The Behaviour of the Mediterranean Tripterygion Species (Pisces,Blennioidei)

The behaviour of the three mediterranean benthic fish Tripterygion tripteronotus, T. xanthosoma, and T. melanurus is described from observations in the field and observations on captive animals. The ♂♂ defend a territory only during the reproductive season; ♀♀ do not defend a territory. At the height of the breeding season, a male T. tripteronotus on average spawns with four ♀♀ Per day. The ♂ defends the territory against egg predators and cleans the eggs. ♀♀ spawn repeatedly during a spawning season. A spawning pair of T. tripteronotus frequently attracts conspecifics. The majority of these “satellites” are small, sexually mature ♂♂, which do not own a territory themselves. The reproductive strategies of the two types of ♂♂ (territorial ♂♂ and satellite ♂♂) and of the ♀♀ are discussed. On the basis of ethological, morphological, and palaegeographic data the evolution of the eastern-atlantic and mediterranean Tripterygiidae is reconstructed. A bibliography of the literature on eastern-atlantic and mediterranean Tripterygiidae is given. As in their morphology and anatomy, benthic fish show convergent adaptations in their behaviour. Some of these are pointed out and discussed.     

Das Paarungsverhalten von Pycnopogon fasciculatus Loew (Diptera,Asilidae)

• 1 Bei der Raubfliege Pycnopogon fasciculatus vollführt das ♂ vor dem sitzenden ♀ eine Flugbalz, die hauptsächlich anhand von Filmaufnahmen analysiert wurde. Das ♂ schwebt bei der Flugbalz dicht vor dem ♀, schwenkt dann bis 10 cm nach hinten aus, um auf der gleichen Flugbahn stoßartig nach vorne vor das ♀ zu fliegen. Diesen Hin- und Herflug wiederholt das ♂ durchschnittlich 28mal. Zu Beginn der Flugbalz orientiert sich das ♂ durch Ertasten des weiblichen Vorderendes. Das ♂ hält die Beine an den beiden Umkehrpunkten der Flugbahn ganz verschieden (vgl. Abb. 2 c), zeigt aber keine Landehaltung. Flugtechnisch scheint die Veränderung der Beinstellung wenig Bedeutung zu haben. Ob die Beinhaltung vor dem ♀ aus einer ritualisierten Beuteübergabe hervorgegangen ist, bleibt offen. Das ♀ zeigt seine Abwehrbereitschaft bei der Flugbalz durch ritualisiertes Wackeln hochgehaltener Hinterbeine.
• 2 Das ♂ vollführt seine Flugbalz auch vor toten, artgleichen ♀ und ♂♂ und auch vor artfremden, z. T. größeren Fliegen. Die Flugbalz ist kürzer als vor lebenden ♀♀ (durchschnittlich nur 14 Anflüge) und führt wegen des Fehlens von Abwehrsignalen des ♂ doppelt so haufig zu einem unmittelbar anschließenden Kopulationsversuch.
• 3 Sitzende ♂♂ schlagen gegen anfliegende ♂♂ ihre Vorderbeine schnell abwechselnd in die Luft. Dieses Vorderbeinwirbeln tritt auch beim Schweben des ♂ vor dem ♀ während der Balz auf und wird als Abwehrhandlung gedeutet. Durch das Vorderbeinwirbeln gegen andere ♂♂ kommt es unter natürlichen Umständen nicht zur Flugbalz vor sitzenden ♂♂.
• 4 ♀♀ vertreiben arteigene ♀♀ und artfremde Fliegen häufig von ihrem Sitzast durch Anlaufen mit schräg angestellten, seitlich abgespreizten Flügeln.
• 5 Das ♂ versucht in 31 % der Fälle die Kopulation unmittelbar nach der Flugbalz (n = 96). Nicht Hochhalten der Hinterbeine des ♀ löst beim ♂ einen Kopulationsversuch aus. Die Kopulation dauert mindestens 15 min und vollzieht sich in der “end-to-end position”.
• 6 Das Paarungsverhalten von Pycnopogon fasciculatus läßt sich als Handlungskette darstellen (Tab. 2).
• 7 Das Paarungsverhalten der räuberischen, in einigen Fällen auch kannibalischen Asilidenfamilie ist sehr unterschiedlich. Außer Flugbalz ist Balz auf fester Unterlage und Überwältigung des ♀ durch das ♂ ohne vorausgehende Balzhandlungen bekannt.

