Evaluation of the Captive Breeding Techniques of Great Hornbills
•Download as PPTX, PDF•
1 like•1,627 views
Presentation on my Semester Project for a Masters in Zoo Management I'm pursuing at CSU. This presentation gives pros and cons to different techniques and methods in breeding Great hornbills in captivity.
Recommended
More Related Content
Viewers also liked
Similar to Evaluation of the Captive Breeding Techniques of Great Hornbills
Similar to Evaluation of the Captive Breeding Techniques of Great Hornbills (20)
Recently uploaded
Recently uploaded (20)
Evaluation of the Captive Breeding Techniques of Great Hornbills
- 1. Evaluation of the Captive Breeding Techniques of Great Hornbills (Buceros bicornis) Christine T. Bui, MBA Colorado State University NSCI 579 December 4, 2012 Photo courtesy of Coraciiformes Taxon Advisory Group
- 2. Overview History Population Statistics Success stories Strategies to attempt Wrap-up Photo: Coraciiformes Taxon Advisory Group
- 3. History of Great Hornbills Diet Composition Figs Non- figs Animals Photo: IUCN Red List 2012
- 4. Breeding and Nesting Photos: Poulsen 1970 & Chan 2008
- 6. Environmental Threats Photos: Wilkipedia 2012 and Pew environment 2012
- 7. Population Statistics Captive Wild 22.18 in AZA Est 20,000-50,000 25.22 including non- AZA Max pop was 79 birds in 1983
- 8. Captive Breeding Populations- What’s the issue? Aging captive population Goals of AZA institutions Difficulties Unsuccessful replication at institutions that had success Strong pair-bonds and behavior Reproductive restraints of species
- 9. Success Stories Jurong Bird Park, Audubon Park and Singapore Zoological Garden 1980 1988 Photos: Arkive 2012 and Wikipedia 2012.
- 10. Success Stories Sacramento Zoo, 1989 Photos: Christine Bui 2007, 2008
- 11. Strategies to attempt Varying diet and frequency with minimal nest disturbance Diet: Figs, non-figs, animals Nesting success coincides with period of max fruit production Nest disturbance was number one reason for nest abandonment
- 12. Strategies to attempt Mimic wild environment Multiple: bird, nest cavities, nest location, nest materials, food locations Pros Cons • Natural expression of • Genetics behaviors • Aggression • Free mate choice • Density • Increase reproductive • Space success
- 13. Strategies to attempt Artificial insemination and Semen collection Recovery of avian populations Massage technique Requires training to minimize stress Must have all other environmental factors in place for success Avenue for future research
- 14. Wrap-up Aging captive population Unsuccessful attempts to create a sustainable captive population has been an ongoing goal of AZA institutions Suggested strategies have the potential to increase captive populations
- 15. Questions? Thank you!!! Photos: Moghe, Sumeet 2009, Timlaman 2012, Kichus 2012, Keep, Lip 2010
Editor's Notes
- Hello and good evening. My name is Christine and the topic of my project this semester is evaluating the captive breeding techniques of Great Hornbills.
- A quick overview for what’s in store tonight:I’m going to start with a little bit of background information about Great hornbills and their historyThen proceed to discuss current population statisticsShare some captive breeding success storiesAnd then suggest strategies institutions can attempt to increase breeding successFinally, I’ll conclude with a brief wrap-up.
- Hornbills are large forest dwelling birds that are native to Southwest Asia. Their habitat is primarily in the canopy of tall evergreen forests. They can be found in countries highlighted here such as Thailand, Vietnam, Bhutan, Malaysia and India.They are listed as a near threatened species by the IUCN red list.They are omnivorous birds whose diets mainly consist of figs, but also includes non-fig items, such as soft fruit, and animals. They’ve been observed to eat animals ranging in size from millipedes to lizards to squirrels.The ecological niche hornbills plays has a significant role in the seed dispersal of fruit trees.
