Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Provide supplementary food for songbirds to increase adult survival Seven studies from Europe and the USA found higher densities or larger populations in various songbird species in areas close to supplementary food. Six studies from Europe, Canada and Japan found that population trends or densities in some species were no different between fed and unfed areas. The American study found that populations appeared to follow food, with populations increasing after feeders were erected and decreasing after they were removed. Four studies from Canada, Europe, Japan and the USA found that birds had higher survival when supplied with supplementary food. However, in two studies this was only apparent in females or in one of two species studied. A controlled study in the USA found no evidence that birds were dependent on supplementary food: when food was removed, previously fed birds did not have lower survival than controls. A replicated, controlled study from the USA found that song sparrows Melospiza melodia had lower survival with feeding stations in their territories. Six studies from Europe and the USA found that birds supplied with supplementary food were in better physical condition or had larger fat supplies than unfed birds. However, in one replicated, controlled study this was only the case for females; in another two, only one of three species showed better condition, with one species in one study showing lower condition when fed; a final replicated and controlled study found that differences between treatments were only apparent in the breeding season. Two studies investigated the effect of feeding on behaviours: a randomised, replicated and controlled study in the USA found that male Carolina wrens Thryothorus ludovicianus spent more time singing when supplied with food; a replicated, controlled study in Sweden found no behavioural differences between wood nuthatches Sitta europaea supplied with food, and unfed birds. Thirteen studies from the UK, Canada and the USA investigated use of feeders. Four studies from the USA and the UK found high use of supplementary food by several species, with up to 21% of birds’ daily energy needs coming from feeders. However, another UK study found very low use of food, possibly because the feeder was not positioned close to natural food sources. One UK study found that use of feeders peaked in midwinter, although another found that the exact timing of peak use varied between species. Two replicated trials from the UK finding that the use of feeders increased with distance to houses and decreased with distance to cover, whilst a replicated Candadian study found that American goldfinches Carduelis tristis preferred using bird feeders in high positions. A large-scale replicated study in the UK found that preferences for feeder locations varied between species. Three studies from the UK argue that placing feeders over 1 km apart, and possibly 1.1–1.3 km apart will maximise their use whilst keeping the intervention practical. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F552https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F552Sat, 22 Sep 2012 17:27:20 +0100Collected Evidence: Collected Evidence: Provide supplementary food for nectar-feeding songbirds to increase adult survival Two studies from Australia and New Zealand found that ten species of honeyeaters and stitchbirds Notiomystis cincta readily used feeders supplying sugar solutions, with seasonal variations varying between species and stitchbirds spending more time foraging for insects when food was supplied. A series of ex situ trials using southern African birds found that most species tested showed a preference for sucrose solutions over glucose or fructose. One study found that sunbirds and sugarbirds only showed such a preference at low (equimolar) concentrations. Two more studies found that two species showed preferences for sucrose when comparing 20% (by weight) solutions, although a third species did not show this preference. All species rejected solutions with xylose (a natural sugar in nectar) added. A final study found that sucrose preferences only became apparent at equicalorific concentrations high enough for birds to subsist on. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F553https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F553Sat, 22 Sep 2012 20:11:36 +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: Provide supplementary food through the establishment of food populations One pre-1950 study in the USA found that waterfowl fed on specially-planted rye grass. Three studies from North America and Sweden found that attempts to support populations by establishing prey did not succeed. Whooping cranes Grus americana in the USA preferentially fed on scattered grains, over planted crops; attempts in Sweden to boost macroinvertebrate numbers were not successful and great horned owls Bubo virginianus in Canada did not respond to induced increases in prey populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F555https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F555Sat, 22 Sep 2012 20:40:45 +0100Collected Evidence: Collected Evidence: Use perches to increase foraging success Two studies from the USA found that raptors and other birds used perches provided, whilst a replicated and controlled study in Sweden found that raptors used clearcuts with perches significantly more than those without. However, a controlled study from the USA found that overall bird abundances were not higher in areas provided with perches and a small controlled cross-over trial on an island in the USA found that San Clemente loggerhead shrikes Lanius ludovicianus mearnsi did not alter their hunting patterns or increase their success rates following the installation of perches in their territories. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F556https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F556Sun, 23 Sep 2012 15:05:36 +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 supplementary water to increase survival or reproductive successA controlled study in Morocco found that water supplemented northern bald ibis Geronticus eremite pairs had significantly higher reproductive success than those far from water sources. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F558https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F558Sun, 23 Sep 2012 15:16:43 +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 +0100Collected Evidence: Collected Evidence: Translocate individualsA review of 239 bird translocation programmes found 63–67% resulted in establishment of self-sustaining populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F566https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F566Sun, 30 Sep 2012 12:46:30 +0100Collected Evidence: Collected Evidence: Translocate megapodesA replicated study from Indonesia found that up to 78% of maleo Macrocephalon maleo eggs hatched after translocation, with higher success if eggs were reburied as they were found. There was only anecdotal evidence that the translocations increased local populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F567https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F567Sun, 30 Sep 2012 12:49:00 +0100Collected Evidence: Collected Evidence: Translocate petrels and shearwatersTwo studies from Australia and one from New Zealand found that colonies of burrow-nesting Procellariiformes were successfully established on two islands, and in uninhabited areas of another following the translocation and hand-rearing of chicks. