History of Jersey Zoo & Durrell Trust ex-situ / in-situ conservation efforts.

Do you know how many BLT were sent to Adelaide ?

 

I seem to remember two pairs, but don't quote me. Unfortunately they never got going, But I did see at least one alive in 98.

 

Just to add to this discussion - there are currently ten holders of Golden Lion Tamarins in Australia [Adelaide; Billabong Zoo; Darling Downs; Gorge; Halls Gap; Mogo; Perth; Symbio; Tasmania Zoo; Wildlife HQ] and two in New Zealand [Auckland and Wellington]. They bred at Adelaide, Symbio and Auckland during 2020.

According to the CITES Trade Database, four Black Lion Tamarins were imported into Australia in 1995 - three from Europe and one from Brazil.

 

Quite a shame that the breeding didn't go very well, but these are a very challenging species so it doesn't suprise me.

Thank you for this @WhistlingKite24 ! Very interesting !

Are these ten holders of golden lion tamarin ?

 

Yes, I have edited my post now to make it clearer.

 

Thats quite a lot of zoos indeed, the GLT is just the total opposite of the poor BLT they really do so much better in terms of breeding in zoos .

 

I've felt a bit conflicted about this earlier post as it didn't really highlight just what a drastic change occurred with the construction of the new bat enclosure.

So I thought I would revisit this topic and the gentle lemur enclosure too (which I also could have done better with) in a comment.

After this I will do a wrap up of the Mauritius kestrel and then two further species that need mentioning as the 90's draw to a close and then the thread on the history of this period should be complete.

 

The evolution of the Jersey Livingstone's fruitbat enclosures (1990 to the present)



The "empyrean" enclosure (1990 - 2003)

The original enclosure for the Livingstone's fruit bats at Jersey zoo which they inhabited from 1990 to 2003 was the peaked roofed netted enclosure known as the "empyrean" shown in the picture below.



This structure had previously housed gorilla and Sumatran orangutang and now currently houses the red billed chough (a far more suitable species for this enclosure than the previous mammal occupants).

The shortcomings of the enclosure and its design for the Livingstone's and Rodrigues fruit bats were recognized fairly early on by staff but it wasnt until the early 2000's that things could be improved upon:

"While Rodrigues fruit bats demonstrated the ability to fly in a relatively small space (7 m × 5 m × 4 m high; Carroll, 1978, 1979), the enclosures initially provided for P. livingstonii (see Table 1) were too small to permit any extended periods of flight, and it was not until 2003 that a space large enough for short flights was created. The height was increased to 4 m in 2011 (Wormell, 2012), and the enclosure now houses both species of bat."

"one enclosure for Livingstone’s fruit bats at Jersey Zoo (see Courts, 1996), in which most of the non‐flying individuals in this study were born, did not appear to be adequate, as the bats rarely flew. This may have been because the enclosure roof was peaked, and as a result, the bats could not start from a position that was both high and gave the opportunity to fly for any distance horizontally."

The rationale for improving the enclosure was based on the growing knowledge of the necessity to preserve natural behaviour in the animals of conservation concern kept in zoos in order that the be primed for future reintroduction and to encourage improved health :

"When keeping any animals for lengthy periods in captivity, preserving natural behavior (or providing appropriate training if an important part of the behavioral repertoire is absent), and maintaining health and physical fitness are both essential if strategies such as translocation and reintroduction are to be successful (e.g. Biggins, Vargas, Godbey, & Anderson, 1999; Griffin, Blumstein, & Evans, 2000; Kleiman, 1989; Reading, Miller, & Shepherdson, 2013)."

"Fruit bats, in common with many other threatened species, may require rapid interventions to prevent extinction, so understanding their care and space needs in captivity is vital to future conservation success."

However, considering these were flying mammals it was essential to provide them with enclosures where they could adequately exercise this critical function and also have enough room to engage in natural behaviours and hierachical spacings present in bat colonies :

"Bats have proved particularly challenging: translocations and reintroductions of bat species are relatively rare, and largely unsuccessful (Ruffell, Guilbert, & Parsons, 2009), but for some Pteropus species, these techniques may be essential if extinction is to be avoided."