     

Affiliation between the Sexes in Common Grackles

Heterosexual affiliation involves behavioral mechanisms that limit bond membership and regulate partners' interactions. Among Common Grackles, Quiscalus quiscula, two characteristic activities of partners, following and vocal answering, develop during group activities and promote the individual specificity of pair bonds. Pairs differ substantially in the durations and seasonal timing of the early stages of nesting activities and in the ♂'s fidelity to his mate through incubation. After the relatively abrupt start of intensive nest-building, the seasonal course of a pair's behavior becomes more regular, an indication that this transition in the ♀'s state is critical in pacing the pair's breeding activities. Aggression serves primarily to adjust the spatial relationships of individuals, both between partners and between unpaired birds. ♂♂ that deserted their mates during incubation had earlier performed precopulatory displays to other ♀♀.     

Guinea-pig Vocalizations: Their Structure,Causation and Function

Feeding, mating behaviour, communication, breeding biology, and development of Pipa carvalhoi are described. Like in other species of the genus Pipa, the eggs are laid onto the ♀ back during several turnovers, and this behaviour cau be observed even in the absence of ♂♂ Acoustic communication involves a mating call and a combat call. The biology and behaviour of Pipa carvalhoi are compared to that of other pipid frogs, and it is suggested that the specialized breeding biology of the genus Pipa evolved as an adaptation to the life in small ponds and ditches which are rich in nutrients but poor in oxygen.     

Interspecific Communication in Fiddler Crabs: Preliminary Report of a Female Rejection Display Directed toward Courting Heterospecific ♂♂

A newly described display is apparently used by female fiddler crabs (genus Uca) in interspecific communication. The display, termed repetitive-high-rise, is directed primarily toward courting heterospecific ♂♂, which approach or are likely to approach the ♀. We postulate that the display serves to indicate the ♀'s unavailability to these ♂♂ for mating. The ♂♂ respond appropriately by ceasing their approach toward displaying ♀♀. Both reproductively receptive and unreceptive ♀♀ were observed to perform this display. ♀♀ appeared to be able to discriminate, not only between conspecific ♂♂ and heterospecific ♂♂, but also among ♂♂ of heterospecific species. The possible significance for this ability is discussed.     

Sex-differences in the Agonistic Behavior of Spiny-mice (Acomys cahirinus)

Observations of 8 groups each containing three adult spiny mice (Acomys cahirinus) revealed that instances of chasing and physical displacement were quite common, while fighting and biting were rarely observed. The relationships between the most frequent behavioral categories were presented in a correlation matrix. In a second, study, ♀♀ tested in their home cages were dominant over ♂♂ In the ♂♂ home cages, however, no differences in the frequency of ♀ vs. ♂ aggression were observed. More instances of aggression were observed in the cages of the ♀♀ than in the cages of the ♂♂.     

NOTES ON THE PEARL-BREASTED SWALLOW HIRUNDO DIMIDIATA IN THE SOUTH-WESTERN CAPE

Earlé R. A. &; Herholdt, J. J. 1988. Breeding and moult of the Anteating Chat Myrmecocichla formicivora. Ostrich 59: 155–161.

