I have nothing to add other than to say Dave Budeau's explanation of
compensatory harvest strategy is fascinating and educational (thanks Dave).
Population dynamics in birds is under-appreciated by the average birder, with
most having little if any understanding of annual mortality rates. The idea of
a "wing bee" put a smile on my face. Having hunters participate in the
collection process was something I was unfamiliar with, but it makes sense and
keeps my taxes down.
This online community, currently the only birding listserv that I subscribe to,
has been the source of lots of great information since its inception and has
maintained that momentum even after the Malheur occupation ended. Thanks to all
who have contributed thoughtful opinions and shared insightful commentary and
articles.
Dave IronsPortland, OR
Date: Fri, 4 Mar 2016 20:39:23 -0800
From: whoffman@xxxxxxxx
To: joel.geier@xxxxxxxx
CC: boo@xxxxxxxxxxxxx; david.a.budeau@xxxxxxxxxxx
Subject: [boo] Re: [Fwd: RE: ODFW Statistics for Greater Sage Grouse Harvested]
Hi - I would like to comment on the concept of "compensatory mortality." Dave
Budeau is certainly correct that the "concept of compensatory mortality is the
foundation for game management." That does not necessarily make it valid,
although history has shown that it seems to work fairly well for quite a few
species. The main problems I am aware of is that the concept is based on two
assumptions that are not always valid. First, it is assumed that all the
individuals in the population are of more or less equal value to the
population. In some cases the invalidity of this assumption can and is
addressed in part by regulations; e.g. different bag limits for males and
females. The second assumption is that hunting mortality is non-selective.
Clearly, in a lot of wildlife populations (including most birds) natural
mortality is much higher in the first year of life, and some of this mortality
is selective, weeding out the weak, and the less wary, for example. If hunters
are behaving enough different from the other causes of mortality, such that
they were targeting different age classes or sexes unequally and at different
rates than the natural mortality agents, this mortality might be additive
rather than compensatory, even at very low harvest rates.As near as I can tell
from the ODFW website, Sage Grouse hunters are not expected to hunt only males.
Females may be more valuable to the population than males (commonly thought to
be the case for lek species). If hunting methods tended to over-harvest
females, the assumption that it is "compensatory" might be wrong. Or, if
behavioral differences made the older, lek-dominant males more vulnerable to
hunting (or if hunters were targeting them as trophies), then even a low rate
of hunter mortality could have profound effects on which individuals got to
mate. (This also applies to trophy hunting for big game, and in some
populations, heavy trophy harvest has led to declines in antler or horn sizes.).
WayneFrom: "joel geier" <joel.geier@xxxxxxxx>
To: "boo" <boo@xxxxxxxxxxxxx>
Cc: "David Budeau" <david.a.budeau@xxxxxxxxxxx>
Sent: Friday, March 4, 2016 7:35:27 PM
Subject: [boo] [Fwd: RE: ODFW Statistics for Greater Sage Grouse Harvested]
Hi all,
I asked Dave Budeau about this. Dave heads up ODFW's upland gamebird
program and has principal responsibility for both Mountain Quail and
Greater Sage-Grouse programs. Dave's comments are forwarded with
permission below.
Disclaimer is that Dave is an old neighbor, as he managed E.E. Wilson
Wildlife Area when we first moved to this area. Once or twice, we may
have even received his mail by mistake since he was just one or two more
stops along the route out of Independence.
But Dave is also far and away the best birder to hold that position
since we arrived here in the late 1990s. From personal experience I know
that he pays close attention to non-game birds and native plants, along
with game birds. His birding credits include a Northern Mockingbird that
was enjoyed by many local birders after he spotted it near the manager's
residence, plus one of the more thorough counts of Solitary Sandpipers
that has ever been conducted on the premises. When Dave was managing
E.E. Wilson, I had every confidence that he was looking out for -- and
truly interested in -- non-game species right along with game species.
So I have very strong confidence in Dave's statements about the Greater
Sage-Grouse program. I also hope that folks will appreciate the
analytical rigor that he's brought into his job.
Joel
-------- Forwarded Message --------
From: David Budeau <david.a.budeau@xxxxxxxxxxx>
To: joel.geier@xxxxxxxx <joel.geier@xxxxxxxx>
Subject: RE: ODFW Statistics for Greater Sage Grouse Harvested
Date: Fri, 4 Mar 2016 18:19:26 +0000
Hi Joel,
Thanks for forwarding. I've answered similar questions in the past
so I have several resources readily at hand that I'll pass along -
It might be more information than you are asking for, but happy to
do it. And yes, I agree these two species should be treated
separately.
