Montag, 13 Januar 2020 10:00

ELSHAFIE, H. & ABDEL BANAT, B. (2018)

The frugivorous white-eared bulbul bird, Pycnonotus leucotis, depredating date fruits: Biology, feeding ecology and management.

Outlooks on Pest Management 29(4):153-157

Abstract:

Date fruits pass through five stages of development; these are the Hababouk (just after fruit setting), Kimri (green small-sized), unripe Khalal or Bisr (50% moisture), ripened Rutab (30-35% moisture), and mature ripened Tamr (10-30% moisture). Birds generally feed on dates during the sweet Khalal, Rutab, and Tamr maturation stages. The most important depredating bird species on date palm fruit are bulbuls, parakeets, house sparrows, crows, and mynas. Bulbuls are by far the most injurious avian pests on date palm in Africa and the Middle East. They are also potential dispersers of noxious weed seeds, besides being vectors and reservoirs for avian diseases and parasites. Bulbuls are mostly used as cage birds where they escape from captivity and establish themselves as feral populations. A good example of populating new areas is the introduction of the white-cheeked bulbul (Pycnonotus leucogenys) into Jordan from Syria and Iraq during 1980s and 1990s as cage birds. There are more than 137 species of bulbul birds worldwide. The genus Pycnonotus comprising 36 species, which are mostly found in Asia and Africa. Of the 36 species of the genus Pycnonotus, 8 species were reported to feed on date fruits. Out of these, 3 are considered serious pests of dates; the common bulbul, Pycnonotus barbatus in Africa, white-cheeked bulbul, P. leucogenys and white-eared bulbul, P. leucotis in Asia. In this article, emphasis was given to the white-eared bulbul due to the large extent of damage in many date producing countries. Information regarding its distribution, biology, feeding ecology, damage to dates, and possible management were highlighted. Date damage by birds was overlooked as no adequate data describing this type of depredation are available. Thus, this article was written with the main objective of giving concise information on bulbul bird damage to date fruits and the possible measures for their management. The white-eared bulbul, Pycnonotus leucotis, is one of the most serious avian pests of date palm. It causes severe depredation on dates that tremendously lowers date quality and results in substantial economic losses. However, the damage to dates inflicted by the bulbuls and their management is overlooked when farmers calculate their production costs. Covering fruit bunches with suitable bags, at the right time of maturation, is the most suitable and practical measure to alleviate bulbul damage on date fruits. In this respect, more research is needed to find cost-effective bunch covers that provide maximum bird protection and least adverse effect on developing date fruits.

elshafie-biblio

Freigegeben in E
Montag, 13 Januar 2020 09:01

TECHACHOOCHERT, S. & ROUND, P. (2013)

Red-whiskered Bulbul: are trapping and unregulated avicultural practices pushing this species towards extinction in Thailand?

Birding Asia 20:49-52

Abstract:

The Red-whiskered Bulbul Pycnonotus jocosus is a relatively common bird of well-watered open country from South to South-East Asia and southern China. It is naturalised elsewhere, in Mauritius, Australia and North America, and its conservation status is Least Concern. In Thailand the species is much in demand due to its sweet, chuckling song, and it is possibly the most widely kept native cage-bird species in the country, but it has nearly vanished from most of its Thai range due to the illegal trapping of wild birds for sale. The only recent national assessment in which the Red-whiskered Bulbul was considered 'nationally Near Threatened' is already too conservative given its precipitous and rapid decline. Thailand's Wild Animal Reservation and Protection Act 1992 permits possession and captive breeding of Red-whiskered Bulbuls only under supposedly stringent safeguards, but this is widely flouted. Most Thai provinces now have their own Red-whiskered Bulbul clubs, with over 100 clubs nationwide. One of these clubs claims more than 50,000 members, each of whom was estimated by the club's director to own at least 5–10 birds, with some having 30 or more birds. The Thai captive population of Red-whiskered Bulbuls therefore now probably numbers in the millions. Some Thai government authorities have inadvertently encouraged the illegal sale and capture of Red-whiskered Bulbuls through, for example, the active promotion of Red-whiskered Bulbul singing contests. Due partly to the active hostility of the huge bulbul fancier lobby, the suppression of trade and wild capture by the Department of National Parks, Wildlife and Plants Conservation (DNP), the government authority charged with biodiversity conservation and law enforcement, has been inadequate, haphazard and inconsistent. Additionally the major burden of caring for confiscated wildlife - 28,139 Red-whiskered Bulbuls were confiscated from illegal bird-traders between 2007–2010 alone—has even led some DNP officials to suggest that the protected status of Red-whiskered Bulbul should be revoked. In addition to the reduction or loss of the wild population, the apparently widespread practice of cross-breeding Red-whiskered Bulbuls with Yellow-vented Bulbuls P. goaivier presents a possible additional threat. The breeders believe that the hybrids are more aggressive, and sing more vigorously than Red-whiskered Bulbuls, giving them an advantage in bird-singing competitions. The hybrids concerned are usually backcrosses with Red-whiskered Bulbuls from which they are almost indistinguishable. Prize-winning Red-whiskered Bulbuls in national competitions are usually valued at a minimum of Baht 200,000 (about £3,800) and the highest price so far recorded is Baht 1.6 million (£31,000). There are also published records of Red-whiskered Bulbuls hybridising in captivity with Red-vented Bulbul P. cafer, White-eared Bulbul P. leucotis, White-spectacled Bulbul P. xanthopygos, Black-crested Bulbul P. melanicterus  and Himalayan Bulbul P. leucogenys. ..

techachoochert-biblio

Freigegeben in T
© Peter Dollinger, Zoo Office Bern hyperworx