Collected Evidence: Collected Evidence: Enforce legislation to protect birds against persecution Two before-and-after studies have evaluated effects of legislative protection on bird species in Europe. Both found that legislation protects bird populations. One found increased population levels of raptors in Scotland, following protective legislation. One found increased survival of kestrels in Denmark stricter protection, but not necessarily population-level responses. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F101https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F101Mon, 24 Oct 2011 21:55:47 +0100Collected Evidence: Collected Evidence: Control invasive non-native plants on farmland (such as Himalayan Balsam, Japanese knotweed) Two randomized, replicated, controlled trials in the Czech Republic found that removing all flower heads of giant hogweed plants at peak flowering time dramatically reduced seed production in giant hogweed.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F104https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F104Mon, 24 Oct 2011 21:59:27 +0100Collected Evidence: Collected Evidence: Control bracken One systematic review found that the herbicide asulam reduced bracken abundance if applied repeatedly, but cutting may be equally effective. A replicated laboratory trial in the UK found that the herbicide asulam inhibited the growth of three common moss species that commonly grow in association with bracken, when exposed over three weeks, but not if only exposed for 24 hours.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F105https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F105Mon, 24 Oct 2011 22:00:36 +0100Collected Evidence: Collected Evidence: Control mink A systematic review found seven studies demonstrating that trapping appears to be an effective method of reducing American mink populations, but firm conclusions could not be made due to limitations in experimental design. A large-scale trapping programme in the UK demonstrated that American mink have been successfully eradicated over a large area and this may have been associated with some localized water vole expansions. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F107https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F107Mon, 24 Oct 2011 22:02:53 +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 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 owls to increase reproductive success Two replicated and controlled trials from Europe and the USA found that owls supplied with supplementary food had higher hatching and fledging rates than control pairs. The European study, but not the American, also found that fed pairs laid earlier  and had larger clutches The American study also found that owls were no more likely to colonise nest boxes provided with supplementary food.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F533https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F533Sun, 09 Sep 2012 19:15:10 +0100Collected Evidence: Collected Evidence: Provide supplementary food for wildfowl to increase adult survival Two studies from Canada and Northern Ireland found that five species of wildfowl readily consumed supplementary food (grains and seeds). Only the Canadian study assessed the physiological effects of feeding, and found that fed birds were heavier and had larger hearts or flight muscles or had more body fat than controls  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F542https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F542Sun, 16 Sep 2012 08:47:27 +0100Collected Evidence: Collected Evidence: Provide supplementary food for raptors to increase adult survivalTwo randomised, replicated and controlled studies in the USA found that nesting northern goshawks Accipiter gentilis were significantly heavier in territories supplied with supplementary food, compared with those from unfed territories.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F546https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F546Sun, 16 Sep 2012 09:12:47 +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 pigeons to increase adult survival A study of a recently-released pink pigeon Nesoenas mayeri population on Mauritius found that fewer than half the birds used supplementary food, and appeared to survive without it. However, a later study of the population found that almost all birds were recorded using supplementary feeders.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F549https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F549Sun, 16 Sep 2012 09:24:17 +0100Collected Evidence: Collected Evidence: Translocate pelicansTwo reviews of a brown pelican Pelecanus occidentalis translocation programme in the USA found high survival of translocated nestlings and that the target population grew enormously, to over 16,000 nests. The authors note that some of the growth may have been due to immigration from the source populations.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F569https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F569Sun, 30 Sep 2012 12:58:02 +0100Collected Evidence: Collected Evidence: Translocate owls A small study from New Zealand found that translocating two male boobook Ninox novaeseelandiae novaeseelandiae allowed the establishment of a small population, when they interbred with the last remaining Norfolk Island boobook N. n. undulata A replicated study in the USA found high survival amongst burrowing owls Athene cunicularia translocated as juveniles, although no breeding was recorded and all birds left the release site and were not seen again.