We have good populations of mt. quail in the state, though they are
likely not as abundant as they once were in western Oregon, but
this is a function of changing habitat (maturing forests/lack of
disturbance). Mt. quail are less abundant in eastern Oregon and
hunting is only permitted in parts of that region. We are in
process of preparing to move another 200 mt. quail to Lake Co.
in the next couple of weeks. It was not too difficult to catch
that number of quail in Douglas Co.
On the agency website, is a map of mt. quail observations through
time. You and Chuck have both contributed data that helped create
this map.
http://www.dfw.state.or.us/resources/hunting/upland_bird/projects/docs/mtn-quail-distribution-2.pdf
There is obvious trend of expanding distribution, which is
consistent with other anecdotal observations the distribution of
mt. quail in eastern Oregon is expanding back into historical
range. The cause of the decline through the 1980's is not
known for sure, but some (e.g. Leonard Brennan) attributed the
decline to loss of riparian habitat, which makes sense in the
more arid regions of the state and also explains why we are
seeing a recovery as more attention and effort is being made to
conserve and restore riparian habitat.
The issue of hunting sage-grouse has certainly been raised
numerous times before and there has been much effort looking into
this issue. Unlike other upland game birds greater sage-grouse
are less productive and longer lived. Consequently, harvest must
be much more controlled to keep any hunting mortality compensatory
and not additive.
Compensatory and additive mortality are biological concepts where
under compensatory mortality any hunting mortality will not reduce
the potential breeding population in the subsequent year.
The concept of compensatory mortality is the foundation for game
management. If the harvest exceeds the threshold of compensatory
mortality it can become additive.
So how does this work? When some of the population is removed
by hunting, less of the remaining population dies from natural
causes, thus compensating for the hunting mortality. The higher
the natural mortality, the greater the chance of compensation
for hunting mortality. In species like quail, natural mortality
in some populations can approach70-80% each year. Consequently
quail can sustain higher harvest levels without influencing the
subsequent years breeding population as compared to a species
like sandhill cranes where they have very high annual survival
and low recruitment. Harvest of cranes would have to much
less to be compensatory.
Here are some hypothetical mechanisms about how compensatory
mortality works. A flock of 10 birds has a little higher chance
of being detected by a predator than a flock of 8 birds. Thus
the probability of survival is little higher for the flock of
8 birds. Similarly a bird in a flock 10 birds has the potential
of catching a disease or getting parasites from 9 other birds,
but a bird in flock of 8, is with only 7 other possible disease
vectors, (instead of 9).
There may be limiting factors too, like the best roost sites to
protect them from weather or predators. If there are a little
fewer birds on the landscape there is a better chance of
getting the best roost sites and food resources, thus
increasing the probability of survival for the remaining birds.
This might not be the best analogy, but you can think of it
like a game of Musical Chairs, but instead of removing chairs,
hunting has removed some of the birds, so when the music stops
there’s a better chance for the remaining birds to find a chair.
In this way the probability of survival, or finding a chair,
increases for the remaining birds. Conversely, removing
chairs, is like losing habitat.
So, the question becomes “At what level might hunting mortality
become additive for sage-grouse?”. Peer-reviewed science
(Connelly et al. 2000) sage-grouse management guidelines
recommend the harvest should be 10% or less. A paper by
Sedinger et al. (2010) which used marked birds from Nevada and
Colorado found that harvest rates of 11% had no significant
impact. In Oregon we have a self-imposed policy to harvest
5% or less of the estimated fall population. The 5% is
the maximum allowed harvest and not a harvest goal.
In practice, Oregon's harvest is about 2.5% of the fall
population, and this is only in the areas where hunting
is allowed. Oregon permits hunting in 10 of 21 wildlife
management units where sage-grouse occur. Hunter numbers
and harvest are managed by a controlled hunt process.
Permit numbers are determined annually based on a
mathematical formula combining spring lek count information,
brood survey information, hunter participation rates,
and results from the analysis of wings taken during the
previous hunting season. Spring lek surveys are used
to estimate the adult male breeding population. Based
on a sage-grouse sex ratio of females per male, the
adult breeding population is then estimated.
A chick/hen ratio is estimated from summer brood surveys
and then applied to the adult breeding population to
estimate the total sage-grouse fall population. Some
studies (e.g. Gibson et al. 2011, Connelly et al. 2003)
have concluded that hunting can become additive for
sage-grouse. In both of these studies, the harvest
likely exceeded harvest recommendations, at least in
some years.
In their ESA listing reviews, obviously the USFWS looked
at hunting mortality as one of the possible threats to
sage-grouse. They found habitat loss/fragmentation and
the lack of regulatory certainty were the two significant
threats to the long-term persistence of sage-grouse
(March 2010 finding). You can look at the USFWS fact
sheet about sage-grouse and find "Hunting: Not a threat
to persistence of species; state management is goal."