The general breeding biology and moult of the Anteating Chat Myrmecocichla formicivora was studied in open grassveld over a two-year period. During the winter (July), groups were significantly smaller than during summer (December) (1,81 ± 0,50 versus 2,85 ± 1,35 birds per group). There was a large turnover of individuals in the study area but the total population stayed the same. The breeding season in the study area lasted from September to February but analysis of nest record cards from a larger area gave a breeding season of August-April. Two types of nests were used: 90,6% were burrows in sand banks or other excavations, but 9,4%were in the mud pellet nests of Greater Striped Swallows Hirundo cucullata (n = 53). Consecutive breeding attempts were never made in the same burrow. Clutches consisted of three, four or five eggs ([Xbar] = 3,73 ± 0,67). Incubation lasted 14–14,5-15 days. The nestling period lasted 15–18 days. Fledgling/egg breeding success was 41,8% with 48,2% of all eggs not reaching the hatching stage. Juveniles showed an unequal sex ratio of 0,57 ♂ ♂: 1,0 ♀ ♀ but adults had a nearly equal ratio (0,9 ♂ ♂: 1,0 ♀ ♀). There was a significant positive correlation between the primary moult score and the week of the seven months in which moult was recorded. Juveniles underwent a complete body moult and partial primary moult 3–4 months after fledging.     

Electric Communication in the Reproductive Behavior of Sternopygus macrurus (Gymnotoidei)

Sternopygus macrurus, eine der dreizehn im Rupununi Distrikt von Guyana beheimateten Messeraal-Arten benutzt elektrische Signale im Fortpflanzungsverhalten. Sternopygus leben in steinigen und sandigen Bächen und kommen nachts aus ihren Verstecken. Ihre Laichzeit beginnt vor Eintritt der Regenzeit Ende April. Sternopygus hat langdauernde Entladungen mit kurzen Pausen, die im Lautsprecher einen summenden Ton ergeben (im Unterschied zu Arten mit kurzen Entladungen und langen Pausen, die “knattern”). Von den vier summenden Fischarten hat S. macrurus eine eigene Tonlage und Tonstärke. Ausgewachsene ♂♂ und ♀♀ erzeugen verschiedene Ruhe-Entladungen. In der Laichzeit reagieren ♂♂ auf Annäherung eines ♀ mit veränderten Entladungen. Diese scheinen ♀♀ anzulocken. Auch ♀♀ können ihre Entladungen variieren. Künstlich über Elektroden ins Wasser gespielte Sinus-Schwingungen mit ♀-Frequenz wurden von ♂♂ richtig beantwortet; auf ♂-Frequenz oder Frequenzen anderer Arten gab es keine Reaktion. Beobachtungen an zwei Sternopygus-Paaren ergaben, daß die Individuen typische Entladungs-Frequenzen haben. Paarpartner können Frequenzen annehmen, die genau eine Oktave auseinander liegen.     

Hybridization and F1 backcrosses between two closely related tropical species of sea urchins (genus Echinometra) in Okinawa

Summary

Four species of sea urchins of the genus Echinometra, designated species A, B, C, and D, occur along the coast of Okinawa; they are distinguished by color pattern and other characteristics. The two most distinct species, Echinometra sp. A (Ea) with white-tipped spines and Echinometra sp. D (Ed) with nearly black spines (possibly E. oblonga), were examined for potential hybridization through a series of fertilization experiments and rearing of the resulting hybrids. Fertilization was reciprocally asymmetrical; Ed ova were readily fertilized by sperm of Ea, but less than 20% of the ova of Ea were fertilized by sperm of Ed. Nevertheless, hybrids resulting from crosses in both directions developed normally through larval and juvenile stages to produce sexually mature adults. Larvae of Ed♀×Ea♂ and Ed♂×Ed♀ were larger than those of Ea♂ × Ed♀ and Ea♂ × Ea♀, reflecting the larger eggs of Ed. However, Ea♂×Ea♀ juveniles and later stages, up to maturity, were consistently larger than those of equivalent ages of the other crosses; largest to smallest were Ea♂×Ea♀, Ed♂×Ea♀, Ea♂ × Ed♀, and Ed♂×Ed♀, respectively. Ova and sperm of the hybrids were viable and fertilizable in all combination of crosses, although fertilization of those of Ed♂×Ea♀ hybrids was consistently higher than those of Ea♂ × Ed♀ hybrids. These experiments represent the first reported successful production of hybrid sea urchins with viable gametes. They indicate that reproductive isolation is achieved by prezygotic isolating mechanisms in these two species. Of these mechanisms, gametic incompatibility is probably only partly involved, if at all, and differences in spawning times, habitat segregation, or other factors appear to be important for maintaining reproductive isolation in these closely related species.     

