This time, they were ready.<\/p>\n
When the state released five male, captive-reared endangered Hawaiian crows (`alala) into the Pu`u Maka`ala Natural Area Reserve on December 14, 2016, managers found out the hard way that some of them weren\u2019t ready to fend off attacks from native Hawaiian hawks (`io) or otherwise survive on their own.<\/p>\n
In 2002, the species had disappeared from the wild and survived only at captive rearing facilities in Keauhou, Hawai`i and Olinda, Maui, run by the San Diego Zoo Global\u2019s (SDZG) Hawai`i Endangered Bird Conservation Program.<\/p>\n
Despite extensive preparation, within two weeks of their celebrated and long-awaited release, three of the released birds were dead. Two were killed by `io, while another simply failed to thrive. Staff with the `Alala Project \u2014 a partnership that includes the state Division of Forestry and Wildlife, the U.S. Fish and Wildlife Service and SDZG \u2014 recaptured the remaining two and went back to the drawing board.<\/p>\n
At the annual Hawai`i Conservation Conference held in Waikiki this past July, project members detailed how they strengthened preparations for the next cohort and proudly proclaimed that all 11 birds (four females and seven males) released in September and October 2017 were still alive and well nearly a year later. What\u2019s more, the birds have been seen banding together to fend off `io attacks, foraging broadly, and perhaps even pairing up, they said.<\/p>\n
Boot Camp<\/i><\/b><\/p>\n
\u201cWe went back to the basics,\u201d said Alison Greggor, a post-doctoral research associate with SDZG\u2019s Hawai\u2018i Endangered Bird Conservation Program of her team\u2019s approach following the recapture of the two survivors of the 2016 release. The team re-evaluated what the captive-raised `alala needed to know before entering the wild. \u201cCaptive environments lack foraging challenges, exposure to predators, natural social groups. We went through and tried to address each one of these,\u201d she said.<\/p>\n
`Alala have large brains for their body size and a long juvenile development period. So compared to other species, `alala have a lot they need to learn because they don\u2019t have as much ingrained behavior, she said.<\/p>\n
\u201cA juvenile needs to see a predator while hearing a danger call of an adult,\u201d she said. Her team experimented with a variety of proxies to see which ones the `alala found the most convincing. The team employed plastic `io or stuffed ones to \u201cfly\u201d over the aviary, while putting a dead corvid under their feet. Ultimately, a combination of different techniques was used, although she said the birds responded most strongly to a live hawk borrowed from the Panaewa Zoo.<\/p>\n
In addition to finding the most effective version of a predator, the team needed to pair that with audible danger cues. The team collected a variety of vocalizations from the captive flock, including distress calls the birds make when they think they\u2019re injured, she said.<\/p>\n
With the visuals and the alarm calls combined, the team essentially created a vivid theater production for the `alala.<\/p>\n
\u201cWe want to make sure we\u2019re actually creating fear,\u201d she said.<\/p>\n
While the predator play proceeded, the team documented the kinds and amount of fear behaviors the `alala exhibited, whether it was making alarm calls or pace flying in the aviary. \u201cPer minute, we were getting 100 fear behaviors in cohorts. We even had some birds come up and mob the `io,\u201d she said, adding that those birds included the ones released in 2016.<\/p>\n
With regard to foraging, she noted that adults of species of the crow family are known to be wary of novel food types and, therefore, may need to be exposed to potential food sources before that wariness takes hold. \u201cBefore they are released, they have to prove they are competent in foraging from these several types [of food],\u201d she said.<\/p>\n
Pre-release, the team also documented the birds\u2019 social networks, which ones interacted best and which ones were aggressive toward one another. Using that information, the team was able to ensure they released a socially intact cohort. \u201cThis allowed us to feel more confident that when we opened those doors they weren\u2019t going to scatter,\u201d she said.<\/p>\n
\u201cTraining can be effective, but you need to evaluate whether all individuals are interacting with the training,\u201d she said, noting that more than 30 percent of animal reintroductions report difficulties related to animal behavior, yet only five percent of all reintroduction papers between 1990 and 2005 mentioned behavior.<\/p>\n
\u201cI\u2019m happy we do have 11 birds all flying and thriving,\u201d she said.<\/p>\n
She explained that training for the birds released in 2016 included some of the same elements in the current program, but was less rigorous and lacked the same level of evaluation. \u201cThe biggest change was making it a strategic plan moving forward,\u201d she said.<\/p>\n
Greggor was asked about how the `alala might respond to predator training using an animal absent from its evolutionary background, such as a small mammal. Feral cats, rats, and mongooses are found throughout the reserve and pose a real threat to the `alala and\/or its eggs, if or when the birds start breeding in the wild. Rats and cats are also hosts of the parasite Toxoplasma gondii<\/i>, which has infected and killed `alala in the past. The state has conducted extensive predator trapping in the release area \u2014 removing 200 rats, 105 mongooses, and 13 cats since 2016 \u2014 but the invasive mammals persist.<\/p>\n