This USFWS fact sheet is available online at:
https://www.fws.gov/greatersagegrouse/factsheets/GreaterSageGrouseCanon_FINAL.pdf
An important benefit of hunting sage-grouse is
collection of essential biological information. In Oregon,
each hunter is provided two wing envelopes and asked
to send in one wing from each bird harvested. Sage-grouse
hunters In Oregon have been exceptionally cooperative and
return wings from about 64%, of the harvest. In the past
Oregon hunters have also collected blood samples for us
to monitor for West Nile virus which resulted in a science
publication by the National Wildlife Health Center (paper
attached). We have even asked hunters to save gut samples
for a parasite studyu. Simply, the season allows us to
gather biological information that would be difficult or
expensive to acquire otherwise. Analysis of the grouse
wings provides an estimate of overall production, hatching
chronology, and pre-winter sex and age composition of
the population. The sex and age composition allows the
prediction of breeding population trends for the
following year.
Age-at-harvest models are also being refined for upland
game birds that allow for population reconstruction based
simply on age at harvest data and known hunting effort.
Without this information it would be very difficult to
determine how sage-grouse populations are performing
through time. It will become even more critical to have
this information as land managers implement habitat
improvement treatments designed to benefit sage-grouse.
Last year we produced a technical report with data from
Oregon and Colorado from a 40+ year period. These data
are currently being used to model sage-grouse populations
in other parts of their range. That technical report is
available online at:
http://www.dfw.state.or.us/wildlife/research/docs/Fall_Popn_Structure_Sage-grouse_v3182015.pdf
Of the western states where sage-grouse are hunted,
Oregon is among the most conservative. Under current harvest
strategies, population data indicate population trends
are within the range of historical variation since 1980.
The controlled hunt process allows the Department to
manage harvest and hunters and collect important information.
Collecting this information by other means would be difficult
and costly.
Eliminating responsible and regulated hunting would likely
mislead the public by implying hunting is responsible for
the current status of sage-grouse, and thus distracting
attention from the real threats to sage-grouse which are
habitat loss and fragmentation.
The Department will continue to evaluate on an annual basis
the limited harvest of sage-grouse in the state; making any
necessary adjustments and/or closures as warranted. The best
available science suggests mortality from hunting at Oregon's
level of harvest will not reduce the subsequent year’s
population.
I know there will be some that have philosophical opposition
to hunting under any conditions. Those folks are welcome
to their view. However, for those willing to accept
science-based management, Oregon's sage-grouse season is
based on the best available science to avoid reducing the
subsequent year's breeding population. And we are not
adverse to making changes to the season structure to
ensure this is the case, i.e. taking an adaptive management
approach.
Coincidentally we held our sage-grouse wing bee this year
on February 11 in Hines. Turned out to be the same day as
the last of the Malheur NWR occupiers surrendered. The "wing
bee" is where biologists meet to look at all of the wings
turned in by hunters. The good news this year was the
juvenile/hen ratio of 2.28, indicating above average
reproduction for sage-grouse in 2015. Our long-term average
is 1.5 juv/hen. We do wing bees for forest grouse too.
In case anybody wants to dig into it further and draw
their own conclusions, below is list of relevant scientific
papers on sage-grouse:
REFERENCES
Blomberg, E. J. 2015. The influence of harvest timing on greater sage-grouse
survival: A cautionary perspective. The Journal of Wildlife Management,
79:10.1002
Braun, C. E. and T. D. I. Beck. 1985. Effects of changes in hunting
regulations on sage grouse harvest and populations. Pp 335-343 in S. L. Beason
and S. F. Roberson, eds., Game harvest management. Proceedings of 3rd
International Symposium Caesar Kleberg Research Institute, Kingsville, TX.
Connelly, J. W., A. D. Apa, R. B. Smith, and K. P. Reese. 2000a. Effects of
predation and hunting on adult sage grouse Centrocercus urophasianus in Idaho.
Wildlife Biology, 6:227-232.
Connelly, J. W., M. A. Schroeder, A. R. Sands, and C. E. Braun. 2000b.
Guidelines to Manage Sage Grouse Populations and Their Habitats. Wildlife
Society Bulletin 28:967–985.
Connelly, J. W., K. P. Reese, E. O. Garton, and M. L. Commons-Kemner. 2003.
Response of greater sage-grouse Centrocercus urophasianus populations to
different levels of exploitation in Idaho, USA. Wildlife Biology 9: 335–340.
Crawford, J. A. 1982. Factors Affecting Sage Grouse Harvest in Oregon. Wildlife
Society Bulletin 10:374–377.
Gibson, R. M., V. C. Bleich, C. W., McCarthy, and T. L. Russi. 2011. Hunting
lowers population size in greater sage-grouse. Pp. 307-316 in B. K. Sandercock,
K. Martin, and G. Segelbacher (editors). Ecology, conservation, and management
of grouse. Studies in Avian Biology Vol. 39, University of California Press,
Berkeley, CA.
