Comparing movement patterns of satellite-tagged male and female polar bears

2001 ◽  
Vol 79 (12) ◽  
pp. 2147-2158 ◽  
Author(s):  
S C Amstrup ◽  
G M Durner ◽  
T L McDonald ◽  
D M Mulcahy ◽  
G W Garner
Keyword(s):  
Life Span ◽  
Adult Male ◽  
The Other ◽  
Polar Bears ◽  
Short Term ◽  
Male And Female ◽  
Adult Females ◽  
Time Period ◽  
Radio Transmitters ◽  
Quality Category

Satellite radiotelemetry has provided great insights into the movements and behaviors of polar bears (Ursus maritimus). The diameter of the neck of adult male polar bears exceeds that of their head, however, and radio collars slip off. This has limited collection of movement information to that from radio-collared females. To overcome this difficulty and gather information about their movements, we surgically implanted satellite radio transmitters into 7 male polar bears during 1996 and 1997. We compared movements of implanted males with those of 104 adult females radio-collared between 1985 and 1995. Transmitters were implanted under the skin on the midline of the top of the neck and were equipped with percutaneous antennae. Implanted transmitters operated for up to 161 days providing 3217 satellite relocations. While transmitting, radios implanted in males provided a larger proportion of the highest quality category of position fixes than was obtained from radio-collared females. However, all implanted radios ceased transmitting before reaching their projected life-span. The abrupt termination of transmission from implanted radios suggested mechanical rather than electronic failure. Mean rates of short-term movement for males (1.18 km/h) were lower than for solitary females, females with cubs, and females with yearlings (1.70, 1.84, and 1.95 km/h, respectively). Net geographic movements from the beginning to the end of each month were comparable for males (mean = 135 km) and females (mean = 114, 152, and 168 km). Mean azimuths of these net movements also appeared to be similar. Monthly activity-area sizes for males (mean = 8541 km2) were comparable to those for females (mean = 3698, 9397, and 10 585 km2) during the time period of comparison. In contrast to the other movement measures, males traveled longer mean distances (387 km) each month than did females (217, 289, and 302 km). Movements of males, it appears, were more directed than those of females, but males confined their travels to similar-sized areas.

Effects of short-term heat stress on the development and reproduction of predatory mite Neoseiulus barkeri (Acari, Phytoseiidae)

2021 ◽  
Vol 26 (4) ◽  
pp. 713-723
Author(s):  
Wei Zhen Li ◽  
Hao Long Li ◽  
Zi Kun Guo ◽  
Su Qin Shang
Keyword(s):  
Heat Stress ◽  
Life Span ◽  
Treatment Time ◽  
Predatory Mite ◽  
Immature Stage ◽  
Oviposition Period ◽  
Hatching Rate ◽  
Short Term ◽  
Developmental Duration ◽  
Adult Females

The predatory mite Neoseiulus barkeri (Acari: Phytoseiidae), which is one of the best natural enemies, has been used as a biological control agent against multiple insect pests, such as spider mite, Tetranychus urticae and thrips. Its growth and development were affected by the environmental temperature changes. This study was conducted to evaluate the hatching rate of the eggs and the immature developmental times of N. barkeri after incubation of the eggs under heat stress at 38, 40 and 42℃, 85% ± 5% RH and a 16h:8h light: dark (L:D) photoperiod for 2, 4 and 6h. After adult females emerged, they were treated under the same conditions again, and the parameters such as oviposition period, fecundity and female longevity were observed. The results showed that with the increase of the temperature and the extension of the duration of the heat stress, the hatching rate was lower. The eggs treated at 42℃ for 2h or more could not hatch, and the developmental duration of each immature stage showed a trend of decreasing at first and then increasing. The fastest development was observed after incubation of eggs at 40℃ for 2h, and the shortest developmental duration was 4.60d. Under the condition of 38℃, the oviposition period and life span of adult females were shortened with the extension of treatment time, and the fecundity decreased at first and then increased. At 40℃, the fecundity, oviposition period and longevity of adult females showed a trend of gradual increase with the extension of treatment time. The shortest oviposition period, the lowest fecundity and the shortest life span of adult females were 12.14d, 18.92 eggs and 16.65d, respectively after incubation of eggs at 40℃, for 2h. Therefore, the short-term heat stress had a significant effect on the hatching rate and the duration of the immature stage, and also had a negative effect on the fecundity, oviposition period and longevity of adult females. In rearing and field release, heat stress should be avoided as much as possible to achieve the best predation and control effect of N. barkeri.

