Hess el al. • MOVEMENTS OF THE HAWAIIAN GOOSE 
483 
TABLE 3. Log-linear model results of elevation and ordinal date for five male None with satellite transmitters during 
2009-2011 on Hawai'i Island. A linearized exponential function took the form: In(elcvation) = h 0 + />|(ordinal date) + 
/^(ordinal date) 2 . None originated from Hakalau Forest National Wildlife Refuge (HENWR) or Big Island Country Club 
golf course i BICC). 
Transmitter 
Origin 
Expife,) 
, >5 r } Cl l.xpl/x,) 
f.xp(|/iil ordinal dale) 
Expl|/'il ordinal dale’) 
F-value 
R : 
90843/49 
HFNWR 
1.243.9 
1.185.5-1.305.1 
1.006 
1.000 
177.76 
0.284 
90848 
HFNWR 
1.846.7 
1.828.1-1.865.6 
1.002 
1.000 
293,94 
0.396 
90853 
BICC 
62.3 
53.1-73.2 
1.035 
0.999 
719.86 
0.616 
90847 
BICC 
264.2 
237.7-293.6 
1.019 
1.000 
432.85 
0.491 
90850 
BICC 
260.4 
237.8-285.2 
1.020 
1.000 
637.00 
0.587 
Johnson and Maclean 1994, Ornelas and Arizmendi 
1995. Hobson et al. 2003). Factors affecting these 
movements may include responses to changes in 
resource availability, predation, parasites, or storms 
(Boyle 2008, 201 o’; Boyle et al. 2010). Aseasonal 
climate conditions within elevation zones of the 
tropics may produce unimodal patterns in these 
factors with little variation: however, orographic 
effects may cause greater seasonal variation in 
phenology over relatively short distances between 
elevation zones (van Schaik et al. 1993). Phyloge¬ 
netic conservatism and physiological constraints 
may also have a role in persistence of seasonal 
movements (Sutherland 1998, Boyle and Conway 
2007). 
Other Hawaiian forest bird species, most 
notably Tivvi ( Vestiaria coccinea) and 'Apapane 
(Himatione sanguined), are also known to make 
high-elevation forays during September-Novem- 
ber (Fancy and Ralph 1997. 1998: Hess et al. 
2001) when Nene begin their descent to breeding 
areas. This contrary movement pattern in Nene 
raises the question: why would one tropical bird 
species make altitudinal movements in the 
opposite direction of most other species? Migra¬ 
tion routes and long-distance movements are 
culturally transmitted from adults to goslings in 
many goose species, including Nene (Sutherland 
1998. Banko et al. 1999). which may allow for 
more evolutionary flexibility in resource tracking 
than in birds with innate migratory behavior 
(Pulido 2007. Sol et al. 2010). 
Food resources may remain one of the most 
important factors associated with movements to 
productive low-elevation grasslands during the 
breeding season. Many parts of the Hawaiian 
Islands receive the greatest annual precipitation 
during November, which contributes to substan¬ 
tial fresh growth of grasses that Nene use lo 
improve body condition prior to nesting, for 
gosling development, and during molt (Baldwin 
1945. Banko et al. 1999). Grassland sites are 
managed year-round at Nene breeding locations, 
thus movements are not necessary to obtain 
seasonally abundant grasses. It is also not clear 
which factors arc associated with Nene moving to 
higher elevation non-breeding areas. Henshaw' 
(1902:104) noted that upland food: “...consists of 
pualele ( Sonchns ole ravens), tender grasses and 
several kinds of berries, especially the ohelo 
(Vaccinium reticulation >. puakeawe ( Cvathores 
\Lcpiccophyllu\ tameiameiae), and the strawberry 
(Fragariu chilenxis |sic]). In summer when the 
latter abound in the upper districts, the geese 
become very fat...” Strawberries are now rare 
and upland ground cover is often patchy barren 
lava unlike the dense grass cover of lower 
elevations, although peak production of ‘ohelo 
berries occurs during the non-breeding season 
(Wagner el al. 1999). 
There is no indication that development of ova, 
embryos, or goslings is limited by physiological 
constraints at higher-elevations but productive 
breeding areas at Hakalau Forest NWR. although 
frequent heavy precipitation may affect gosling 
survival during cooler months. Nene are unique as 
they arc the only Northern Hemisphere goose that 
breeds during September-Febniary (Johnsgard 
1978). There is no indication that phylogenetic 
conservatism may have a role in the seasonal 
timing of migration, yet continental species such 
as Canada Geese ( Brant a canadensis) from which 
Nene evolved —890.000 years ago (Paxinos et al. 
2002a) begin long-distance migrations that rough¬ 
ly correspond to the timing of Nene movements. 
Other potential factors such as the altitudinal 
distribution of parasites have not been quantified 
in Nene. but migration patterns art* consistent with 
seasonal storm avoidance (Boyle et al. 2010). 
Frontal storm systems are generally less common 
