January
The Philippine Eagle has so many striking features that it had to be my first species of the month.
Key features
1) It is one of the largest eagles in the world standing at 90-100 metres tall with a wing span of 2 metres and can weigh up to 6.5kg.
2) Incredibly long lived as it can reach 60 years of age.
3) Locally named the 'monkey-eating eagle' due to this being its favoured choice of prey
4) Now the rarest eagle in the world, with approximately only 250 pairs left in the wild
A little more detail...
This eagle is endemic to the Philippines although now it's range is restricted to certain islands (Samar, Luzon, Mindanao and Leyte) and its habitat is dipterocarp forest (certain family of trees found in old tropics). These eagles pair for life and produce one chick per breeding cycle, which lasts for 2 years. Chicks fledge after 4-5 months although they will stay in their parents territory for another 17 months as the parents continue to take care of it.
Threats...
This species relies on relatively specific habitat, such as high canopy's in which to build their nests, so destruction of this habitat is their primary threat. This is caused by clearing of forest for the extraction of commercial timber, shifting cultivation and mining. Further threats include hunting which was originally for food but now often for zoos exhibits and trade and naive young eagles are particularly vulnerable to capture. Also, a recent threat to this species has been the accumulation of pesticides which is thought to have reduced the successful reproduction in these eagles.
Help at hand...This species is now protected by law in the Philippines and it is also under CITES appendix I and II which prevents illegal trade. The Philippine Eagle Foundation has also been been created to combine strategies in which to save this species. For example, captive breeding centres have been set up which has successfully reared 14 chicks to date in hope of releasing them in them in the future.
Field research is a critical part of this recovery as allows information to be gathered about the biology of this species which can provide the basis of plans to manage wild populations. Information gathered includes locating active nests, monitoring breeding success and understanding the extent of the eagle's home ranges. So far, this information has been used to establish biological corridors connecting areas of fragmented forest to increase available habitat.
This foundation also works to increase public awareness on the plight of these birds in both local communities and further afield to gain support.
An unusual and majestic species which makes its current plight even more devastating.
A short video to see this eagle in action:
February
This species of the month came to my attention after watching
'Iniside the Animal Mind' which recently demonstrated the amazing cognitive
skills of a variety of species, the most impressive being the New Caledonian
crow. This species is endemic to New
Caledonia and primary habitat is forest although it can adapt to other environments,
such as savanna. This species has
attracted the attention of many researchers in the last few years due to their
impressive cognitive abilities that is demonstrated through their superior use
of tools. Apart from primates, tool use
is rarely found in the animal kingdom as it is often viewed as a human
characteristic.
Research has tested this species ability to solve problems,
often through the use of tools, and the results have been remarkable as demonstrated by the following video.
Along with this evidence, further research has indicated that this species possesses the skill of imagination which is uses to plan ahead for future events.
Many reasons have been suggested to explain the cognitive abilities of this species. The first and perhaps most obvious explanation is that this species has a very large brain, which is in fact the same size of Chimpanzees in relation to its body size.
This species may need such a large brain because, like humans, they are omnivores so often need to possess adaptable thinking in order to exploit a variety of food sources. This is the likely reason behind the evolution of tool use as this can be a very useful skill, such as using twigs to extract insects from tree crevices.
Another significant factor that could have increased these birds intellect is that this is a very social species that can live in large groups. Social rules can be very complicated and require a variety of cognitive skills, such as predicting another member of the group's actions and reacting accordingly. Many species that live in groups often demonstrate adaptable cognitive skills such as primates, dolphins, elephants etc. In this species of crow, the knowledge of tool use is passed on through family groups and there is even some evidence that future generations improve previous methods. This suggests that this species intelligence is still growing which is a very exciting prospect.
It is worth noting that this is not the only bird that has demonstrated these abilities as other species within the Corvid family (e.g. crows, jackdaws, magpies etc) show similar impressive intellect. I have experienced this personally when looking after corvids at Hessilhead Wildlife Rescue Centre (see previous June blog post) through these bird's ability to manipulate everyone working there to exploit food at every opportunity.
This evidence demonstrates that the term 'bird-brained' is redundant, particularly when applied to these species. Next time you encounter one of these birds, just remember that they likely to know exactly what your thinking...or close enough!
March
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| Photo provided by Miguel McMinn |
The Balearic Shearwater is the only critically endangered
(ICUN) European sea bird. It is now on
the BAP (Biodiversity Action Plan) list as it faces extreme threat of global
extinction due to its rapid population decline and small population size. Research had indicated that this species
could be globally extinct in 40 years if current trends continue.
Fact file
Distribution: this species breed in the Balearic Islands in
Spain in late summer and then migrates to feeding grounds along North Atlantic
coasts. Recent surveys have shown that
of the coast of southwest England are important as 10% of this species’
populations visit these waters. This increase
on feeding birds in Britain is likely due to climate change through increased
sea temperatures which shifts bird’s food source northwards.
Habitat: breeds on cliffs but little is known about their
foraging habitats.
Foraging: they feed during the day, sometimes individually
but often in large groups. Their main
food source is small fish such as herring and sprat which they obtain through
plunge diving.
Breeding: this
species breeds between February and June.
Adults don’t commence breeding until their third year and they only lay
one egg
Population: estimated 3,193 breeding pairs with a world population
of 8,000-10,000 although there is variation in these estimates as survey
techniques have improved.
Threats
Predation
Introduced mammals such as rats, cats and martens are a
threat to breeding colonies.
Fishing
This can cause a reduction in their food source due to
overexploitation.
By-catch
The main cause of by-catch in longline fishing which involves lines with baited fish and birds become impaled in these hooks (either
bill, bodies or wings) so are unable to free themselves and drown. Research has also indicated that trawling can
cause mortalities. These birds can be
killed in large numbers due to the fact that they are often in large groups in
close proximity to fishing boats.
Pollution
Acute pollution effects could potentially pose a very
serious problem (e.g. oil spills) due to this species congregatory behaviour
(i.e. often found in close colonies).
Conservation
BAP action plan 2 main aims
- Get population growth rate to the state where there is no decline within 10 years
- Maintaining and improving effective environmental status of breeding colonies and marine hotspots through site protection, management and habitat restoration if necessary.
Monitoring
British and Mallorcan researchers fitted birds tracking devices with tracking devices in 2010
with the aim to provide information about this species movements, including:
- Main foraging areas both during the breeding season and all year round
- Where young birds go during their first 3 years before breeding
- Do birds revisit the same foraging areas each year?
- Daily activity patterns, e.g. roosting, flying, foraging
- Depth at which birds dive for fish which can be related to geographical location and potentially provide insights into foraging behaviour around fishing vessels
Monitoring has also involved stable isotope analysis to
provide information about the bird’s diet and infra-red cameras at nests to
examine their behaviour.
Protected areas
This information can be used to designate marine protected
areas and the Spanish government has already begun implementing these, with the
French government planning to do the same.
All this species breeding sites are already Special Protected Areas.
Eradication of predators
The Balearic government has already implemented a rat eradication
programme in 2011 that appears to have been successful as there have been no
sightings of rats since.
If these conservation strategies gets the support they deserve then I hope these beautiful birds will be around for many years to come.
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| Photo provided by Miguel McMinn |
Acknowledgements: Many thanks to RSPB Ramsey Island and Miguel McMinn for their help with this post
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