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F576https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F576Sun, 30 Sep 2012 14:32:21 +0100Collected Evidence: Collected Evidence: Use techniques to increase the survival of species after capture A small controlled study from the USA found that providing dark, quiet environments with readily-available food and water increased the survival of small birds after capture and increased the probability that they would accept captivity. A study from Hawaii found that keeping birds warm in a ‘mock’ translocation in Hawaii increased survival, although all birds suffered some loss of condition.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F581https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F581Sat, 06 Oct 2012 21:18:18 +0100Collected Evidence: Collected Evidence: Ensure translocated birds are familiar with each other before releaseTwo controlled trials from New Zealand found no evidence that translocating birds which were familiar with each other was more likely to succeed than translocating unfamiliar birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F582https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F582Sat, 06 Oct 2012 21:23:28 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear penguins in captivityTwo replicated and controlled studies from South Africa found that hand-reared and released African penguins Spheniscus demersus had similar survival and breeding success as birds which were not orphaned and hand-reared.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F605https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F605Sat, 13 Oct 2012 17:08:04 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear cranes in captivityA replicated and controlled study and a small study, both from the USA, found that hand-reared birds showed normal reproductive behaviour and higher survival than parent-reared birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F609https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F609Sat, 13 Oct 2012 17:44:21 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear bustards in captivity A review of a houbara bustard Chlamydotis undulata macqueenii captive breeding programme in Saudi Arabia found that there was no difference in survival between artificially and parentally incubated eggs. A second review of the same programme found that removing eggs from clutches as they were laid increased the number laid by females.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F610https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F610Sat, 13 Oct 2012 17:57:07 +0100Collected Evidence: Collected Evidence: Artificially incubate and hand-rear storks and ibises in captivityA small study in the USA describes the successful artificial incubation and hand-rearing of two Abdim’s stork Ciconia abdimii chicks, whilst a review of northern bald ibis Geronticus eremita conservation found that only very intensive rearing of a small number of chicks appeared to allow strong bonds to form between chicks – thought to be important for the successful release of birds into the wild.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F612https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F612Sun, 14 Oct 2012 11:55:51 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of storks and ibisesA replicated study and a review of northern bald ibis Geronticus eremita release programmes in Europe and the Middle East found that only one of four had resulted in a wild population being established or supported, with many birds dying or dispersing, rather than forming stable colonies.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F624https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F624Sun, 14 Oct 2012 14:38:18 +0100Collected Evidence: Collected Evidence: Release captive-bred individuals into the wild to restore or augment wild populations of owls A study in the USA found that a barn owl Tyto alba population was established following the release of 157 birds in the area over three years. A replicated, controlled study in Canada found that released burrowing owls Athene cunicularia had similar reproductive output, but higher mortality than wild birds, and no released birds returned after migration, although return rates for released birds’ offspring were no different from wild birds.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F627https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F627Sun, 14 Oct 2012 22:47:34 +0100Collected Evidence: Collected Evidence: Use appropriate populations to source released populations A replicated study from Sweden and a small study from France found that birds sourced from populations distant from where they were released were less successful than birds from the area. In Sweden, released white storks Ciconia ciconia from North Africa produced fewer than half the chicks as those that naturally re-colonised, whilst both studies found that storks and little bustards Tetrax tetrax were less likely to migrate than birds originating in the release area.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F631https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F631Sun, 14 Oct 2012 23:16:17 +0100Collected Evidence: Collected Evidence: Use ‘anti-predator training’ to improve survival after release A review from Pakistan and a small trial from Saudi Arabia found that pheasants and bustards had higher survival after release, when given pre-release predator training, compared to birds without training, many of which were predated. The Saudi Arabian study found that introducing a model fox (as opposed to a live predator) to cages did not increase post-release survival. Introducing a live fox to the cage increased post-release survival more than other techniques used.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F637https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F637Sun, 14 Oct 2012 23:49:41 +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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