|Small Gruiformes Usage in Mixed Species Exhibits
Daniel AW Boritt
Smithsonian National Zoological Park
3001 Connecticut Ave, NW
Washington DC 20008
Wild birds are becoming harder for American Zoo and Aquarium Association (AZA) accredited facilities to acquire (Final Report 5). With the increasing difficulties of augmenting captive populations with wild caught birds breeding for sustainability will become increasingly important. Directors will continue to push for popular, charismatic crowd-favorites adding to pressure on such groups as Gruiformes (2006 AZA Eastern Regional Sustainability Workshop). With inadequate off exhibit holding, mixed species exhibits will become increasingly vital for the long term sustainability of captively managed birds (Sheppard 199).
Small Gruiformes, due to their cryptic coloration, and secretive lifestyle are typically not considered to be good exhibit birds. Bird facilities limited access to off-exhibit breeding facilities makes the propagation of this order difficult, and other, more popular species are often given priority. With no small Gruiformes population currently numbering above 100 individuals in AZA facilities, the impact of reduced wild acquisition is particularly pertinent for these taxa (ISIS population data). The common perceptions that these birds can be aggressive toward heterospecific species further complicated the space available to small Gruiformes. Proper mixed species exhibitory is therefore vital for the long term sustainability of these birds.
In January of 2008 a survey was sent to 45 AZA institutions that housed small Gruiformes according to the International Species Inventory System (ISIS). Of those 45 institutions as well as several topic specific list serves twenty-two (22) individuals (48.8% response rate) responded giving me information on fifty-six (56) exhibits housing small Gruiformes in a mixed species environment. A copy of the survey follows as an appendix to this paper.
The survey sought input on 13 (thirteen) species of small Gruiformes currently housed in AZA facilities. I received input on 12 (twelve) of those 13 (thirteen) including a survey on one species which I had not sought due to its rarity within AZA (only one organization currently holds this species). The species I sought input on were: from the family Turnicidae the Madagascar button quail (Turnix nigricollis); from the family Eurypygidae the sunbittern (Eurypyga helias); from the family Otididae the buff-crested bustard (Lophotis ruficrista) and the white-bellied bustard (Eupodotis senegalensis); from the family Psophiida the grey-winged trumpeter, (Psophia crepitans); from the family Cariamidae the red-legged seriema (Cariama cristata); from the family Rallidae, the banded rail (Gallirallus philippensis), the Guam rail (Rallus owstoni), the black crake (Limnocorax flavirostra), the sora (Porzana carolina), the purple swamphen (Porphyrio porphyrio), the purple gallinule (Porphyrio martinicus) and the common moorhen (Gallinula chloropusI). I also received a survey on the sole remaining black bustard (Eupodotis afra) kept in an AZA accredited zoo.
I received a high of 14 responses for sunbitterns, and a low of 1 response for black bustard and Madagascar button quail. I received zero (0) responses for the common moorhen. With the common moorhen removed, the average number of responses per species was 4.9. When the single response species were eliminated, that average number of exhibits per species increased to 5.6.
As previously mentioned there is not a single Gruiformes species with over 100 individuals currently managed in AZA institutions (graph based on isis data).
Sunbittern (Eurypyga helias)
Sunbitterns, the most heavily reported of the species with fourteen, were cited as aggressive forty-three (43%) percent of the time. In all but one report aggression was nothing more than simple threat displays, and was typically associated with live prey (insects) scatter feeding. Aggression was cited throughout the entire year, with moderate increases during breeding season. Exhibit size did not appear to be a factor in aggression, nor did foliage cover. Both sexes aggressed toward heterospecifics, with the aggression heightened toward fellow insectivorous birds.
Birds reported to be successfully housed with sunibtterns include: various ground doves, small waterfowl, frugiverous passerines (tanagers, dacnis and euphonias), various fruit doves, various white-eyes, small to medium psitticines, troupials, boat-billed heron (Cochlearius cochlearius) and white-faced ibis( Plegadis chihi). Those species most frequently reported to cause aggressive behavior were: blue-crowned motmot (Momotus momota), Guira Cuckoo (Guira guira), various rollers, scarlet ibis, large pheasants and various toucans.
Based on the lack of physical aggression exhibited by this species there is no reason to caution against displaying the sunbittern in mixed species exhibits. The threat displays are even encouraged by some zoos as they are reported as crowd pleasing. They do well in large flighted aviaries, as well as smaller exhibits. Breeding occurs well in mixed species exhibits, making this an ideal species to be housed in this manner.