Description of a new species of the genus Paraedes (Diptera: Culicidae) in Assam, India

Zootaxa ◽  
2019 ◽  
Vol 4691 (3) ◽  
pp. 286-292
Author(s):  
R. NATARAJAN
Keyword(s):  
New Species ◽  
Adult Male ◽  
Male Genitalia ◽  
Male And Female ◽  
Northeastern India ◽  
Adult Females ◽  
A New Species

A new species, Paraedes jambulingami, is described from Assam, northeastern India. The adult male and female are described in detail and an illustration of the male is provided. This species is easily distinguished from all known species of the genus Paraedes by the presence of broad silvery or golden scales on the paratergite and the outer arm of the basal mesal lobe of the male genitalia bearing a long, flattened blade-like seta. Dichotomous keys are provided for the identification of the adult females and males of the five species of the genus that are known to occur in India. 

scholarly journals Polar bear (Ursus maritimus) use of the Cape Bathurst polynya and flaw lead

2021 ◽  
Author(s):  
Erin M. Henderson ◽  
Andrew E. Derocher
Keyword(s):  
Polar Bear ◽  
Step Length ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Long Distance ◽  
Subadult Male ◽  
Male And Female ◽  
Habitat Features ◽  
Adult Females ◽  
Pack Ice

The Cape Bathurst polynya and flaw lead (CBP) are major, predictable habitat features with ≤15% ice cover in an otherwise ice-covered Beaufort Sea, and thought to provide hunting opportunities for polar bears (Ursus maritimus Phipps, 1774). We assessed 78 adult (female; with and without cubs) and subadult (male and female) polar bears’ use of the CBP from October – June, 2007–2014. The CBP was up to 725 km wide in autumn, ice-covered in winter, and <306 km wide in spring. Seventy-nine percent (n = 62) of the bears used the CBP (≥1 location <2.4 km, or one 4 h step length, from the CBP). Use was higher for solitary adult females and subadult males, which travelled faster with low turning angles along wider sections than females with offspring and subadult females. Bears were closest to the CBP during the spring hyperphagia season. While a wider CBP did not prevent crossing, bears primarily crossed from the coast towards pack ice at locations 53% narrower than areas not crossed. Bears might avoid crossing when it would require a long-distance swim. The CBP affects polar bear ecology by providing hunting habitat and a corridor that could increase prey encounters but may affect movement.

Recognition of conspecific odors by the western red-backed salamander, Plethodon vehiculum

1988 ◽  
Vol 66 (6) ◽  
pp. 1293-1296 ◽  
Author(s):  
K. Ovaska
Keyword(s):  
Chemical Communication ◽  
Adult Male ◽  
The Other ◽  
Social Significance ◽  
Male And Female ◽  
Reproductive Female ◽  
The Family ◽  
Choice Tests ◽  
Conspecific Odors ◽  
Random Manner

Lungless salamanders of the family Plethodontidae possess an elaborate system of glands that potentially can be used in chemical communication. I used an olfactometer to examine the behavior of adult male and female western red-backed salamanders, Plethodon vehiculum, towards airborne odors of conspecific individuals. In two-choice tests, P. vehiculum of both sexes chose the side with no odor over that with the odor of a male; however, they entered the sides at random when presented with no salamander odor on one side and the odor of a nonreproductive female on the other. Therefore, P. vehiculum was able to recognize and avoided odors of conspecific males. Odors of nonreproductive females either were not recognized or carried no social significance. Males may use pheromonal markers to space themselves out for mating purposes. Contrary to predictions, males did not prefer the odor of a reproductive female over that of a nonreproductive female when simultaneously presented with the two odors, but entered the sides in a random manner.