The Lek-like Mating System of Halichoeres melanochir (Pisces: Labridae) at Miyake-jima,Japan1

Reproductive behavior and social organization of the labrid fish Halichoeres melanochir were studied at Miyake-jima, Izu Islands, Japan. ♂♂ set up contiguous territories from early to mid-afternoon daily during the breeding season, with ♂♂ at the center of the spawning site experiencing significantly higher spawning success than those at the periphery. Unlike other labrids with lek-like mating systems previously reported, H. melanochir is sexually monochromatic and shows only minimal sexual size-dimorphism. The spawning behavior and mating system are described and compared with current theories on labrid reproductive strategies.     

Scent Marking by Male Golden Hamsters (Mesocricetus auratus) II. The role of the flank gland scent in the causation of marking

Investigated the role of the odor of the flank gland in the stimulation of flank marking by male hamsters, Mesocricetus auratus. In the first experiment it was shown that a ♂ has customary marking posts and that a second ♂ introduced into the first ♂'s area will mark in the same places. In experiment 2 nine test ♂♂ flank marked less in the home cages of flank glandectomized ♂♂ than in the cages of normal ♂♂. In experiment 3 it was shown that flank glandectomized ♂♂ marked at within the range of frequencies for normal ♂♂.     

Reproductive isolating mechanisms contributing to asymmetric hybridization in Killifishes (Fundulus spp.)

When species hybridize, one F1 hybrid cross type often predominates. Such asymmetry can arise from differences in a variety of reproductive barriers, but the relative roles and concordance of pre-mating, post-mating prezygotic, and post-zygotic barriers in producing these biases in natural animal populations have not been widely investigated. Here, we study a population of predominantly F1 hybrids between two killifish species (Fundulus heteroclitus and F. diaphanus) in which >95% of F1 hybrids have F. diaphanus mothers and F. heteroclitus fathers (D♀ × H♂). To determine why F. heteroclitus × F. diaphanus F1 hybrids (H♀ × D♂) are so rare, we tested for asymmetry in pre-mating reproductive barriers (female preference and male aggression) at a common salinity (10 ppt) and post-mating, pre-zygotic (fertilization success) and post-zygotic (embryonic development time and hatching success) reproductive barriers at a range of ecologically relevant salinities (0, 5, 10, and 15 ppt). We found that F. heteroclitus females preferred conspecific males, whereas F. diaphanus females did not, matching the observed cross bias in the wild. Naturally rare H♀ × D♂ crosses also had lower fertilization success than all other cross types, and a lower hatching success than the prevalent D♀ × H♂ crosses at the salinity found in the hybrid zone centre (10 ppt). Furthermore, the naturally predominant D♀ × H♂ crosses had a higher hatching success than F. diaphanus crosses at 10 ppt, which may further increase their relative abundance. The present study suggests that a combination of incomplete mating, post-mating pre-zygotic and post-zygotic reproductive isolating mechanisms act in concert to produce hybrid asymmetry in this system.     

Nuptial Flight in two Ponerine Ants,Pachycondyla Impressa and P. Fauveli,Overlooking Machu Picchu,Peru

We report on a simultaneous nuptial flight of ants of two sympatric ponerine species, Pachycondyla impressa and P. fauveli, on the top of Huayna Picchu (2700 m), Peru. After flying in and landing on the flat, hare rocks of the summit, the conspecific sexuals approached, antennated and mated without any previous female calling behaviour. During one hour of observation, the number of approximately 30 ♂ ♂ and ♀ ♀ Pachycondyla impressa and 70–86 of P. fauveli on the site remained constant because of individuals continuously arriving and leaving. Although nuptial flight seems to be the most common type of mating system in ants, this is one of the very few reports on the occurrence of this behaviour in ponerine species.     

