Wounding in Hawaiian monk seals (Monachus schauinslandi)

1993 ◽  
Vol 71 (3) ◽  
pp. 458-468 ◽  
Author(s):  
Lisa M. Hiruki ◽  
William G. Gilmartin ◽  
Brenda L. Becker ◽  
Ian Stirling
Keyword(s):  
Coral Reef ◽  
Adult Male ◽  
Marine Debris ◽  
Adult Males ◽  
Monachus Schauinslandi ◽  
Aggressive Interactions ◽  
Size Classes ◽  
Adult Females ◽  
Northwestern Hawaiian Islands ◽  
Monk Seals

Injuries observed on endangered Hawaiian monk seals (Monachus schauinslandi) at Laysan Island and French Frigate Shoals in the northwestern Hawaiian Islands in 1988 and 1989 were classified into six major types, based on the source of the wounds: mating attempts by adult male monk seals; nonmating aggressive interactions with other seals; attacks by large sharks; attacks by cookiecutter sharks (Isistius brasiliensis); contact with coral reef or debris; and entanglement in netting or marine debris. At both locations, injuries inflicted by adult male seals during mobbing incidents, in which many males attempt to mate with one seal, were seen more frequently than other types of injuries in 1988 and 1989. Injury data from 1982 – 1987 at Laysan Island and from 1985 – 1989 at French Frigate Shoals were used to compare the distribution of mating injuries inflicted by adult males and injuries inflicted by large sharks over size and sex classes of seals. Mating injuries caused by adult male seals were seen primarily on adult females but were also seen on seals in other size classes. Mating injuries inflicted by adult males occurred earlier in the year and with greater frequency at Laysan Island than at French Frigate Shoals. Injuries inflicted by large sharks were observed more often on adult male seals than on seals in other size classes at Laysan Island; however, no such difference was seen among size classes at French Frigate Shoals.

Significance of wounding to female reproductive success in Hawaiian monk seals (Monachus schauinslandi) at Laysan Island

1993 ◽  
Vol 71 (3) ◽  
pp. 469-474 ◽  
Author(s):  
Lisa M. Hiruki ◽  
Ian Stirling ◽  
William G. Gilmartin ◽  
Thea C. Johanos ◽  
Brenda L. Becker
Keyword(s):  
Reproductive Success ◽  
Adult Male ◽  
Reproductive Rate ◽  
Lactation Period ◽  
Female Reproductive Success ◽  
Monachus Schauinslandi ◽  
Lower Survival Rate ◽  
Adult Females ◽  
Pup Survival ◽  
Monk Seals

We studied reproductive rate, length of lactation period, pup survival, and mortality of injured and uninjured female Hawaiian monk seals (Monachus schauinslandi) on Laysan Island, northwestern Hawaiian Islands, in 1983 – 1989. The severity and timing of nonfatal injuries were influential in determining their effect on female reproductive success. There was a tendency towards a shorter mean lactation period and lower survival rate of pups for females with major injuries than for uninjured females. Females with minor injuries were similar to uninjured females in terms of reproductive rate, length of lactation, and pup survival. For females injured shortly before the birth of their pup or during lactation, pup survival was lower than for uninjured females, whereas for females injured during the year prior to pupping, measures of reproductive success were not significantly different from those for uninjured females. Immature (aged 4 – 8 years) females entering the reproductive population were injured by adult male seals significantly more often than females aged 0 – 3 years, but at a similar rate to adult females. The major effect of injuries on female reproductive success is an increase in female mortality: 87.5 % of the adult females (n = 16) that died on Laysan Island in 1983 – 1989 sustained injuries from adult male seals.

scholarly journals Reproductive morphology and status of female Hawaiian monk seals (Monachus schauinslandi) fatally injured by adult male seals

Reproduction ◽  
1994 ◽  
Vol 100 (1) ◽  
pp. 225-230 ◽  
Author(s):  
S. Atkinson ◽  
B. L. Becker ◽  
T. C. Johanos ◽  
J. R. Pietraszek ◽  
B. C. S. Kuhn
Keyword(s):  
Adult Male ◽  
Monachus Schauinslandi ◽  
Reproductive Morphology ◽  
Monk Seals

scholarly journals Patterns of pair formation and mating in an ectoparasitic caligid copepod Lepeophtheirus salmonis (Krøyer 1837): implications for its sensory and mating biology

