Fertility control in female eastern grey kangaroos using the GnRH agonist deslorelin. 1. Effects on reproduction

2006 ◽  
Vol 33 (1) ◽  
pp. 41 ◽  
Author(s):  
C. A. Herbert ◽  
T. E. Trigg ◽  
D. W. Cooper
Keyword(s):  
Urban Areas ◽  
East Coast ◽  
Slow Release ◽  
Fertility Control ◽  
Minimum Duration ◽  
Reproductive Management ◽  
Adult Females ◽  
Gonadotrophin Releasing Hormone ◽  
Negative Side Effects ◽  
Control Technologies

Eastern grey kangaroos are widespread on the east coast of Australia and frequently reach high densities in reserves and parkland near urban areas. Management of these populations is highly contentious and non-lethal fertility-control technologies are sought as an alternative option to manage population size. This study evaluated the potential of slow-release gonadotrophin-releasing hormone agonist (deslorelin) implants to inhibit reproduction in female kangaroos. Deslorelin treatment effectively inhibited reproduction in adult females for periods of 559 ± 111 days (n = 6) and 651 ± 21 days (n = 5) after administration of one or two 10-mg implants respectively. Animals treated with the lower dosage tended to resume breeding earlier than those that received a total of 20 mg of deslorelin (minimum duration of 18 months). Deslorelin treatment had no effect on blastocyst reactivation in a single treated female and repeat treatment had no negative side-effects. This study has demonstrated that slow-release deslorelin implants can successfully inhibit reproduction for extended periods in the female eastern grey kangaroos. This approach may have potential application in reproductive management of problem kangaroo populations.

Fertility control in female eastern grey kangaroos using the GnRH agonist deslorelin. 2. Effects on behaviour

2006 ◽  
Vol 33 (1) ◽  
pp. 47 ◽  
Author(s):  
R. Woodward ◽  
M. E. Herberstein ◽  
C. A. Herbert
Keyword(s):  
Gnrh Agonist ◽  
Slow Release ◽  
Fertility Control ◽  
Management Option ◽  
Control Techniques ◽  
Acceptable Alternative ◽  
Behavioural Effects ◽  
Effective Inhibition ◽  
Immunological Approach ◽  
Gonadotrophin Releasing Hormone

In recent years fertility control has been proposed as an ethically acceptable alternative to lethal control techniques when managing overabundant kangaroo populations. A promising non-steroidal, non-immunological approach to contraception in female kangaroos involves the use of slow-release implants containing the gonadotrophin-releasing hormone (GnRH) agonist deslorelin. The practicality of using deslorelin implants as a management option is dependant on its effective inhibition of reproduction without negative physical or behavioural side-effects. This study investigated the behavioural effects of deslorelin implants in female eastern grey kangaroos. Treatment had no detectable effects on crepuscular activity. Alterations in the frequency of sexual interactions were observed in deslorelin-treated females, with a behavioural oestrus induced ~3 days after combined removal of pouch young and deslorelin administration. Copulation was observed during this early oestrous period, but conception was not achieved and pouch young were not observed in any treated females. Control females gave birth within 69.6 ± 10.4 days (mean ± s.e.m., n = 9) of placebo implant administration. The first births observed in treated animals were on Days 510, 637 and 643 after treatment. The remaining seven treated animals had not bred by the end of the study, a period of 647 days.

Long-term efficacy of levonorgestrel implants for fertility control of eastern grey kangaroos (Macropus giganteus)

2008 ◽  
Vol 35 (6) ◽  
pp. 520 ◽  
Author(s):  
Graeme Coulson ◽  
Christopher D. Nave ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Urban Areas ◽  
Fertility Control ◽  
The Other ◽  
Control Group ◽  
Acceptable Alternative ◽  
Term Efficacy ◽  
Adult Females ◽  
Free Ranging ◽  
Over Time

Overabundant populations of kangaroos pose substantial management problems in small parks on the fringe of urban areas in Australia. Translocation is impractical and culling is often not publicly acceptable, but fertility control offers an acceptable alternative. One potential contraceptive is levonorgestrel, which provides effective long-term contraception in women, and prevents births in some marsupials for up to five years. We evaluated the long-term efficacy of levonorgestrel in free-ranging eastern grey kangaroos (M. giganteus) at two sites in Victoria, Australia. We trapped 25 adult females at one site (Portland Aluminium), treating 18 with two subcutaneous 70-mg levonorgestrel implants and seven with control (inert) implants. We darted 25 adult females at the other site (Woodlands Historic Park), treating all with two 70-mg levonorgestrel implants. We monitored the reproductive status of the kangaroos, as indicated by the obvious presence of a pouch young, in spring each year for up to seven years. In the first three years at Portland, 81–86% of levonorgestrel-treated females were infertile, compared with 12–29% in the control group, but the effectiveness of fertility control declined over time. At this site, the proportions of treated females breeding in the fourth, fifth, sixth and seventh years of the trial were 36%, 50%, 67% and 100% respectively. Fecundity at Woodlands was similar. Although this protocol achieved fertility control for several years, it was likely that more than one treatment or a higher dose rate would be required for effective fertility control in this long-lived species.

