bluuebunny/crossref_metadata_2025_split huggingface dataset:
Memory for Locations of Stored Food in Willow Tits and Marsh Tits
Authors: Healy Susan D. , Suhonen Jukka 
Published: April 2008

AbstractSome food-storing animals use spatial memory in food retrieval. There is variation amongst food-storing species in the duration over which food is stored and it is positively correlated with differences in the size of the part of the brain that is involved with memory for storage locations, the hippocampus. For example, British marsh tits (Parus palustris) are generally thought to retrieve their stores after a few hours or days whereas Scandinavian willow tits (P. montanus) have been shown to store their food for several weeks to months. Marsh tits also have a smaller hippocampus than do willow tits. This experiment tested the hypothesis that retrieval success (and thus memory capacity) of the two species differs depending on the usual length of time for which food is stored. Individuals of both species were tested on their ability to retrieve five stored food items after two differing delays: 2-3 h ('short') and 17 days ('long'). The prediction was that there would be no differences in retrieval performance between the species after the short delay but that willow tits would be more accurate at retrieving their stores than marsh tits after the long delay. The results did not provide support for this hypothesis as there were no differences between the species in retrieval performance following either delay: both species successfully retrieved food after both delays.
Genetic Influences On Coping Behaviour in House Mouse Lines Selected for Aggression: Effects of the y cHromosome
Authors: Sluyter Frans , Van Oortmerssen Geert A. , Koolhaas Jaap M. 
Published: April 2008

Abstract
Male wild house mice selected for Short Attack Latency (SAL) show an active coping style to environmental challenges, whereas males selected for Long Attack Latency (LAL) generally exhibit a passive coping style. Previous studies showed that the aggressive SAL males develop routines more quickly and show more resistance to environmental changes than the less aggressive LAL ones; the latter behave more flexibly in non-social situations. Furthermore, using reciprocal F1s and backcross lines for SAL and LAL males, a Y chromosomal effect on aggression has been demonstrated. The aim of this study was to examine possible effects of the Y chromosome on behavioural flexibility. For this purpose six genotypes (SAL, LAL, their reciprocal F1s and their congenics for the non-pseudoautosomal part of the Y chromosome) were tested for their behavioural flexibility in a Y-maze. Differences between SAL and LAL were reproduced. Congenic lines showed identical scores to their parental ones. Regarding the reciprocal F1s, differences in aggression were not associated with behavioural flexibility. Therefore, it may be concluded that the Y chromosome does not influence aggression-related behavioural flexibility.
The Foraging Behaviour of Mongolian Gerbils: a Behavioural Need or a Need To Know?
Authors: Forkman Björn 
Published: April 2008

AbstractIn the present paper Mongolian gerbils (Meriones unguiculatus) were shown to prefer to forage from an unprofitable food source when it contained hidden food, but not when the food was clearly visible. Four experiments were performed, in each experiment the animal could forage from either a food source with easily accessible food or from a food source which required more work. In the first experiment the animal could choose between seeds with husks and those without, and in the second experiment between seeds glued to a stick and seeds in a bowl. In both these experiments the animals could see the food of both food sources. The animals chose to forage from the most profitable food source, i.e. the seeds without husks and the seeds in a bowl respectively. In the third experiment the animals could choose between eating seeds hidden under lids or seeds in a bowl, and finally in the fourth experiment they could forage for seeds on a camouflaging surface or on a surface where the seeds were clearly visible. In these last two experiments it was impossible to see the food in the unprofitable food sources without working for it. In these situations the animals choose to forage from the unprofitable food source, i.e. from underneath the lids and on the camouflaging surface. These results are in accordance with exploration being the driving force behind contrafreeloading (learned industrioussness). The results cannot be explained by classical optimal foraging theory.
Environmental Stimuli Influence Oestrogen-Dependent Courtship Transitions and Brain Aromatase Activity in Male Ring Doves
Authors: Hutchison R.E. , Opromolla G. , Hutchison J.B. 
Published: April 2008

