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.

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.

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).

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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