Poachers positively select parrot species based on their attractiveness

October 19th, 2020 | by David Waugh
Poachers positively select parrot species based on their attractiveness
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News has arrived about a phenomenon that many of us suspected was true, but in practice has remained unexamined objectively until now, not least due to the difficulties of estimating species abundances in the wild. Poachers do not randomly trap every kind of parrot they encounter, but instead increasingly select the species that are considered to be progressively more attractive. This is the main message from a recently published study* conducted in 2019 in Colombia by Spanish scientists from the Doñana Biological Station, University of Pablo de Olavide, University of Oviedo and National Museum of Natural Sciences, and supported by the Loro Parque Fundación. Colombia is one of the most biodiverse countries in the world, where trapping and keeping native animals as pets is entrenched, but punishable by law since 1977.

Map of Colombia showing the itinerary (black line) crossing the Andean, Pacific and Caribbean regions, roadside parrot surveys (in red), and localities where poached pets were recorded (white dots).

The scientists conducted a large-scale survey in Colombia which simultaneously estimated the relative abundances (individuals per kilometre for each species) of wild parrots, by means of roadside surveys, and of household, illegally trapped pets by visiting villages. Their study route traversed no less than 2,221 km of low-transit and unpaved roads through the Caribbean, Pacific and Andean regions of the country, surveying the main biomes across a wide altitudinal range (4–3,520 m.a.s.l). The route passed through patches of habitat categorized as pristine natural, degraded natural, mixed natural/agricultural, agricultural and urban. Similar to other roadside parrot surveys, the driver and two experienced observers drove a 4×4 vehicle at low speed (10–40 km/h) from dawn to dusk (approx. 06:00 – 18:00), avoiding rain and hot middays when parrot activity declines, and briefly stopping when needed to identify species and to count the number of individuals in flocks.

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Yellow-eared Parrot: not selected by poachers.

The number of native parrots in each village visited was recorded as a direct measure of domestic poaching pressure, the pet owners confirming that all native individuals were poached. There was no evidence of attempts to breed them in captivity. Most people did not hide their pets, nor were they afraid to keep them illegally, and were willing to give additional information, such as the price they paid for a parrot.

The scientists rated the attractiveness of each parrot species based on its body size, colouration, and ability to imitate human speech, using a uniform scoring method. Parrot colouration was scored as the proportion of the body (bright body) and head (bright head) covered by bright colours, and the total number of colours observed when the parrot is perched. The ability of each individual pet to imitate human speech was ranked into five categories, from individuals unable to imitate to individuals able to imitate human speech very well, sing songs, and imitate other domestic animals or other sounds. Scores were averaged for each species.

Relative abundance of parrots in Colombia as pets (grey bars) and in the wild (white bars), and the selectivity index: black dots – significant positive selection; black triangles – significant negative selection; white dots – not selected.

To check the validity of local opinion about mimicry, the same question was asked of five people from USA, France, Germany and Spain with >20 years of experience breeding and keeping a large variety of parrot species in captivity. The average scores provided by these experts correlated well with those provided by local pet owners. Finally, the researchers used a statistical method to obtain a composite variable that describes the attractiveness of each parrot species as a function of its colour, body size, and ability to speak. The researchers also used a selectivity index to assess whether parrot species are poached proportionally to their abundances in the wild. This was based on the number of parrots of each species recorded in the wild, as so-called units of resource availability, and numbers recorded as pets as units of the resource used.

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Graphic image of parrot attractiveness based on body size, colouration
(bright body, bright head and number of colours) and ability to mimic human speech.

From the 2,221 km of roadside surveys, the scientists recorded 10,811 wild individuals of 25 parrot species, covering a wide variety of biomes with different degrees of human alteration. Overall abundance reached 4.87 individuals/km, but 80.3% of records were of only two species, the Orange-chinned parakeet (Brotogeris jugularis) and Brown-throated parakeet (Eupsittula pertinax). The other species were present in low numbers, were extremely rare or even unrecorded in the wild. Simultaneously, they recorded 1,179 pets from 21 native parrot species, out of a total of 2,465 pets from 124 animal species kept by 818 owners in 92.9% of the 282 villages surveyed. Of the 358 local people who ventured information, 58.4% of them kept poached native parrot pets at the time of the survey or at least recently, and 38.0% knew other people also keeping them.

Orange-chinned Parakeet: an abundant species of little interest to poachers, i.e. negatively selected.

In absolute numbers, B. jugularis and E. pertinax comprised 45.2% of all pet parrots, but in fact these species were negatively selected when considering their high abundances in the wild. By contrast, most amazons (Amazona spp.), large macaws (Ara spp.) and Blue-crowned Parakeets (Thectocercus acuticaudatus), mostly uncommon or extremely rare in the wild, were strongly positively selected as pets. For the other species there was no significant selection, being kept as pets in proportion to their availability in the wild. The attractiveness value was positively related to the selectivity index, showing that the most attractive species were poached in larger numbers than expected based on their availability in the wild. The price of the species increased with their attractiveness but was unrelated to their abundances in the wild, indicating that the most attractive but not the rarest species were more valuable. Example average local prices (in US$) were just 5.68 for a Brown-throated Parakeet, but 145.22 for a Scarlet Macaw (Ara macao), with in-between cases being 16.46 for a Blue-headed Parrot (Pionus menstruus), 34.41 for Yellow-crowned Amazon (Amazona ochrocephala) and 43.57 for Blue and Yellow Macaw (Ara ararauna).

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Wild-caught macaws confiscated by the Colombian National Police.

As the scientists conclude from the results of their study in Colombia, parrot poaching is not an opportunistic, but a selective wildlife crime, with potentially serious ecological and conservation consequences. In ecological terms, the selective poaching of the largest parrot species (macaws and amazons) may have a disproportionately strong negative impact, because these species are the main, and sometimes the only, effective long-distance seed dispersers of palms and trees with large-sized fruits, which are key species in several ecosystems. In conservation terms, the trade of some attractive parrot species has been shown to cause negative population trends. In Colombia there is evidence that poaching has caused large population declines and distribution contractions of the Yellow-crowned amazon, considered as the species that best imitates human speech, and of the highly demanded Scarlet Macaw was considered the most abundant macaw species in the region in the 1950s, in contrast with its rarity in 2019.

The results of this study will help guide targeted actions for the conservation of those parrot species highlighted as at most risk.

Author: David Waugh, Correspondent, Loro Parque Fundación

Photos: title – Travis Isaacs-Wiki; 1,3,4 – Romero-Vidal et al 2020; 2 -Fundación Vida Silvestre; 5 – Félix Uribe-Wiki; 6 – Diálogo

* Romero-Vidal, P., Hiraldo, F., Rosseto, F., Blanco, G., Carrete, M. and Tella, J.L. (2020) Opportunistic or non-random wildlife crime? Attractiveness rather than abundance in the wild leads to selective parrot poaching. Diversity12: 314. https://doi.org/10.3390/d12080314

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