Cooperative begging in banded mongoose pups

Vivid begging displays are common in species with parental care [1, 2]. They are usually seen as the way that rival offspring selfishly compete over parental investment [3], and individuals are expected to respond to the begging of rivals by increasing their own begging intensity [4, 5]. Here I show the opposite - that potential rivals gain direct benefits from begging by littermates, so that begging behavior becomes a collective enterprise, similar to other cooperative activities. I investigate begging in communally breeding banded mongooses (Mungos mungo), where each pup forms an exclusive relationship with a single helper (its "escort"), minimizing competition over food allocation. Escorts were influenced by the total signal emanating from a litter, so that pups who begged at low rates received more food as litter size increased. Focal pups increased their begging when litters were experimentally reduced or littermates were induced to beg at low rates, but they received food at similar rates and showed reduced weight gain - indicating that they were paying a higher cost for a similar reward. These results suggest that offspring can benefit from companions despite conflicts over the allocation of parental investment [6, 7]. Such benefits provide an explanation for observed variation in the expression of parent-offspring conflict.     

Population dynamics and food habits of the banded mongoose

A population of approximately 100 banded mongooses living in six packs was studied for over 2 years in Rwenzori National Park, Uganda. The packs were relatively stable, cohesive social units composed of approximately equal numbers of males and females and varied in size from six to thirty-five adults and subadults. Breeding was synchronized within the packs with several females producing their litters at approximately the same time. The packs bred up to four times per year. Mortality of animals over 6 months old was approximately 10% annually. Less than 50% of juveniles survived to the age of 3 months. The banded mongoose feeds primarily on invertebrates, particularly millipedes and beetles. Ants, crickets, termites and earwigs are also important elements of the diet. Vertebrate remains were found in 12% of the droppings analysed. Although the pack forages as a unit each individual finds its own food. The mean home range size of five of the packs was 80-4 ha; the two largest packs had ranges exceeding 1 km². The banded mongoose is strictly diurnal typically leaving a den in the hour following sunrise and returning a few minutes before sunset with a prolonged rest during the heat of the day. Dens were in termite mounds (usually in thicket clumps), erosion gullies, aardvark holes and occasionally in man-made structures. Most were used for only a few days and then abandoned but a few preferred dens were occupied for periods up to 54 days and re-used repeatedly. Interactions between packs were aggressive and appeared to function in spacing the packs. The result of an encounter depended upon pack size with larger packs dominating smaller ones; the area of occurrence did not appear to affect the outcome. Mating between packs was observed during aggressive encounters. Group life is of adaptive significance in protecting the individual from predators and in care of the young. The pack bunches around young mongooses when disturbed and also bunches to attack certain predators and competitors. One or more adults remain at the den to guard the young when the pack forages.     

Strategic adjustment of begging effort by banded mongoose pups

Variation in the intensity of conspicuous displays raises three basic questions: (i) the relationship between internal state and display intensity, (ii) the relationship between display intensity and receiver response, and (iii) the effect of variation in receiver responsiveness on signaller behaviour. Here, I investigate the interaction between pups and helpers in the communally breeding banded mongoose (Mungos mungo), where each pup forms an exclusive relationship with a single adult helper (termed its 'escort'). By experimentally manipulating pup need, I demonstrate that changes in begging rate correspond to changes in short-term need. The data then suggest that escorts in good condition may be more responsive to increased begging and that pups associating with them increase their begging more than do pups paired with escorts in poor condition. Escorts also appear more responsive to increased begging by female pups, and female pups increase their begging more than do male pups. These results suggest that banded mongoose pups may strategically adjust their investment in begging in relation to variation in the expected pay-off. I argue that such adjustment is likely to be a general phenomenon: wherever there is variation in responsiveness to signals, signallers will be selected to identify different categories of receiver and adjust their signals in order to maximize the pay-offs. Therefore, differences in signal intensity may be as much a product of context as an indication of variation in individual phenotypic or genotypic state.     

