ENR 5.6  Bird Migration and Areas with Sensitive Fauna

1   BIRD MIGRATION

The spring migration takes place between mid-FEB and the end of MAY, the most active part being in APR and MAY. This migration is more dispersed and less spectacular than the autumn one. The principal direction over Belgium is NE.

The autumn migration lasts for more than three months. The first flight movements can already be seen from the end of JUL, while the last movements of any significance are completed by the end of NOV. They have a typical stream of movement with periods of relative calm interspersed with periods of very intense migration. Between mid-AUG and mid-NOV migratory birds are particularly active. The movement takes place in a mostly SW direction.

When on actual migration, most birds make long flights at often high levels in contrast to their flying at relative low altitudes during their stay in the concentration areas.

Although a great part of the bird population that is dangerous to aircraft, start migrating from concentration areas, according to radar observations migration often appears to take place over a broad front, covering nearly the entire Belgian territory.

As a result of radar observations it is known that mass migration takes place when

This can be completely in contrast to what will be observed visually.

Heavy night migration may occur early in autumn (from mid-AUG onwards) and later in spring (till the end of MAY). During the winter months sudden snow and frost may stimulate very large numbers of water- and open land birds (geese, ducks, waders, starlings, thrushes and larks) to move to the south.

The bird strike risk resulting from these winter flights (during a period of sudden thaw, in opposite direction) is particulary high in the northern part of the country.

2   CONCENTRATIONS

As elsewhere in the world, headlands, inland waters and shallow estuaries attract flocks of birds for breeding, roosting and feeding at various times of the year. Within 10 NM or so of such locations concentrations of birds flying mostly below 1 000 FT may be encountered.

In order to lessen the risk of bird strikes, pilots of low flying aircraft should, whenever possible, avoid flying at less than 1 000 FT above surface level over areas where birds are likely to concentrate. Where it is necessary to fly lower than this, pilots should bear in mind that the risk of bird strike increases with speed (it is a fact that birds rarely hit an object moving slower than 80 KT).

Apart from endangering aircraft by flying close to bird colonies, the breeding of the birds may be upset and the practice should be avoided on conservation grounds. It should also be appreciated that, especially in the case of sea bird colonies, concentrations of birds may be soaring on lee waves downwind of the areas where they breed.

3   AREAS WITH SENSITIVE FAUNA

IdentificationAreaBird species
Ettenhovense polderA circle, 200 M radius, centred on 511858N 0042122EBlue throats
KuifeendA circle, 1 000 M radius, centred on 511756N 0042114EBlue throats, ducks, swans, herons, raptors
MolsbroekA circle, 2 000 M radius, centred on 510550N 0040130EWaterfowls
ZwinA circle, 3 000 M radius, centred on 512000N 031700EHighest concentration of birds along the coast (ducks, swans, gulls, mergansers, shorebirds)

4   MILITARY BIRD MIGRATION OBSERVATION SYSTEM

Military training and flight operations usually take place at low altitudes, where a lot of birds are present, especially near coasts and during migration periods. To prevent bird strikes, the Aviation Safety Directorate (ASD) of Belgian Defence has put in place a warning system in cooperation with national and/or international agencies.

4.1   BIRD MIGRATION OBSERVATION SYSTEM

The bird migration observation system is based upon the following networks and technical means:

  1. General studies:

    • According to scientific studies, probable altitudes and migration routes are determined for each bird species, in relation with the weather and geographical conditions;
    • Daily collection of data by the Bird Control Section (BCS) from ornithological sites on the internet provides the aviation world with useful information on bird activities;
  2. Radar observation:

    • A computer programme called 'Radar Observation of Bird Intensity' (ROBIN) uses specific software to monitor moving targets and detect movements of bird flocks;
    • The precision approach radars at the military aerodromes can detect important bird movements in the approach zone of the RWY axes;
  3. Visual observation:

    In the aerodrome vicinity zones in-flight reports by aircrews, reports by ATC, weather observers and the local Bird Control Units (BCU) remain concrete sources of information;

  4. Warning and reporting system:

    It remains a national decision to establish or not bird strike warning/risk organization and procedures for its area of responsibility. Belgian Defence has put in place a warning and reporting system in cooperation with national and/or international agencies. Its zone of responsibility has been divided in GEOREF squares and for each one a BIRDTAM can be issued;

  5. For the squares above the Brussels FIR, the BCS within Aviation Safety Directorate is responsible to issue the BIRDTAM based upon:

    • the ROBIN system;
    • the general ornithological situation;
    • foreign BIRDTAM concerning the Brussels FIR;
    • any other useful information;
  6. For each military aerodrome and shooting range:

    A Local Bird Intensity (LBI) warning can be proposed by the BCU and officially issued by the Supervisor of Flying Activities (SOF) based upon visual observations and possible local radar observations and being in force for the local very close traffic pattern of the related aerodrome. If no LBI is issued, the general BIRDTAM applicable to the GEOREF square where the aerodrome is located, remains in force.

