Notes on the biology of the threatened Island Thrush Turdus poliocephalus xanthopus in New Caledonia

2019 ◽  
Vol 29 (4) ◽  
pp. 616-626
Author(s):  
PASCAL VILLARD ◽  
THOMAS DUVAL ◽  
CHRISTIAN PAPINEAU ◽  
JEAN-JÉRÔME CASSAN ◽  
JÉRÔME FUCHS
Keyword(s):  
New Caledonia ◽  
Rattus Rattus ◽  
Coastal Forest ◽  
Significant Component ◽  
Predator Species ◽  
Black Rat ◽  
New Caledonian Crow ◽  
Caledonian Crow ◽  
Nest Predator ◽  
Corvus Moneduloides

SummaryThree subspecies of Island Thrush Turdus poliocephalus were historically found in New Caledonia. All these subspecies were considered extinct until 1978, when T. p. xanthopus was rediscovered on two small islands, Néba (∼ 3.5 km2) and Yandé (∼ 13 km2). On Néba, we estimated the population at 44–58 individuals. This Island Thrush population is dependent on the coastal forest, the richest habitat for invertebrates. However, the coastal forest habitat has been degraded in quality and extent. The Island Thrush forages in the litter by removing leaves with its bill. Fruits (diameter < 10 mm), picked from trees and swallowed whole, are also a significant component of its diet. Néba and Yandé are currently free of two nest predator species, the black rat Rattus rattus and the New Caledonian Crow Corvus moneduloides. On Néba, a low breeding success rate of 15.4% was found. To ensure conservation of these relict thrush populations, two actions at least should be implemented: setting up a biosecurity programme to keep islands free of black rats and increasing the area of coastal forest. The latter could be done by cutting down coconut trees in abandoned groves and planting tree species used by the Island Thrush to provide shade, fruits, good leaf litter, and nest support.

scholarly journals Threat recognition and response in an avian brood-parasite host from New Caledonia

2020 ◽  
Author(s):  
Alfredo Attisano ◽  
Kasper Hlebowicz ◽  
Roman Gula ◽  
Jörn Theuerkauf
Keyword(s):  
Brood Parasitism ◽  
Nest Predation ◽  
New Caledonia ◽  
Brood Parasite ◽  
Brood Parasites ◽  
New Caledonian Crow ◽  
Caledonian Crow ◽  
Threat Recognition ◽  
Recognition And Response ◽  
Nest Predator

Abstract Nest predation and avian brood parasitism are the main sources of nest failure in many passerine birds. Large predators threaten both brood and parents, whereas brood parasites pose only a danger to eggs or nestlings. The fan-tailed gerygone Gerygone flavolateralis from New Caledonia is subjected to high rates of nest predation by the New Caledonian crow Corvus moneduloides (responsible for about 20–40% of predation) and moderate rates of brood parasitism by the shining bronze-cuckoo Chalcites lucidus (parasitizing about 18% of nests), which also depredates nests that are too advanced for parasitism (13% of nests). To test if fan-tailed gerygones are able to discriminate predators from brood parasites, we presented 3 bird models at active gerygone nests: a brood parasite/small nest predator (shining bronze-cuckoo), a large nest predator (crow), and a small non-native bird (common chaffinch Fringilla coelebs), which is unknown to the gerygone, as a control. We assessed the response of adult gerygones to the presentation of each model by measuring the minimum approach distance, number of alarm calls, number of attacks, and time to first nest visit after the presentation (latency). Adult gerygones often attacked the cuckoo, approached but never attacked the chaffinch and always avoided the crow. Latency was shorter after an attack response and during brooding, but similar among models. We did not find any link between the cuckoo model presentation and later ejection of cuckoo nestlings. We conclude that adult fan-tailed gerygones discriminate between different models and respond accordingly to the level of threat, but do not show awareness of parasitism risk and increase of nestling ejection rates following exposure to the cuckoo model.

scholarly journals Risk-taking behavior of bull-headed shrikes that recently colonized islands