Molecular characterization of a Cryptosporidium isolate from a banded mongoose Mungos mungo

Cryptosporidium spp. has been found in more than 150 species of mammals, but there has been no report in mongooses. In this study, we report the isolation of Cryptosporidium sp. in a banded mongoose Mungos mungo, which was brought from Tanzania to Japan; the isolate was analyzed genetically to validate the occurrence of a new, host-adapted genotype. Cryptosporidium diagnostic fragments of 18S ribosomal RNA and 70-kDa heat shock protein genes were amplified from this isolate and compared with the other Cryptosporidium species and genotypes reported previously. Analyses showed that the mongoose isolate represents a new genotype, closely related to that of bears.     

Helpers benefit offspring in both the short and long-term in the cooperatively breeding banded mongoose

Helpers in cooperative and communal breeding species are thought to accrue fitness benefits through improving the condition and survival of the offspring that they care for, yet few studies have shown conclusively that helpers benefit the offspring they rear. Using a novel approach to control for potentially confounding group-specific variables, I compare banded mongoose (Mungos mungo) offspring within the same litter that differ in the amount of time they spend with a helper, and hence the amount of care they receive. I show that pups that spend more time in close proximity to a helper are fed more, grow faster and have a higher probability of survival to independence than their littermates. Moreover, high growth rates during development reduce the age at which females breed for the first time, suggesting that helpers can improve the future fecundity of the offspring for which they care. These results provide strong evidence that it is the amount of investment per se that benefits offspring, rather than some correlate such as territory quality, and validate the assumption that helpers improve the reproductive success of breeders, and hence may gain fitness benefits from their actions. Furthermore, the finding that helpers may benefit offspring in the long-term suggests that current studies underestimate the fitness benefits that helpers gain from rearing the offspring of others.     

Pup escorting in the communal breeding banded mongoose: behavior, benefits, and maintenance

In cooperatively breeding species, helpers typically providefood to offspring, and distribute food throughout the broodor litter. However, in the communal breeding banded mongoose(Mungos mungo), some group members escort individual pups duringtheir period of dependence, and escorts consistently associatewith the same pup, although not all pups have an escort. Theaim of the present study was to determine whether group membersactively care for pups, pups benefit from association, and escortsor pups maintain association. Adult banded mongooses provision,protect, carry, groom, and play with pups. Although escortsfed pups more than did nonescorts, escorted pups were neitherlarger nor in better condition than were nonescorted pups atthe end of the association period. Nevertheless, escorted pupswere more likely to survive the association period than werenonescorted pups, providing evidence that carers confer beneficialeffects on their recipients. However, the recipients are unlikelyto be the genetic offspring of the escort because it is thepup that maintains the pup-escort association, and escorts,rather than showing a preference for provisioning their pairedpup, follow a "feed the closest pup" rule. Although carers gainindirect fitness benefits through increasing survival of relatedpups, the lack of kin discrimination means carers are unableto maximize their fitness by preferentially escorting theirown offspring or the offspring of closer relatives.     

Genetic population structure in the yellow mongoose, Cynictis penicillata

Phylogeographic structure was determined for the yellow mongoose, Cynictis penicillata , using mtDNA RFLPs and control region sequences. The RFLP analysis revealed 13 haplotypes which showed weak geographical patterning consistent with a recent range expansion from a refugial population(s). An analysis of molecular variance ( AMOVA ) revealed no correspondence between mtDNA phylogeography and subspecies delimitation, nor between matrilines and areas characterized by a high incidence of the viverrid-type rabies, of which the yellow mongoose is the principal vector. The lack of structure was also shown by control region sequences although four of the maternal lineages shared a near-perfect 81 bp repeat. We speculate that regional hot spots of the viverrid rabies biotype reflect population density differences in the yellow mongoose that are not underscored by genetic partitioning, at least at the level of resolution provided by our analyses.     