AbstractIn paired ring doves, Streptopelia risoria, male and female reproductive behaviour undergoes a series of synchronised transitions. The duration of each phase depends on the reproductive development of the pair. This study examines the effect of the environment in which behaviour is shown on both oestrogen-dependent courtship transitions and formation of oestrogen in the brain. The structuring of the cage environment had an immediate effect on transitions in male courtship behaviour. Males which were tested with females in a cage environment with a perch and a nest bowl (complex cage) displayed significantly less aggressive courtship and more nest-orientated behaviour than males tested with females in a cage environment without perch or nest bowl (simple cage). The response of males, which showed aggressive and nest-orientated courtship behaviour, to reproductively advanced females (abdominal length 1.4-1.6 cm) about to lay eggs or females in earlier stages of reproductive development (abdominal length 0.8-1.1 cm) did not differ initially. On the eighth day of 15-min daily tests, there was, however, an increase in aggressive courtship to females with smaller abdomens. This result suggests that male aggressiveness is more likely when the male and female reproductive cycles are not synchronised. We also tested whether environmental factors and the male's hormonal condition, which affect male courtship interactions, influence the formation of behaviourally effective oestrogen by aromatisation of testosterone in the brain. The aromatase activity was measured in the preoptic and anterior hypothalamic areas in relation to the time spent in interaction with females each day. Both intact and castrated males which interacted intermittently (15 min each day for 9 days) had higher preoptic aromatase activity than males which interacted continuously with females. The males which had high brain aromatase activity and had interacted intermittently with females were considered to represent the initial stages of the cycle. We conclude that cage environment and female reproductive condition influence the course of courtship interactions. Oestrogen formation in the male brain is affected by the type of interaction.
Is Group-Living Associated With Social Learning? a Comparative Test of a Gregarious and a Territorial Columbid
Authors: Lefebvre Louis , Palameta Boris , Hatch Karen K. 
Published: April 2008

AbstractGroup-living is often thought to be associated with social learning. Comparative tests are useful in evaluating the link between ecological variables and learning specializations, but controls are required to guard against possible confounding variables. In this paper, we test the association between group-living and social learning by comparing two opportunistic, urbanized, Columbids in a set of experiments involving shaping and individual learning controls. In part 1, we provide quantitative field data on foraging group size for the two species, the feral pigeon (Columba livia) studied in central Montréal and the Zenaida dove (Zenaida aurita) studied in coastal Barbados. The data confirm anecdotal reports that contrast the gregarious social organization of C. livia with the territorial organization of coastal Z. aurita. In part 2, we test pigeons and Zenaida doves on two food-finding tasks and show (1) that feral pigeons are better than Zenaida doves at solving all variants of the tasks presented, whether individually or socially learned, and (2) that once general species differences are taken into account, territorial Zenaida doves are not less efficient than gregarious feral pigeons at using food-finding information provided by a conspecific tutor. The results do not support the association between group-living and social learning and show that procedures like shaping and control variants of the task may help interpret interspecific differences in learning.
Mate Choice On Multiple Cues, Decision Rules and Sampling Strategies in Female Pied Flycatchers
Authors: Dale Svein , Slagsvold Tore 
Published: April 2008