"Pteropodids in particular frequently fly tens or even hundreds of kilometers between feeding and roosting sites (e.g. Breed, Field, Smith, Edmonston, & Meers, 2010; Tidemann & Nelson, 2004; Robert, Catterall, Eby, & Kanowski, 2012; Oleksy, Racey, & Jones, 2015). Bringing them into captivity, with its constraints on movement and activity, is therefore likely to have consequences for weight, fitness and ultimately health and reproduction unless adequate space is provided for extended flight. Captive Livingstone’s fruit bats, though not Rodrigues fruit bats, are prone to obesity and, probably as a result, cardiac disease (Charnley, Goatman, Thomasson, Routh, & Barbon, 2017; Dickson, Davies, Routh, Killick, & Barbon, 2016; Killick et al., 2017)."

The development of a new enclosure : bat roost 1. & 2.



In 2003 the plans for a new home at the Jersey zoo for the Livingstone's and Rodrigues fruit bats were put into action with the construction of a new enclosure that was called the "bat tunnel" and then "bat roost 1.".

This was a polythene tunnel measuring approximately 38 m × 7 m × 3 m that had been adapted from prior use as an agricultural tunnel used for growing vegetables. The benefit of the design was / is that the structure is heated which ensures that these tropical animals are kept at the right temperature in Jersey's seasonal climate and this is never less than 18°C..

It was felt that it would also better serve the bat colony as an enclosure in which they could conduct flight and where higher rates of breeding of the critically endangered Livingstone's would occur. A picture of the original "bat tunnel" is shown in the image below:



In 2011 the enclosure was widened by digging out the floor giving the enclosure an extra 1 metre height and planting and furnishing of the enclosure was further improved to provide both as naturalistic an environment possible and to allow maximum enrichment opportunities:

"It was heavily planted with clumps of fig (Ficus sp.) on each side of the tunnel and Tradescantia lining the bottom of the trench. Artificial turf covered the ground level keeper walkways around the perimeter of the tunnel and down the central trench. The ceiling and walls were covered in netting and ropes, which the bats could use to move around the enclosure."


Feeding the bats is done via dispensers attached to the netting :

"65 dispensers (cups suspended from vertical ropes attached to the ceiling and short lengths of gutter attached to the walls of the enclosure), with the aim of reducing competition for food. Each feeding site can be moved, enabling staff to put more food in areas where bats are concentrated if needed. This approach enables old or immobile bats as well as the most subordinate juveniles to have equal access to food."

Recent further improvements

A further extension to the enclosure was added recently which allows the bats to use a looped flight path if 80 meters in circumfurence :

"The exhibit was doubled in size, creating an elongated “donut” flight path approximately 80 m in circumference."

The benefits to the wellbeing of the bats that occupy the bat roosts are enormous :

"After moving to the Island Bat Roost, bats that had not flown before began to do so (pers. obs.), even though food was still accessible without flying (bats could crawl along ropes and across mesh to reach food sites)."

"Since then, we have observed bats making repeated full circuits of the enclosure. This indicates that access to food is not the only motivation for flight: Elements of flight may be involved in social signaling, for example as an indicator of fitness (Byers, Hebets, & Podos, 2010; Chaverri et al., 2018)."






Photo credit to @demonmoth, @Gigit , @jerseygorilla ,@gentle lemur and @Rick J (some photos of bats taken at Bristol zoo).

Source: "Flight patterns in zoo‐housed fruit bats (Pteropus spp.)", Edward Bell et all , 2019 (Journal: Zoo Biology).

 

The Lac Alaotran gentle lemur enclosures (1990 - 2011)

From the late 1990's onwards the enclosure design increasingly began to incorporate a more naturalistic layout and landscaping.

These adaptions reflected both pramatism and what was being discovered through important in-situ research about the ecology of the species in the wild.


The gentle lemurs were originally held in a more traditional style enclosure within the grounds of the zoo, however, in 1997 the population of this at Jersey was augmented by the arrival of ten more individuals from Madagascar which were brought in to increase genetic diversity:

"From 1990 to 1997 the breeding programme produced nine surviving off spring (Beattie and Feistner, 1998). However, seven of these nine captive-bred individuals represent a single gene line from a founder pair, and the remaining two are sired by a female who is also an off spring of this original founder pair. Also, by 1997 five (2.3) of the founders had died. It was therefore decided that for the captive breeding programme to be successful, more founder animals were needed to increase genetic diversity, and in 1997, 10 (6.4) more wild-caught animals were imported to JWPT (Feistner and Beattie, 1998)."