Buff-crested Bustard (Lophotis ruficrista)
Buff-crested bustards were reported to aggress toward others in only one of eight reported exhibits (>13%). The single report of aggression occurred during a feeding session, and appears to be unique. These bustards were housed in all sized exhibits with success. Foliage density varied greatly with no discernable affect. The single aggressive incident occurred based on food, however there appeared to be no correlation between food pans remaining and aggressive incidents. The single aggressive incident occurred between buff-crested bustards and superb starling (Lamprotornis superbus) and Taveta golden weavers (Ploceus castaneiceps). Heterospecifics most frequently housed with buff-crested bustard include: golden-breasted starling (Cosmopsarus regius), blue-naped mousebirds (Urocolius macrourus), hamerkop (Scopus umbretta), various turaco species, oriole warbler (Hypergerus atriceps), African pygmy goose (Nettapus auritus), red bishop (Euplectes orix), various starlings, D'Arnaud's barbet (Trachyphonus darnaudii), carmine bee-eater (Merops nubicoides), various rollers and various pigeons and doves.
Based on the overwhelming survey results it appears that the buff-crested bustard is an ideal species to be used in mixed species exhibits. In addition to their predominately passive behavior these birds are know to breed successfully in exhibits with relatively high densities.
White-bellied Bustard (Eupodotis senegalensis)
White-bellied bustards, according to the two surveys received, are an ideal species of small Gruiformes for use in mixed species exhibits. They were not reported to aggress toward heterospecifics and were successfully housed with: various turaco species, magpie shrikes, racquet-tailed rollers (Coracias spatulatus) and small conures.
Black Bustard (Eupodotis afra)
Black bustards, according to the single AZA institution keeping this species, do not report aggression from the species. They are currently exhibited with dove species in a 15 x 15 x 15 foot exhibit with very light foliation and 2 feeding stations which remain 24 hours a day.
Grey-necked Wood Rail (Aramides cajanea)
The grey-necked wood rail, based on three surveys, is readily housed with other species. All reported exhibits were large (>5000 square feet) with heavy (greater than 50%) foliage. Species reported to be successfully housed with this species include: scarlet macaw (Ara macao), sun conure (Aratinga solstitialis), Guira cuckoo, green oropendola (Psarocolius viridis), scarlet ibis (Eudocimus ruber), bare-faced curassow (Crax fasciolata), screaming piha (Lipaugus vociferans), red-crested cardinal (Paroaria coronata), blue-grey tanager (Thraupis episcopus), Salvin's pigeon (Columba oenops), scarlet-headed blackbird (Amblyramphus holosericeus), silver-beaked tanager (Ramphocelus carbo,), sunbittern, cinnamon teal (Anas cyanoptera) and blue-crowned motmot.
Purple Gallinule (Porphyrio martinicus)
The purple gallinule, according to three received surveys, does not demonstrate aggression toward other species in mixed exhibits. Successful exhibits varied in size from 500 square feet to over 9000 square feet, and all were heavily (>50%) foliated. Species successfully housed with the purple gallinule include: various currasows, blue-bellied rollers (Coracias cyanogaster), various tanagers, red-capped cardinals(Paroaria gularis), various orioles, various starlings, Nicobar pigeons (Caloenas nicobarica), pied imperial pigeons (Ducula bicolor), green-winged doves (Chalcophaps indica), various kingfishers, blue-crowned motmots and a variety of ducks and small passerines.
One responder noted that these birds, though not aggressive, are extremely secretive and often times hard for visitors to see in large mixed species habitats.
Sora (Porzana carolina)
The sora, based on three responses, did not exhibit aggression toward other species. Sora were housed in exhibits ranging in size from 64 square feet to large outdoor flight aviaries. Succesful cohabitants include: eastern bluebird (Sialia sialis), northern cardinal (Cardinalis cardinalis), bobwhite quail (Colinus virginianus), Baltimore oriole (Icterus galbula), American robin (Turdus migratorius), mourning dove (Zenaida macroura), various turaco species, racquet-tailed rollers, and small conures, common snipe (Gallinago gallinago), American coot (Fulica americana), purple gallinule, various sparrows, various warblers, red-winged blackbird, eastern meadowlark and small North American ducks.
Purple Swamphen (Porphyrio porphyrio)
Purple swamphen, based on a pair of surveys, do not show aggression toward other species. Both exhibits were larger than 1000 square feet. Successful cohabitants include: painted stork (Mycteria leucocephala), white-winged wood duck (Cairina scutulata), various tangers, grey-necked wood rail, various small waterfowl and various doves and pigeons.
Banded Rail (Rallus philippensis)
Banded rail, based on four surveys, does not exhibit aggression toward heterospeciefics in mixed species exhibits. Habitats varied in size and foliage cover, but all were larger than 500 square feet in size. Species successfully housed with banded rails include: red capped cardinal, blue-grey tanager , chestnut teal (Anas castanea), Australian shelduck (Tadorna tadornoides), pied imperial pigeon, western crowned pigeon (Goura cristata), spangled cotinga (Cotinga cayana), various fruit doves, black-naped oriole (Oriolus chinensis), pheasant pigeon (Otidiphaps nobilis), scarlet headed blackbirds and masked plover (Vanellus miles).