Aspects of Aggressive Behaviour in Polecats

• 1 Das Verhalten von Iltissen und Frettchen in einer 16-m²-Arena gegen Artgenossen wird beschrieben.
• 2 Außerhalb der Fortpflanzungszeit werden Fremde belästigt (hier ?ritual aggression” genannt), aber nicht besiegt.
• 3 Während der Fortpflanzungszeit (März bis Juli) kämpfen ♂♂ mit Fremden: sie ergreifen den Eindringling im Nacken, halten ihn fest, versuchen ihn zu schütteln und schleppen ihn umher. Der Gepackte rollt sich über den Boden, bis der andre loslassen muß, und versucht, seinerseits ebenso zuzupacken.
• 4 Ein unterlegener Iltis droht abwehrend mit gekrümmtem Rücken und hochgehaltenem Kopf, öffnet das Maul und weist dem Gegner unter Pfauchen oder Kreischen die Zähne. Der Sieger dreht den Kopf zur Seite und geht breitseits vor.
• 5 ♀♀ sind weniger angriffslustig als ♂♂; sie kämpfen gelegentlich, aber kurz und ohne den Gegner zu unterwerfen. ?Ritual aggression” zeigen sie nur gegen fremde ♀♀.
• 6 Begegnungen zwischen ♂ und ♀♀ in der Paarungszeit sind beschrieben. Ist das ♀ bereit, so kommt es zur Kopula; sonst versucht das ♂ zu kopulieren, das ♀ aber dreht sich auf den Rücken und schnappt sanft nach Genick und Schnauze des ♂. Läßt sich das ♂ nicht abweisen, so kann es zum Kampf kommen: das ♂ schleppt das ♀ am Genick umher und schüttelt es, das ♀ droht, quiekt und schnappt nach dem ♂. Das ♀ wird nicht besiegt. Auch das ♂ kann einen Kampf beginnen, vor allem, wenn es paarungsbereit ist und das ♂ nicht mitmacht. Das ♀ geht dann in Abwehrstellung und droht.
• 7 Im Januar–März werden die Hoden der Iltis-♂♂ größer und diese angriffslustiger: sie beißen öfter einen Partner ins Genick und halten ihn länger fest. Aber auch in heftigen Kämpfen wird der Gegner nicht unterworfen. Es kommt zu Pseudokopulationen mit ihm, wahrscheinlich ausgelöst durch seine Bewegungslosigkeit.
• 8 Im Iltiskampf fehlt das Drohen vor einem Angriff, entsprechend fehlt jedes Vorspiel vor dem Aufreiten und den Kopulationsversuchen.
• 9 Die Beziehungen zwischen Angriffs-, Sexual- und Spielverhalten sind erortert.

     

Urine Marking and Territoriality in Galago alleni (Waterhouse, 1837 — Lorisoidea,Primates) — A Field Study by Radio-telemetry

Behavioral interactions among color-marked individual Vidua chalybeata that shared common song dialects were observed for 5 years in two populations at Lochinvar National Park, Zambia. Social interactions involved ♂♂ visiting and competing for mating sites and ♀♀ visiting ♂♂ in an apparent sampling of potential copulating partners. Differences in mating success among the polygynous ♂♂ were compared with male behavior and territory resources, and criteria were developed to test the importance of intrasexual male competition and female mate choice in explaining the mating system of the populations. Song behavior best explained differences in mating success of ♂♂ with lesser effects of neighboring ♂♂ and the defensible resources around the call-sites. The social organization of song populations resembles that of a dispersed lek with ♀♀ visiting many ♂♂ but mating with few ♂♂. We discuss the observations on indigobirds in relation to behavioral selection, sexual selection, and mating systems. Mating systems of certain populations and species are compared using statistics of individual mating success.     