The mate sampling behaviour and mate choice of 125 individually marked female pied flycatchers, Ficedula hypoleuca, was recorded with video cameras. Females visited on average 3.1 males within a period of less than 1 day. Females had independent preferences for unmated males, brightly coloured males and males with nestboxes that had small entrance holes; 77-86% of the females chose a male that was the best one among the males sampled in relation to at least one of these factors. When having a choice only on mating status 91 % of the females made a correct choice; corresponding values for plumage colour and nest site quality were 64% and 73%, respectively. Females made 'mistakes' more often when differences between males were small, at least regarding plumage colour. When given simultaneous choices on two cues, females gave priority to the cue with the largest differences between males. Females returned to some males before rejecting them and these males tended to have brighter plumage or better nestboxes than males that were visited only once. The final choice of mate was not related to the order in the sequence of males visited, suggesting that many females used a pool-comparison strategy. However, about one third of the females visited only one male, and one third sampled males in a way conforming to threshold or sequential comparison strategies as well as a pool-comparison strategy. The temporal pattern of female visits suggested that they either sampled males at once and then settled, or that they visited one male repeatedly and made occasional visits to other males, often after a long period of residency. Twenty-eight females (22%) made visits to other males after they had settled
(i.e.
started nest building) with one male, and this resulted in mate switching in seven cases (6% of all females). These results show that females compare and choose mates on the basis of at least three different cues, and that most females are able to pick out the best or one of the best males among those sampled. However, females sample few males, probably because of competition between females for a mate, so that they must sometimes accept dull or mated males, or males with poor-quality nest sites. Limited choice reduces the strength of sexual selection even when female preferences are strong. This may help explain why plumage colour variation and polygyny exist in the pied flycatcher.
Female Aquatic Warblers (Acrocephalus Paludicola) Are Attracted By Playback of Longer and More Complicated Songs
Authors: Catchpole Clive K. , Leisler Bernd 
Published: April 2008

Abstract
Male aquatic warblers are relatively unusual in producing three different song structures, A, B and C. The shorter A-B songs have been shown to function in male-male aggressive interactions, and it was speculated that the longer and more complex C songs might function in female attraction. The present playback experiments were carried out on hormone-implanted females in a large, experimental aviary. When playback was of a male singing C songs, females were attracted faster and for longer periods than when the same male produced A-B songs. Females gave relatively few sexual displays, but gave more in response to playback of C songs than to A-B songs. Aquatic warblers have an unusually promiscuous mating system with high rates of extra-pair fertilisation and multiple paternity within broods. Sexual selection through intense sperm competition may have accentuated the evolution of structurally distinct songs for female attraction and aggressive interactions between rival males.
Mate Guarding in Male Sand Lizards (Lacerta Agilis)
Authors: Olsson Mats , Gullberg Annica , Tegelström Hakan 
Published: April 2008

Abstract
We investigated factors that may determine mate guarding tactics in male sand lizards. In a sample of lizards from a museum collection, larger males had larger testis, but in laboratory experiments and in a natural population larger males did not sire more offspring. Males with long inter-copulatory intervals were more successful in sperm competition than males with short inter-copulatory intervals. In the wild, the operational sex ratio (OSR, No of receptive females/No of sexually active males) declined throughout the mating season. Mean duration of mate guardings was unaffected by OSR, time to ovulation, female age and mass, and clutch size. Larger males guarded females longer and were more likely to mate guard a female of similar age. Larger males had more partners but there was no correlation between male size or guarding time and the proportion of young that males sired in clutches from females mated with several partners. Males with more partners were more successful at siring offspring in clutches from females that mated with more than one partner. We suggest that fitter males are better at both mate acquisition and have more competitive sperm.
Chaffinch (Fringilla Coelebs) Epaulette Display Depends On the Degree of Exposure But Not Symmetry of Intruder's Epaulettes
Authors: Jablonski P.G. , Matyjasiak P. 
Published: April 2008

Abstract1. Epaulettes, white wing patches, are exposed in agonistisc displays between territorial chaffinch males. 2. As with many bilateral traits one should expect that asymmetrical development of the two wing patches could indicate poorer individual. Therefore it is likely that territory owners change their display toward asymmetrical competitor. 3. We tested the effect of exposure and symmetry of epaulettes of a stuffed bird on epaulette exposure of the territorial male. The results showed that: 4. males increased the degree of their epaulette exposure in response to larger epaulette on the mount; 5. males did not respond to the asymmetry of epaulettes on the mount. 6. The results aggree with the interpretation that the males' display of exposed epaulettes to each other could be regarded as communication. The epaulette display could be a signal of high aggressive motivation in the chaffinch.
Larval Prepupation Behaviour of Drosophila Pavani, Drosophila Gaucha and Their Reciprocal Hybrids
Authors: Godoy-Herrera Raúl , Silva José Luis 
Published: April 2008