Madagascar Button Quail (Turnix nigricollis)
Madagascar button quail, according to a single survey, did not exhibit aggression toward cohabitants in a mixed species exhibit. The single reported exhibit was 10 feet x 10 feet x 15 feet. Birds reported as successfully housed with Madagascar button quail are: golden-rumped tinkerbird (Pogoniulus bilineatus), lavender waxbill (Estrilda caerulescens), cutthroat finch (Amadina fasciata), yellow-fronted canary (Serinus mozambicus), swee waxbill (Estrilda melanotis) and blue-capped cordon-bleu (Uraeginthus angolensis). Based on this single response (therefore limiting the effectiveness) this species appears to be a good candidate for mixed species usage.
Red-legged Seriema (Cariama cristata)
Red-legged seriema were reported to show aggression toward heterospecifics in four out of five (80%) surveys. Seriemas were reported in all cases to continue their aggression until removal of either the seriemas or the victim species. Exhibit size ranged from 180 square feet to over 1500 square feet. While aggression occurred throughout the year, aggression was increased during the breeding season. Aggression was also reported to occur during feeding times, as well as when birds are housed over night.
Aggression ranged from chasing, to feather pulling, to killing of smaller birds. As previously stated aggression did not cease without altering the species makeup of the exhibit. Several zoos attempted various methods of decreasing aggression seriemas without success. Breeding was reported to be limited or non-existent in the presence of other species, though it quickly picked up when the victims were removed from the enclosure. Seriemas were successfully housed with ringed teal (Callonetta leucophrys) and plush crested jays (Cyanocorax chrysops).
Based on the repeated aggression in is hard to recommend the red-legged seriema as an appropriate small Gruiformes for a mixed species exhibit. While aggression is reduced during the non-breeding season, it may still be hazardous to house seriemas with other birds, especially ground dwelling birds. While there has been successful mixed species exhibitry with this species, it seems unlikely that this is a good species.
Grey-winged Trumpeter (Psophia crepitans)
Grey-winged trumpeters were reported to show aggression toward other species in five out of nine (56%) surveys. Aggression was heightened during the breeding season, though it reportedly occurred year round to a lesser degree. Trumpeters tended to be more aggressive when housed in male/female pairs, though same sex pairs were also reported to be aggressive. The aggressive bouts were typically chasing, with occasional feather pulling. One institution reported a pair of female trumpeters killing a male trumpeter introduced to the exhibit.
Trumpeters were reported to be more aggressive toward primarily terrestrial birds, as well as birds that were cavity nesters. Management of the aggression failed to be successful, with removal of aggressor or victim as the only effective means of management. Smaller birds were typically not harassed, while larger birds tended to draw the ire of the trumpeters. Birds successfully housed with trumpeters include: red-crested cardinals, plush-crested jays, Cuban amazons (Amazona leucocephala), guira cuckoo, blue-crowned motmot, boat-billed herons (Cochlearius cochlearius), various doves and various tanagers.
While trumpeters have been successfully housed with other species in various exhibits, the majority of the time the set up is not aggression free. Due to their ability to inflict serious harm caution is advised. When considering what species to use with grey-winged trumpeters, smaller, arboreal birds have a higher rate of success.
Black Crake (Limnocorax flavirostra)
Black crakes were reported to show aggression in four out of seven (57%) of surveys. Aggression was typically initiated by the introduction of live prey. Black crakes were also frequently reported as disturbers, or suspected disturbers of eggs, mainly nest sites of ground nesters. Crakes were less likely to aggress toward larger birds. They were more likely to chase terrestrial birds, even causing the death of a crested wood partridge. The single occurrence of death occurred when a crested wood partridge attempted to escape the assault of the crake, breaking its neck on the glass front of the exhibit.
The single reported death appears to be more of an isolated incident than the norm with this species. While they are aggressive in a majority of mixed species settings, much of the aggression is minor physical contact or egg raiding. Larger exhibits tended to result in lessened reported aggression, though small exhibits (<100 square feet) were also successful. Species successfully housed with black crakes include: carmine bee eaters, blue-breasted kingfisher (Halcyon malimbica), various rollers, white-crowned robin-chat (Cossypha albicapilla), various orioles, hammerkop, sacred ibis (Threskiornis aethiopicus), various starlings, cattle egrets (Bubulcus ibis), hottentot teals (Anas hottentota), green wood hoopoe (Phoeniculus purpureus) and common bulbul (Pycnonotus barbatus).
While aggression occurred in a majority of mixed species exhibits it tended to be minor. If trying to breed ground nesting birds, breeding by those ground nesters may be greatly compromised. While caution should be used when mixing species with the black crake it can be successful, particularly in larger, well planted exhibits.
Small Gruiformes have the capacity to be good mixed species exhibit animals. While some species such as the red-legged seriema, Guam rail and grey-winged trumpeter may not be advisable, others consistently work well. Although this taxa has a reputation for aggression, when properly matched this issue is greatly mitigated. As space becomes increasingly sparse, mixed species exhibits will gain increased importance in our quest for avian sustainability. While these results are preliminary they do lay a groundwork for which Gruiformes may work with which heterospecifics. While further research must be gathered this paper has presented numerous pairings which have worked and will hopefully continue to work.
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