Background
The Black-eared Miner, Manorina melanotis, is a honey eating bird species native to the mallee woodland in southeastern Australia. Due to a decline in number in the 1980s, the bird was declared as an endangered species under the Australian Environment Protection and Biodiversity Conservation Act 1999 and the International Union for Conservation of Nature (IUCN). Manorina melanotis closely resembles the much more common Yellow-throated Miner, Manorina flavigula (Australian Government, 2010, para. 2). Several conservation efforts have been undertaken but these have not been adequate and the bird continues to listed as endangered more than 20 years after the first studies were made.
Habitat and Breeding
M. melanotis lives mainly in the Murray Mallee region in Southern Australia (Threatened Species, 2005, para. 2). A few birds can be found in the northwestern Victoria with the greatest numbers found in the Murray Sunset, NP. In NSW, it lives in the mallee in the Scotia region. Before the reduction in number, the species might have been present in the mallee region throughout southwest NSW.
Black-eared Miners are mainly found in large tracts of mature mallee with a post fire age greater than 25 years although they prefer a mallee vegetation that has not been burned for the past 50 years. They feed mainly on arthropods such as grasshoppers, weevils, spiders, ants, and flies. During breeding periods, the birds live in colonies of between 8 and 40. Breeding is usually opportunistic and may occur when conditions are fitting, however, highest breeding rates occur between September and December.
Researchers have disagreed over the taxonomy of this bird with some considering it a variant of M. flavigula. The birds are co-operative breeders (individuals assist in caring for the young that are not their own), live in large flocks during the breeding season, and separate during non-breeding periods.
Threats
The main reason for the decline in the number of birds stems from the clearance of their mallee habitat. Although settlers arrived at the Murray Mallee in the mid 19th century, it was not until the start of the 20th century that extensive clearance of these habitats for agricultural purposes began. This increased in the 1930s when the settlers dug dams and channels to improve water flow. This has led to encroachment and subsequent displacement of the bird with the Yellow-throated species that lives in open lands.
The number has further reduced due to interbreeding between the two Miner species, this poses the greatest risk to the survival of M. melanotis. A study of the two bird species from different areas of the world show a significant increase in hybridization around the mid-20th century as dam construction and clearance of habitats increased (Bird Life, N. d., para. 7).
Another cause of decline in numbers is due to wildfires. The bird species prefers mallee vegetation that has not burnt for at least 50 years, however, such a habitat is difficult to find in Australia as wild fires are a common phenomenon. Wildfires cause direct deaths of birds and long-term changes to the structure of the flora. Fires also increase leaf litter that is unfavorable for the species and may boost predation, such ecosystems may not sustain a viable population of the Black-eared Miner.
For example, a fire in Bookmark BR towards the end of 2006 burnt 115,000 ha of the Black-eared Miner’s mallee habitat. The fire reduced the bird’s habitat to a third of the original area, however, it also created a natural extinguisher for the unburnt areas. The present ability of the habitat to put off fires has certainly led to a drop in the number of wildfires, however, this has led to a reduction in the habitat area for the species (Threatened Species, 2005, para. 4).
The final threat to the survival of M. melanotis is climate change. The species is thought to be easily affected by variations in climatic conditions with long periods of drought hindering breeding and long rains promoting breeding. Harsh climatic conditions have altered specific parts of Australia that were previously inhabited by the Black-eared Miner in such a way that these regions can no longer sustain viable populations. In developing a recovery plan, all these threats must be taken into consideration, the plan must design ways of abating or reversing the threats.
Objectives of the Recovery Plan
The short-term aim of this plan is to increase the present range and numbers of the species in habitats around Australia and to improve the quality of chosen colonies. Achieving this goal will stabilize bird populations and increase their breeding activities. This will mainly include translocation of bird species to other habitats and reducing the threats that they face as discussed above.
The long-term objectives of the plan is to attain and keep a viable population of pure breeds of Black-eared Miners in at least five selected habitats in Australia. This will increase the birds’ population to more than 5,000 mature individuals ten years from today across the country, a big jump from the current number estimated at 500 (Bird Life, N. d., para. 4).
