The use of supplementary foods by Australian magpies Gymnorhina tibicen: Implications for wildlife feeding in suburban environments

Abstract The provision of foods to wild birds is an extremely common practice among householders throughout the Western world. Nonetheless, concerns over potential impacts of the practice are currently being raised, including the possibility that some species may become reliant on human‐provided food. We compared the foraging and breeding ecology of pairs of fed and unfed Australian magpies Gymnorhina tibicen living in suburban environments in Brisbane, Queensland, Australia. Detailed behavioural observations of both foraging and chick provisioning were made for males and females of both groups throughout the breeding season. Natural foods dominated the diets of both fed and unfed magpies, making up 76% and 92% of all items consumed respectively. During the morning, fed magpies obtained fewer food items during ground foraging than did unfed birds, apparently because they visited suburban feeding stations more often during the early part of the day. At other times, the amount of food items obtained during foraging was similar for both fed and unfed birds. Magpies utilizing suburban feeding stations started all breeding activities significantly earlier than unfed magpies, except during the fledgling phase. Both fed and unfed magpie parents provisioned their chicks predominantly with natural food. Magpies were not reliant or dependent on supplementary food provided by wildlife feeders at any time during the breeding season. Although many magpies did utilize suburban feeding stations extensively, they continued to forage for and provision their chicks with natural food.     

Effect of supplementary feeding of Oecophylla longinoda on their abundance and predatory activities against cashew insect pests

Many studies have shown the efficiency of using weaver ants (Oecophylla species) as natural biocontrol agents against agricultural pests. Supplementary feeding could promote fast growth of this ant's population and discourage them from moving away. However, such artificial feeding might slow down ants search rates and in this way make them less efficient bio-agents. The experiments were conducted for two consecutive seasons at Naliendele Research Station. Cashew trees planted at a spacing of 12 m × 12 m in 2002 were used to investigate whether supplementary feeding could enhance foraging behaviour of Oecophylla longinoda. Fed O. longinoda colonies fed weaver ants (FWA) were supplemented with a 30% sugar solution and approximately 22 g of finely ground fish meat at two-week intervals while the unfed colonies unfed weaver ants (UWA) had access to only naturally occurring food sources. Weaver ant densities and pest damage were monitored fortnightly on newly damaged shoots, panicles and fruits and nut yields assessed after each harvest season. The results revealed that there was a significant difference (P < 0.05) with higher weaver ant densities in the FWA compared to UWA colonies and significantly lower (P < 0.05) pest damage levels were recorded on weaver ant treatments compared to plots without weaver ants. No significant differences (P > 0.05) in yields and mean damage levels were recorded between the two weaver ant treatments. Highest nut yield (4.22 ± 0.30 kg/tree and 5.37 ± 0.27 kg/tree) was recorded in the fed colonies, followed by non-fed colonies (4.20 ± 0.30 kg/tree and 4.88 ± 0.24 kg/tree) and the least (2.66 ± 0.19 kg/tree and 2.99 ± 0.19 kg/tree) was recorded from the untreated controls in 2012/2013 and 2013/2014, respectively. The studies indicated that supplementary feeding could boost weaver ants to higher population levels without reducing their effectiveness as biocontrol agents.     

Effects of supplementary feeding on territoriality, breeding success and survival of pheasants

1. The effects of supplementary food in spring on subsequent pheasant breeding in an intensively farmed area in southern England were assessed by a large-scale, replicated field experiment.
2. Territorial cock pheasants were counted in April, and the breeding success and survival of radio-tagged hens were monitored in six 1-km² plots during 1994 and 1995. Total numbers of young reared and post-breeding pheasant densities were found by August counts. In 1994, three randomly selected plots were supplied with wheat grains via hoppers along woodland edges and hedgerows. The other three plots acted as controls and the treatments were reversed in 1995.
3. The density of cock territories increased significantly in food-supplemented plots (44 ± 8 km−2) in relation to control plots (29 ± 8 km−2), and the presence of hoppers significantly affected the locations of territories. However, similar proportions of territorial males acquired harems in the control and food-supplemented plots. Hen density did not increase and, consequently, the mean harem size was significantly lower with supplementary feeding.
4. Hens given supplementary food did not nest earlier and the number of nests initiated, clutch sizes and the proportion of successful nests did not differ significantly from those of controls. However, hens supplied with supplementary food re-nested significantly more quickly following the loss of a nest or brood.
5. Radio-tagged hens did not rear significantly more young with supplementary feeding. Hen survival was unchanged and post-breeding pheasant densities were no higher.
6. On present evidence, spring feeding cannot be advocated as a management technique to improve the breeding success of pheasants surviving the winter.     

In situ feeding as a new management tool to conserve orphaned Eurasian lynx (lynx lynx)

High human‐caused mortality due to wildlife‐vehicle‐collisions and illegal killing leads to frequent cases of orphaned Eurasian lynx juveniles. Under natural conditions, this would result in starvation of the young. To avoid this, wildlife managers conventionally rear animals in captivity and release them later. However, this measure is an undesirable outcome for species conservation, managers, and animals alike. Increased awareness of Eurasian lynx orphaned by human‐caused mortality means managers must often intervene in endangered populations. In this study, we report for the first time a successful case of in situ feeding designed to avoid captivity of two orphaned Eurasian lynx. We exposed 13 roe deer and 7 red deer carcasses in the field to successfully support two orphans to the age of independence and confirm dispersal from the natal range. We present this management approach as a feasible and complimentary tool that can be considered in small or isolated large carnivore populations where every individual counts toward population viability.