How
we benefit by conserving the Blue Swallow
e-zine:
The
Blue Swallow is an ambassador for a vital South African
ecosystem namely grasslands. The South African grasslands
form the major portion of our water catchment areas.
More than 60% of the Grassland Biome has already been
modified - forestry and agriculture playing largest roles.
In South Africa only 2,23% of the Grassland Biome is
formally conserved. The Grassland Biome is the least
conserved, most transformed and therefore most highly
threatened of South Africa's 7 biomes.
The
people of South Africa and the Blue Swallows are equally
dependent upon the good management of the grasslands
as "water factories". The Blue Swallow is specialised
to living in two grassland types in South Africa namely
North-Eastern Mountain Sourveld and Natal Mist Belt.
Of all the grassland types in South Africa in need of
conservation, the two highest priority types are North-Eastern
Mountain Sourveld and Natal Mist Belt. Both grassland
types are located along the eastern South African escarpment
in the Northern Province, Mpumalanga and KwaZulu-Natal.
As
a globally threatened species the Blue Swallow, as a
component of its unique grassland ecosystems in South
Africa and Africa, should be viewed as the ambassador
for the conservation of all of the other faunal and floral
components and processes of its unique grassland ecosystem.
Conserving the Blue Swallow will therefore result in
the survival of other unique grassland species for which
there is no working group and thus no conservation efforts.
South
Africa is world-renowned for its biodiversity. Our grasslands
are amongst the richest habitats for this biodiversity
and are home to many fascinating endemic bird species,
bird species only found in South Africa and nowhere else
in the world. Birding is the fastest growing recreational
activity in the world. The effective conservation of
our bird-life will maintain unique birding areas that
foreign tourists will visit and from which local communities
will benefit. Protection of South Africa's high biodiversity
systems will be good for biodiversity, good for water
quantity and quality, provide tangible benefits to local
communities and be good for the Blue Swallow.
Current
Conservation Status
The
Blue Swallow is considered to be South Africa's most
endangered bird species (Brooke 1984). There are currently
81 known nests and a further 39 possible nests in South
Africa and Swaziland. The numbers were obtained after
extensive surveys conducted over the past fourteen years.
Optimistically it may be possible to add a further ten
nests once certain localities in the former Transkei
and certain of the tribal trust-land areas in KwaZulu-Natal
have been investigated for the presence of Blue Swallows.
An
assessment for the total African distribution range of
the Blue Swallow in 1985 listed it as near-threatened.
By 1994 the Blue Swallow's status had deteriorated and
it is currently considered to be vulnerable (Collar & Stuart
1985, Collar et al. 1994). Since the 1994 assessment
at least for South Africa and Kenya the species status
has probably deteriorated from vulnerable to endangered
(Nasirwa & Njoroge 1996). Countries for which information
is minimal at this stage are the Democratic Republic
of Congo, Zambia and Mozambique.
As
a species of high conservation priority the Blue Swallow,
as a component of its unique grassland ecosystems in
South Africa and Africa, should be viewed as the ambassador
for the conservation of all of the other faunal and floral
components and the processes of its preferred grassland
ecosystems. The Blue Swallow therefore ensures the long-term
survival of other grassland species for which there is
no working group and thus no conservation efforts.
Current
global population
An
optimistic assessment indicates that there are only 1500
breeding pairs of Blue Swallows remaining for their entire
African breeding distribution range. The adult breeding
population total is approximately 3 000 individuals.
A total
of 89 definite and 34 possible breeding pairs are thought
to occur in Southern Africa. An estimated 20 breeding
pairs occur in Swaziland. In South Africa KwaZulu-Natal
contains 51 definite and a further 19 possible nests,
Mpumalanga contains 27 definite and a further 3 possible
nests and the Northern Province contains 1 definite and
a further 2 possible nests.
Elsewhere
in Africa, numbers of breeding birds are estimated as
follows: 300 pairs in the eastern-highlands of Zimbabwe,
with another 100 pairs possible in adjacent Mozambique;
360 pairs in Malawi; 400 pairs in the southern highlands
of Tanzania and 100 pairs in each of northeastern Zambia
and southeastern Democratic Republic of Congo (DRC),
respectively.