2020 ◽  
Author(s):  
Shoji Hamao ◽  
Hisahiro Torikai ◽  
Midori Yoshikawa ◽  
Yutaka Yamamoto ◽  
Tugeru Ijichi
Keyword(s):  
Risk Taking ◽  
Natural Environment ◽  
Rattus Rattus ◽  
Predation Rate ◽  
Nest Site Selection ◽  
Predator Species ◽  
Black Rat ◽  
Lanius Bucephalus ◽  
Risk Taking Behavior ◽  
Selection Of

Abstract Individuals which have invaded urbanized environments are reported to engage in riskier behaviors, possibly influenced by the scarcity of predators in urbanized areas. Here, we studied the risk-taking behavior of birds which had invaded a new natural environment, rather than an artificial urban environment, using recently established populations of the bull-headed shrike Lanius bucephalus, which naturally colonized three subtropical islands in Japan. We compared flight initiation distance (FID), the distance at which an individual approached by a human initiates flight, between the islands and the temperate mainland. FID was longer for the insular shrikes compared with the mainland shrikes after controlling for other factors, indicating that the individuals which had invaded a new natural environment had a lower propensity for risk-taking. A possible explanation for these results is that low risk-taking behavior might be adaptive on the islands due to predation by the black rat Rattus rattus, an unfamiliar predator not found in shrike habitats on the temperate mainland. Further studies are needed to examine the nest predation rate, predator species, and nest site selection of these insular shrike populations.

scholarly journals Is primate tool use special? Chimpanzee and New Caledonian crow compared

2013 ◽  
Vol 368 (1630) ◽  
pp. 20120422 ◽  
Author(s):  
W. C. McGrew
Keyword(s):  
Material Culture ◽  
Pan Troglodytes ◽  
Tool Use ◽  
Field Research ◽  
Extractive Foraging ◽  
New Caledonian Crow ◽  
Elementary Technology ◽  
Caledonian Crow ◽  
Sustained Field ◽  
Corvus Moneduloides

The chimpanzee ( Pan troglodytes ) is well-known in both nature and captivity as an impressive maker and user of tools, but recently the New Caledonian crow ( Corvus moneduloides ) has been championed as being equivalent or superior to the ape in elementary technology. I systematically compare the two taxa, going beyond simple presence/absence scoring of tool-using and -making types, on four more precise aspects of material culture: (i) types of associative technology (tools used in combination); (ii) modes of tool making; (iii) modes of tool use; and (iv) functions of tool use. I emphasize tool use in nature, when performance is habitual or customary, rather than in anecdotal or idiosyncratic. On all four measures, the ape shows more variety than does the corvid, especially in modes and functions that go beyond extractive foraging. However, more sustained field research is required on the crows before this contrast is conclusive.

Morphology and sexual dimorphism of the New Caledonian Crow Corvus moneduloides, with notes on its behaviour and ecology

Ibis ◽  
2004 ◽  
Vol 146 (4) ◽  
pp. 652-660 ◽  
Author(s):  
Benjamin Kenward ◽  
Christian Rutz ◽  
Alex A. S. Weir ◽  
Jackie Chappell ◽  
Alex Kacelnik
Keyword(s):  
Sexual Dimorphism ◽  
New Caledonian Crow ◽  
Caledonian Crow ◽  
Corvus Moneduloides

MODULATION OF TRIGLYCERIDES IN FEMALE RATTUS RATTUS WITH STEROID CONTRACEPTIVE ALGESTONE ACETOPHENIDE (DHPA)

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
ASHOK KUMAR ◽  
ALPANA PARMAR ◽  
ANAND KUMAR BAJPEYEE
Keyword(s):  
Mixed Type ◽  
Rattus Rattus ◽  
Young Female ◽  
Female Rats ◽  
Control Group ◽  
Black Rat ◽  
Long Acting ◽  
Steroid Contraceptive

Young female Black rat (Rattus rattus), were administered monthly long acting steroid contraceptive to induce hypertriglyceridemia. It was observed that by 3 weeks of the second injection of estrogen containing mixed type of contraceptive, female rats developed consistent and frank hyperglyceridemia . TG in the treated rats was 195.8 ± 7.44 mg /100 ml as compared to 91.5 ± 6.27 mg/100ml in plasma of the control group.

Sign in / Sign up

Export Citation Format

Share Document