- Hornbills form strong monogamous pairs and are a species of birds that are known as “cavity dwellers”. They find a natural tree cavity in the trunks of dead trees or the primary limbs of living trees, as pictured above. When the female is ready to lay her eggs, she enters the cavity and seals herself in using a mix of feces, wood, and food debris. During this time, the female is solely dependent on the male, who will bring her food through the small slit that is left after walling. After incubating 1-2 eggs for 38-40 days, the female will remain in the nest until chicks are about one month old, after which she will exit the nest and the chicks will wall themselves back in. Both parents will then provide for the chicks until they are ready to fledge at about 15 weeks of age.
- Here is a series of photos of a Great hornbill who has found a natural cavity in a tree. **CLICK** You can see how small the opening is and appreciate **CLICK** how the bird is able to get in and out of the narrow cavity.
- Deforestation and the logging industry are the main threats to the survival of Great hornbills. These practices remove both breeding sites and eliminate food sources for the birds. Since hornbills are cavity dwellers, females and chicks are easy targets for poachers. The birds are hunted for subsistence, medicinal and ritualistic purposes. You can see in the photos above natives using the casques and bills of the birds in their cultural head dresses.
- The current captive population in AZA institutions report 22 males and 18 females. Including non-AZA institutions, the statistic increases to 25 males and 22 females. These statistics do not include birds that are privately owned.The maximum captive population of hornbills was reported at 79 birds in 1983.The current estimated number of Great hornbills in the wild is anywhere from 20,000-50,000 birds.
- So far it seems like the population numbers are OK, right? So what’s the big deal?**CLICK**The captive population of hornbills are aging. The majority of captive hornbills were wild caught in the early 1900s and were passed through the pet industry before entering AZA institutions. Since 1990, there has been increasing number of reports of Great hornbills succumbing to squamous cell carcinoma in their casques. To date, no explanation has been found for the tendency of neoplasia in this location. Also the underlying infectious agent has not been identified.The goal of AZA institutions that participate in the Great hornbill studbook program has been to create a sustaining population of great hornbills in captivity. However captive breeding of this species has encountered many difficulties.When replicating the protocol of successful breeding institutions, attempting institutions have not been able to share the same rate of success. A major factor that can be playing a role is the necessity of a strong pair-bond to be formed between the birds and the birds’ natural behaviors or personalities. In addition, reproductive restraints exist in this species. Hornbills have an average captive life span of 50 years. They are sexually dimorphic at 5-6 years of age and reports have suggested they cannot reproduce successfully until they are 10 years of age. It has been supported that if a hornbill has SCC, it cannot reproduce successfully beyond 30 years of age. Other reports also suggest sperm quality and motility can decrease with age. With an older captive population, the number of viable males may not be in sufficient quantities to reach the goal of population sustainability.
- In 1980, we saw the first published report of a successful hatching from a pair of great hornbills. This occurred at the Jurong Bird Park in Singapore. The nest cavity provided was cylindrical in shape and the square entrance measured 32cm high by 25 cm wide. The exhibit was rather large (measuring 6.5m long x 10.8m tall x 3.4m wide) and was heavily planted with vegetation such as bamboo, fern, and grasses. Not much else was provided in this report but we do know the park provided a diet of fruit and minced meat that was supplemented with live mealworms twice a day and the birds were minimally disturbed after the chick hatched. **CLICK**This report was followed by the Audubon Park and Zoological Garden in 1988 reporting the 4 consecutive successful breed seasons of the pair of Rhinoceros hornbills. Rhinoceros hornbills are in the same genus as the Great and share the same captive management practices so were included in this project.The Audubon Park allowed a 2 month introduction period of their hornbills through side-by-side housing. Birds were allowed to exhibit and form their pair-bond during this time. Then, the female was transferred to the male’s exhibit and a nest box was provided. Due to aggression exhibited by the male, the exhibit was expanded to double that of the original width to now measure 7.6m long x 7m high x 2.5 m wide. Although the first season together produced a chick, for unknown reasons the female killed the chick. The following season, the only reported change was the addition of sphagnum moss, cedar mulch, and moistened dirt into the nest box. The subsequent 4 years resulted in successful breeding and rearing of chicks.
