Featured Research

from universities, journals, and other organizations

Indian rhinoceroses: Reproductive tract tumors reduce female fertility in early stages

Date:
March 26, 2014
Source:
Forschungsverbund Berlin e.V. (FVB)
Summary:
Reproduction of the Indian rhinoceros faces greater difficulties than was previously recognized. Researchers discovered that benign vaginal and cervical tumors cause infertility even in young females. This substantially affects breeding success in zoological gardens.

Indian rhinoceros (Rhinoceros unicornis).
Credit: Steven Seet

Reproduction of the Indian rhinoceros faces greater difficulties than was previously recognised. Researchers from the German Leibniz Institute for Zoo and Wildlife Research Berlin (IZW) together with American colleagues discovered that benign vaginal and cervical tumours cause infertility even in young females. This substantially affects breeding success in zoological gardens.

At the age of three years Indian rhinoceroses become sexually mature. They can reach an age of up to 40 years. Although females should reproduce until the very end of their life, on average the females in zoological gardens give birth to their last young at the age of 18 years. This is revealed by records in the international studbook for Indian rhinoceros which registers the life histories and reproductive success of all 189 Indian rhinos living in zoos worldwide. The researchers found another curiosity while investigating the studbook: If rhinos gave birth to their first young by the early age of five years, they produced up to six juveniles. Rhinos with an age at first reproduction older than that rarely gave birth to more than two calves.

It is known that female Indian rhinos often suffer from tumours in the reproductive tract. Robert Hermes, Frank Gφritz und Thomas Hildebrandt, all veterinarian scientists at the IZW, and their colleague Monica Stoops from Cincinnati Zoo analysed ultrasound data of 23 female Indian rhinos. Over the last 20 years these animals were examined several times.

The finding: "Already at the age of 13 years all animals had developed tumours! The tumours grow rapidly, uncontrolled and lifelong until the vagina and cervix are completely covered in them." This process may be associated with necrosis and inflammations. "Besides the pain which the female must be experiencing because of the tumour, the mating act becomes almost impossible and even if successful, there is no free passage available to the sperm anymore," explains Robert Hermes.

Looking for an organism with comparable tumours the researchers found an unexpected model species -- the human being. "Eighty per cent of all women have such leiomyomas at the onset of their menopause. Leiomyomas can already start to develop in adolescence and they grow as a function of ovarian activity. In contrast to the rhinos the mostly benign tumours in women are located in the uterus and remain without symptoms," says Hermes. Because of the special hormonal condition during pregnancy or lactation, leiomyomas do not grow during these periods. Furthermore women, who gave birth to at least one child, have a 40 % reduced risk to develop leiomyomas.

This analogy provides an indication why those female Indian rhinos who have their first pregnancy at a younger age produce a higher number of offspring than females whose first pregnancy is delayed to an advanced age: Pregnancy inhibits tumour growth. This also suggests a prospective therapy for animals that suffer from inflammation and pain because of massive tumours. "By suppressing ovarian activity, we should be able to induce the menopause, thus putting a halt to further tumour growth," Hermes stated.

Indian rhinos are threatened with extinction. Only 2,900 animals remain in the wild. Robert Hermes cautions: "We should not rely on higher rates of reproduction in free-living Indian rhinos than those in captivity," says Robert Hermes. "Zoological gardens are responsible for a coordinated breeding programme which uses the genetic diversity of the entire population. It would be disastrous, if only because of early tumour diseases breeding is confined to only a few animals who may produce a high number of offspring and the majority bear fewer or no calves." The authors strongly recommend to start breeding at an early stage and to optimise breeding conditions to maximise the chance of females becoming pregnant.

Most zoos hesitate too long until the conditions for natural mating are created -- sometimes 12 or 13 years, deplores Hermes. "This is too late, since all female Indian rhinos do already have tumours in this stage of life. More than one calf is then unlikely." Because several Indian rhinos usually grow up in close proximity in zoological gardens, young females may not have a regular ovulation. In such cases, assistance is necessary. There is a wide range of methods: from a hormonal impulse to a more active support for searching a suitable partner.


Story Source:

The above story is based on materials provided by Forschungsverbund Berlin e.V. (FVB). Note: Materials may be edited for content and length.


Journal Reference:

  1. Robert Hermes, Frank Gφritz, Joseph Saragusty, Monica A. Stoops, Thomas B. Hildebrandt. Reproductive Tract Tumours: The Scourge of Woman Reproduction Ails Indian Rhinoceroses. PLoS ONE, 2014; 9 (3): e92595 DOI: 10.1371/journal.pone.0092595

Cite This Page:

Forschungsverbund Berlin e.V. (FVB). "Indian rhinoceroses: Reproductive tract tumors reduce female fertility in early stages." ScienceDaily. ScienceDaily, 26 March 2014. <www.sciencedaily.com/releases/2014/03/140326181943.htm>.
Forschungsverbund Berlin e.V. (FVB). (2014, March 26). Indian rhinoceroses: Reproductive tract tumors reduce female fertility in early stages. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2014/03/140326181943.htm
Forschungsverbund Berlin e.V. (FVB). "Indian rhinoceroses: Reproductive tract tumors reduce female fertility in early stages." ScienceDaily. www.sciencedaily.com/releases/2014/03/140326181943.htm (accessed September 22, 2014).

Share This



More Plants & Animals News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) — The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) — Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) — A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins