Collected Evidence: Collected Evidence: Provide supplementary foodA replicated, controlled study from Europe found that overall, gardens with supplementary food did not contain more species than those without. However, there was some evidence that gardens with supplementary food in five countries did contain more species than unfed ones, when countries were analysed separately.   For specific interventions see: provide supplementary foodCollected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F521https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F521Sat, 08 Sep 2012 13:18:10 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gannets and boobies to increase reproductive success A small controlled study in Australia found that Australasian gannet Morus serrator chicks were significantly heavier if they were supplied with supplementary food, but only in one of two years. Fledging success of fed nests was also higher, but not significantly so. A randomised replicated and controlled study in the Galapagos Islands found that fed female Nazca boobies Sula granti were more likely to produce two-egg clutches if they were fed, and that second eggs were significantly heavier.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F523https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F523Sat, 08 Sep 2012 13:25:20 +0100Collected Evidence: Collected Evidence: Provide supplementary food for auks to increase reproductive success Two replicated and controlled studies from the UK found that Atlantic puffin Fratercula arctica chicks provided with supplementary food were significantly heavier than control chicks. One study found differences between populations, suggesting some are more food-limited than others. The two UK studies found that fed chicks fledged at the same time as controls, whilst a randomised, replicated and controlled study from Canada found that tufted puffin Fratercula cirrhata chicks supplied with supplementary food fledged later than controls. The Canadian study found that fed chicks had faster growth by some, but not all, metrics.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F524https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F524Sat, 08 Sep 2012 13:32:31 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gamebirds to increase reproductive successA controlled study in Tibet found that Tibetan eared pheasants Crossoptilon harmani that were fed supplementary food laid significantly larger eggs and clutches than control birds. Nesting success and laying dates were not affected.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F527https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F527Sun, 09 Sep 2012 17:34:24 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gamebirds to increase adult survival Two European studies found increased numbers of grey partridge Perdix perdix in fed areas, compared to unfed areas. In one study there was no change in the overall population in the study area, in the second there was an increase. One cross-over study from the USA found that northern bobwhites Colinus virginianus had higher overwinter survival in fed areas, one found lower survival and a literature review found no overall effect of feeding.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F544https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F544Sun, 16 Sep 2012 09:01:06 +0100Collected Evidence: Collected Evidence: Provide supplementary food for cranes to increase adult survivalA before-and-after study from Japan and a global literature review found that local crane populations increased after the provision of supplementary food.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F547https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F547Sun, 16 Sep 2012 09:19:25 +0100Collected Evidence: Collected Evidence: Provide supplementary food for gulls, terns and skuas to increase adult survivalA randomised, replicated and controlled study in the Antarctic found that female south polar skuas Catharacta maccormicki that were fed lost more weight whilst feeding two chicks than unfed birds. There was no difference for birds with single chicks, or male birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F548https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F548Sun, 16 Sep 2012 09:21:14 +0100Collected Evidence: Collected Evidence: Can supplementary feeding increase predation or parasitism? A replicated, controlled study in the USA found that providing seeds in predictable areas did not increase predation on seven species of songbird. A replicated and controlled trial in Spain found higher levels of potentially dangerous gut microflora when fed on livestock carrion, compared to those fed on wild rabbits. A replicated study in Spain found higher levels of predation on artificial nests close to carcasses provided for vultures.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F554https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F554Sat, 22 Sep 2012 20:37:07 +0100Collected Evidence: Collected Evidence: Place feeders close to windows to reduce collisionsA randomised, replicated and controlled experiment in the USA found that placing bird feeders close to windows reduced the number of collisions with the windows and the number of fatal collisions.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F557https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F557Sun, 23 Sep 2012 15:13:35 +0100Collected Evidence: Collected Evidence: Provide calcium supplements to increase survival or reproductive success Eight studies from across the world, including a literature review from across the world found evidence for positive effects of calcium supplementation on several bird species. Positive effects included lower incidence of bone disease, higher fledging succes, larger broods, higher quality eggs or chicks and better physical condition of female parents. Not all species reacted similarly. Six studies including a literature review did not find any evidence for increased reproductive success in at least one of the species supplied with supplementary calcium. One replicated study from Europe found that birds took calcium supplied, and birds at polluted sites took more than those at cleaner sites. The effects on fitness were not monitored.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F559https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F559Sun, 23 Sep 2012 15:19:49 +0100
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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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