1998 ◽  
Vol 353 (1369) ◽  
pp. 753-764 ◽  
Author(s):  
M. Q. Hull ◽  
A. W. Pike ◽  
A. J. Mordue ◽  
G. H. Rae
Keyword(s):  
Adult Male ◽  
Host Finding ◽  
Pair Formation ◽  
Adult Males ◽  
Unmated Female ◽  
Female Ratio ◽  
Genital Complex ◽  
Adult Females ◽  
Mating Biology ◽  
Reproductive Events

Non–invasive observations of single cohort and manipulated populations of the sealouse on laboratory–maintained salmon established the sequence of reproductive events and mating. Protandry occurs with adult male emergence synchronized with pre–adult II female emergence, the stage at which most pair formation and pre–copular guarding takes place. Male competence for pair formation and mating was achieved within 24 h of the final moult and pairing occurred according to the preference hierarchy, virgin adult females greater than pre–adult II females much greater than pre–adult I females. This hierarchy broke down when the adult male to unmated female ratio increased rapidly. Males mated successfully not only with newly moulted adult females, but also with older virgin females in which enlargement of the genital complex and premature extrusion of egg strings had occurred. Multiple mating by adult males was demonstrated and may be widespread. Significant inter–host transfer was also demonstrated. Adult males were more mobile than adult females and showed significantly more inter–host transfer. Ablation of the distal tip of the antennules significantly reduced the success of host–finding, pair formation and males' mating.

Female Dominance and Social Structure in Alaotran Gentle Lemurs

Behaviour ◽  
2003 ◽  
Vol 140 (10) ◽  
pp. 1235-1246 ◽  
Author(s):  
◽  
Keyword(s):  
Social Behaviour ◽  
Spatial Configuration ◽  
Social Systems ◽  
Female Dominance ◽  
Adult Males ◽  
Aggressive Interactions ◽  
Adult Females ◽  
The Social ◽  
Hapalemur Griseus ◽  
Group Movements

AbstractLemur social systems have the striking social feature, that adult females consistently evoke submissive behaviour of adult males. In the Alaotran gentle lemur, Hapalemur griseus alaotrensis, however, female dominance has not been studied yet. Here we confirm female dominance over males on the basis of a 5-month field study of the social behaviour of four groups, in the Lake Alaotra marshland of eastern Madagascar. Further, we found that dominant individuals initiated aggressive interactions significantly more often than lowerranking ones, they initiated group movements more often and higher-ranking individuals were groomed more often. The spatial configuration was remarkable, since individuals were closer in space to those more distant in rank.

Dispersion of adult male Peromyscus leucopus in relation to female reproductive status

1989 ◽  
Vol 67 (4) ◽  
pp. 1047-1052 ◽  
Author(s):  
Xuhua Xia ◽  
John S. Millar
Keyword(s):  
Mating System ◽  
Adult Male ◽  
Early Pregnancy ◽  
Peromyscus Leucopus ◽  
Natural Populations ◽  
Negative Relationship ◽  
Late Pregnancy ◽  
Adult Males ◽  
Adult Females ◽  
Female Reproductive Status

We studied dispersion of adult male Peromyscus leucopus in relation to the stage of pregnancy of adult females in natural populations monitored with Longworth live traps. Because postpartum mating is common in P. leucopus and days to parturition measures how far a female is from her next mating, we predicted that a female in early pregnancy (many days to parturition) would have fewer adult males in her neighbourhood than a female in late pregnancy (few days to parturition). Number of adult males caught within 30 m of each adult female was recorded and number of days to parturition for each female was obtained by bringing females back to the laboratory and allowing them to give birth. A negative relationship was found between number of adult males in a female's neighbourhood and days to parturition of the female (r = −0.419, p < 0.01), with the latter accounting for 8.8% of the variance in the former. These results support the hypothesis of a promiscuous mating system in P. leucopus.

scholarly journals Sexual dimorphism in thyroid function and type 1 iodothyronine deiodinase activity in pre-pubertal and adult rats