Johnson, K. H., and C. E. Braun. 1999. Viability and conservation of an
exploited sage grouse population. Conservation Biology 13:77-84.
Moynahan, B. J., M. S. Lindberg, and J. W. Thomas. 2006. Factors contributing
to process variance in annual survival of female greater sage-grouse in
Montana. Ecological Applications, 16:1529-1538.
Reese, K. P., and J.W. Connelly. 2011. Harvest management for greater
sage-grouse: a changing paradigm for game bird management. Pp. 101-111 in S.
T. Knick and J. W. Connelly (editors). Greater Sage-grouse: ecology and
conservation of a landscape species and its habitats. Studies in Avian Biology
Vol. 38, University of California Press, Berkeley, CA.
Reese, K. P, J. W. Connelly, E. O. Garton, and M. L. Commons-Kemner. 2005.
Exploitation and greater sage-grouse Centrocercus urophasianus: a response to
Sedinger and Rotella. Wildlife Biology 11:377-381.
Sedinger, J. S., and J. J. Rotella. 2005. Effect of harvest on sage-grouse
populations: What can we learn from the current data? Wildlife Biology
11:371–375.
Sedinger, B. S., Sedinger, J. S., Espinosa, S., Atamian, M. T., and E.
Blomberg. 2011. Spatial-temporal variation in survival of harvested greater
sage-grouse. Pp. 317-328 in B. K. Sandercock, K. Martin, and G. Segelbacher
(editors). Ecology, conservation, and management of grouse. Studies in Avian
Biology Vol. 39, University of California Press, Berkeley, CA.
Sedinger, J. A., G. C. White, S. Espinosa, E. T. Partee, and C. E. Braun.
2010. Assessing compensatory versus additive harvest mortality: An example
using greater sage-grouse. Journal of Wildlife Management 74(2):326–332; 2010.
Taylor, R. L., B. L. Walker, D. E. Naugle, and L. S. Mills. 2012. Managing
multiple vital rates to maximize greater sage-grouse population growth. The
Journal of Wildlife Management, 76: 336–347.
Zablan, M. A., C. E. Braun, and G. C. White. 2003. Estimation of Greater
Sage-Grouse Survival in North Park, Colorado. The Journal of Wildlife
Management, 67: 144–154.
Dave Budeau
Upland Game Bird Coordinator
Oregon Dept. of Fish and Wildlife
4034 Fairview Industrial Dr. SE
Salem, OR 97302-1142
Ph: (503) 947-6323
e-mail: david.a.budeau@xxxxxxxxxxx
-----Original Message-----
From: Joel Geier [mailto:joel.geier@xxxxxxxx] ;
Sent: Thursday, March 03, 2016 5:38 PM
To: David Budeau
Subject: Fwd: ODFW Statistics for Greater Sage Grouse Harvested
Hi Dave,
Just thought you might want to be aware of this question which was raised by
Chuck Gates on Oregon's new "free-for-all" birding list, BOO.
BOO is an unmoderated forum that was created during the Malheur occupation, to
take the pressure of political discussions off of OBOL.
This is actually long over due in my view, since birders have been avoiding a
lot of topics that they ought to be talking about, just because someone or
other thinks the topic is too sensitive.
Chuck is a pretty even-keeled guy, born & raised in central Oregon, so if he's
asking these questions, I'd guess others might too.
I'll respond briefly on the Mountain Quail part of the question (basically,
populations are not that dire and maybe even expanding in eastern Oregon, and
driven by early-seral habitat west of the Cascades).
But have to admit, I have the same question about Greater Sage-Grouse myself.
All the best,
Joel
* From: Charles Gates <cgates326@xxxxxxxxx>
* To: boo@xxxxxxxxxxxxx
* Date: Thu, 3 Mar 2016 12:15:00 -0800
I used to be a hunter. I don't hunt anymore. It's a personal choice I've made.
My family all still hunt as do several of my friends. I'm not militant about
this issue. But I was very surprised to come across the ODFW statistics for
Greater Sage Grouse and Mt Quail harvest over the last 10 years. You can view
the statistics yourself at
http://www.dfw.state.or.us/resources/hunting/upland_bird/harvest/index.asp#Statistics.
I really am surprised at the numbers of Mt Quail and Sage Grouse that are
harvested. It's my understanding that both species are declining. All over
Eastern Oregon, ranchers, biologists, land managers and other interested
parties are regularly gathering to meet and devise mitigation strategies. I
guess I naively assumed a simple way of stopping a population decline is to
stop shooting reproductively viable adults.
--
It ain't what you don't know that gets you into trouble. It's what you know for
sure that just ain't so.
Mark Twain
Chuck Gates