scholarly journals Long-term effects of deslorelin implants on reproduction in the female tammar wallaby (Macropus eugenii)

Reproduction ◽  
2005 ◽  
Vol 129 (3) ◽  
pp. 361-369 ◽  
Author(s):  
C A Herbert ◽  
T E Trigg ◽  
M B Renfree ◽  
G Shaw ◽  
D C Eckery ◽  
...  
Keyword(s):  
Gnrh Agonist ◽  
Slow Release ◽  
Tammar Wallaby ◽  
Term Treatment ◽  
Long Term Effects ◽  
Macropus Eugenii ◽  
Reproductive Management ◽  
Long Term Treatment ◽  
Negative Side Effects

The contraceptive and endocrine effects of long-term treatment with implants containing the GnRH agonist deslorelin were investigated in female tammar wallabies (Macropus eugenii). Fertility was successfully inhibited for 515 ± 87 days after treatment with a 5 mg deslorelin implant (n= 7), while control animals gave birth to their first young 159 ± 47 days after placebo implant administration (n= 8). The duration of contraception was highly variable, ranging from 344 to 761 days. The strict reproductive seasonality in the tammar wallaby was maintained once the implant had expired. This inhibition of reproduction was associated with a significant reduction in basal LH concentrations and a cessation of oestrous cycles, as evidenced by low progesterone concentrations. There was evidence to suggest that some aspect of either blastocyst survival, luteal reactivation, pregnancy or birth may be affected by deslorelin treatment in some animals. These results show that long-term inhibition of fertility in the female tammar wallaby is possible using slow-release deslorelin implants. The effects of deslorelin treatment were fully reversible and there was no evidence of negative side effects. Slow-release GnRH agonist implants may represent a practicable method for reproductive management of captive and semi-wild populations of marsupials.

Observations on social behaviour of Atlantic walruses (Odobenus rosmarus (L.)) during terrestrial haul-out

1980 ◽  
Vol 58 (3) ◽  
pp. 461-463 ◽  
Author(s):  
R. E. Salter
Keyword(s):  
Social Interactions ◽  
Social Behaviour ◽  
East Coast ◽  
Adult Males ◽  
Agonistic Interactions ◽  
Age Composition ◽  
Body Contact ◽  
Adult Females ◽  
Odobenus Rosmarus

Social interactions in walrus herds of mixed sex and age composition were recorded at a haul-out site on the east coast of Bathurst Island, N.W.T., during July–August 1977. Most walruses maintained body contact with at least one other walrus while hauled out on land; herds were usually circular in shape. Adult males, adult females, and immatures all displaced other walruses, and thus entered herds, by jabbing with the tusks. Dominance during agonistic interactions was related to relative tusk length and sex and age of interactants. Behaviour of walruses on land suggested an energetic advantage in mutual body contact, which would be maximized by occupation of interior positions within herds.

Maputo

2020 ◽  
Author(s):  
David Morton
Keyword(s):  
South Africa ◽  
Foreign Investment ◽  
Urban Areas ◽  
East Coast ◽  
18Th Century ◽  
Colonial Rule ◽  
Late 18Th Century ◽  
The Indian Ocean ◽  
Indian Ocean World ◽  
The City

Maputo (Lourenço Marques until 1976) is the capital of Mozambique and one of the busiest port cities on the east coast of Africa. The Bay of Lourenço Marques had already been a source of ivory for the Indian Ocean world and Europe for centuries when, in the late 18th century, Portugal established a permanent garrison there, among the Mpfumo and other Xi-ronga-speaking clans. From 1898 until independence in 1975, the fort-turned-city was the administrative headquarters of Portugal’s territory of Mozambique, a home to many Portuguese settlers, and a stark example of racialized exploitation and urban segregation under colonial rule. It was also the principal transit hub for hundreds of thousands of southern Mozambican men recruited to labor in neighboring South Africa. Following independence, the city became a laboratory of revolutionary socialist experimentation as well as an overcrowded safe haven for refugees of Mozambique’s long and terrible civil war. Despite closer historical ties to South Africa than to most of Mozambique, Maputo is the country’s economic center and its gateway for foreign investment. According to 2017 census figures, the metropolitan population exceeded 2.5 million, making it one of the larger urban areas in southern Africa.