4.2   FLYING RESTRICTIONS

Based on the risk level, local authorities apply flying restrictions that are published in the COMOPSAIR directive ACOT-GID-DOCSOP-ASBD-200.

4.3   BIRD INTENSITY SCALE

The military NOF will provide bird strike risk warning (BIRDTAM) based on the following observation intensity scale:

Bird Intensity Scale
0Practically no risk
1Extremely small risk
2Very small risk
3Small risk
4Fairly small risk
5Fairly great risk
6Great risk
7Very great risk
8Extremely great risk

The intensity digit is acquired after interpretation of Meteo Radar data by ASD / BIRDTAM office (located in Beauvechain) and relayed to the military NOF (Steenokkerzeel ATCC). It relates only to the bird migration in the Brussels FIR.

4.4   GEOGRAPHIC REFERENCE

The Brussels FIR is situated within the following geographic references (GEOREF):

Square defined by
GEOREFParallelsMeridians
NKCG510000N to 515959N0020000E to 0025959E
NKDG510000N to 515959N0030000E to 0035959E
NKEG510000N to 515959N0040000E to 0045959E
NKFG510000N to 515959N0050000E to 0055959E
NKCF500000N to 505959N0020000E to 0025959E
NKDF500000N to 505959N0030000E to 0035959E
NKEF500000N to 505959N0040000E to 0045959E
NKFF500000N to 505959N0050000E to 0055959E
NKGF500000N to 505959N0060000E to 0065959E
NKEE490000N to 495959N0040000E to 0045959E
NKFE490000N to 495959N0050000E to 0055959E
NKGE490000N to 495959N0060000E to 0065959E
4.5   BIRDTAM TEXT AND FORMAT

BIRDTAM will only be issued when migrations reach intensity 5 or higher.

The text will include a serial number preceded by the word 'BIRDTAM'. This serial number begins, each calendar year, with 0001.

The format will be the ICAO NOTAM format with special code 'QBIRD' in the military NOTAM serie M, originator EBSZYNYX and

BIRDTAM
ITEM 'A'FIR
ITEM 'B'Valid from (DTG - UTC)
ITEM 'C’Valid till (DTG - UTC)
ITEM 'E’

BIRDTAM nr

BIRD INTENSITY BELGIUM

Intensity of Bird migration (see § 4.3)

Geographic reference (see § 4.4) per square

Additional information

ITEM 'F’Lower height limit of the hazard (in feet AGL)
ITEM 'G’Upper height limit of the hazard (in feet AGL)

The BIRDTAMs are always issued with the priority ‘DD’, through the Aeronautical Fixed Telecommunication Network (AFTN) to the group address EBZZALEB.

This group address contains the following AFTN addresses:

Group Address for BIRDTAM
EBZZALIDENTIFICATION
1EBBEZPZXW OPS BEAUVECHAIN
2EBBLZPZXW OPS KLEINE-BROGEL
3EBBRYNYNskeyes NOF
4EBCIZPZXAIS CHARLEROI/BRUSSELS SOUTH
5EBCIZTZXTWR CHARLEROI/BRUSSELS SOUTH
6ETARYXYX�
KRCHYXYX
BASE OPS - ATS CHIEVRES
7EBFNZPZXATC KOKSIJDE
8EBFSZPZXW OPS FLORENNES
9EBGLZGZXAIS CRC
10EBMBZPZXW OPS MELSBROEK
11EBMIZGZFSTEENOKKERZEEL ATCC ARO
12EDDFYFYJGROUP ADDRESS
13EGVCYOYXAIDU NORTHOLT
14EGZZAKXXGROUP ADDRESS
15EHZZNTXXDUTCH GROUP ADDRESS
16EKMCYOYXKARUP
17ELLXYNYXLUXEMBOURG
18ETAAYOYXUSAFE NOTAM CENTRE
19ETAAZPZXUSAFE
20ETCKYFYXGROUP ADDRESS
21ETCZYOYXGERMAN MIL NOF
22ETGTYTYXMIL MET COMM CENTRE
23ETNGZPZXGEILENKIRCHEN MIL
24EUECYIYNEUROCONTROL EAD
25KCNFYNYXUS NOF WASHINGTON DC
26LFLFSITXORLEANS COMM
27LFZZNQEBGROUP ADDRESS
28LIZZNCEBGROUP ADDRESS
29LPAMYNYXLISBON MIL AIS
30LSZZNAEBSWISS GROUP
31LTAAYNYXANKARA NOF
32LZIBYWYAGROUP ADDRESS
33RKZZNKXXKOREA GROUP
34UDDDYNYXARMENIA NOF
35UGTBYNYXGEORGIA NOF
36UTTAYNYXUKRAINE NOF