Greggor responded that she wasn\u2019t aware of any cognitive biases the birds might have to such training. \u201cWe\u2019re working on it. \u2026 What are the limits of this training? It\u2019s still being figured out,\u201d she said.<\/p>\n
Looking Good<\/i><\/b><\/p>\n
Joshua Pang-Ching, research coordinator for the Hawai\u2018i Endangered Bird Conservation Program, detailed how the birds have done, post-training.<\/p>\n
Before they were released, the birds were transferred to a custom-built aviary within the reserve where they could practice flying and build their muscles. They were also banded (orange for the males, white for the females) and fitted with tracking harnesses.<\/p>\n
\u201cNow that the birds are out, the biggest portion of the work is tracking, making sure they\u2019re healthy,\u201d he said, adding that managers follow and observe the birds at least once a day, taking note of their overall health, location, movements, behavior, and social interactions. A spring scale\/feeder set out in the forest also allows the team to monitor the birds\u2019 weight.<\/p>\n
Pang-Ching reported that the birds have improved their overall flight competency, maneuvering with greater confidence. They\u2019ve been tracked doing 700-meter jaunts and exploring new foraging habitat, he said, adding that his team is hoping to see the birds start to establish territories and select breeding locations.<\/p>\n
<\/b>\u201cThe furthest flight that we know of was 2,200 meters away from the aviary. They\u2019re not moving too far, but they are moving pretty far for us to keep track of \u2018em,\u201d he said.<\/p>\n
On two occasions, managers have seen multiple `alala chasing and scuffling with `io, with feathers flying and alarm calls ringing through the trees. \u201cHow many other interactions are going on? \u2026 I\u2019d like to say [the predator training] was a success. The birds are surviving where there\u2019s two `io almost every day,\u201d he said.<\/p>\n
While the birds have often been seen eating the wild foods they\u2019re supposed to, pecking through `ohi`a flowers, looking for insects in bark and leaf litter, pulling out worms from dead logs, and \u201cjust having a great time,\u201d Pang-Ching said, they still receive supplemental food.<\/p>\n
Managers provide papaya, melons, food pellets, peas, and carrots to help the birds overcome any diet obstacles, he said, adding that peas and carrots are the birds\u2019 least favorite. The food is set out before light and any leftovers are removed after dark. However, Pang-Ching said his team is going to try to eventually wean the birds off supplemental food.<\/p>\n
Another promising development: managers believe a male and a female seen hanging out together may be a potential mating pair. \u201cNext year is going to be pretty exciting, coming to the breeding season, seeing what those two do,\u201d he said.<\/p>\n
Before then, he said the team plans to release another group of birds. A site elsewhere in the NAR has been chosen and a new pre-release aviary is being built.<\/p>\n
He stressed that re-establishing a thriving population of `alala in the wild will be a long process, reminding the audience that the endangered Hawaiian goose, or nene, is a good example of what to expect. In 1960, there were an estimated 30 nene left in Hawai`i. But with captive breeding, predator control, and habitat protection, \u201c[t]oday, more than 2,800 nene live across all of the Hawaiian Islands,\u201d states a webpage for Island Conservation, a company that specializes in removing invasive species from islands to aid protected species. The U.S. Fish and Wildlife Service has proposed that nene be downlisted from endangered to threatened.<\/p>\n
\u201cIt took a long time to get the [nene] population back,\u201d Pang-Ching said.<\/p>\n
For now, he\u2019s enjoying the success made by the `Alala Project so far. He recalled how he used to be jealous of veteran U.S. Geological Survey wildlife biologist Paul Banko, who spent years working to save the `alala and was able to see and hear the birds in Hawaiian forests before they went extinct in the wild. Now, Pang-Ching said, \u201cI’m jealous of myself. I get to see it and talk about it.\u201d<\/p>\n
\u201cTheir calls have become part of the beautiful [dawn] chorus. \u2026 Probably the sound is my favorite thing,\u201d he said.<\/p>\n
(For more background, read, \u201cNARS Commission Grants Permit For \u2018Alala Release at Pu\u2018u Maka\u2019ala,<\/a>\u2019 from our May 2016 issue. Visit @alalaproject on Instagram to track developments.)<\/p>\n \u2014 Teresa Dawson<\/i><\/b><\/p>\n","protected":false},"excerpt":{"rendered":" This time, they were ready. When the state released five male, captive-reared endangered Hawaiian crows (`alala) into the Pu`u Maka`ala Natural Area Reserve on December 14, 2016, managers found out the hard way that some of them weren’t ready to … Continued<\/a><\/p>\n","protected":false},"author":1,"featured_media":10572,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[440],"tags":[3],"class_list":["post-10597","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-september-2018","tag-teresa-dawson"],"_links":{"self":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/10597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10597"}],"version-history":[{"count":0,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/posts\/10597\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=\/wp\/v2\/media\/10572"}],"wp:attachment":[{"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/environment-hawaii.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}