The rationale for building a new enclosure therefore came down to practical considerations with both the increase in the population of the species at the zoo and a desire to educate visitors about the biodiversity of Madagascar:

"The addition of more animals to the breeding programme highlighted the need for extra accommodation at JWPT. In response to this the opportunity was taken to modify an area of wetland habitat bordering a natural stream within the zoo grounds for a new Alaotran gentle lemur exhibit. This area is located next to the new Madagascar teal aviary and therefore provides a unique teaching opportunity."

Creation of the first enclosure



The construction of the new 800 meter sized enclosure used existent landscape features and was further enhanced with naturalistic planting :

"The new Alaotran gentle lemur exhibit measures 800 m and is planted with natural grasses, bamboo, reeds, shrubs, and willow trees. It was planted out with the aim of providing the lemurs with a large variety of natural forage. The three willow trees already existed within the site and are fully grown. The entire area was seeded with a mixture of broad leafed rye grass and couch grass. "

(The planting and landscaping of the enclosure included the use of perennial grasses, papyrus, bamboo, reed, willow, sedge, red dogwood, green dogwood, winter beauty and Chusan palms)

An electric fence was installed around the area for the enclosure to prevent the lemur escaping:

"The enclosure is surrounded by an electric fence, the first time this method has been used as a barrier for this lemur. The fence measures 1.24 m high with 6000 V run ning through it. An electrified gate can be disconnected to allow keeper access to the enclosure for servicing. The fence is held up by wooden posts which are 3.26 m apart and measure 4 cm in width. These poles hold three electrified lengths of white tape that are 13 cm apart. These prevent the animals from jumping on top of the posts from the ground. The public view the enclosure from a raised wooden boardwalk."

An indoor enclosure was constructed for the animals to utilize in cold weather:

"The lemurs have access to a heated shed (240 cm x 179 cm x 220 cm high) within the exhibit, with an attached outside enclosed mesh area (285 cm x 243 cm x 185 cm high), constructed from 2.5 cm mesh. The shed is separated inside into two areas, divided by two layers of 2.5 cm mesh that are 5 cm apart. These inside divisions are connected by a slide that can be operated from outside the shed. Slides also give access to the outside enclosed area and to the main enclosure."

The lemurs are introduced to their new home



A family breeding group of six gentle lemurs first occupied the enclosures but this soon became eight when twins were born that same year:

"The group of lemurs chosen to live in this new exhibit was a family initially consisting of six individuals. When the group was first put into the enclosure the family was composed of an adult pair, one adult male, twin juvenile males, and one infant female (see Table II). Twins were born into the group in October 1998. This family was selected as they were a stable breeding group. It was also thought that, being the largest group at JWPT at the time, they would benefit from the extra space."

Benefits of enclosure


One of the chief benefits of the new enclosure was the shift towards naturalistic behaviour in the lemurs in terms of feeding and foraging:

"There are many positive reasons for housing this lemur in this naturalistic habitat. First, it allows the animals to exhibit natural foraging behaviour. They are no longer limited by the leaf forage that the keeper brings on a daily basis, and are free to eat growing trees and grasses. In fact, on days when the other Alaotran gentle lemurs in the zoo receive willow or grass forage, it is not even necessary to feed the group in the valley exhibit."

The reeds and grass planted provided the animals with a greatly enhanced diet:

"In the wild Alaotran gentie lemurs are known to eat 1 different types of reeds and grasses (Mutschler, 1997, in press). The food Sources within the enclosure are also seasonal which is again similar to food availability in the wild (Mutschler, 1997, in press)."

The benefits in terms of maintenance and education of the public were also judged to be excellent:

"The maintenance required for this type of enclosure is minimal. The inside area need only be spot cleaned daily and fully cleaned on a weekly basis. The outside area needs little maintenance, the most important task being the cutting of grass close to the electric fence, as excess vegetation on the electric wires can cause the fence to short out. The public also benefit from viewing the animals in a far more natural setting and seeing them display more natural behaviour."

Today there are four enclosures for the different gentle lemur groups that are kept at the zoo landscaped in the style of the original 1997 enclosure. Studies conducted at the zoo have shown that the lemurs kept in these more naturalistic enclosures show a behaviour and activity budget that closely mirrors that of Alaotran gentle lemurs in their natural habitat.


Photo credits to @Rick J.


