Southward Bound

After returning from its' trip to the Tamri area on 31st October, Aylal moved southwards, beyond the mouth of the Oued Massa.Early in the morning of November 5th it was very close to the southernmost border of the Souss Massa National Park. It seems that it had travelled too far to return to its' usual roosting spot and so had stayed overnight in the area, probably with other ibis.
Aylal's behaviour is providing us with a lot of information on the patterns of movement and habitat use of this species and we hope to enhance out knowledge even more by tagging more individuals in the future.
Nader has been a bit less adventurous lately and didn't join Aylal for the journey southwards, staying instead in the northern area of the National Park.

Aylal's escape

Aylal, the adult ibis tagged with the GPS transmitter, made a getaway to the Tamri colony last Sunday (30th) and spent the night there before returning to the Souss Massa National Park on Halloween. Nader didn't follow its parent, confirming that although the birds are using the same feeding and roosting areas, they are now independent.

Although we are missing some data on Aylal's journey up north, on its return to its feeding grounds in the National Park it flew almost 60 km between two consecutive records, which equates to an average speed of at least 30 km/hour. This is the most northerly point reached by Aylal since it was tagged in July, and it actually went beyond the colony to some feeding grounds in the north where it has probably bred in the past.

Tagged ibis, together again

It seems that in recent weeks, Nader and Aylal have met again. 

The data received from their tags indicate that both are back in the northern area of ​​Souss Massa National Park, confirming the great importance of preserving this area where ibis spend a large part of the year, using the large and rich feeding areas.

They have probably lost their family behaviour due to the time they spent appart, but they move in the same group at least during part of the day.

The Little Ice Age

Attempts to attribute historical events to variations in climate are often criticised but there is no doubt that climate has always had a huge impact on humans, affecting the success of harvests, disease epidemics and many other events.

In the not too distant past, Europe experienced a remarkable number of climate changes. From the tenth century, warm temperatures in the North Atlantic region allowed vineyards to be cultivated in England and the Vikings were able to migrate northwards and colonise parts of Greenland and Newfoundland.

Ruins of the Hvalsey church in Norse Greenland. The Viking settlement had disappeared by the early fifteenth century.

This Medieval Warm Period allowed humans to cultivate areas further north and at higher altitudes. The milder climate and the expansion of crops and pastureland probably resulted in other species expanding their ranges as well.

The name of  Waldrapp  (forest crow) seems to link the northern bald ibis to woodlands, an ecosystem that now seems shocking, but maybe in the medieval warm period NBI was not uncommon in the clearings of the alpine forests.

The climate in Europe then became cooler, and from the second half of the seventeenth century to the mid-nineteenth century there was a period of intense cold, referred to as the Little Ice Age. This led to massive changes in agriculture and to the abandonment of crops at higher latitudes and altitudes, in addition to the loss of pastureland, as it was replaced by forests. Weather conditions would also have become more severe and it would have been much more difficult for birds to have crossed the Alps on their migration routes. The loss of the northern bald ibis from Central Europe has been attributed, at least in part, to this cold period.

The Mer de Glace from the Montenvers, Mont Blanc region. On the left is a painting done shortly after the maximum of the Little Ice Age and on the right is a photo from 2000. The arrows allow you to compare the different levels of ice at the same two points. Painting from the Gugelmann Collection, Swiss National Library, Bern. Photo by MJ Hambrey (2000).

There were other events which occurred over this period, such as the constant wars and the Black Death of the fourteenth century, which would also have resulted in population declines over large areas. The picture above shows a physician dealing with the plague, wearing a birdlike mask. Could it represent some kind of crow? Maybe, but the beak is too long and curved….

Informative scientific documentation for these periods is abundant, detailing changes in glaciers, sedimentology, floods, droughts, heavy snows, famines and the price of grain, all indicative of weather conditions at the time.

Waldrapp by Gesner

Unfortunately, there is less information about changes in wildlife but it seems that apart from the disappearance of the bald ibis, there was a reduction in the range of the Alectoris partridge (called Steinhuhn in German). This species was apparently common in the Rhine Valley in the 16^th century but it now has a much more southerly distribution. 

How do Aylal and Naders’ satellite tags work?

It has been mentioned in previous posts that the tags on Aylal and Nader have different levels of accuracy and this is due to the fact that two different systems are being used: Argos and GPS. Both tags use the Argos system but one tag also has a GPS transmitter.

The Argos system is named after the mythical giant with 100 eyes, who was the perfect, all-seeing guardian. This system is based on a series of six polar-orbiting satellites, i.e. which pass over both poles, at an altitude of 850 km. These satellites belong to the National Oceanic and Atmospheric Administration (NOAA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and other agencies will join in the future.

Each platform, i.e. the animal or object carrying the transmitter, can be reached, in theory, about 14 times per day. The position of the platform is calculated using the Doppler Effect, i.e. the variation in the wave frequency (produced by the transmitter) between two objects moving relative to each other (in our case the transmitter and the satellite).