Morphological description of the pupa and fourth-instar larva and redescription of the adults of Psorophora (Psorophora) pallescens Edwards (Diptera: Culicidae)

Zootaxa ◽  
2009 ◽  
Vol 2306 (1) ◽  
pp. 51-58 ◽  
Author(s):  
MARINA STEIN ◽  
MAGDALENA LAURITO ◽  
GUSTAVO CARLOS ROSSI ◽  
WALTER RICARDO ALMIRÓN
Keyword(s):  
Adult Male ◽  
Male Genitalia ◽  
Instar Larva ◽  
Fourth Instar ◽  
The Other ◽  
Morphological Description ◽  
Fourth Instar Larva ◽  
Male And Female ◽  
First Time

The adult male and female of Psorophora (Psorophora) pallescens Edwards are redescribed. The pupa and fourth-instar larva are described for the first time. The male genitalia, pupa and fourth-instar larva are illustrated. Information on distribution, bionomics and taxonomy is also included. Psorophora pallescens adults differ from the other species of the subgenus in the coloration of the scutum and abdomen. The larva can be distinguished from Psorophora ciliata based on characters of the head, thorax and abdomen.

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.

The effect of handling and blood removal on plasma levels and hepatic deiodination of thyroid hormones in adult male and female rainbow trout, Oncorhynchus mykiss

2002 ◽  
Vol 80 (2) ◽  
pp. 372-375 ◽  
Author(s):  
Keith J Todd ◽  
J Geoffrey Eales
Keyword(s):  
Rainbow Trout ◽  
Thyroid Hormones ◽  
Oncorhynchus Mykiss ◽  
Adult Male ◽  
Plasma Levels ◽  
Temporary Increase ◽  
Male And Female ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Adult Females ◽  
The Mean

We studied the effects of handling and blood removal (0.4% of body mass) on the thyroid system of fasted ~1000-g adult male and female rainbow trout, Oncorhynchus mykiss, over a 3-day period. Relative to undisturbed controls, bleeding lowered the mean hematocrit (HCT) by 19% and on day 1 increased the hepatic inner-ring deiodination of 3,5,3'-triiodothyronine (T3) (T3IRD), but did not alter thyroxine (T4) outer-ring deiodination (T4ORD) or inner-ring deiodination (T4IRD) activity or plasma T4 or T3 levels. Regardless of treatment, hepatic T4ORD activity and HCT were lower in females than in males, and over the 3 days following bleeding, the plasma T3 level increased and the plasma T4 level decreased progressively for both sexes. We conclude that handling and bleeding induce a temporary increase in hepatic T3 conversion to 3,3'-diiodothyronine with no change in T4 conversion to reverse T3. This is consistent with independent control of T3IRD and T4IRD activities. Furthermore, HCT and hepatic T4ORD activity are lower in adult females, and 10 days after transfer of trout to smaller tanks, plasma T4 and T3 levels may still be adjusting.

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.

Alteration of Mitochondria in Oxythiamine-Induced, Acute Thiamine Deficiency in the Mouse

1976 ◽  
Vol 34 ◽  
pp. 284-285
Author(s):  
Itaru Watanabe ◽  
Dante G. Scarpelli
Keyword(s):  
Electron Microscopy ◽  
Adult Male ◽  
Thiamine Deficiency ◽  
Light And Electron Microscopy ◽  
Fatty Change ◽  
Deficient Diet ◽  
Subcutaneous Injections ◽  
Swiss Mice ◽  
Time Period ◽  
Ad Libitum

Acute thiamine deficiency was produced in mice by the administration of oxythiamine, a thiamine analogue, superimposed upon a thiamine deficient diet. Adult male Swiss mice (30 gm. B.W.) were fed with a thiamine deficient diet ad libitumand were injected with oxythiamine (170 mg/Kg B.W.) subcutaneously on days 4 and 10. On day 11, severe lassitude and anorexia developed, followed by death within 48 hours. The animals treated daily with subcutaneous injections of thiamine (300 μg/Kg B.W.) from day 11 through 15 were kept alive. Similarly, feeding with a diet containing thiamine (600 μg/Kg B.W./day) from day 9 through 17 reversed the condition. During this time period, no fatal illness occurred in the controls which were pair-fed with a thiamine deficient diet.The oxythiamine-treated mice showed a significant enlargement of the liver, which weighed approximately 1.5 times as much as that of the pair-fed controls. By light and electron microscopy, the hepatocytes were markedly swollen due to severe fatty change and swelling of the mitochondria.

Sign in / Sign up

Export Citation Format

Share Document