| predators of the tick amblyomma variegatum (acari: ixodidae) in guadeloupe, french west indies. | some vertebrate species in guadeloupe are predators of free or parasitic stages of amblyomma variegatum (fabricius). among birds, 1.9% of the 421 identified animals found in the stomachs of grackles (quiscalus lugubris), 1.6% of the 364 animals found in the stomachs of free-ranging chickens, and 0.3% of the 4642 animals found in the stomach of cattle egrets (bubulcus ibis) were a. variegatum ticks. the most efficient predator of ticks was the tropical fire ant, solenopsis geminata, which was obs ... | 1991 | 1773677 |
| wildlife as hosts for ticks (acari) in antigua, west indies. | a survey was conducted to determine the status of wild mammals and birds as hosts for amblyomma variegatum (f.) and other tick species in antigua. surveys of wild mammals and birds were conducted periodically from september 1988 through may 1991. wild mammals surveyed included the small indian mongoose (herpestes auropunctatus hodgson), norway rat (rattus norvegicus berkenhout), and house mouse (mus musculus l.), but only mongooses were surveyed intensively. larvae and nymphs of a. variegatum, l ... | 1994 | 8158630 |
| flexible expression of a food-processing behaviour: determinants of dunking rates in wild carib grackles of barbados. | dunking, the softening of dry food in water to speed up consumption time, is normally a very rare behaviour in wild carib grackles (quiscalus lugubris) of barbados. its frequency can be experimentally increased when large numbers of dry items are repeatedly placed near a standing source of water in conditions that minimize intraspecific competition and risk of theft. to reconcile the normally low frequency of the behaviour in the wild with the high rates obtained in previous experiments, we test ... | 2007 | 17587511 |
| stealing of dunked food in carib grackles (quiscalus lugubris). | the use of tool or tool-like food processing behaviours can render animals vulnerable to theft (kleptoparasitism) because (1) large, nutritious items are usually involved, (2) value is added to the food due to long and/or complex handling, and (3) physical control of items is often temporarily lost during handling. in barbados, carib grackles (quiscalus lugubris) immersing items in water before consumption (a behaviour known as food dunking) lose a larger proportion of items to conspecific food ... | 2006 | 16989960 |
| speed-accuracy trade-off, detour reaching and response to pha in carib grackles. | performance on different cognitive tasks varies between individuals within species. recent evidence suggests that, in some species, this variation reflects the existence of coherent cognitive strategies bringing together positive and negative relationships between tasks. for example, carib grackles show a speed-accuracy trade-off, where individuals that are fast at solving novel problems make more errors at discrimination learning than individuals that are slow solvers. pathogens are thought to ... | 2019 | 30929104 |
| spermatid differentiation, with particular reference to acrosomogenesis, in the passeridan bird, carib grackle (quiscalus lugubris). | only a few studies on the development of the passerine spermatozoon are available, yet species variations in the conformation as well as structure of the generally helical acrosome have been reported. this study of spermiogenesis in the carib grackle (quiscalus lugubris) intended to provide a deeper understanding of the development of the sperm, and in particular to investigate the bi-partite nature and development of the acrosome as well as its relationship with the nucleus, in the absence of a ... | 2019 | 31759412 |
| innovative foraging behaviour in birds: what characterizes an innovator? | innovative foraging behaviour has been observed in many species, but little is known about how novel behaviour emerges or why individuals differ in their propensity to innovate. here, we investigate these questions by presenting 36 wild-caught adult male carib grackles (quiscalus lugubris) with a novel problem-solving task. twenty birds solved the task ("innovators") while 16 did not ("non-innovators"). we compared innovators to non-innovators and explored variation in latency to innovate to det ... | 2011 | 21704684 |
| problem-solving and learning in carib grackles: individuals show a consistent speed-accuracy trade-off. | the generation and maintenance of within-population variation in cognitive abilities remain poorly understood. recent theories propose that this variation might reflect the existence of consistent cognitive strategies distributed along a slow-fast continuum influenced by shyness. the slow-fast continuum might be reflected in the well-known speed-accuracy trade-off, where animals cannot simultaneously maximise the speed and the accuracy with which they perform a task. we test this idea on 49 wild ... | 2015 | 25381576 |
| structural features of the spermatozoon of a passeridan bird, the carib grackle, quiscalus lugubris. | the spermatozoon of the carib grackle, quiscalus lugubris, a member of the family icteridae, is generally similar in organization to the passerine-type of spermatozoon, in being highly elongated and displaying a helical structure of the acrosome, nucleus and principal piece of the tail. there are subtle variations in acrosomal structural features between this organelle in the grackle and that in some of the very few passerine species of birds in which the spermatozoon has been studied. the proxi ... | 2017 | 28242104 |
| feeding innovations in a nested phylogeny of neotropical passerines. | several studies on cognition, molecular phylogenetics and taxonomic diversity independently suggest that darwin's finches are part of a larger clade of speciose, flexible birds, the family thraupidae, a member of the new world nine-primaried oscine superfamily emberizoidea. here, we first present a new, previously unpublished, dataset of feeding innovations covering the neotropical region and compare the stem clades of darwin's finches to other neotropical clades at the levels of the subfamily, ... | 2016 | 26926278 |
| bajan birds pull strings: two wild antillean species enter the select club of string-pullers. | string-pulling is one of the most popular tests in animal cognition because of its apparent complexity, and of its potential to be applied to very different taxa. in birds, the basic procedure involves a food reward, suspended from a perch by a string, which can be reached by a series of coordinated pulling actions with the beak and holding actions of the pulled lengths of string with the foot. the taxonomic distribution of species that pass the test includes several corvids, parrots and parids, ... | 2016 | 27533282 |
| [trichocephaloidis beauporti n. sp., new cestode of charadriiformes and some passeriformes in guadelupa (author's transl)]. | description of a new species of dilepididae, trichocephaloidis beauporti n. sp., parasite of charadriiform birds (tringa flaviceps; micropalama himantopus; gallinago gallinago delicata; squatarola squatarola) of guadelupa and also of a passeriforme, quiscalus lugubris. this species can easily be separated from other trichocephaloidis by the structure of bifid rostellum and the length of hooks (70-77 mu). trichocephaloidis charadrii is synonym of trichocephaloidis megalocephala. | 2006 | 970865 |
| mode of foraging competition is related to tutor preference in zenaida aurita. | this study compared the direction of social learning in 2 populations of barbados zenaida doves (zenaida aurita). one population (st. james) is territorial; it competes aggressively with conspecifics but scramble competes with heterospecifics. the other population (deep water harbour) forages in large homospecific flocks. field observations were conducted to quantify intraspecific and interspecific patterns of foraging association and aggression. wild-caught doves from both areas were then teste ... | 1996 | 8851552 |