Rotenberg el al. • HARPY EAGLE NESTING IN BELIZE 
295 
a live chicken on 27 May 2011 at 0900 hrs to 
encourage the young eagle to hunt and capture the 
chicken on its own. The juvenile observed the live 
chicken for ~ 15 min from a branch 3 m off the 
ground. The eagle flew directly towards the 
chicken and inserted its talons into the chicken's 
breast. The kill seemed immediate upon impact, 
after which the eagle Hew a short distance from the 
feeding station to a log on the ground. The eagle 
plucked breast feathers off the chicken for 5-10 min 
before feeding and then consumed nearly the entire 
chicken that morning before 1200 hrs. The Harpy 
Eagle subsequently hunted, captured and fed on 
four additional live chickens until we ceased our 
feeding program on 11 June 2011. We attempted to 
emulate adult delivery rates while feeding the 
juvenile as reported in observations in both Panama 
and South America of —2-3 days (Rettig 1978, 
Seymour el al. 2010) and our own previous 
observations, resulting in a rate of one chicken 
every 2.15 days over a 28-day period. 
Wc did not find the Harpy Eagle at the feeding 
station on 14 June 2011. The GPS satellite data 
showed the juvenile eagle had flown -500 m 
north of the nest, the furthest distance the juvenile 
had ilown from the nest up to that date. We 
located the juvenile on 27 June 2011 using the 
OPS satellite data and the VIIE signal in a large 
'■~45 ni) Ceiba pentcmdni tree 300 m northwest 
ot the nest. The adult male Harpy Eagle w as with 
the juvenile and offered an unknown prey item to 
the juvenile. The young eagle explored the entire 
v alley after this date, and proceeded on to a 
smaller, similar valley directly adjacent in July 
-dll for a total travel area of —3.2 km between 
14 April and 20 July 2011 (tracked by satellite 
only between 27 Jun and 20 Jul 2011). 
DISCUSSION 
Our discovery of an active Harpy Eagle nest is 
'he first official nest record for Belize (H. L. 
Jones, pers. comm.). We believe the pair in the 
BNR represents one of the northernmost known 
vxtant breeding pairs of Harpy Eagles in the 
Americas (Fig. 1). There has been only one 
Published account of a juvenile (3rd yr bird) 
Har Py Eagle north of Panama in recent years 
-b02), at the Marenco Biological Station in the 
Oso Peninsula, Costa Rica, which suggests the 
Presence of a breeding pair ( Jones 2002), and only 
one observation of a nest and pair previous to that 
in 1994 from Oaxaca, Mexico (Peterson et al. 
2 °03). All other Harpy Eagle reports north of 
Panama are of single adults, and suggest a 
continued presence of Harpy Eagles in these 
areas (Table 3). There was an observation of a 
single adult Harpy Eagle possibly constructing a 
nest in Chiapas. Mexico outside of published 
accounts in the ornithological literature, as cited 
in a local newspaper in February 2011 (Morales 
201 I). which remains unconfirmed. 
Our observations of prey delivery at the nest do 
not differ significantly from data collected in 
South America. On average, our rates in Belize 
(2.04-3.33 days) arc similar to those reported by 
Rettig (1978) (2.5-3.5 days) and Seymour et al. 
(2010) (2.1-2.4 days); however, both studies 
reported fewer days per delivery (i.e., delivery' 
with greater frequency) as the nestling grew. We 
observed the opposite trend in Belize: observed 
prey deliveries occurred with a greater number 
of days in between (i.e., deliveries with less 
frequency) (Table 2). We also note the male made 
significantly fewer deliveries (3. 18%) than the 
female (14. 82%) while, in the South American 
studies, males had a much greater role. For 
example, Rettig (1978) observed male prey 
delivery at one prey item every 3.5 days until 
about 20 weeks of age at which time the male 
remained at the nest while the female hunted more 
frequently, and Seymour el al. (2010) observed 
male prey delivery at one prey item every 2.4 days 
over this same period. We observed the male 
make one final visit to the nest in Belize when 
the juvenile was about 21 weeks ot age. The 
behaviors of the Belizean Harpy Eagles weic 
similar to those in Sena da Bodoquena National 
Park in Brazil (Martins Pereira and Salzo 2006) 
where the male also visited the nest only a few 
times. 
We speculate as to why these behavioral 
differences occur based on two factors. First. 
Belizean Harpy Eagles are breeding at the fringe 
of their natural range where prey choice and 
availability may be limited. Harpy Eagles in the 
south of their range prey on sloths (Bradypus spp. 
and Choloepus spp.). and a variety of species of 
monkeys with these mammals comprising large 
parts of eagle diets (Galetti and de Carvalho 2000. 
Lenz and Marajd dos Reis 2011). Belize is north 
of the range for sloths and only supports two 
primate species. Thus, one would predict the diet 
of Harpy Eagles in Belize would be quite 
different, as indicated by our observations. We 
observed troops of Central American spider 
monkey (Ateles geoffroyi ) in close proximity to 