Brushtail possums (Trichosurus vulpecula) in metropolitan Sydney: population biology and response to Suprelorin contraceptive implants

2013 ◽  
Vol 61 (1) ◽  
pp. 78 ◽  
Author(s):  
J. Eymann ◽  
D. W. Cooper ◽  
C. A. Herbert
Keyword(s):  
Urban Areas ◽  
Population Biology ◽  
Local Population ◽  
Fertility Control ◽  
Main Peak ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Management Options ◽  
Contraceptive Implants ◽  
Over Time

The cohabitation of the common brushtail possum (Trichosurus vulpecula) with people in urban areas often causes conflict. Basic biological parameters are needed to evaluate potential new management options such as fertility control. This study investigated the biology of an urban brushtail possum population and the effects of Suprelorin contraceptive implants on individual females within that population. Trapping success remained constant over time, with 2.8 ± 0.2 individuals trapped per residential property. Recapture rates for males declined rapidly over time, with only 30% of males recaptured on the same property 12 months after initial capture (n = 30) and no males recaptured after 18 months (compared with female recapture rates of 58% after 18 months, n = 33). These data, combined with the preponderance of males observed within the lower age classes, suggests that male possum turnover is high within urban areas. This may be partially compensated for by the male-bias (1.8 : 1) observed in pouch young. Breeding was seasonal with the main peak of births in autumn, and a secondary smaller peak in spring. Suprelorin contraceptive treatment effectively inhibited reproduction in adult females for a minimum duration of 519 ± 7 (n = 5) and ≥700 ± 20 (n = 5) days after administration of one or two 4.7-mg implants, respectively, with no negative side-effects obvious. The concurrent collection of data on contraceptive efficacy and population-specific life-history parameters provides a unique opportunity to highlight the importance of understanding local population dynamics when evaluating the likely efficacy and implementation of fertility control programs to manage problem wildlife.

Landside Access to Seaports in Urban Areas: A Case Study

1997 ◽  
Vol 1602 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Arun Chatterjee ◽  
Joseph E. Hummer ◽  
David B. Clarke ◽  
Scott M. Ney
Keyword(s):  
United States ◽  
North Carolina ◽  
Land Use Planning ◽  
Urban Areas ◽  
East Coast ◽  
The United States ◽  
Local Communities ◽  
Planning Processes ◽  
Local Levels

Seaports in the United States usually are located in urban areas. They are major traffic generators on the landside. However, the landside access needs of ports often are overlooked by the transportation and land-use planning processes. A case study of three ports on the East Coast of the United States was performed: Savannah, Georgia; Wilmington, North Carolina; and Morehead City, North Carolina. Both highway and rail access issues were examined at regional and local levels. Several serious issues and problems are identified and discussed in the paper, including effects on local communities.

Use of a new drug delivery formulation of the gonadotrophin-releasing hormone analogue Deslorelin for reversible long-term contraception in male dogs

2003 ◽  
Vol 15 (6) ◽  
pp. 317 ◽  
Author(s):  
A. Junaidi ◽  
P. E. Williamson ◽  
J. M. Cummins ◽  
G. B. Martin ◽  
M. A. Blackberry ◽  
...  
Keyword(s):  
Slow Release ◽  
Semen Quality ◽  
Animal Health ◽  
Plasma Concentrations ◽  
Testicular Volume ◽  
Releasing Hormone ◽  
Detectable Range ◽  
Effect Of Treatment ◽  
Gonadotrophin Releasing Hormone

In the present study, we tested the effect of treatment with a slow-release implant containing the gonadotrophin-releasing hormone agonist DeslorelinTM (Peptech Animal Health Australia, North Ryde, NSW, Australia) on pituitary and testicular function in mature male dogs. Four dogs were treated with Deslorelin (6-mg implant) and four were used as controls (blank implant). In control dogs, there were no significant changes over the 12 months of the study in plasma concentrations of luteinising hormone (LH) or testosterone, or in testicular volume, semen output or semen quality. In Deslorelin-treated dogs, plasma concentrations of LH and testosterone were undetectable after 21 and 27 days, testicular volume fell to 35% of pretreatment values after 14 weeks and no ejaculates could be obtained after 6 weeks. Concentrations returned to the detectable range for testosterone after 44 weeks and for LH after 51 weeks and both were within the normal range after 52 weeks. Semen characteristics had recovered completely by 60 weeks after implantation. At this time, the testes and prostate glands were similar histologically to those of control dogs. We conclude that a single slow-release implant containing 6 mg Deslorelin has potential as a long-term, reversible antifertility agent for male dogs.

Sign in / Sign up

Export Citation Format

Share Document