- Sacramento Zoo reported an extensive and detailed report on success they had from their breeding pair in 1989. This particular breeding pair had consistently laid infertile eggs prior to these changes.A nest box was made out of plywood and measured 39” long x 40” high x 24” wide. The elongated entrance measured 7.5”wide by 14”high, as seen in the first photo on your left. Pieces of soft woods such as cork were provided on the inside of the nest box and the bottom was lined with pine shavings. Both of these substrates would be used to assist in the walling process as pictured in the middle and photo on your right.Sacramento Zoo took further steps to monitor the behavior and success of their breeding pair. A camera was mounted in a mailbox with a plexiglass window in the corner of the exhibit. This provided 24 hr coverage of the birds activities and confirmed copulation. The back of the nest box was fitted with a lens peep-hole, similar to that on one’s front door. This allowed minimal disturbance and quiet observation of the female while she was in the nest box. Finally, a thin access door located at the the bottom of the nest box was incorporated to allow keepers to safely remove the egg for candling purposes.The diet offered included a variety of fruit, bird of prey, mice, chickens, and soaked zoo preem monkey biscuts, which was offered twice a day. In addition, live chicks, mice, crickets, and snails were offered in a bucket. 2 years after the introduction of this nest box arrangement, **CLICK** the breeding pair successfully hatched a chick, who is pictured here in 2008.
- 1- Chaisuriyanun et al. 20112- Stauffer and Smith 20043- Poonswad 1987As you can see, there are many factors that managers incorporate into the breeding protocols for their Great hornbills. I will now transition to my suggested strategies institutions can attempt with their Great hornbills.**CLICK**The first is to vary the diet and frequency with minimal nest disturbance. Reports have concluded wild Great honrbills’ diets consist of 54% figs, 42% non-figs and 5% animals. Other studies have also concluded that nesting success coincides with a period of maximal fruit production and minimal nest disturbance. Creating a nest box similar to what the Sacramento Zoo provided with the peep hole allows observation of the birds with minimal nest disturbance. The successful stories I shared with you only provided food twice a day. Providing an ample diet that mimics wild observations frequently by perhaps providing food 3 or more times a day, can aid in the effort to increase breeding success. To minimize nest disturbance with an increased frequency of food, an institution can create an external method to deposit food for the birds without Keepers having to physically enter the exhibit.
- My second suggested strategy is to mimic the wild environment as much as possible. This includes offering an exhibit that houses multiple great hornbills, multiple nesting cavities that vary in location and substrate. In addition providing ample food at various locations in the exhibit can increase reproductive success.**CLICK**Researchers have observed great hornbills living in groups of up to 40 birds. Studies have suggested the free choice of a mate can be the key to the reproductive success of birds. This strategy can allow natural expression of behaviors, such as foraging, and selection of mate and nest cavity, all of which can increase the chances of reproductive success.However there are some limitations and precautions institutions should be aware of with this strategy. Free selection of a mate will not ensure the genetic diversity match AZA studbooks hope for. Male Great hornbills are notorious for being aggressive during the breeding season. With competition of all resources in this strategy, injury to other birds and keepers are possible. Studies have found the nesting density of wild breeding pairs is.33km^2 . This is a number that should be considered when trying to figure out the number of birds and nests offered. Finally the main limitation to this is the space required. Many institutions are limited to the amount of land they own and are able to landscape with.
- My final suggested strategy is artificial insemination and semen collection. This is a method that has been used previously to recover avian populations such as the whooping crane, peregrine falcon, and houbara bustard.The method utilizes a massage technique for semen collection and manual restraint and manipulation of the cloaca for inseminationIn order to minimize stress, there have been many reports of successfully training a bird to cooperate and accept physical manipulation or being placed in a restraining device. Training of the birds is highly suggested for this strategy.For this strategy to be successful, all other environmental and physiological factors previously discussed need to be present. These factors will allow the breeding pair to exhibit natural behaviors and hormones, while providing an environment set up for reproductive success. Although this strategy seems plausible, further research needs to be conducted regarding female hormones and breeding cycles to time the insemination for optimal success.
- In conclusion, the aging captive population of great hornbills paired with the unsuccessful attempts to replicate successful breeding strategies exhibited by certain institutions has been an ongoing concern for AZA institutions that are trying to create a sustainable great hornbill population.The 3 strategies I suggested in this presentation are plausible strategies institutions can attempt in order to successfully increase captive population size.