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F568https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F568Sun, 30 Sep 2012 12:54:24 +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 auksA replicated study in the USA and Canada found that 20% of 774 translocated Atlantic puffins Fratercula arctica remained in or near the release site, with up to 7% breeding. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F570https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F570Sun, 30 Sep 2012 13:02:20 +0100Collected Evidence: Collected Evidence: Translocate wildfowl Three studies of two duck translocation programmes in New Zealand and Hawaii found high post-release survival, breeding and the successful establishment of new populations. A replicated study in USA found that none of 391 blue-winged teal Querquedula discors stayed in the release site and that there was high mortality after release. A replicated, controlled study in the USA found that wing-clipping female wood ducks Aix sponsa during translocation prevented them from abandoning their ducklings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F571https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F571Sun, 30 Sep 2012 13:18:26 +0100Collected Evidence: Collected Evidence: Translocate gamebirds Three studies from the USA found that translocation of gamebirds resulted in population establishment or growth, or an increase in lekking sites. Four studies from the USA found high survival of translocated birds, although one, from Alaska found that translocated birds had high initial mortality, which then fell to levels close to those in resident birds. Two studies from the USA found high mortality in translocated birds. Four studies from the USA found breeding rates that were high, or similar to resident birds, amongst translocated birds. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F572https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F572Sun, 30 Sep 2012 13:50:44 +0100Collected Evidence: Collected Evidence: Translocate rails Three reviews of two translocation programmes in the Seychelles and New Zealand found high survival amongst translocated rails. All studies found that translocated birds bred successfully, although one found that translocated takahe Porphyrio hochstetteri had lower reproductive success than birds in the source population. The other New Zealand study found no differences in breeding success between recently and formerly translocated takahe. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F573https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F573Sun, 30 Sep 2012 13:58:55 +0100Collected Evidence: Collected Evidence: Translocate raptors Six studies of three translocation programmes in the UK and the USA found that all three successfully established populations of white-tailed eagles Haliaeetus albicilla, red kites Milvus milvus and ospreys Pandion halieatus. However, the latest review of the programme to reintroduce red kites to England and Scotland reported that one of six populations was very small, with only four pairs, despite 90 birds being released. A replicated study in Spain found high survival and establishment of translocated Montagu’s harrier Circus pygargus fledglings. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F574https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F574Sun, 30 Sep 2012 14:09:28 +0100Collected Evidence: Collected Evidence: Translocate herons, storks and ibisesA before-and-after study in the USA found that a colony of black-crowned night herons Nycticorax nycticorax was successfully moved, with the new colony producing chicks the year after translocation. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F575https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F575Sun, 30 Sep 2012 14:25:50 +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: Translocate woodpeckers All five translocation programmes studied were for red-cockaded woodpeckers Picoides borealis in the southern USA. Six studies of four programmes found that >50% of translocated birds remained in their new sites, with two studies of the same programme reporting a large population increase. Birds from four programmes were reported as forming pairs or breeding, although some translocated pairs split up and some translocated nestlings were abandoned. One study found that translocated nestlings fledged at similar rates to native chicks. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F577https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F577Sun, 30 Sep 2012 14:34:11 +0100Collected Evidence: Collected Evidence: Translocate parrots Three studies of two translocation programmes from the Pacific and New Zealand found that populations of parrots were successfully established on islands following translocations, including the colonisation of other islands in the New Zealand study. Survival of translocated birds was monitored in five studies of four programmes from across the world and ranged from 41% over 60 days for red-fronted parakeets Cyanoramphus novaezelandiae in New Zealand to 98% for kakapos Strigops habroptila in New Zealand. Survival for translocated thick-billed parrots Rhynchopsitta pachyrhyncha in the USA was higher than for captive-bred birds. Despite very high survival, kakapos that were translocated had very low reproductive output in New Zealand. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F578https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F578Sun, 30 Sep 2012 14:41:44 +0100Collected Evidence: Collected Evidence: Translocate songbirds Nine studies from across the world, including a review of 31 translocation attempts in New Zealand found that translocations led to the establishment of songbird populations. The review found that 79% and 100% of translocation programmes for saddlebacks Philesturnus carunculatus and New Zealand robins Petroica australis, respectively, were successful in establishing populations. Eight of the studies were from islands, mostly following predator removal. Three studies from Zimbabwe, New Zealand and the USA report on three translocation programmes that failed to establish populations. A methodological paper found that the nesting success of saddlebacks decreased as the latitudinal difference between source area and release site increased. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F580https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F580Sat, 06 Oct 2012 12:49:36 +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: Ensure genetic variation to increase translocation success We did not find any studies on the effects of ensuring genetic variation in translocated birds. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F583https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F583Sat, 06 Oct 2012 21:25:41 +0100