Sources: -"NEW NATURAL EXHIBIT FOR THE ALAOTRAN GENTLE LEMUR Hapalemur griseus alaotrensis AT THE JERSEY WILDLIFE PRESERVATION TRUST", Jane Beattie, 1998 (Journal: "The Dodo")

- "A Study of Enclosure Effect on the Behaviour of the Alaotran Gentle Lemur (Hapalemur griseus alaotrensis) at Jersey Zoo and Implications for Captive Management and Welfare", Elena Mather.

 

You could be right, But I am sure I saw a tv program some years ago where they said that they had them!

 

Rather interestingly, the CITES Trade Database has a record of a Golden-headed Lion Tamarin entering Australia from Singapore in 2003. I wonder what happened to it.

Edit: In the 2008 golden lion tamarin studbook, it is noted that a golden lion tamarin moved from Jurong to Adelaide in January 2004 - so perhaps it's an error?

 

As far as I can recall Adelaide had the ultra rare species

 

I believe that errors do occasionally crop up on these records. There have been a host of species that were supposedly imported but were incorrect.

 

Wrap up of the Mauritius Kestrel at Jersey zoo (1990-2003)

There is an irony inherent in the story of the Mauritius Kestrel at Jersey zoo which is hard to avoid in this wrap up.

The little raptor has the somber distinction of being the only species so far mentioned that arrived during the 90's that is no longer kept at Jersey zoo yet it is also one of the Durrell Trust's greatest in-situ and ex-situ achievements in species conservation.

Sadly a mere decade after their arrival at Jersey an institutional fatigue appears to have crept in towards the keeping of the species.

By the year 2003 with the deaths of the last ageing individuals of the Mauritius kestrel a decision was taken by management to phase out / discontinue the keeping of the species at the zoo.

It remains to be seen whether the Mauritius kestrel will be kept by Jersey zoo once again in the future.

However, a compelling argument could well be made for the suitability or even necessity of the return of this emblematic little raptor to the collection.

The Mauritius kestrel is afterall a species that ultimately showcases the triumphs of the Durrell trust in ex-situ and in-situ conservation like none other having been brought back from the prescipice of extinction by the vision, dedication and tenacity of @Carl Jones.

Though the wild population has grown significantly (from four individuals to four hundred!) thanks to the in country efforts of the Durrell Trust the species is not yet out of the woods and therefore the need for an ex-situ presence outside of its range cannot and should not be ruled out.

Photo credit to @gentle lemur and @dean (photos of species taken at Chester zoo).

 

This is an interesting and accurate summary of what happened to the Mauritius Kestrels at Jersey Zoo. The zoo went out of the species when it was recovering nicely in the wild. There was also an issue in placing captive-bred birds since most colections found the species problematic to keep. Pairs are choosy about their partners and females will harrase and kill males they do not like. Most collections would only want to keep a pair and few had compatible pairs, and many did not have the requisite skills to successfully breed them.
Some went to bird of prey centres although they were always undervalued compared to the more spectacular large falcons, eagles and vultures.

There are some important lessons to be leant from his species in captivity since it illustrates how collections have a problem with the long-term management of some of the less-spectacular and more challenging to keep species. Their success in captivity often rests on the drive and interest of individual senior staff/curators and when these leave interest in these species wanes.

The Mauritius Kestrel has declined in the wild in recent years, although there are three sepearte populations and one of these is healthy and stable at about 50 pairs. There is a need for long term-management, and London Zoo have helped with this in recent years.

 

@Carl Jones Thank you for your brilliant comment, very much appreciated !

I totally agree that there are some crucial lessons to be learned from the far too brief history of the Mauritius kestrel in zoos.

My own opinion is that just as long-term commitment in In-situ conservation is imperative so it should also be a pre-requisite in Ex-situ conservation of species within zoos. I think it should be fundamental even if the species in question poses challenges in terms of husbandry and despite institutional changes in staff and curators.

I find it very disturbing indeed that the future of so many species ex-situ often rests precariously on the drive and interests of individual staff working within zoos and that institutionally speaking projects often do not have a long-term vision.

I'm not sure what the solution to this is but I wholeheartedly share your view that this is a problem that will have to be addressed by the zoo community and that it cannot afford to be swept under the carpet any longer. With the extinction crisis that is now upon us which will be further compounded by climate change the stakes are just far too high.