Recovery Plan
The recovery plan is drawn from past conservation efforts and from the threats that the Black-eared Miner faces. Past conservation efforts have included survey and monitoring of individual bird species by Birds Australia staff and volunteers and lately by La Trobe University. Other efforts have centered on finding the most suitable habitats for the bird, habitat protection, translocations, and studies into the biology and ecology of the bird.
Major activities for achieving the recovery plan objectives are outlined below:
- Effective control of fire outbreaks in the mallee habitat. This entails regular patrols by staff on foot and from the air, this enables early detection and putting of fires. These patrols will be more frequent during long periods of drought as fire outbreaks tend to be more common during such periods. To ensure that the plan is effective, adequate fire fighting equipment will be supplied in all surveillance points at habitat areas. The staff will be trained on fire fighting skills , with mock fire outbreaks carried out twice or thrice a year to check on the readiness of the fire-fighting staff (IUCN Red List, 2010, para. 6).
- Studies on the possibility of a translocation process of birds to habitats with suitable conditions for breeding have been undertaken previously and have proved that such a move can bird populations. Birds will be moved from areas with unfavorable climatic conditions and those that have been encroached by the Yellow-throated Miners. Since suitable climatic conditions enhance breeding among the birds, translocation will increase their number, besides, interbreeding with the Yellow-throated Miners will be eliminated, ensuring high-quality (pure) offspring. A translocation exercise must take into consideration the impacts on the source population and other operational management issues, such as habitat suitability and contact with Yellow-throated Miners at the destination habitat.
- M. melanotis requires a mallee vegetation that has not been burnt for at least 50 years, this requires that current mallee vegetation in various parts of the country must be maintained. In addition, we shall plant more mallee vegetation for our long-term strategy.
- Another recovery plan involves the identification of man-made water points within M. melanotis habitats that may pose a threat to the birds. These water points will either be closed or rehabilitated. In case the water point is the major source of water for the neighboring human populations, the birds may be moved to other areas. Other actions may include banning of pastoral activities in areas with mallee vegetation.
- To realize the goals of the recovery plan, we will include major landowners and residents around NSW and other major M. melanotis habitat areas. The landowners will promote our conservational efforts at community level due to their influence.
- We will integrate all information relating to M. melanotis from all habitats around the country and enter it into a common database such that it will be easier to access information on the progress of conservation efforts being undertaken in these places. This information will include bird population, area of habitat, and all translocation activities.
Evaluating the Efficacy of the Recovery Plan
Effective management practices, funding from relevant institutions and co-ordination between implementation should ensure success of the recovery strategy. However, due to the importance and intricacy of this activity, the progress of the conservation process must be assessed periodically to ensure the efficacy of the plan. Assessments will be carried out in the following ways:
- Every three years, a bird count exercise will be carried out. The process will not just record the number of birds, it will include male birds, female birds, offspring within the last three years, mature members of the population, number of birds per square kilometer, and other information relating to the mallee vegetation. Other information such as the number of fires within the last three years will also be recorded. The information will assist in identifying areas that need more resources, habitats that are overpopulated, and those that require translocation.
- To ensure that the long-term goals of the recovery plan are achieved, the area occupied by mallee vegetation will be calculated. This will give the area of land capable of supporting the Black-eared Miner population and the level of success in the maintenance of the current vegetation and planting new trees.
Conclusion
Current conservation efforts for the Black-eared Miner are not adequate, moreover, such efforts have not adequately addressed the issues that have led to the reduction in the number of the birds, such as wildfires, encroachment of human into its habitat, and interbreeding with the Yellow-throated Miner. As a result, the bird continues to be listed as an endangered species more than two decades after the first studies on the bird were made (IUCN Red List, 2010, Para. 2). Studies have shown that the species is doomed to genetic swamping and extinction unless elaborate efforts are put in place. On a positive note, the bird has the ability to recover, therefore, adoption of this recovery plan will ensure that the Black-eared Miner will survive for hundreds of years to come.
References
Australian Government. (2010). Manorina melanotis – Black-eared Miner. Web.
Bird Life. (N. d.). Black-eared Miner, Manorina melanotis. Web.
IUCN Red List. (2010). Manorina melanotis. Web.
Threatened Species. (2005). Black-eared Miner- Profile. Web.