2007 ◽  
Vol 192 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Michelle P Marassi ◽  
Rodrigo S Fortunato ◽  
Alba C Matos da Silva ◽  
Valmara S Pereira ◽  
Denise P Carvalho ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Adult Male ◽  
Gonadal Hormones ◽  
Adult Males ◽  
Adult Rats ◽  
Iodothyronine Deiodinase ◽  
Adult Females ◽  
Serum T3 ◽  
Serum Tsh

Iodothyronine deiodinase activities are regulated by sex steroids; however, the mechanisms underlying the reported sexual dimorphism are poorly defined. In the present report, we aimed to investigate whether type 1 deiodinase (D1) sexual dimorphism exists early in sexual development by studying pre-pubertal male (Pm) and female (Pf) rats, as well as adult controls (C) and gonadectomized male and females rats. Adult male Wistar rats were studied 21 days after orchiectomy (Tex), and adult females were studied 21 days after ovariectomy (Ovx), and after estradiol benzoate (Eb) replacement. Serum total triiodothyronine (T3) was higher in pre-pubertal (P) rats than in the matching adults, with no difference between genders, although in adult males T3 was significantly lower than in females. There were no sex or age differences in serum total T4. Serum TSH in pre-pubertal (P) rats was within the adult female range, and both were significantly lower than in adult males. D1 activity in liver was greater in Pm than in Pf. In adult females, liver D1 activity was lower, while in adult males it was higher than in P rats. The same pattern of D1 activity was found in kidney. In thyroid and pituitary, D1 activity was similar in Pm, Pf, and adult females, which were all significantly lower than in the adult male. There were no differences in serum T3 and T4 between C and Tex males, but serum TSH was significantly decreased in Tex rats. Hepatic and renal D1 activities were lower in Tex than in C, but no changes were detected in thyroid and pituitary. In Ovx females, T3 was significantly lower than in the C group. Serum T4 was significantly decreased by estradiol replacement therapy in Ovx rats, in both doses used, whereas TSH was unchanged. Eb replacement increased liver and thyroid D1 activity, but in the kidney, only the highest estradiol dose promoted a significant D1 increase. In conclusion, in males, hepatic and renal D1 activity appears to be significantly influenced by gonadal hormones, in contrast to females, in which only exogenous Eb treatment stimulated D1 activity. The comparison between pre-pubertal and adult rats suggests that serum T3 is not the main regulator of D1 activity, and other factors, besides T3 and gonadal hormones, can modulate D1 activity during murine maturation.

scholarly journals Adult male coatis play with a band of juveniles

2013 ◽  
Vol 73 (2) ◽  
pp. 353-355 ◽  
Author(s):  
CJ Logan ◽  
JT Longino
Keyword(s):  
Costa Rica ◽  
Breeding Season ◽  
Adult Male ◽  
Model System ◽  
Adult Males ◽  
La Selva ◽  
Biological Station ◽  
Nasua Narica ◽  
Adult Females ◽  
Post Hoc

This study examined the play behaviour in one group of coatis (Nasua narica) at La Selva Biological Station in Costa Rica. We incidentally found adult males playing with juvenile coatis, and conducted post-hoc analyses to investigate this interaction. Coati groups consist of adult females and juveniles of both sexes until male juveniles reach two years of age and leave the band to become solitary. Adult males only tolerate juveniles for a brief period during breeding season when the males court females to mate. Outside of the breeding season, adult males are known to prey on juveniles. In this study, when adult males were present with the band, play occurred more than was expected by chance, and adult males engaged in many of these play bouts. Because the mechanisms driving infanticidal behaviour are not well understood, and adult male coatis show a range of behaviours from infanticide to highly affiliative interactions with juveniles, using coatis as a model system may elucidate mechanisms underlying infanticide.

POPULATION ATTRIBUTES OF BLUE GROUSE IN SOUTHWESTERN ALBERTA

1966 ◽  
Vol 44 (5) ◽  
pp. 799-814 ◽  
Author(s):  
D. A. Boag
Keyword(s):  
Mortality Rate ◽  
Adult Male ◽  
Age Distribution ◽  
Older Age ◽  
Home Ranges ◽  
Adult Males ◽  
Age Classes ◽  
Adult Females ◽  
Dendragapus Obscurus ◽  
Breeding Grounds