Overlap of the areas covered by two successive passes of the Argos satellite system (http://www.argos-system.org)

With the Argos system there is a certain limit to the number of locations that can be received from each transmitter but it is ideal for following long-distance movements of birds. It is also small and light - the transmitter on Nader weighs just 9 grams (1/4 ounce).

The transmitter on Aylal also carries a GPS unit. The GPS system relies on a denser system of satellites, with 24 satellites (four in each of six different orbits), at an altitude between 10,100 and 20,200 km. Each transmission from the platform is picked up by several satellites and the position can be calculated by measuring the distance from each one. This provides an accurate, three-dimensional location (latitude, longitude and altitude). Not surprisingly, this accurate technique was originally developed for military use.

GPS satellite network, showing how the number of satellites visible from the transmitter varies according to the earth’s rotation and the orbit pattern of the satellites (from Wikipedia)

This type of transmitter was deployed on Aylal to provide us with detailed data on small-scale movement patterns of the species within its normal range. This will help us to identify any potential threats and will complement the day to day work done by the guards on the ground. The transmitter on Nader will provide us with more broad-scale data on the large-scale dispersal patterns of juveniles of this species. This is the same system which has been used to tag ibises in Syria and Turkey.

Funds for these two tags were donated by Dublin Zoo (Aylal) and RSPB (Nader) and installation costs were covered by a collaborative project with Prince Albert II of Monaco Fundation. An expert from MMARM led the tagging operation and provided advice on the capture and taggingprocedures.

The fundraising campaign for the conservation of the bald-headedibis aims to raise money to buy more transmitters such as these, to tag moreindividuals. The data provided from these tags greatly increases our knowledgeof species movements and habitat use and allows us to identify potentialthreats.  

Where are the ibis now?

Aylal and Nader are still apart – Aylal (the adult) has spent a few days moving around the area north of Agadir but hasn’t remained in the same specific location for any length of time. Nader (the juvenile) is still in the SMNP. Although it was known before that Tamri birds visited the Souss-Massa area outside the breeding season, the data from Aylal and Nader are providing important details on the frequency of these movements. 

Latest news from “our” ibis in Souss-Massa: Nader and Aylal have separated

The signals received from Aylal show that she moved north at the beginning of last week, back to the area where she was caught 2 months ago and she has been using the same roosting and feeding areas as before.

While the accuracy of the transmitter on Nader is lower, we saw that this bird also moved north, but was in the vicinity of Tamri, near the river mouth. Soon after, it returned to the Souss-Massa National Park, so it is apparent that the parent and its young have separated, at least for now.

Although the information provided from Nader is less accurate than for Aylal, keep in mind that up till now we had no data at all on the relationship between parents and their offspring after fledging, so this represents a big leap forward in our knowledge of this species. It is possible of course that the other parent is still with Nader, but this is unlikely. 

Nader and Aylal are still in SMNP

The latest data received from the satellite tags show that Aylal and Nader (a mother and her offspring) are still active and are within the Souss-Massa National Park.

These two birds were tagged at the end ofJuly near Agadir and then moved, most likely with the whole group of about 20 adults and young ibis, to the National Park.  This movement is normal outside of the breeding season as there is plenty of food available at this time of year in the north of the park. Aylal (the adult bird) will most likely remain in this area for several months until the breeding season begins again. Thanks to the highly accurate GPS data we know that it only uses about two feeding sites, all within the protected area. As for Nader, we’ll have to wait and see – it may remain with the rest of the group or it may disperse to a new area within the next few weeks, as many juveniles do at this point in their lives. 

Nader and Aylal have moved to SMNP

GOOD NEWS!

The signals from our two bald ibis have revealed that they have left the area north of Agadir, where they were feeding and sleeping in a nearby cliff, and have moved to the Souss Massa National Park.

Nader and Aylal are still together, although the signal from Aylal is more accurate due to the GPS tag. In the last few days, this bird has been in the steppes area around the Massa estuary, accompanied by a large number of other ibis.

Studies of habitat availability and use have indicated that this national park area is very important to this species outside the breeding season.

The fact that we caught and tagged two related individuals is great as it will provide valuable insight into when the separation of juveniles from their parents occurs. 

Dublin Zoo funds satellite tag for NBI

Dublin Zoo helps fund a number of in situ conservation programmes. While maintaining breeding populations in zoos is beneficial, it is of paramount importance that wild populations and their habitats be understood and conserved.

The Northern bald ibis is one of the most endangered birds in the world. The Souss-Massa National Park in Morocco and surrounding area is vitally important for this species survival as the entire population breed within this area. The main threat to this species is the increase in leisure tourism and the subsequent disturbance to Waldrapp ibis nesting sites and feeding areas.

A National Species Action Plan was drawn up and one of the priorities was the satellite tagging and colour ringing of some birds to discover more on this species’ seasonal movements and area use outside of the national park.

In 2010, Dublin Zoo provided funding for satellite tagging, but the capture of an adequate bird should be done just after breeding. Thus, in July 2011, one adult bird, named Aylal, was equipped with a GPS tag that allows to know accurately where's the bird, thus permiting to identify key sites or potential threats.