The effects of host race, gender, and host plant distribution on alighting behavior, mating, and oviposition in Eurosta solidaginis

Eurosta solidaginis Fitch (Diptera: Tephritidae) has formed host races on Solidago altissima L. and Solidago gigantea Ait. (Asteraceae), and reproductive isolation between these host races is brought about in part by host‐associated assortative mating. Any non‐assortative mating creates the potential for gene flow between the populations, and we investigated the conditions that favored non‐assortative mating. We hypothesized that the frequency of non‐assortative mating would be influenced by differences in the behaviors of the host races and sexes and by the presence and pattern of distribution of the two host species. To test these hypotheses, we caged flies on four combinations of 32 potted host plants: all S. altissima, all S. gigantea, and cages with both host species arranged in either two pure species blocks or randomly dispersed. We recorded the number of flies of each host race that alighted on each host species and the frequency of mating within and between the host races. Males of both host races were observed on plants more frequently than females. Flies of the host race from S. gigantea (gig flies) were observed on plants in greater absolute numbers, and they mated more frequently than flies of the host race from S. altissima (alt flies). In all treatments, gig flies of both sexes were found on non‐natal host plants significantly more frequently than alt flies, and gig females showed a weaker preference for their host species than did gig males or alt flies of either gender for their respective natal hosts. Assortative mating predominated in all treatments, and flies from each host race mated more frequently in cages containing their own host plant. The frequency of non‐assortative mating varied among treatments, with the matings between alt ♀ × gig ♂ being more common in the pure S. altissima treatment and the gig ♀ × alt ♂ being more frequent in the pure S. gigantea and random treatments. Matings between gig ♂ × alt ♀ were more common overall than the reciprocal mating, because gig males were more active in pursuing matings and in alighting on the non‐natal host plant than alt flies. Non‐assortative matings were more frequent in the random than in the block treatments, but this difference was not significant. Because of strong selection against oviposition into the alternate host, we hypothesized that host plant distribution would not affect oviposition preference. We tested this hypothesis by examining the oviposition behavior of naïve, mated females in two treatments in which both host species were present: either arranged in blocks or randomly dispersed. Females oviposited only into their natal host, regardless of host plant distribution.     

Inter-generational competition and selection for helping behaviour

A model is presented which considers the effects of inter-generational competition (IC) for breeding status on selection for helping behaviour. The model shows that for species with both high inter-generational overlap and high frequency of breeding opportunities within the individual's lifespan, helping behaviour is selected if the relatives raised by the helper through helping (i.e. present indirect fitness gains) do not decrease the helper's future direct fitness as a breeder. This effect is dependent on the value of α, the coefficient of IC. The occurrence of high α values can explain those cases in which a non-breeding member of a social group does not help. The effect of α can be reduced by means of establishing an age-based queueing system to attain breeding status. The breeders' acceptance of a non-helping individual within their territory may be explained as extended parental care or parental facilitation.     

Laboratory and field studies on the reproductive ecology of Parocneria orienta (Lepidoptera: Lymantriidae) in China

To lay a foundation for the monitoring, prevention and control of Parocneria orienta, a pest moth in China, we investigated the reproductive ecology of P. orienta, including the environmental factors affecting reproduction and the effects of pheromones in field traps. The results showed that the mating duration is shorter when the temperature is higher, with the optimal temperature range for P. orienta reproduction being 22–27°C. The sex ratio had an effect on the male mating capacity, which significantly increased when the sex ratio was ♀:♂ ≥ 3:1. The average number of matings was 2.44 for males, while female P. orienta mated only once in a lifetime. Males were more attracted to virgin females than to mated females, and the temperature and light period had an effect on the release of sex pheromones by females. Field trap tests using virgin females supported the results obtained in the laboratory, showing that the release of sex pheromones by P. orienta follows a distinct circadian rhythm.     

Male Territoriality in the Bumblebee Wolf,Philanthus bicinctus (Mickel) (Hymenoptera,Sphecidae): Observations on the Behaviour of Individual ♂♂

Observations were made on the behaviour of male Philanthus bicinctus (Mickel) which defend territories around the nesting burrows of ♀♀. ♂♂ were individually identified with small number tags and focal-animal samples were taken of the behaviour of these ♂♂. Intense interactions were observed between territorial ♂♂ and 1) conspecifics and 2) intruding insects which resembled conspecifics. Evidence is presented which suggests that ♂♂ scent mark their territories.