Abstract
The behavioural mechanisms by which the larvae of the sibling species D. pavani and D. gaucha, and their reciprocal hybrids select pupation sites are described in terms of larval substrate preferences. If the larval behaviour of the parental species and their reciprocal hybrids during pupation leads them to pupate in different substrates, such preferences could be used to identify environmental factors and genetic mechanisms involved in the evolution of that behaviour. Confronted with dry substrates, interspecific hybrid larvae pupated in the rearing cup, while the parental species pupated both outside and inside the cup. Like the parental species, the hybrids pupated outside, when humid substrates surrounded the rearing cup. Larvae from D. pavani and D. gaucha showed a broader norm of reaction than the hybrids. D. pavani larvae occupied dry and humid substrates to pupate, while D. gaucha larvae tended to prefer only humid substrates. Larvae of D. pavani burrowed into dry sand pupated preferently in the deep layers of the substrate. Few D. gaucha larvae burrowed; they tended to pupate in the upper layers of dry sand. D. pavani larvae pupated on the moist sand, while most of D. gaucha larvae burrowed and formed puparia in the upper layers of the substrate. The hybrid larvae showed no burrowing behaviour in either dry or moist sand.
The Importance of Different Paternity Guards in the Polygynandrous Penduline Tit (Remiz Pendulinus)
Authors: Schleicher B. , Ho H. , Valera F. , Hoi-Leitner M. 
Published: April 2008

Abstract
It is well documented that extra-pair copulations are a strategy by which males can increase their reproductive success and females may obtain genetic benefits. Whereas in monogamous species extra-pair copulations are the only way for both sexes to increase their reproductive success, in polygamous systems both partners can benefit from mating with several individuals. Here we examine the intensity of sperm competition and the rate of extra-pair fertilizations in relation to male anti-cuckoldry tactics in a small passerine, the polygynandrous penduline tit (Remiz pendulinus), where both sexes have the opportunity to become polygamous. The results revealed rather low rates of extra-pair paternity for this species: 6.9% (14 out of 201) of young being sired by an extra-pair male. Males build elaborate nests to attract females and because of this high initial investment, one would expect males to evolve anti-cuckoldry tactics to ensure paternity. However, male mate guarding intensity as well as within-pair copulation frequency were rather low in comparison to other polygynandrous species, and hence both strategies are unlikely to ensure paternity. In fact our results show that those males which deserted their females early in their fertile cycle (already before the second egg is laid) did not lose paternity, whereas those males which tended to guard their females throughout their whole fertile period were more likely to be cuckolded. Thus, although no obvious anti-cuckoldry tactics exist in this species, extra-pair paternity is very low. This indicates a tendency in females to cooperate with their pair-males rather than seek extra-pair copulations.
Distribution of Parental Investment and Sibling Competition in the Herring Gull, Larus Argentatus
Authors: Davis Jennifer , Quinn James S. 
Published: April 2008

Abstract
Herring gulls, Larus argentatus, typically lay three eggs. The third laid egg is smaller, hatches later, and hatches a lighter, smaller chick than the first two. The third hatched chick also has a lower chance of survival. Observations of parent-chick and chick-chick interactions were conducted at two Ontario sites in the Great Lakes to determine whether and how parents might behaviorally bias investment in their chicks after the incubation period, and how interactions among chicks might add to the third chick disadvantage. Little evidence was found for behavioral discrimination against the third chick by either its parents or its siblings. The last hatched (C) chick was not less likely than its older siblings (A or B) to get to the food first, and while A and B were more likely to target C when initiating tugs-of-war over food, they were not more likely than C to initiate tugs-of-war in general. C pecked siblings the most, and, despite its younger age and smaller size, was not more likely to lose tugs-of-war with its siblings. It is likely that the locations where this study was conducted represent relatively benign environment in which to raise chicks compared to the marine populations observed in other studies. Given this, parents might be expected to reduce chick asymmetries if they are able. There was a high degree of hatching synchrony in Hamilton Harbor. In 7 out of 28 nests the C chick hatched on the same day as the B or A and B chicks.
Incomplete Female Knowledge of Male Quality May Explain Variation in Extra-Pair Paternity in Birds
Authors: Slagsvold Tore , Lifjeld Jan T. 
Published: April 2008

