Conservation in Action - nest tree maintenance

by Tony PITTMAN. Published in Just Parrots, 1997, Issue 18

Ongoing nesting tree inspection and maintenance has always been a very important part of Neiva Guedes' work on the Hyacinthine Macaw project in the Brazilian Pantanal. 95% of the nest sites are in manduvi (Sterculia striata) trees. This tree grows to 17 to 20 m (55-65 ft) and has a large trunk with very thick branches. It is a favourite source of lumber by the local ranchers. It has, however, a soft core that rots rapidly. The trees can become very hollow and lose branches or topple during one of the frequent storms, which sweep across the vast flat expanse of the Pantanal.

Lack of suitable nesting sites is a critical factor in the conservation of this magnificent macaw. There is no shortage of food with numerous palm trees of the two species preferred by the macaws (acuriand bocaiuva), which produce abundantly throughout the year. This abundance enables many pairs of both the Hyacinthine Macaw (Anodorhynchus hyacinthinus) and the Green-winged Macaw (Ara chloroptera) to raise two young successfully to independence.

The competition for nest sites with other species is quite intense. The latest report sent to me by Neiva covering the period January 1996 to April 1997 elaborates on this. During this period Neiva monitored 160 nest sites - 143 natural and 17 artificial - out of a total of 193 available sites on 21 ranches. 61 were occupied by Hyacinthine Macaws, 12 by Green-winged Macaws, 3 by Black Vultures (Coragyps atratus), 12 by bees (Apis melifera), 3 by the Collared Forest Falcon (Micrastur semitorquatus). 1 by the Muscovy Duck (Cairina moschata) and 1 by the Toco Toucan (Ramphastos toco). Of the remaining 67 nest sites, 29 were not used for reasons unknown and 38 disputed.

35 of these were disputed by the Hyacinthine Macaws with other species - 13 with Green-winged Macaws, 6 with Black Vultures, although the latter usually breed earlier so that the nest is vacated in time for the macaws to occupy, 5 with the Collared Forest Falcon, 4 with bees, 2 were disputed with both bees and Black Vultures. Three nest sites were violently disputed with Toco Toucans and for the second year running broken toucan skulls and beaks were discovered in a nest cavity. Two nest sites were disputed with Muscovy Ducks, who normally use the cavities after the macaws have finished breeding. Problems occur when the breeding period of the macaws is delayed.

Apart from the problem with decaying trees, deforestation is increasing in some areas. Repair work to damaged trees is all the more important, particularly in areas, where felling is occurring. 13 such damaged trees were repaired during the period under review. 2 artificial nestboxes of recycled tree trunks were set up. This is demanding, time-consuming work, which is also quite dangerous because of the size and weight of the artificial nest-boxes. Hyacinthine Macaws bred successfully in four of these repaired, managed natural sites. No success was achieved in the above-mentioned two tree trunk nest boxes set up in 1996, although a pair of Blue-fronted Amazons (Amazona aestiva) bred in one.

Success was achieved this year however in the artificial nest box constructed by a small group of German aviculturists in June 1995 and set up in August of the same year. Readers may recall my account in the April/May 1996 issue of Just Parrots of how we discovered a pair using the box in January 1996. They laid two eggs, which hatched, but were sadly predated. The same pair used the box again in the next breeding season and a young macaw was successfully reared to independence.

In May 1997 another small group of German aviculturists with Thomas Arndt as guide visited the Pantanal and built more boxes for Neiva to install. Since then she has had more constructed locally of planks measuring 55 x 50 x 40 x 50 cm. and installed 46 of them during July 1997. 24 more are to be installed before this year's breeding season starts.

In a recent e-mail Neiva related how she was installing nest boxes in the Pantanal and night started to fall. She decided to leave the box at the bottom of the tree and return early next morning. When she returned she was astonished to discover as she quietly approached a pair of Hyacinthine Macaws exploring the box. She hid and watched them for a while nibbling at the entrance hole and climbing all over it. Then a second pair arrived, but were driven off by the first pair. This story illustrates how much in demand the artificial nest boxes are likely to be.

There are problems with installing and maintaining artificial nestboxes. They are heavy and cumbersome as well as difficult to fix to the tree. After giving a slide presentation on progress with the project at a recent meeting of the Parrot Society Nottingham area, one of the members suggested I contact the Ministry of Defence to get details of a device with a ratchet used to affix satellite communication dishes to tall trees. I have taken this up and hope this might help solve this particular problem.

We are very proud of the project, which we regard as unique in that it involves long-term, ongoing conservation using husbandry techniques in the wild. All the other parrot conservation projects are last-ditch efforts to save a species from extinction (Spix's Macaw, Echo Parakeet and Kakapo). The scope of the project is being widened with 200 nest sites now being managed over a large area of the Pantanal in Mato Grosso do Sul. Later this year more radio collars will be fitted to young macaws to monitor flight patterns and territories. The hard work with repairing and maintaining nesting trees and installing artificial nest boxes will also continue.

Ref: Relatorio Technico Anual do Projeto Arara Azul/UNIDERP 1996 Neiva Maria Robaldo Guedes, Project Coordinator and Researcher

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Quotes

 " Naturam expellas furca, tamen usque recurret "

( If you drive out nature with a pitchfork, she will soon find a way back)

Horace (65-8 BC)