A Segmental Semi Markov Model for protein secondary structure prediction

Hidden Markov Models (HMMs) are practical tools which provide probabilistic base for protein secondary structure prediction. In these models, usually, only the information of the left hand side of an amino acid is considered. Accordingly, these models seem to be inefficient with respect to long range correlations. In this work we discuss a Segmental Semi Markov Model (SSMM) in which the information of both sides of amino acids are considered. It is assumed and seemed reasonable that the information on both sides of an amino acid can provide a suitable tool for measuring dependencies. We consider these dependencies by dividing them into shorter dependencies. Each of these dependency models can be applied for estimating the probability of segments in structural classes. Several conditional probabilities concerning dependency of an amino acid to the residues appeared on its both sides are considered. Based on these conditional probabilities a weighted model is obtained to calculate the probability of each segment in a structure. This results in 2.27% increase in prediction accuracy in comparison with the ordinary Segmental Semi Markov Models, SSMMs. We also compare the performance of our model with that of the Segmental Semi Markov Model introduced by Schmidler et al. [C.S. Schmidler, J.S. Liu, D.L. Brutlag, Bayesian segmentation of protein secondary structure, J. Comp. Biol. 7(1/2) (2000) 233-248]. The calculations show that the overall prediction accuracy of our model is higher than the SSMM introduced by Schmidler.     

Genetic structure, relatedness and helping behaviour in the yellow mongoose in a farmland and a natural habitat

The yellow mongoose Cynictis penicillata is a facultatively social species and provides an opportunity to study the evolution of social behaviour. We examined genetic structure, relatedness and helping behaviour in the yellow mongoose in natural habitat in the Kalahari Desert, where the species lives in small family groups of up to four individuals and shows no cooperative breeding; and in farmland in the Western Cape Province of South Africa, where they live in larger groups of up to 13 individuals, engage in numerous social interactions and show cooperative breeding. The farmland population showed significant inbreeding, and lower genetic variability than the desert population, but there was no evidence of a recent population bottleneck. The genetic relatedness between individuals within social groups and that between future potential helpers and pups were higher in the farmland population than in the desert population. However, based on a limited sample, helping effort (in the farmland population) was not preferentially directed towards kin. Thus, the origin of helping in the farmland population is consistent with kin selection, but in the absence of kin discrimination, future research should investigate whether long-term breeding opportunities or group augmentation contribute to maintaining cooperative breeding in this population.     

Cathemerality in the mongoose lemur, Eulemur mongoz

Results of a 10 month study of the mongoose lemur (Eulemur mongoz) at Anjamena are presented. The activity pattern is documented in detail for both wet and dry seasons based on observations conducted over the entire 24 h period. E. mongoz was found to be cathemeral throughout the year but exhibited shifts towards more diurnal activity in the wet season and more nocturnal activity in the dry season. The cathemeral activity pattern in the mongoose lemur appears to be coordinated with sunrise, sunset, and day length and modulated by an inhibitory effect of low nocturnal light intensity in the forest during the wet season, resulting in mainly diurnal activity. Temperature and rainfall may also influence the activity pattern. Few advantages to food-related behavior appear to derive from this activity pattern, although resource accessibility may be enhanced by nocturnal behavior in the dry season, leading to reduction in interspecific competition. Cathemerality may also represent a behavioral thermoregulatory mechanism allowing the mongoose lemur to conserve energy by being active during the cool nights of the dry season. In addition, nocturnal behavior in the dry season probably allows avoidance of predation by raptors at the time of year when least protection is afforded by vegetation.     

Mating relationships and breeding suppression in the dwarf mongoose

Dwarf mongooses live in packs containing a dominant breeding pair. The alpha female produces litters at regular intervals, usually three times per year. Other sexually mature females come into oestrus in synchrony with the alpha female and occasionally become pregnant but may not raise their offspring. Some females which had not been visibly pregnant nursed the young of other females. Early in the alpha female's oestrous cycle the alpha male maintains proximity and copulates with her exclusively, attacking any other adult males which approach. Later he also copulates with other adult females and the beta male mates with the alpha female. The alpha pair are likely to be the parents of the great majority of young born in the pack.