Large
breeding populations of Blue Swallows currently in protected
areas are Nyanga National Park (580 km²) in Zimbabwe
(estimate of 200 breeding pairs) and Nyika National Park
(3134 km²) in Malawi (conservative estimate of 260
breeding pairs) (Worsley pers comm., Holroyd & Quinni
in prep).
Distribution
range
The
Blue Swallow's global distribution range is limited to
10 countries in sub-Saharan Africa and is subsequently
an intra-African migrant (Turner 1989). It breeds in
KwaZulu-Natal, Swaziland, Mpumalanga, Northern Province,
eastern Zimbabwe and adjacent Mozambique in southern
Africa. In east Africa the Blue Swallow breeds in Malawi,
north-eastern Zambia, south-eastern part of Democratic
Republic of Congo and south-western Tanzania (Turner
1989). The birds arrive at their breeding grounds in
South Africa and Swaziland towards the end of September
(Parker 1994), and depart again in mid-April (Keith et
al. 1992). From throughout their breeding range the Blue
Swallows migrate in the non-breeding season to Uganda,
western Kenya, north-eastern part of Democratic Republic
of Congo and possibly also north-western Tanzania in
central Africa but do not breed there (Earle 1987).
The
furthest north that a Blue Swallow has ever been recorded
is Kidepo Valley National Park that has its north-western
boundary on the border between Uganda and Sudan in the
north-eastern part of Uganda (Butchard 1996). The Blue
Swallow range states are Democratic Republic of Congo,
Uganda, Kenya, Tanzania, Malawi, Zambia, Zimbabwe, Mozambique,
South Africa and Swaziland.
Habitat
The
Blue Swallow prefers high altitude, high rainfall (> 1000
mm p.a.), undulating, open, primary mist-belt grasslands
(Allan et al. 1988). The preferred sour grasslands generally
have a sward height of < 0.5 meters. The Blue Swallow
ecosystem throughout its breeding range in Africa is
characterised by the occurrence of mist, during the birds
breeding periods. In South Africa and Swaziland the bird
is specialised to and therefore only found within the
two grassland types known as north-eastern mountain sourveld
and Natal Mist-Belt (Acocks 1975). Natal Mist-Belt is
the grassland type in which the Blue Swallow is found
at the southernmost limit of its African distribution
range - KwaZulu-Natal in South Africa. From information
published in 1967 the grassland type in which the Blue
Swallow is found in Zimbabwe, Mozambique, Malawi and
Zambia appears to be similar to the grassland type known
as North-Eastern Mountain Sourveld in South Africa and
Swaziland (Wild et al. 1967). At this stage the grassland
type in which the birds are breeding in Tanzania and
the Democratic Republic of Congo is believed to be similar
to that of their range in Zimbabwe, Mozambique, Malawi
and Zambia. As yet no information could be obtained on
the grassland composition or type that the birds inhabit
in north-western Tanzania. In South Africa North-Eastern
Mountain Sourveld contains 130 endemic plant species
and Natal Mist-Belt contains 51 endemic plant species.
The
two grassland types in urgent need of conservation in
South Africa are North-Eastern Mountain Sourveld and
Natal Mist Belt (Duthie 1994; Low & Rebelo 1996).
Nest,
Eggs and Nestlings
Blue
Swallows construct a cup-shaped nest out of a mixture
of mud and grass. The nest is attached to the wall of
natural or artificial holes. Natural holes currently
used by the birds are natural sinkholes and Aardvark
burrows or artificial sites such as abandoned mine shafts.
The birds prefer holes with an overhang under which the
nest is constructed so as to protect the exposed cup
from the wind and rain. Nests in suitable nest sites
are often repaired each breeding season and used over
many seasons. Both the male and female contribute to
nest building or repair. The female carrying out most
of the work.