I'm very glad that the kestrel is still with us and that with your help and dedication it has proved to be such a resilient species

 

@Carl Jones, I had to share this.

I was just looking through an issue of "The Dodo" journal from 1999 to find out some information on the arrival of the mountain chicken and Montserrat oriole and I just happened to find this brief article "Management guidelines for Mauritius kestrels Falco punctatus" right at the back.

It was written by your colleague Hilary French on the Mauritius kestrel and is quite interesting but also very poignant indeed because within only a couple of years of the article being written the species would be phased out at Jersey zoo.

However, at that time it doesn't seem from the tone in which French writes that institutional fatigue has quite sunk in:

"Breeding first occurred in 1991, and offspring were sent to other collections. From 1991 to 1998 inclusive, 34 young were successfully reared to fledging. Of these, 28 were at Jersey, while three other institutions each bred kestrels once (a total of six young)."

She does allude to the steep challenges that Jersey had in maintaining the species though:

"Lack of widespread breeding success has been coupled with high mortality. Causes of death include adenovirus, males killed by females, and reproductive disorders. Deaths of birds less than three years old have been particularly high."

I think the most moving part though is here where French talks about there still being some of the original founding birds that you sent from Mauritius alive and well at the zoo:

"Mauritius kestrels should have a reproductive life of 8–9 years, and when too old to produce fertile eggs are used for fostering. Kestrels can remain healthy to an advanced age. At the time of writing (December 1999), the oldest bird at the Zoo is a 14-year-old female still in excellent condition."

I do think that Jersey zoo should have stuck with the species and that it was a mistake to have discontinued its keeping.

 

Hilary did a wonderful job looking after the Mauritius Kestrels in Jersey Zoo and gave them the attention they required. It is after Hilary left that the zoo went out of Mauritius Kestrels. At the time the population of the wild kestrels was thought to be in better shape than we now know it is.

 

Yes, Hilary certainly seems to have been very committed to the kestrels while she was at Jersey and she wrote a few very interesting papers in "the dodo" on the subject that I've used as sources.

I see, that is really very sad to know that the individual keeping the interest in the kestrel going at Jersey was Hilary.

I think sort of familiarising myself with the history of the zoo and its ex-situ conservation programe programs for this thread has been fascinating but also sad in parts and particularly regarding this species.

But somehow I have a sneaking feeling that the kestrel may once again be kept by Jersey in the future.

 

The arrival of the mountain chicken at Jersey zoo (1999)

In the summer of 1999 a new species arrived at Jersey zoo in what was to be the the begining of an ex-situ captive breeding programe that the Durrell Trust continues to be heavily involved with up to the present day.

This was the Mountain chicken, a large frog species endemic to the islands of Monteserrat and Dominica in the Caribbean.

On Montserrat island where the original Jersey mountain chickens were collected from several volcanic eruptions had occured in the Soufrière Hills (volcanic massif's that are spread across the island) through the mid to late 1990's causing extensive deforestation.

Meanwhile in Dominica the species continued to both be hunted by locals for its meat which was / is considered a delicacy and threatened by the spread of chytrid.

An emergency assessment study in 1998 had concluded that :

"Although the frogs appear to be coping with the volcanic crisis rather better than one might expect, we cannot be sure that the population will continue to thrive in the future. Mountain chickens continue to be hunted, albeit less intensively than in the past, and the intense volcanic activity is damaging their remaining habitat and possibly their prey base. We are regrettably ignorant of the potential long term effects of exposure to volcanic pollution to frogs, and do not know whether they can continue to breed under these conditions. There is still a very real danger that the mountain chicken population in Montserrat could collapse, thereby disrupting the island’s fragile ecology and putting the future of the whole species in question."

One of the recommendations for the species was to therefore establish it ex-situ :

"If the monitoring programme reveals that L. fallax is severely threatened, the most important recommended conservation activities are to ban hunting, ensure full protection of all remaining habitat and - if continued survival on Montserrat seems improbable - captive breeding off-island."

In response to these threats a founding population of nine individuals were collected from the wild and were brought back to Jersey zoo to be housed within a large terrarium within the reptile house.




Photo credits to @gentle lemur and @JerseyLotte.

Sources: -"MOUNTAIN CHICKEN EMERGENCY ASSESSMENT: Findings of Field Work in January and February, 1998", Jenny C. Daltry et al, 1998 (Journal: Fauna & Flora International).