A population of blue grouse (Dendragapus obscurus) was studied over a 10-year period in southwestern Alberta. During this time a number of population attributes were documented. Density declined from a maximum of 47 adult males in 1955 to a minimum of 6 in 1964 on the 620-acre study area. Dispersion of adult male blue grouse on the breeding grounds was accomplished by establishing territories which averaged 1.5 ac. Adult females inhabited overlapping home ranges which averaged 43 ac in size. The age distribution among marked birds on the breeding grounds in May and June indicated 75% adult (2 years and older) and 25% subadult (1 year of age). Of the adults, approximately one-half were 2-year-olds with decreasing proportions in older age classes until none remained after they were 9 years old. Juveniles formed 40% of the fall population each year. The average hatch was 5.1 chicks per breeding female. Recruitment to the population has been inadequate to maintain numbers. Excessive mortality or dispersal rates must account for this. Minimum recorded loss of chicks during their first summer averaged 27%. Mortality rate of birds more than 1 year old averaged 56% per annum. Dispersal to other breeding ranges was recorded only in juvenile grouse.

Profilicollis botulus (Acanthocephala) abundance in the eider duck (Somateria mollissima) on the Ythan estuary, Aberdeenshire

Parasitology ◽  
1985 ◽  
Vol 91 (3) ◽  
pp. 563-575 ◽  
Author(s):  
A. B. Thompson
Keyword(s):  
Adult Male ◽  
Seasonal Pattern ◽  
Developmental Rate ◽  
Somateria Mollissima ◽  
Adult Males ◽  
Male And Female ◽  
Shore Line ◽  
Adult Females ◽  
Significant Difference ◽  
Almost All

SUMMARYThe abundance of Profilicollis botulus was monitored in eider ducks for 3 years. No significant difference in P. botulus abundance was found between eiders taken alive and those collected dead from the shore line, or between adult males and adult females. Adult male eiders had a seasonal pattern of infection. Incubating female eiders lost their infection in almost all cases, suggesting that a seasonal pattern of infection must also occur in these birds. Eiders in their first winter had P. botulus abundances which were approximately 10 times that of adult eiders, but by the following summer the abundance had declined to that found in adults. Data are compared with previous studies undertaken on the Ythan estuary. Captive eiders were used to determine the developmental rate of female P. botulus and the percentage of administered cystacanths which established in the intestine. There was no evidence to suggest that male and female P. botulus have different life–spans.

scholarly journals Estimating pre-harvest density, adult sex ratio and fecundity of white-tailed deer using wildlife cameras

2021 ◽  
Author(s):  
Jon Brommer ◽  
Jenni Poutanen ◽  
Jyrki Pusenius ◽  
Mikael Wikström
Keyword(s):  
Sex Ratio ◽  
Adult Male ◽  
Space Use ◽  
Camera Traps ◽  
Total Density ◽  
Adult Males ◽  
Population Parameters ◽  
Male And Female ◽  
Adult Females ◽  
Adult Sex Ratio

Adult sex ratio and fecundity are key population parameters in sustainable wildlife management, but inferring these requires estimates of the density of at least three age/sex classes of the population (male and female adults and juveniles). We used an array of 36 wildlife camera traps during 2–3 weeks in autumn prior to harvest during two consecutive years, and recorded white-tailed deer adult males, adult females and fawns from the pictures. Simultaneously, we collected fecal DNA (fDNA) from 92 20mx20m plots placed in 23 clusters of four plots between the camera traps. We identified individuals from fDNA samples with microsatellite markers and estimated the total sex ratio and population density using Spatial Capture Recapture (SCR). The fDNA-SCR analysis concluded equal sex ratio in the first year and female bias in the second year, and no difference in space use between sexes (fawns and adults combined). Camera information was analyzed in a Spatial Capture (SC) framework assuming an informative prior for animals’ space use, either (1) as estimated by fDNA-SCR (same for all age/sex classes), (2) as assumed from the literature (space use of adult males larger than adult females and fawns), (3) by inferring adult male space use from individually-identified males from the camera pictures. These various SC approaches produced plausible inferences on fecundity, but also inferred total density to be lower than the estimate provided by fDNA-SCR in one of the study years. SC approaches where adult male and female were allowed to differ in their space use suggested the population had a female-biased adult sex ratio. In conclusion, SC approaches allowed estimating the pre-harvest population parameters of interest and provided conservative density estimates.

Sign in / Sign up

Export Citation Format

Share Document