Two
to three eggs are laid at 24 to 48 hours between each
successive egg. Only the female incubates the eggs for
14 - 16 days. The female incubates the nestlings. Both
the male and female feed the nestlings. At the peak of
their development the adult birds arrive at the nest
with food for the nestlings at a rate of once every 2
minutes. Nestlings fledge 20 to 24 days after hatching
and remain in the nest area for two to three weeks during
which time the parents continue feeding them. The nestlings
gradually begin feeding themselves during this period.
When conditions are favourable Blue Swallows are double
brooded, certain pairs being capable of raising two sets
of nestlings in a single breeding season. Adverse weather
conditions as a result of mist and rain often result
in Blue Swallow eggs not hatching or nestlings not fledging
(Evans & Bouwman 2000). In some seasons this seriously
affects breeding success. Fiscal Shrike has been recorded
predating both Blue Swallow eggs and nestlings.
Threats
The
major reason for the reduction in surface areas and fragmentation
of these two grassland types and the concomitant endangered
status of the Blue Swallow has largely been as a result
of commercial forestry for the timber, pulp and paper
industry (pine, eucalyptus and wattle plantations). The
high altitude, high rainfall, mist-belt grassland areas
that are characteristic Blue Swallow habitat are unfortunately
also highly suited for the commercial cultivation of
these exotic trees. In Zimbabwe the borders of Nyanga
National Park are easily found as wattle and pine plantations
have been planted right up to the edge of the park. Private
ownership of the mineral rights to most of the Blue Swallow
localities in Mpumalanga represents a current and potential
future threat (Evans 1996). Increased tourism activity
and development has resulted in the loss of Blue Swallow
breeding pairs in the Mac Mac and Graskop Townlands area.
This highlights the need for careful consideration and
proper planning of tourism ventures (Evans 1997). Other
reasons for the decline in and vulnerable status of the
Blue Swallow and its grassland habitats are habitat destruction
and fragmentation due to potato, maize and sugar cane
cultivation, road construction, overgrazing and inappropriate
annual burning of grasslands to improve grazing potential.
The annual burning of grassland types that should be
burnt every two to three year's results in a drastic
decrease in overall biodiversity. A factor resulting
in a reduction in the breeding success of Blue Swallows
in certain breeding areas is disturbance of the birds
at the nest by the young boys herding the cattle on tribal
grazing lands (Boycott pers comm).
Conservation
Due
to the migratory nature of the Blue Swallow it is necessary
to focus conservation action, advocacy and monitoring
over its entire distribution range. Conservation activity
should be aimed at preventing the status of the Blue
Swallow from deteriorating further. This is achieved
by working at resolving conflicts between the requirements
of the Blue Swallow and the factors threatening the future
existence of those requirements.
The
Blue Swallow is listed on both Appendix I and II of the
international Convention for the Conservation of Migratory
Species of Wild Animals (CMS).
Protected
Areas, Natural Heritage Sites and Important Bird Areas
Malolotja
Nature Reserve (IBA SW001) in Swaziland and Impendle
Nature Reserve (IBA SA077) in KwaZulu-Natal are the only
formally protected areas holding breeding Blue Swallows;
with totals of eight pairs each. Another 22 breeding
pairs of Blue Swallows are protected in six Natural Heritage
Sites; three in Mpumalanga and three in KwaZulu-Natal.
The KwaZulu-Natal Mistbelt Grasslands (IBA SA078), a
series of disjointed grassland patches in a farmland
mosaic, hold 38-55 Blue Swallow breeding pairs (Johnson
et al. 1998). The nine breeding pairs in the Blue Swallow
Natural Heritage Site (IBA SA014) in Kaapsehoop represents
the highest breeding density for South Africa (1 pr/52
ha) (Allan et al. 1988). The Graskop Grasslands (IBA
SA011) and Misty Mountain Natural Heritage Site (IBA
SA013) hold 14 and 2 breeding pairs of Blue Swallows
respectively. Blyde River Canyon (IBA SA010) contains
a single breeding pair with the possibility of a further
pair.
End