes with wild conspecificsA small study in Canada found high rates of fledging for whooping crane Grus americana eggs fostered to first time breeders (which normally have very low fertility).  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F512https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F512Thu, 06 Sep 2012 16:13:08 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of bustards with wild conspecificsA small study in Saudi Arabia found that a captive-bred egg was successfully fostered to a female in the wild.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F513https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F513Thu, 06 Sep 2012 16:18:42 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of woodpeckers with wild conspecifics Three studies from the USA found that red-cockaded woodpecker Picoides borealis chicks fostered to conspecifics had high fledging rates. One small study found that fostered chicks survived better than chicks translocated with their parents.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F514https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F514Thu, 06 Sep 2012 16:29:20 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of parrots with wild conspecifics A replicated study from Venezuela found that yellow-shouldered Amazon Amazona barbadensis chicks had high fledging rates when fostered to conspecific nests in the wild. A second replicated study from Venezuela found significantly lower poaching rates of yellow-shouldered Amazons Amazona barbadensis when chicks were moved to foster nests closer to a field base.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F515https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F515Thu, 06 Sep 2012 16:34:58 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of petrels and shearwaters with wild non-conspecifics (cross-fostering)A replicated and partially controlled study from Hawaii found that Newell’s shearwater Puffinus newelli eggs fostered to wedge-tailed shearwater P. pacificus nests had high fledging rates.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F516https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F516Thu, 06 Sep 2012 16:54:21 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of waders with wild non-conspecifics (cross-fostering) A replicated and controlled study from the USA found that killdeer Charadrius vociferus eggs incubated and raised by spotted sandpipers Actitis macularia had similar fledging rates to parent-reared birds. A replicated and controlled study from New Zealand found that cross-fostering black stilt Himantopus novasezelandiae chicks to black-winged stilt H. himantopus nests significantly increased nest success, but that cross-fostered chicks had lower success than chicks fostered to conspecifics’ nests.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F517https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F517Thu, 06 Sep 2012 17:03:55 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of cranes with wild non-conspecifics (cross-fostering)Two studies from the USA found low fledging success for cranes fostered to non-conspecifics’ nests.    Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F519https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F519Thu, 06 Sep 2012 17:13:19 +0100Collected Evidence: Collected Evidence: Foster eggs or chicks of songbirds with wild non-conspecifics (cross-fostering) A replicated study from the USA found that the survival of cross-fostered yellow warbler Dendroica petechia chicks was lower than previously-published rates for the species, although incubation and nestling periods were very similar. A replicated and controlled study from Norway found that the success of cross-fostering small songbirds varied depending on the species of chick and foster birds. However, only great tits P. major raised by blue tits P. caeruleus had lower pairing success than control birds, whilst blue tits raised by coal tits P. ater had higher recruitment than controls, or those raised by great tits.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F520https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F520Thu, 06 Sep 2012 17:37:20 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gulls, terns and skuas to increase reproductive success Four studies of three experiments from Europe and Alaska found that providing supplementary food increased fledging success or chick survival in two gull species, although a study from the UK found that this was only true for one island, with abnormally low breeding success. A second island with higher success was not affected by feeding. Two of the experiments fed parent birds and one fed the chicks directly. One study from the Antarctic found no effect of feeding parent skuas on productivity. One study from Alaska found increased chick growth when parents were fed; one study from the Antarctic found no increase in chick growth.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F525https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F525Sat, 08 Sep 2012 13:37:48 +0100
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.

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