Abstract
We present and discuss an hypothesis to explain inter- and intraspecific variation in levels of extra-pair paternity (EPP) in birds. In species with biparental care, females may be willing to engage in extra-pair copulation (EPC) to improve the genetic quality of the offspring. However, it may be costly to sample males and difficult to assess their genetic quality. Hence, we suggest that variation occurs in the extent of such knowledge between females, causing variation in the extent to which they are willing to engage in EPC. From the hypothesis we present nine predictions on occurrence of EPP in birds, e.g. cuckolders should mainly be resident, close neighbours; rate of EPP should be positively related to breeding density, to rate of male intrusion, to female opportunity to assess male quality from competitive interactions between males, to early arrival time of females relative to time of egg laying, and to breeding synchrony. Finally, we discuss implications on male behaviour. We suggest a new function of male mate guarding, namely that mate guarding is a means to prevent the social mate from obtaining essential information about the quality of potential extra-pair mates.
The Freshwater Calanoida (Copepoda) of the Philippines
Authors: Lai H.C. , Mamaril A. , Fernando C.H. 
Published: April 2008

Abstract
Cinq espèces de copépodes calanoides de l'eau douce des Philippines, avec leurs distributions et leur taxonomies, sont décrites. Deux espèces d'entre eux, Tropodiaptomus gigantoviger et Filipinodiaptomus insulanus n. g., sont endèmes pour les îles des Philippines. T. vicinus est abondant dans les provinces du sud. Monglodiaptomus birulai est présent seulement dans les endroits isolés à côté de la Ville Baguio. Une clé taxonomique pour les copépodes calanoides de l'eau douce des îles des Philippines est formulé.
Cirolanidae (Isopoda) From French Polynesian Coral Reefs: Description of Three New Species
Authors: Muller H.-G. , Salvat B. 
Published: April 2008

AbstractThis first contribution on cirolanid isopods from shallow water coral reef locations in French Polynesia (Bora Bora, Moorea) reports on three new species of the genera Cirolana and Metacirolana. They are described in detail, with remarks on their intergeneric affinities, habitat preference and biogeography.
Larval Development of the Hermit Crab Diogenes Miles (Herbst, 1791) (Decapoda, Anomura, Diogenidae) in the Laboratory
Authors: Shenoy Shakuntala , Sankolli K.N. 
Published: April 2008

Abstract
Hermit crabs are the commonest intertidal anomuran crustaceans. Diogenes miles (Herbst) is an inhabitant of surf-beaten sandy shores along coasts of peninsular India. This species is outstanding among other diogenid hermit crabs in having, unlike others, an extremely flat and broad body well adapted for its occurrence in long, narrow-mouthed gastropod shells mostly of Oliva and to lesser extent Gypraea and Conus. During the present study it was observed that, contrary to what was expected, D. miles docs not breed throughout the year but appears to have its breeding season restricted to the summer months. This was indicated by the collection of ovigerous females of the species only during the summer months near Bombay, Ratnagiri and Karwar along the Indian west coast. Eggs are minute, bright crimson to scarlet when immature and are easily shed, even with slight disturbance. Larval development consists of 3 zoeal and a megalopa stages, described in the present paper, after specimens reared in the laboratory. Some of the salient features of the zoea larvae are: a long, pointed rostrum, smooth carapace, usual triangular telson with process formula 7 + 7 in the first zoea but complete reduction of the 4th process in the third zoea. The megalopa has the typical unequal chelipeds, the left being larger, only 3 pairs of pleopods, and the telson is rectangularly rounded. Though the deep curve of the carpus develops right from the megalopa stage, the inward right-angled bend of the cheliped, so characteristic of the adult, is not fully developed even in the 5 subsequent instars.